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Sample records for surfactant benzalkonium chloride

  1. Benzalkonium Chloride and Glaucoma

    OpenAIRE

    Rasmussen, Carol A.; Kaufman, Paul L.; Kiland, Julie A.

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapo...

  2. Benzalkonium chloride and glaucoma.

    Science.gov (United States)

    Rasmussen, Carol A; Kaufman, Paul L; Kiland, Julie A

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology.

  3. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    OpenAIRE

    Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

    2012-01-01

    Topical application of benzalkonium chloride (BAK) to the eye causes dose-related corneal neurotoxicity. Corneal inflammation and reduction in aqueous tear production accompany neurotoxicity. Cessation of BAK treatment leads to recovery of corneal nerve density.

  4. EVALUATION OF BACTERICIDAL EFFECTIVENESS OF BENZALKONIUM CHLORIDE

    Directory of Open Access Journals (Sweden)

    K. Imandel

    1996-06-01

    Full Text Available Benzalkonium chloride is a quaternary ammounium Compounds derivative under different names such as Afxhang, Hamoon, Mahan etc, which have great and expanded use in sanitation and medical affairs. Bactericidal activity of these disinfectants was fulfilled according to National Standard Method No.2842 on Staph. Aureus, Sal. Typhimouium and E. coli. This laboratory test showed that, except Mahan that has not bactericidal efficacy on E.coli at concentration 0.4 percent, other disinfectants under the study in concentrations of 0.4, 0.8, 1, 1.2 percent have reliable antibacterial properties, and bacterial resistance to benzalkonium chloride has not occurred yet.

  5. Aspergilli Response to Benzalkonium Chloride and Novel-Synthesized Fullerenol/Benzalkonium Chloride Nanocomposite

    OpenAIRE

    Nikola Unković; Milica Ljaljević Grbić; Miloš Stupar; Jelena Vukojević; Vesna Janković; Danica Jović; Aleksandar Djordjević

    2015-01-01

    A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles’ dimensions within 30–143 nm and maximum number...

  6. Benzalkonium chloride. Health hazard evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    Bernholc, N.M.

    1984-01-01

    Health hazards associated with the use of benzalkonium chlorides (BAC) are reviewed. Benzalkonium chloride is extensively used as a cationic disinfectant. It is found in a great many over-the-counter and prescription eye products, disinfectants, shampoos, and deodorants, and is used in concentrations that range from 0.001 to 0.01% in eyedrops, up to 2.5% in concentrated liquid disinfectants. Solutions of 0.03 to 0.04% BAC may cause temporary eye irritation in humans but are unlikely to cause any skin response except in persons allergic to quaternary ammonium compounds. Inhalation of a vaporized 10% solution of BAC produced a bronchospasmodic reaction in a previously sensitized individual. At present no other human health effects from BAC have been documented or inferred from exposure to such dilute concentrations.

  7. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    OpenAIRE

    Güler, Ekrem; Olgar, Şeref; Davutoğlu, Mehmet; Garipardıç, Mesut; Karabiber, Hamza

    2011-01-01

    Benzalkonium chloride (BAC) is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is ...

  8. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    OpenAIRE

    Ekrem Güler; Şeref Olgar; Mehmet Davutoğlu; Mesut Garipardıç; Hamza Karabiber

    2014-01-01

    Benzalkonium chloride (BAC) is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is...

  9. EVALUATION OF BACTERICIDAL EFFECTIVENESS OF BENZALKONIUM CHLORIDE

    OpenAIRE

    K. Imandel; M.B. Shaywaard; F. Mobaraki

    1996-01-01

    Benzalkonium chloride is a quaternary ammounium Compounds derivative under different names such as Afxhang, Hamoon, Mahan etc, which have great and expanded use in sanitation and medical affairs. Bactericidal activity of these disinfectants was fulfilled according to National Standard Method No.2842 on Staph. Aureus, Sal. Typhimouium and E. coli. This laboratory test showed that, except Mahan that has not bactericidal efficacy on E.coli at concentration 0.4 percent, other disinfectants under ...

  10. Inactivation of Viruses by Benzalkonium Chloride

    Science.gov (United States)

    Armstrong, J. A.; Froelich, E. J.

    1964-01-01

    Benzalkonium chloride (as Roccal or Zephiran) was found to inactivate influenza, measles, canine distemper, rabies, fowl laryngotracheitis, vaccinia, Semliki Forest, feline pneumonitis, meningopneumonitis, and herpes simplex viruses after 10 min of exposure at 30 C or at room temperature. Poliovirus and encephalomyocarditis virus were not inactivated under the same conditions. It was concluded that all viruses tested were sensitive except members of the picorna group. The literature was reviewed. PMID:4288740

  11. Anaphylactic reaction following administration of nose drops containing benzalkonium chloride

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    Mezger Elke

    2012-10-01

    Full Text Available Abstract We describe a case of anaphylactic reaction in a 46-year-old female post application of decongestant nose drops containing benzalkonium chloride (BAC. With some latency, the patient complained of cough, dyspnea, sensation of heat, croakiness and pruritus. Since she showed all of these symptoms, typical of an anaphylactic reaction, we proceeded some weeks later with a prick test with solutions containing BAC, a cationic surfactant commonly used as an antibacterial preservative in many medical solutions. The prick test was positive, confirming the assumption of a hypersensitive reaction to BAC.

  12. Anaphylactic reaction following administration of nose drops containing benzalkonium chloride

    Science.gov (United States)

    2012-01-01

    We describe a case of anaphylactic reaction in a 46-year-old female post application of decongestant nose drops containing benzalkonium chloride (BAC). With some latency, the patient complained of cough, dyspnea, sensation of heat, croakiness and pruritus. Since she showed all of these symptoms, typical of an anaphylactic reaction, we proceeded some weeks later with a prick test with solutions containing BAC, a cationic surfactant commonly used as an antibacterial preservative in many medical solutions. The prick test was positive, confirming the assumption of a hypersensitive reaction to BAC. PMID:23078861

  13. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    Directory of Open Access Journals (Sweden)

    Ekrem Güler

    2011-06-01

    Full Text Available Benzalkonium chloride (BAC is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is to draw attention to the fact that BAC application to the scalp for treating pediculosis capitis may resemble the herpes encephalitis clinical picture.

  14. AGING OF ADHESIVE INTERFACES TREATED WITH BENZALKONIUM CHLORIDE AND BENZALKONIUM METHACRYLATE

    OpenAIRE

    Sabatini, Camila; Pashley, David H.

    2015-01-01

    Inhibition of endogenous dentin matrix metalloproteinases (MMPs) within incompletely infiltrated hybrid layers can contribute to the preservation of resin-dentin bonds. This study evaluated the bond stability of interfaces treated with benzalkonium chloride (BAC) and benzalkonium methacrylate (MBAC), and its inhibitory properties in dentin MMP activity. Single-component adhesive ALL-BOND UNIVERSAL, modified with BAC or MBAC in concentrations of 0, 0.5, 1.0 and 2.0% was used for microtensile b...

  15. Aspergilli Response to Benzalkonium Chloride and Novel-Synthesized Fullerenol/Benzalkonium Chloride Nanocomposite.

    Science.gov (United States)

    Unković, Nikola; Ljaljević Grbić, Milica; Stupar, Miloš; Vukojević, Jelena; Janković, Vesna; Jović, Danica; Djordjević, Aleksandar

    2015-01-01

    A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles' dimensions within 30-143 nm and maximum number of particles at 44 nm. The effect of pure and fullerenol nanocarrier-bound biocide was evaluated in eight Aspergillus species. In mycelial growth assay, nanocomposite was more potent, as fungicidal effect of 1.04/0.6 μg mL(-1) was obtained in all but one of the isolates (A. niger), while proportional concentration of pure biocide (0.6 μg mL(-1)) completely inhibited mycelial growth of only three Aspergillus species. However, conidia appear to be less susceptible to nanocomposite treatment, as lower fungistatic (MIC) and fungicidal (MFC) concentrations were obtained with biocide alone (MIC in range from 0.03 to 0.15 μg mL(-1) and MFC from 0.075 to 0.45 μg mL(-1)). To a different degree, both substances stimulated aflatoxin B1 production and inhibited ochratoxin A synthesis. Very low mycelium biomass yield, in range from 1.0 to 3.0 mg dry weight, was documented in both biocide and nanocomposite enriched medium.

  16. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    Science.gov (United States)

    Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

    2012-01-01

    Purpose. The aim of this study was to determine and characterize the effect of topical application of benzalkonium chloride (BAK) on corneal nerves in vivo and in vitro. Methods. Thy1-YFP+ neurofluorescent mouse eyes were treated topically with vehicle or BAK (0.01% or 0.1%). Wide-field stereofluorescence microscopy was performed to sequentially image the treated corneas in vivo every week for 4 weeks, and changes in stromal nerve fiber density (NFD) and aqueous tear production were determined. Whole-mount immunofluorescence staining of corneas was performed with antibodies to axonopathy marker SMI-32. Western immunoblot analyses were performed on trigeminal ganglion and corneal lysates to determine abundance of proteins associated with neurotoxicity and regeneration. Compartmental culture of trigeminal ganglion neurons was performed in Campenot devices to determine whether BAK affects neurite outgrowth. Results. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P < 0.05). These changes were most significant after 0.1% BAK treatment. The extent of inflammatory cell infiltration in the cornea showed a significant negative correlation with NFD. Sequential in vivo imaging of corneas showed two forms of BAK-induced neurotoxicity: reversible neurotoxicity characterized by axonopathy and recovery, and irreversible neurotoxicity characterized by nerve degeneration and regeneration. Increased abundance of beta III tubulin in corneal lysates confirmed regeneration. A dose-related significant reduction in neurites occurred after BAK addition to compartmental cultures of dissociated trigeminal ganglion cells. Although both BAK doses (0.0001% and 0.001%) reduced nerve fiber length, the reduction was significantly more with the higher dose (P < 0.001). Conclusion. Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous

  17. Interactions of benzalkonium chloride with soft and hard contact lenses

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, J.M.; Cheeks, L.; Green, K. (Medical College of Georgia, Augusta (USA))

    1990-02-01

    We measured the uptake and washout of benzalkonium chloride, using radioactive tracer, by representative hard and soft contact lenses. Uptake by soft contact lenses after 7 days of continuous exposure is high (30 to 56 micrograms/mg of lens weight), with a low percentage of washout in 24 hours (between 0.2% and 1.5% of total uptake). High-water content lenses absorb greater quantities of benzalkonium than do low-water content lenses. Hard lenses take up a much smaller quantity of benzalkonium but release between 30% and 60% of total uptake during washout for 24 hours. Fluorosilicone-acrylate polymer lenses adsorb and release the most preservative, while polymethylmethacrylate lenses (Paragon Optical Inc, Mesa, Ariz) adsorb and release the least. The released benzalkonium from either soft or hard lenses is of a sufficient concentration to be at or above the upper limits of safety.

  18. Controversy: Is Benzalkonium Chloride Necessary in Antiglaucoma Drops?

    Science.gov (United States)

    Louati, Y

    2012-01-01

    ABSTRACT Medical therapy is the first-line option in glaucoma management, with benzalkonium chloride (BAC) being the most frequently used preservative in antiglaucoma medications. Its use is however, known to be associated with deleterious effects on the ocular surface. This review is an attempt to critically evaluate whether BAC really is indispensable for better bioavailability of antiglaucoma drugs and consequently, better IOP control. How to cite this article: Louati Y, Shaarawy T. Controversy: Is Benzalkonium Chloride Necessary in Antiglaucoma Drops? J Current Glau Prac 2012;6(3):104-107. PMID:26997764

  19. Aspergilli Response to Benzalkonium Chloride and Novel-Synthesized Fullerenol/Benzalkonium Chloride Nanocomposite

    Directory of Open Access Journals (Sweden)

    Nikola Unković

    2015-01-01

    Full Text Available A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles’ dimensions within 30–143 nm and maximum number of particles at 44 nm. The effect of pure and fullerenol nanocarrier-bound biocide was evaluated in eight Aspergillus species. In mycelial growth assay, nanocomposite was more potent, as fungicidal effect of 1.04/0.6 μg mL−1 was obtained in all but one of the isolates (A. niger, while proportional concentration of pure biocide (0.6 μg mL−1 completely inhibited mycelial growth of only three Aspergillus species. However, conidia appear to be less susceptible to nanocomposite treatment, as lower fungistatic (MIC and fungicidal (MFC concentrations were obtained with biocide alone (MIC in range from 0.03 to 0.15 μg mL−1 and MFC from 0.075 to 0.45 μg mL−1. To a different degree, both substances stimulated aflatoxin B1 production and inhibited ochratoxin A synthesis. Very low mycelium biomass yield, in range from 1.0 to 3.0 mg dry weight, was documented in both biocide and nanocomposite enriched medium.

  20. A hybridization approach to efficient TiO{sub 2} photodegradation of aqueous benzalkonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Suchithra, Padmajan Sasikala, E-mail: schithraps@gmail.com [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium); Carleer, Robert [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium); Ananthakumar, Solaippan [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019 (India); Yperman, Jan, E-mail: jan.yperman@uhasselt.be [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium)

    2015-08-15

    Graphical abstract: Hybridization of AC onto TiO{sub 2} tends the catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic surfactants. The photodegradation of benzalkonium chloride (BKC) is investigated. - Highlights: • Activated carbon-TiO{sub 2} composite (ACT) surface tends negative upon UV irradiation. • ACT effectively photodegrade cationic surfactant benzalkonium chloride (BKC). • Optimum pH for UV-photodegradation of BKC is 8 to 9 and reaction time is 2 h. • Aromatic moiety of BKC is degraded faster than long alkyl chain. • UV–vis spectroscopy is sensitive to detect aqueous BKC from 1 μg/mL. - Abstract: TiO{sub 2} get positively charged upon UV-irradiation and repel the cationic pollutants away from the surface. Hybridization of AC onto TiO{sub 2} (ACT) tends catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic pollutants. The photodegradation of benzalkonium chloride (BKC), a quaternary ammonium surfactant and a pharmaceutical, is investigated with ACT. The surface charge of the catalyst in surfactant and non-surfactant aqueous dispersion under UV-irradiation is investigated and explained. The anomalous increase in COD values at the beginning of BKC-photodegradation is explained. The intermediate products formed are identified in both solution and solid phase. Trace amount of dodecane remained adsorbed on the catalyst surface after 1 h UV-irradiation, but complete mineralization of BKC is achieved with 2 h UV-irradiation. We propose that BKC photodegradation starts by central fission of benzyl C−N bond followed by dealkylation, and demethylation steps.

  1. Resistant mechanism study of benzalkonium chloride selected Salmonella Typhimurium mutants.

    Science.gov (United States)

    Guo, Wei; Cui, Shenghui; Xu, Xiao; Wang, Haoyan

    2014-02-01

    Benzalkonium chloride is one of the invaluable biocides that is extensively used in healthcare settings as well as in the food processing industry. After exposing wild-type Salmonella Typhimurium 14028s or its AcrAB inactivation mutant to gradually increasing levels of benzalkonium chloride, resistance mutants S-41, S-150, S-AB-23, S-AB-38, and S-AB-73 were selected and these mutants also showed a 2-64-fold stable minimum inhibitory concentration (MIC) increase to chloramphenicol, ciprofloxacin, nalidixic acid, and tetracycline. In S-41 and S-150, the expression of acrB was increased 2.7- and 7.6-fold, and ΔtolC or ΔacrAB mutants of S-41 and S-150 showed the same MICs to all tested antimicrobials as the equivalent Salmonella Typhimurium 14028s mutants. However, in S-AB-23, S-AB-38, and S-AB-73, the expression of acrF was increased 96-, 230-, and 267-fold, respectively, and ΔtolC or ΔacrEF mutants of S-AB-23, S-AB-38, and S-AB-73 showed the similar MICs to all tested antimicrobials as the ΔtolC mutant of Salmonella Typhimurium 14028s. Our data showed that constitutively over-expressed AcrAB working through TolC was the main resistance mechanism in ST14028s benzalkonium chloride resistance mutants. However, after AcrAB had been inactivated, benzalkonium chloride-resistant mutants could still be selected and constitutively over-expressed, AcrEF became the dominant efflux pump working through TolC and being responsible for the increasing antimicrobial resistance. These data indicated that different mechanisms existed for acrB and acrF constitutive over-expression. Since exposure to benzalkonium chloride may lead to Salmonella mutants with a decreased susceptibility to quinolones, which is currently one of the drugs of choice for the treatment of life-threatening salmonelosis, research into the pathogenesis and epidemiology of the benzalkonium chloride resistance mutants will be of increasing importance.

  2. Mechanism of resistance to benzalkonium chloride by Pseudomonas aeruginosa.

    OpenAIRE

    Sakagami, Y; Yokoyama, H; Nishimura, H.; Ose, Y; Tashima, T.

    1989-01-01

    The mechanisms of resistance of Pseudomonas aeruginosa to benzalkonium chloride (BC) were studied. The effluence of cell components was observed in susceptible P. aeruginosa by electron microscopy, but resistant P. aeruginosa seemed to be undamaged. No marked changes in cell surface potential between Escherichia coli NIHJC-2 and a spheroplast strain were found. The contents of phospholipids (PL) and fatty and neutral lipids (FNL) in the cell walls of resistant P. aeruginosa were higher than t...

  3. A hybridization approach to efficient TiO2 photodegradation of aqueous benzalkonium chloride.

    Science.gov (United States)

    Suchithra, Padmajan Sasikala; Carleer, Robert; Ananthakumar, Solaippan; Yperman, Jan

    2015-08-15

    TiO2 get positively charged upon UV-irradiation and repel the cationic pollutants away from the surface. Hybridization of AC onto TiO2 (ACT) tends catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic pollutants. The photodegradation of benzalkonium chloride (BKC), a quaternary ammonium surfactant and a pharmaceutical, is investigated with ACT. The surface charge of the catalyst in surfactant and non-surfactant aqueous dispersion under UV-irradiation is investigated and explained. The anomalous increase in COD values at the beginning of BKC-photodegradation is explained. The intermediate products formed are identified in both solution and solid phase. Trace amount of dodecane remained adsorbed on the catalyst surface after 1h UV-irradiation, but complete mineralization of BKC is achieved with 2h UV-irradiation. We propose that BKC photodegradation starts by central fission of benzyl CN bond followed by dealkylation, and demethylation steps.

  4. The contribution of histamine release to bronchoconstriction provoked by inhaled benzalkonium chloride in asthma.

    Science.gov (United States)

    Miszkiel, K A; Beasley, R; Rafferty, P; Holgate, S T

    1988-01-01

    1. To investigate the possibility that benzalkonium chloride-induced bronchoconstriction results from the endogenous release of histamine, we examined the effect of the selective histamine antagonists terfenadine and astemizole, on the airways response to inhaled benzalkonium chloride and histamine in 12 asthmatic subjects. 2. Double-blind concentration- and time-course studies were undertaken, 3 h after treatment with terfenadine or matched placebo. 3. Benzalkonium chloride and histamine caused concentration-related falls in FEV1 in all subjects with benzalkonium chloride being 7.4 times less potent as a bronchoconstrictor agonist than histamine. Terfenadine displaced to the right the benzalkonium chloride and histamine concentration-response curves by 3.7 and 111 fold respectively. Terfenadine attenuated the initial (5 min) bronchoconstrictor response to benzalkonium chloride by 40%. However, over the whole 45 min period, the response was reduced by only 13% compared with 86% inhibition of the response to histamine. 4. In an open study, eight of the 12 subjects undertook a time course study with inhaled benzalkonium chloride after pretreatment with the chemically unrelated histamine antagonist astemizole. Astemizole inhibited benzalkonium chloride-induced bronchoconstriction to an almost identical degree as that achieved with terfenadine. 5. We conclude that the initial bronchoconstrictor effect of benzalkonium chloride is due, in part, to histamine release. However, the majority of the adverse effect relates to other, as yet unrecognised effects of this bacteriocidal substance. PMID:2451929

  5. Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

    OpenAIRE

    Youngbeom Ahn; Jeong Myeong Kim; Ohgew Kweon; Seong-Jae Kim; Jones, Richard C.; Kellie Woodling; Goncalo Gamboa da Costa; LiPuma, John J.; David Hussong; Marasa, Bernard S.; Cerniglia, Carl E.

    2016-01-01

    ABSTRACT Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethyl...

  6. Aging of adhesive interfaces treated with benzalkonium chloride and benzalkonium methacrylate.

    Science.gov (United States)

    Sabatini, Camila; Pashley, David H

    2015-04-01

    Inhibition of endogenous dentin matrix metalloproteinases (MMPs) within incompletely infiltrated hybrid layers can contribute to the preservation of resin-dentin bonds. This study evaluated the bond stability of interfaces treated with benzalkonium chloride (BAC) and benzalkonium methacrylate (MBAC), and the inhibitory properties of these compounds on dentin MMP activity. Single-component adhesive ALL-BOND UNIVERSAL, modified with BAC or MBAC at concentrations of 0, 0.5, 1.0, and 2.0%, was used for microtensile bond strength (μTBS) evaluation after 24 h, 6 months, and 1 yr. Beams produced from human dentin were treated with 37% phosphoric acid, dipped in 0.5% BAC, 1.0% BAC, or water (control) for 60 s, and then incubated in SensoLyte generic MMP substrate to determine MMP activity. A significant decrease in the μTBS after 6 months and 1 yr was observed for the control group only. No significant differences among groups were shown at 24 h. After 6 months and 1 yr, the control group demonstrated significantly lower μTBS than all treatment groups. When applied for 60 s, 0.5% BAC inhibited total MMP activity by 31%, and 1.0% BAC inhibited total MMP activity by 54%. Both BAC and MBAC contributed to the preservation of resin-dentin bonds, probably because of their inhibitory properties of endogenous dentin proteinases.

  7. EVALUATION OF FUNGICIDAL EFFICIENEY OF IRANIAN MADE BENZALKONIUM CHLORIDE

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    K. Imandel

    1995-12-01

    Full Text Available Fungicidal efficiency of Iranian made benzalkonium chloride named Akhgar, Afshang and Hamoon were evaluated on pure culture species of Aspergillus nijer, Candida ablicans and Mucour according to the standard method No. 2442 issued by the Institute of Standards and Industrial Research of Iran, from October 1993 to March 1994. Suspensions were prepared in a way that each cubic centimeter having 3.5×107 condia of Aspergillus nijer, 4×107 Candida albicans yeast cell and 2×107 Mucour spore, and Improved Neubauer slide counting cell were used for enumeration. These laboratory study showed that Lecithine and Tween were the best neutralizers with equal power. Usage of five dilutions of 0.4, 0.6, 0.8, 1 fungus separately at 6.5 to 6.7 pH, confirmed the correctness of dilution figure of 0.4 percent proposed by producer companies and showed that these fungi are still sensitive against Benzalkonium Chloride disinfectants.

  8. Benzalkonium chloride and sulfamethoxazole adsorption onto natural clinoptilolite: effect of time, ionic strength, pH and temperature.

    Science.gov (United States)

    Farías, Tania; de Ménorval, Louis Charles; Zajac, Jerzy; Rivera, Aramis

    2011-11-15

    The influence of different physical factors on the adsorption of the cationic surfactant benzalkonium chloride (BC) and the model drug sulfamethoxazole by a purified natural clinoptilolite (NZ) has been studied in order to employ zeolite-surfactant-drug composites as drug deliverer. It has been demonstrated that the adsorption of BC and sulfamethoxazole onto NZ depends of the time, the temperature, the ionic strength and the pH of the aqueous medium. The optimal conditions for the preparation of the zeolite-surfactant and zeolite-surfactant-drug composite materials are established. The results of the composite characterization support the presence of BC and sulfamethoxazole, as well as the structural stability of NZ during the treatments performed. The release experiments in acid medium demonstrate that the adsorption of sulfamethoxazole is reversible. It is also confirmed that the drug release profile corresponds to a diffusion or zero-order mechanism as a function of the compression pressure.

  9. [Toxicity research status of benzalkonium chloride on ocular surface].

    Science.gov (United States)

    Huang, Caihong; Chen, Wensheng; Chen, Yongxiong; Liu, Zuguo

    2014-04-01

    Benzalkonium chloride (BAC) is the most commonly used preservative in ophthalmic preparations.So far large bodies of clinical and experimental studies have shown that use of topical drugs containing BAC can induce a series of ocular surface diseases, such as apoptosis.However, recently, some clinical studies have shown that ocular toxicity in patients treated with eye drops containing BAC has not apparent correlated with BAC.Some scholars consider that the limitations of the research lead people to recognize the BAC toxicity exaggeratedly.Here we summarize numerous clinical and experimental studies of BAC in the past few years, and focus on reviewing recent researches of the toxic effect of BAC on ocular surface.

  10. Matrix metalloproteinase inhibitory properties of benzalkonium chloride stabilizes adhesive interfaces.

    Science.gov (United States)

    Sabatini, Camila; Patel, Shaival K

    2013-12-01

    This study evaluated the effects of different concentrations of benzalkonium chloride (BAC) on the preservation of adhesive interfaces created with two etch-and-rinse adhesives and its inhibitory properties on dentin matrix metalloproteinase (MMP) activity. The following groups were tested with the adhesive systems Optibond Solo Plus and All-Bond 3: Group 1, adhesive without inhibitor (control); Group 2, topical 2.0% chlorhexidine (2.0% CHX); Group 3, phosphoric acid with 1.0%wt BAC (BAC-PA); Group 4, 0.25% BAC-adhesive (0.25% BAC); Group 5, 0.5% BAC-adhesive (0.5% BAC); Group 6, 1.0% BAC-adhesive (1.0% BAC); and Group 7, 2.0% BAC-adhesive (2.0% BAC). Composite cylinders were fabricated, and shear bond strength (SBS) was evaluated after 24 h, 6 months, and 18 months of storage. Extracts from concentrated demineralized human dentin powder were subjected to SDS-PAGE and incubated in the presence of 0.25, 0.5, 1.0, and 2.0% BAC. Overall, stable bonds were maintained for 18 months. Improved bond strengths were seen for 0.5% BAC and 1.0% BAC when bonding with Optibond Solo Plus, and for 0.25% BAC and 0.5% BAC when bonding with All-Bond 3. Zymographic analysis revealed complete inhibition of gelatinolytic activity with BAC. Benzalkonium chloride, at all concentrations, inhibited dentin proteolytic activity, which seems to have contributed to the improved bond stability after 18 months for specific combinations of BAC concentration and adhesive.

  11. Granular parakeratosis induced by benzalkonium chloride exposure from laundry rinse aids.

    Science.gov (United States)

    Robinson, Aaron J; Foster, Rachael S; Halbert, Anne R; King, Emma; Orchard, David

    2016-09-19

    Benzalkonium chloride is a quaternary ammonium cationic detergent present in a number of household products, which can act as a major skin irritant. We present the case of six children who developed granular parakeratosis after exposure to benzalkonium chloride in laundry rinse aids, presenting as a brightly erythematous, tender but minimally pruritic, intertriginous eruption followed by superficial desquamation. The eruptions resolved over 3-4 weeks after cessation of exposure.

  12. Benzalkonium Chloride Accelerates the Formation of the Amyloid Fibrils of Corneal Dystrophy-associated Peptides*

    Science.gov (United States)

    Kato, Yusuke; Yagi, Hisashi; Kaji, Yuichi; Oshika, Tetsuro; Goto, Yuji

    2013-01-01

    Corneal dystrophies are genetic disorders resulting in progressive corneal clouding due to the deposition of amyloid fibrils derived from keratoepithelin, also called transforming growth factor β-induced protein (TGFBI). The formation of amyloid fibrils is often accelerated by surfactants such as sodium dodecyl sulfate (SDS). Most eye drops contain benzalkonium chloride (BAC), a cationic surfactant, as a preservative substance. In the present study, we aimed to reveal the role of BAC in the amyloid fibrillation of keratoepithelin-derived peptides in vitro. We used three types of 22-residue synthetic peptides covering Leu110-Glu131 of the keratoepithelin sequence: an R-type peptide with wild-type R124, a C-type peptide with C124 associated with lattice corneal dystrophy type I, and a H-type peptide with H124 associated with granular corneal dystrophy type II. The time courses of spontaneous amyloid fibrillation and seed-dependent fibril elongation were monitored in the presence of various concentrations of BAC or SDS using thioflavin T fluorescence. BAC and SDS accelerated the fibrillation of all synthetic peptides in the absence and presence of seeds. Optimal acceleration occurred near the CMC, which suggests that the unstable and dynamic interactions of keratoepithelin peptides with amphipathic surfactants led to the formation of fibrils. These results suggest that eye drops containing BAC may deteriorate corneal dystrophies and that those without BAC are preferred especially for patients with corneal dystrophies. PMID:23861389

  13. Zinc-related actions of sublethal levels of benzalkonium chloride: Potentiation of benzalkonium cytotoxicity by zinc.

    Science.gov (United States)

    Mitani, Tsuyoshi; Elmarhomy, Ahmed Ibrahim Elhossany; Dulamjav, Luvsandorj; Anu, Enkhtumur; Saitoh, Shohei; Ishida, Shiro; Oyama, Yasuo

    2017-04-25

    Benzalkonium chloride (BZK) is a common preservative used in pharmaceutical and personal care products. ZnCl2 was recently reported to significantly potentiate the cytotoxicity of some biocidal compounds. In the present study, therefore, we compared the cytotoxic potency of BZK and then further studied the Zn(2+)-related actions of the most cytotoxic agent among BZK, using flow cytometric techniques with appropriate fluorescent probes in rat thymocytes. Cytotoxicity of benzylcetyldimethylammonium (BZK-C16) was more potent that those of benzyldodecyldimethylammonium and benzyldimethyltetradecylammonium. ZnCl2 (1-10 μM) significantly potentiated the cytotoxicity of BZK-C16 at a sublethal concentration (1 μM). The co-treatment of cells with 3 μM ZnCl2 and 1 μM BZK-C16 increased the population of both living cells with phosphatidylserine exposed on membrane surfaces and dead cells. BZK-C16 at 0.3-1.0 μM elevated intracellular Zn(2+) levels by increasing Zn(2+) influx, and augmented the cytotoxicity of 100 μM H2O2. Zn(2+) is concluded to facilitate the toxicity of BZK. We suggest that the toxicity of BZK is determined after taking extracellular (plasma) and/or environmental Zn(2+) levels into account.

  14. Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride.

    Science.gov (United States)

    Ahn, Youngbeom; Kim, Jeong Myeong; Kweon, Ohgew; Kim, Seong-Jae; Jones, Richard C; Woodling, Kellie; Gamboa da Costa, Gonçalo; LiPuma, John J; Hussong, David; Marasa, Bernard S; Cerniglia, Carl E

    2016-11-22

    Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethylbenzylammonium chloride (C10BDMA-Cl), hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB) to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.

  15. Benzalkonium Chloride Induced Bronchoconstriction in Patients with Stable Bronchial Asthma

    Science.gov (United States)

    Lee, Byoung Hoon

    2007-01-01

    Background Although benzalkonium chloride (BAC)-induced bronchoconstriction occurs in patients with bronchial asthma, BAC-containing nebulizer solutions are still being used in daily practice in Korea. The aim of this study was to evaluate the effects of inhaled aqueous solutions containing BAC. Methods Thirty subjects with bronchial asthma and 10 normal controls inhaled up to three 600 µg nebulized doses of BAC using a jet nebulizer. FEV1 (forced expiratory volume at one second) was measured 15 minutes after each dose. Inhalations were repeated every 20 minutes until FEV1 decreased by 15% or more (defined as BAC-induced bronchoconstriction) or the 3 doses were administered. Results The percent fall in FEV1 in response to BAC inhalation was significantly higher in asthmatics than in normal subjects (p<0.05). BAC administration in subjects with asthma reached a plateau (maximal effect). BAC-induced bronchoconstriction was found in 6 asthmatics (20%), with two responders after the 2nd inhalation and after the 3rd inhalation. The percent fall in FEV1 in response to the 1st inhalation of BAC was significantly higher in asthmatics with higher bronchial hyperresponsiveness (BHR) than in those with lower BHR. Conclusions This study suggests that the available multi-dose nebulized solution is generally safe. However, significant bronchoconstriction can occur at a relatively low BAC dose in asthmatics with severe airway responsiveness. PMID:18309682

  16. Ocular toxicity of benzalkonium chloride homologs compared with their mixtures.

    Science.gov (United States)

    Okahara, Akihiko; Tanioka, Hidetoshi; Takada, Koichi; Kawazu, Kouichi

    2013-12-01

    This study was performed to assess the in vivo ocular toxicity of benzalkonium chloride (BAK) homologs compared with commercially available BAK (BAK mixture) and to assess the ocular toxicity of BAK homolog after repeated ocular application. Rabbit eyes were examined by ophthalmology and scanning electron microscopy (SEM) after 10 applications of BAK homologs with C12 (C12-BAK) and C14 (C14-BAK) alkyl chain lengths and a BAK mixture at concentrations of 0.001% (w/v), 0.003% (w/v), 0.005% (w/v), 0.01% (w/v) and 0.03% (w/v). The ocular toxicity of C12-BAK to rabbit eyes was examined by ophthalmology and histopathology after repeated ocular application for 39 weeks. In addition, the antimicrobial activities of C12-BAK and C14-BAK against A. niger, S. aureus and P. aeruginosa were assessed. Ocular toxicity of C12-BAK was less than those of the BAK mixture and C14-BAK. No ocular toxicity was noted after ocular application of 0.01% C12-BAK to rabbits for 39 weeks. C12-BAK showed antimicrobial activities at a concentration of 0.003%. These results suggest that the use of C12-BAK to replace BAK mixture as a preservative in ophthalmic solutions should be considered in order to reduce the incidence of the corneal epithelial cell injury induced clinically by BAK.

  17. Mechanism of resistance to benzalkonium chloride by Pseudomonas aeruginosa.

    Science.gov (United States)

    Sakagami, Y; Yokoyama, H; Nishimura, H; Ose, Y; Tashima, T

    1989-01-01

    The mechanisms of resistance of Pseudomonas aeruginosa to benzalkonium chloride (BC) were studied. The effluence of cell components was observed in susceptible P. aeruginosa by electron microscopy, but resistant P. aeruginosa seemed to be undamaged. No marked changes in cell surface potential between Escherichia coli NIHJC-2 and a spheroplast strain were found. The contents of phospholipids (PL) and fatty and neutral lipids (FNL) in the cell walls of resistant P. aeruginosa were higher than those in the cell walls of susceptible P. aeruginosa. The amounts of BC adsorbed to PL and FNL of cell walls of BC-resistant P. aeruginosa were lower than those for BC-susceptible P. aeruginosa. Fifteen species of cellular fatty acids were identified by capillary gas chromatography and gas chromatography-mass spectrometry. The ability of BC to permeate the cell wall was reduced because of the increase in cellular fatty acids. These results suggested that the resistance of P. aeruginosa to BC is mainly a result of increased in the contents of PL and FNL. In resistant P. aeruginosa, the decrease in the amount of BC adsorbed is likely to be the result of increases in the contents of PL and FNL. Images PMID:2506813

  18. Adsorption of the disinfectant benzalkonium chloride on montmorillonite. Synergistic effect in mixture of molecules with different chain lengths.

    Science.gov (United States)

    Zanini, Graciela P; Ovesen, Rikke Gleerup; Hansen, H C B; Strobel, Bjarne W

    2013-10-15

    The biocide benzalkonium chloride (BAC) is a mix of cationic alkylbenzyldimethylammonium surfactants having different alkyl chain lengths. A comparative study of adsorption on the phyllosilicate clay montmorillonite of two of these surfactants, with alkyl chains having respectively 12 C atoms (BAC-12) and 14 C atoms (BAC-14), and a mixture of both surfactants is presented in this work. Adsorption isotherms were performed for individual surfactants and for a 1:1 mixture BAC-12+BAC-14. The adsorption was investigated in an ample concentration range that covers almost seven orders of magnitude in concentrations (from 1 nM to 10 mM), range that includes environmentally relevant concentrations. Quantification of BAC was performed by HPLC-UV and LC-MS and the results were completed with powder X-Ray diffraction. The adsorption of both surfactants leads to adsorption isotherms with two well differentiated steps. The first step corresponds almost exclusively to a cation exchange process, and the binding constant is very similar for both surfactants. The second step of the isotherms is observed at higher concentrations and adsorption is mainly driven by lateral interactions between surfactant molecules. The binding constant of this step is larger for BAC-14 than for BAC-12. Adsorption from a BAC-12+BAC-14 mixture shows a synergistic behaviour, possibly due to a better packing arrangement in the interlayer. Calculations show that in natural systems silicate clays are major sorbents of BAC at low concentrations whereas binding to humic acid is predominant at high concentrations.

  19. The influence of ipratropium bromide and sodium cromoglycate on benzalkonium chloride-induced bronchoconstriction in asthma.

    Science.gov (United States)

    Miszkiel, K A; Beasley, R; Holgate, S T

    1988-01-01

    1. Benzalkonium chloride, an antibacterial preservative that is added to nebuliser solutions, has been shown to cause bronchoconstriction when inhaled by asthmatic subjects. 2. To investigate the potential role of reflex and mast cell-dependent mechanisms in the pathogenesis of bronchoconstriction produced by benzalkonium chloride we examined the effects of ipratropium bromide and sodium cromoglycate on this response in both concentration-response and time-course studies in nine asthmatic subjects. 3. Pretreatment with inhaled ipratropium bromide (1 mg) and sodium cromoglycate (40 mg) displaced the benzalkonium chloride concentration-response curves to the right by a mean 2.2 fold and 3.1 fold respectively. 4. Ipratropium bromide and sodium cromoglycate markedly attenuated the airway response to benzalkonium chloride throughout the 45 min time course period, inhibiting the overall response by 56% and 78% respectively. 5. We conclude that benzalkonium chloride provokes bronchoconstriction in asthmatic subjects through a combination of mast cell activation and stimulation of peripheral and central neural pathways. PMID:2972308

  20. Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

    Directory of Open Access Journals (Sweden)

    Youngbeom Ahn

    2016-11-01

    Full Text Available Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl, dodecyldimethylbenzylammonium chloride (C12BDMA-Cl, decyldimethylbenzylammonium chloride (C10BDMA-Cl, hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.

  1. Benzalkonium chloride suppresses rabbit corneal endothelium intercellular gap junction communication.

    Directory of Open Access Journals (Sweden)

    Zhenhao Zhang

    Full Text Available Gap junction intercellular communication (GJIC plays a critical role in the maintenance of corneal endothelium homeostasis. We determined if benzalkonium chloride (BAK alters GJIC activity in the rabbit corneal endothelium since it is commonly used as a drug preservative in ocular eyedrop preparations even though it can have cytotoxic effects.Thirty-six adult New Zealand albino rabbits were randomly divided into three groups. BAK at 0.01%, 0.05%, and 0.1% was applied twice daily to one eye of each of the rabbits in one of the three groups for seven days. The contralateral untreated eyes were used as controls. Corneal endothelial morphological features were observed by in vivo confocal microscopy (IVCM. Immunofluorescent staining resolved changes in gap junction integrity and localization. Western blot analysis and RT-PCR evaluated changes in levels of connexin43 (Cx43 and tight junction zonula occludens-1 (ZO-1 gene and protein expression, respectively. Cx43 and ZO-1 physical interaction was detected by immunoprecipitation (IP. Primary rabbit corneal endothelial cells were cultured in Dulbecco's Modified Eagle Medium (DMEM containing BAK for 24 hours. The scrape-loading dye transfer technique (SLDT was used to assess GJIC activity.Topical administration of BAK (0.05%, 0.1% dose dependently disrupted corneal endothelial cell morphology, altered Cx43 and ZO-1 distribution and reduced Cx43 expression. BAK also markedly induced increases in Cx43 phosphorylation status concomitant with decreases in the Cx43-ZO-1 protein-protein interaction. These changes were associated with marked declines in GJIC activity.The dose dependent declines in rabbit corneal endothelial GJIC activity induced by BAK are associated with less Cx43-ZO-1 interaction possibly arising from increases in Cx43 phosphorylation and declines in its protein expression. These novel changes provide additional evidence that BAK containing eyedrop preparations should be used with caution to

  2. The anti-MMP activity of benzalkonium chloride

    Science.gov (United States)

    Tezvergil-Mutluay, Arzu; Mutluay, M. Murat; Gu, Li-sha; Zhang, Kai; Agee, Kelli A.; Carvalho, Ricardo M.; Manso, Adriana; Carrilho, Marcela; Tay, Franklin R.; Breschi, Lorenzo; Suh, Byoung-In; Pashley, David H.

    2013-01-01

    SUMMARY Objective This study evaluated the ability of benzalkonium chloride (BAC) to bind to dentine and to inhibit soluble recombinant MMPs and bound dentine matrix metalloproteinases (MMPs). Methods Dentine powder was prepared from extracted human molars. Half was left mineralized; the other half was completely demineralized. The binding of BAC to dentine powder was followed by measuring changes in the supernatant concentration using UV spectrometry. The inhibitory effects of BAC on rhMMP-2, -8 and -9 were followed using a commercially available in vitro proteolytic assay. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized beams. Each beam was either dipped into BAC and then dropped into 1 mL of a complete medium (CM) or they were placed in 1 mL of CM containing BAC for 30 d. After 30 d, changes in the dry mass of the beams or in the hydroxyproline (HYP) content of hydrolyzates of the media were quantitated as indirect measures of matrix collagen hydrolysis by MMPs. Results Demineralized dentine powder took up 10-times more BAC than did mineralized powder. Water rinsing removed about 50% of the bound BAC, while rinsing with 0.5 M NaCl removed more than 90% of the bound BAC. BAC concentrations 0.5 wt% produced 100% inhibition of soluble recombinant MMP-2, -8 or -9, and inhibited matrix-bound MMPs between 55-66% when measured as mass loss or 76-81% when measured as solubilization of collagen peptide fragments. Conclusions BAC is effective at inhibiting both soluble recombinant MMPs and matrix-bound dentine MMPs in the absence of resins. PMID:20951183

  3. Assessment of the efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and Tetrahymena spp.

    Science.gov (United States)

    Vaerewijck, M J M; Sabbe, K; Baré, J; Spengler, H-P; Favoreel, H W; Houf, K

    2012-03-01

    The efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and two Tetrahymena spp. was determined based on the European Standard EN 1276:2009 suspension test. Trophozoite viability was assessed by determination of the membrane integrity using flow cytometry as a fast screening technique. Bovine serum albumin was added to simulate clean (0.3 g/liter) and dirty (3 g/liter) conditions. Benzalkonium chloride caused cell lysis at concentrations above 50 mg/liter under clean and dirty conditions. A concentration of 50 mg of free chlorine per liter had a strong biocidal effect on acanthamoebae and tetrahymenae after 15 min under clean and dirty conditions. Our results suggest that benzalkonium chloride and sodium hypochlorite were effective against the three microorganisms at concentrations commonly applied in the food industry.

  4. Postadaptational Resistance to Benzalkonium Chloride and Subsequent Physicochemical Modifications of Listeria monocytogenes

    Science.gov (United States)

    To, Monica S.; Favrin, Stacy; Romanova, Nadya; Griffiths, Mansel W.

    2002-01-01

    Many studies have demonstrated that bacteria, including Listeria monocytogenes, are capable of adapting to disinfectants used in industrial settings after prolonged exposure to sublethal concentrations. However, the consequent alterations of the cell surface due to sanitizer adaptation of this pathogen are not fully understood. Two resistant and four sensitive L. monocytogenes strains from different sources were progressively subcultured with increasing sublethal concentrations of a surfactant, benzalkonium chloride (BC). To evaluate the effects of acquired tolerance to BC, parent and adapted strains were compared by using several morphological and physiological tests. Sensitive strains showed at least a fivefold increase in the MIC, while the MIC doubled for resistant strains after the adaptation period. The hydrophobicities of cells of parent and adapted strains were similar. Serological testing indicated that antigen types 1 and 4 were both present on the cell surface of adapted cells. The data suggest that efflux pumps are the major mechanism of adaptation in sensitive strains and are less important in originally resistant isolates. A different, unknown mechanism was responsible for the original tolerance of resistant isolates. In an originally resistant strain, there was a slight shift in the fatty acid profile after adaptation, whereas sensitive strains had similar profiles. Electron micrographs revealed morphological differences after adaptation. The changes in cell surface antigens, efflux pump utilization, and fatty acid profiles suggest that different mechanisms are used by resistant and sensitive strains for adaptation to BC. PMID:12406712

  5. Effect of Oxygen Limitation and Starvation on the Benzalkonium Chloride Susceptibility of Escherichia coli

    DEFF Research Database (Denmark)

    Bjergbæk, L.A.; Haagensen, Janus Anders Juul; Molin, Søren

    2008-01-01

    Aims: To investigate the effect of oxygen limitation, glucose-starvation and temperature on the susceptibility of Escherichia coli towards the quaternary ammonium biocide benzalkonium chloride (BAC). Methods and Results: The effect of BAC on planktonic and sessile cells were investigated using...

  6. Sodium perbarate and benzalkonium chloride induce DNA damage in Chang conjunctival epithelial cells.

    Science.gov (United States)

    Zhang, Huina; Wu, Han; Yang, Jun; Ye, Juan

    2017-02-06

    Content and objective: To investigate and compare the toxic effects of benzalkonium chloride (BAC) and new type oxidative preservative sodium perborate (NaBO3) on DNA damage, reactive oxygen species (ROS), and cell survival in immortalized human Chang conjunctival cells.

  7. Gene expression in Listeria monocytogenes exposed to sublethal concentration of benzalkonium chloride.

    Science.gov (United States)

    Tamburro, Manuela; Ripabelli, Giancarlo; Vitullo, Monia; Dallman, Timothy James; Pontello, Mirella; Amar, Corinne Francoise Laurence; Sammarco, Michela Lucia

    2015-06-01

    In this study, tolerance at sublethal concentration of benzalkonium chloride and transcription levels of mdrL, ladR, lde, sigB and bcrABC genes in Listeria monocytogenes strains were evaluated. Viable cells reduction occurred in 45% of strains and clinical isolates showed lower sensitivity than isolates from foods. An increased transcription of an efflux system encoding gene was found in 60% of strains, and simultaneous mdrL overexpression and ladR underexpression occurred in 30% of isolates. A significant association between reduced benzalkonium chloride activity and both mdrL and sigB overexpression was observed; sigB expression also correlated with both mdrL and ladR genes. The bcrABC gene was only found in six strains, all isolated from foods and sensitive to benzalkonium chloride, and in four strains an underexpression was observed. Disinfection at sublethal concentration was less effective in clinical isolates, and mdrL and sigB expression was significantly affected by disinfection. Further insights are needed to understand the adaptation to benzalkonium chloride and to evaluate whether changes in gene expression could affect the L. monocytogenes virulence traits and persistence in the environment.

  8. Effect of benzalkonium chloride on the stability of the precorneal tear film in rabbit and man.

    Science.gov (United States)

    Wilson, W. S.; Duncan, A. J.; Jay, J. L.

    1975-01-01

    Benzalkonium chloride, a surface-active preservative commonly used in eyedrop preparations, has been shown to hasten the drying of the precorneal tear film. In the rabbit, 0.01 per cent benzalkonium (the concentration usually employed as a preservative) shortened the time required for the appearance of dry spots on the corneal surface by a factor of about four. In man, an approximately twofold hastening was demonstrated. This effect is thought to preclude the use of this substance as a preservative in eyedrop preparations for use as local anaesthetics. PMID:1203224

  9. Comparative biocidal activity of peracetic acid, benzalkonium chloride and ortho-phthalaldehyde on 77 bacterial strains.

    Science.gov (United States)

    Bridier, A; Briandet, R; Thomas, V; Dubois-Brissonnet, F

    2011-07-01

    Despite numerous reports on biocide activities, it is often difficult to have a reliable and relevant overview of bacterial resistance to disinfectants because each work challenges a limited number of strains and tested methods are often different. The aim of this study was to evaluate the bactericidal activity of three different disinfectants commonly used in industrial or medical environments (peracetic acid, benzalkonium chloride and ortho-phthalaldehyde) against 77 bacterial strains from different origins using one standard test method (NF EN 1040). Results highlight the existence of high interspecific variability of resistance to disinfectants and, contrary to widespread belief, Gram-positive strains generally appeared more resistant than Gram-negative strains. Resistance was also variable among strains of the same species such as Bacillus subtilis to peracetic acid, Pseudomonas aeruginosa to benzalkonium chloride and Staphylococcus aureus to ortho-phthalaldehyde.

  10. Epidemic septic arthritis caused by Serratia marcescens and associated with a benzalkonium chloride antiseptic.

    Science.gov (United States)

    Nakashima, A K; McCarthy, M A; Martone, W J; Anderson, R L

    1987-01-01

    During a 6-week period, 10 patients were admitted to a hospital for treatment of knee or shoulder joint infections due to Serratia species. Isolates from eight patients were identified as Serratia marcescens with identical biochemical characteristics and antibiotic susceptibility patterns. Before the onset of infections, all patients had been treated by two orthopedic surgeons who shared an office. Studies revealed that infections were associated with previous joint injections (P = 4.44 X 10(-5] of methylprednisolone and lidocaine. Environmental cultures revealed that a canister of cotton balls soaked in aqueous benzalkonium chloride and two multiple-dose vials of methylprednisolone previously used by office personnel were contaminated with the epidemic strain of S. marcescens. The canister may have served as a potential reservoir for contamination of sterile solutions and equipment used for joint injections, of skin at the injection site, and of hands of personnel. No further cases occurred after the use of aqueous benzalkonium chloride was discontinued. PMID:3298308

  11. Fourteen-year survival of Pseudomonas cepacia in a salts solution preserved with benzalkonium chloride.

    Science.gov (United States)

    Geftic, S G; Heymann, H; Adair, F W

    1979-01-01

    A strain of Pseudomonas cepacia that survived for 14 years (1963 to 1977) as a contaminant in an inorganic salt solution which contained commercial 0.05% benzalkonium chloride (CBC) as an antimicrobial preservative, was compared to a recent clinical isolate of P. cepacia. Ammonium acetate was present in the concentrated stock CBC solution, and served as a carbon and nitrogen source for growth when carried over into the salts solution with the CBC. The isolate's resistance to pure benzalkonium chloride was increased step-wise to a concentration of 16%. Plate counts showed 4 x 10(3) colony-forming units per ml in the salts solution. Comparison of growth rates, mouse virulence, antibiotics resistance spectra, and substrate requirements disclosed no differences between the contaminant and a recently isolated clinical strain of P. cepacia. The results indicate that it is critical that pharmaceutical solutions containing benzalkonium chloride as an antimicrobial preservative be formulated without extraneous carbon and nitrogen sources or be preserved with additional antimicrobial agents. PMID:453827

  12. Biodegradation of benzalkonium chlorides singly and in mixtures by a Pseudomonas sp. isolated from returned activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Adnan Hossain, E-mail: akhan462@uwo.ca [Department of Chemical and Biochemical Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada); Topp, Edward, E-mail: Ed.Topp@AGR.GC.CA [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Department of Biology, University of Western Ontario, London, ON N6A 5B7 (Canada); Scott, Andrew, E-mail: Andrew.Scott@AGR.GC.CA [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Sumarah, Mark, E-mail: Mark.Sumarah@agr.gc.ca [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Macfie, Sheila M., E-mail: smacfie@uwo.ca [Department of Biology, University of Western Ontario, London, ON N6A 5B7 (Canada); Ray, Madhumita B., E-mail: mbhowmic@uwo.ca [Department of Chemical and Biochemical Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada)

    2015-12-15

    Highlights: • Pseudomonas sp. degraded two benzalkonium chlorides: BDDA and BDTA. • Although BDTA biodegraded at low concentration, it inhibited the degradation of BDDA. • For BDDA, two transformation products indicate two sites of bacterial activity. • {sup 14}C-labelled BDDA was mineralized to {sup 14}CO{sub 2} within 300 h. - Abstract: Bactericidal cationic surfactants such as quaternary ammonium compounds (QACs) are widely detected in the environment, and found at mg kg{sup −1} concentrations in biosolids. Although individual QACs are amenable to biodegradation, it is possible that persistence is increased for mixtures of QACs with varying structure. The present study evaluated the biodegradation of benzyl dimethyl dodecyl ammonium chloride (BDDA) singly and in the presence of benzyl dimethyl tetradecyl ammonium chloride (BDTA) using Pseudomonas sp., isolated from returned activated sludge. Growth was evaluated, as was biodegradation using {sup 14}C and HPLC-MS methods. BDTA was more toxic to growth of Pseudomonas sp. compared to BDDA, and BDTA inhibited BDDA biodegradation. The benzyl ring of [U-{sup 14}C-benzyl] BDDA was readily and completely mineralized. The detection of the transformation products benzyl methyl amine and dodecyl dimethyl amine in spent culture liquid was consistent with literature. Overall, this study demonstrates the antagonistic effect of interactions on biodegradation of two widely used QACs suggesting further investigation on the degradation of mixture of QACs in wastewater effluents and biosolids.

  13. Survival of Serratia marcescens in benzalkonium chloride and in multiple-dose medication vials: relationship to epidemic septic arthritis.

    Science.gov (United States)

    Nakashima, A K; Highsmith, A K; Martone, W J

    1987-01-01

    In an epidemic of septic arthritis due to Serratia marcescens, the intra-articular injection of contaminated methylprednisolone may have played a key role. The epidemic strain was found in used multiple-dose vials of methylprednisolone and in a canister of cotton balls soaked in benzalkonium chloride. The cotton balls had been used for antisepsis and disinfection. Growth characteristics of the epidemic strain of S. marcescens were compared with those of control strains of S. marcescens which had been obtained from unrelated nosocomial outbreaks. The epidemic strain was able to survive in 1:100 dilutions of benzalkonium chloride and was able to grow to greater than 10(5) CFU/ml in multiple-dose vials of methylprednisoline; control strains could not be recovered after 24 h in the same solutions. The preservative in methylprednisolone is gamma-myristyl picolinium chloride, a compound chemically related to benzalkonium chloride. We speculate that the epidemic strain of S. marcescens, which was resistant to benzalkonium chloride, had cross-resistance to gamma-myristyl picolinium chloride. If the cotton balls were used to disinfect the tops of the multiple-dose vials of methylprednisolone, small numbers of organisms subsequently introduced into the solution could have grown to high concentrations. PMID:3298309

  14. Inactivation of human immunodeficiency virus type 1 in tissue culture fluid and in genital secretions by the spermicide benzalkonium chloride.

    Science.gov (United States)

    Wainberg, M A; Spira, B; Bleau, G; Thomas, R

    1990-01-01

    We have shown that the spermicidal agent benzalkonium chloride can exert a direct inhibitory effect on the viral reverse transcriptase activity of human immunodeficiency virus type 1 (HIV-1) when utilized at concentrations of 0.05% and higher. Exposure of HIV-1 to this disinfectant at concentrations of more than 0.05% was able to completely destroy viral infectivity, as assessed on susceptible target cells. We have further shown that HIV-1, which is present in both seminal and genital secretions, can be inactivated in such fluids by direct exposure to benzalkonium chloride. PMID:1688873

  15. A capillary liquid chromatography method for benzalkonium chloride determination as a component or contaminant in mixtures of biocides.

    Science.gov (United States)

    Prieto-Blanco, M C; Argente-García, A; Campíns-Falcó, P

    2016-01-29

    A method for quantifying benzalkonium chloride (BAK), an alkyl dimethyl benzyl ammonium compound, in several biocides formulations is proposed. A tertiary amine like N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine (TA) and a straight-chain alkyl ammonium compound like trimethyl-tetradecyl ammonium chloride (TMTDAC), have been employed as trade surfactants besides BAK. Two capillary analytical columns with different polarities are tested: inertsil CN-3 capillary column (150mm×0.5mm i.d., 3μm particle diameter) and a non endcapped Zorbax C18 capillary column (35mm×0.5mm i.d., 5μm particle diameter). This latter column provided the best separation of the BAK homologues in less than 12min using acetonitrile:acetate buffer (50mM, pH 5) 85:15 at 20μLmin(-1). The proposed method combines on-line in-tube solid-phase microextraction (IT-SPME) coupled to capillary liquid chromatography (CapLC) and UV diode array detection. Matrix effect was present when TA were in excess to BAK. If TMTDAC is the co-biocide, matrix effect is always present. A decreasing of analytical response mainly for C12-BAK homologue was found using both chromatographic columns. The charged amount of mixture in the system was the most important parameter for obtaining reliable results. 1mL was the on line processed sample volume optimum for concentrations lower than 35μgmL(-1) of total surfactants. LODs were 0.03μgmL(-1) and 0.006μgmL(-1) for C12-BAK and C14-BAK, respectively. This method is also of use to evaluate the unwanted presence of BAK in biocide formulations due to industrial processes.

  16. Listeria monocytogenes Strains Selected on Ciprofloxacin or the Disinfectant Benzalkonium Chloride Exhibit Reduced Susceptibility to Ciprofloxacin, Gentamicin, Benzalkonium Chloride, and Other Toxic Compounds▿

    Science.gov (United States)

    Rakic-Martinez, Mira; Drevets, Douglas A.; Dutta, Vikrant; Katic, Vera; Kathariou, Sophia

    2011-01-01

    Listeria monocytogenes is a leading agent for severe food-borne illness and death in the United States and other nations. Even though drug resistance has not yet threatened therapeutic interventions for listeriosis, selective pressure associated with exposure to antibiotics and disinfectants may result in reduced susceptibility to these agents. In this study, selection of several L. monocytogenes strains on either ciprofloxacin (2 μg/ml) or the quaternary ammonium disinfectant benzalkonium chloride (BC; 10 μg/ml) led to derivatives with increased MICs not only to these agents but also to several other toxic compounds, including gentamicin, the dye ethidium bromide, and the chemotherapeutic drug tetraphenylphosphonium chloride. The spectrum of compounds to which these derivatives exhibited reduced susceptibility was the same regardless of whether they were selected on ciprofloxacin or on BC. Inclusion of strains harboring the large plasmid pLM80 revealed that MICs to ciprofloxacin and gentamicin did not differ between the parental and plasmid-cured strains. However, ciprofloxacin-selected derivatives of pLM80-harboring strains had higher MICs than those derived from the plasmid-cured strains. Susceptibility to the antimicrobials was partially restored in the presence of the potent efflux inhibitor reserpine. Taken together, these data suggest that mutations in efflux systems are responsible for the multidrug resistance phenotype of strains selected on ciprofloxacin or BC. PMID:22003016

  17. Nosocomial transmission of Serratia marcescens in a veterinary hospital due to contamination by benzalkonium chloride.

    Science.gov (United States)

    Fox, J G; Beaucage, C M; Folta, C A; Thornton, G W

    1981-01-01

    During a 1-year period, Serratia marcescens was isolated from 50% of all contaminate intravenous catheters from dogs and cats in a large veterinary hospital. S. marcescens was also isolated from respiratory tracts, genitourinary tracts, skin, and other sites in hospitalized animals. A total of 55% of the clinical isolates and 66% of the intravenous catheter isolates had the same API biochemical profile. The source of the S. marcescens was determined to be aqueous benzalkonium chloride (0.025%) sponge pots located in the intensive care unit, surgery rooms, and outpatient clinic areas of the hospital. Of the 11 S. marcescens isolates submitted to the Centers for Disease Control for serotyping (6 from aqueous benzalkonium chloride sponge pots, 5 from intravenous catheters), 8 were identified as serotype O10:H11. All S. marcescens isolates tested for antibiotic susceptibilities were multiply resistant; isolates were most frequently resistant to streptomycin, cephalothin, and ampicillin. This study demonstrates that improper use of disinfectants plays an important role in the nosocomial transmission of S. marcescens. PMID:7024303

  18. Resistance of Pseudomonas to Quaternary Ammonium Compounds. I. Growth in Benzalkonium Chloride Solution

    Science.gov (United States)

    Adair, Frank W.; Geftic, Sam G.; Gelzer, Justus

    1969-01-01

    Resistant cells of Pseudomonas aeruginosa and a waterborne Pseudomonas sp. (strain Z-R) were able to multiply in nitrogen-free minimal salts solution containing various concentrations of commercially prepared, ammonium acetate-buffered benzalkonium chloride (CBC), a potent antimicrobial agent. As the CBC concentration increased, growth increased until a point was reached at which the extent of growth leveled off or was completely depressed. Minimal salts solutions of pure benzalkonium chloride (PBC) containing no ammonium acetate did not support bacterial growth. When ammonium acetate was added to PBC solutions in the same concentrations found in CBC solutions, growth patterns developed that were comparable to those found with CBC. Likewise, (NH4)2SO4 added to PBC solutions supported growth of both organisms. P. aeruginosa was initially resistant to CBC levels of 0.02% and it was adapted to tolerate levels as high as 0.36%. Strain Z-R was naturally resistant to 0.4% CBC. Since ammonium acetate, carried over by the CBC used in drug formulations and disinfectant solutions, has the potential to support the growth of resistant bacteria and thus make possible the risk of serious infection, it is suggested that regulations allowing the presence of ammonium acetate in CBC solution be reconsidered. PMID:4984761

  19. Cluster of postinjection abscesses related to corticosteroid injections and use of benzalkonium chloride.

    Science.gov (United States)

    Olson, R K; Voorhees, R E; Eitzen, H E; Rolka, H; Sewell, C M

    1999-01-01

    Benzalkonium chloride (BC) is an unreliable disinfectant. A matched case-control study and environmental investigation were conducted to determine the cause of and risk factors for a cluster of postinjection abscesses at a private medical clinic where BC was used as a disinfectant. Twenty-eight case-patients who had an abscess at the injection site were matched with 126 control patients who had received an intramuscular injection at the clinic on the same day. Risk factors for abscess development in a multivariable logistic model were corticosteroid injection and being female. All case-patients had received a corticosteroid injection from a multidose vial. Cultures of abscesses from 20 of 23 case-patients grew Pseudomonas aeruginosa. Cultures of BC prepared at the clinic also grew P aeruginosa, suggesting that BC was the source of infection. Injection site cleaning with BC did not appear to be the route of infection since use of BC at the time of injection was not associated with abscess development. A more likely route of infection was injection of contaminated corticosteroid from multidose vials that could have been inoculated with pseudomonads via needle puncture after vial septa were wiped with contaminated BC. Benzalkonium chloride should not be used to clean injection vial septa or injection sites. PMID:10214100

  20. Cytotoxicity of prostaglandin analog eye drops preserved with benzalkonium chloride in multiple corneoconjunctival cell lines

    Science.gov (United States)

    Ayaki, Masahiko; Iwasawa, Atsuo

    2010-01-01

    Purpose: This study evaluated the cytotoxicity of five prostaglandin analog ophthalmic solutions on four ocular surface cell lines, ie, Chang (human conjunctiva), SIRC (rabbit cornea), RC-1 (rabbit cornea), and BCE C/D-1b (bovine cornea). Methods: Cell viability was measured by neutral red and MTT assays in cells treated for 10, 30, or 60 minutes with various doses of prostaglandins (undiluted, and 2- and 10-fold dilutions). The number of cell lines with viability ≥50% in the presence of selected dilution of the drug (CVS50) was used for comparison. In addition, 24 cell viability comparisons (four cell lines, two assays, and three exposure times) were made between latanoprost (Xalatan®) and each other solution at each dose. A comparison between the newly introduced tafluprost (Tapros®) with 0.01% benzalkonium chloride was also made. Results: The order of cell viability determined by CVS50 was Travatan Z® (travoprost with the SofZia system) > Tapros ≥ Travatan® (travoprost) = Xalatan > Rescula® (unoproston). This was consistent with the results of direct comparisons between Xalatan and the other drugs. There was no clear difference in cell viability between Tapros and benzalkonium chloride. Conclusions: Use of two assays, multiple cell lines, and various dilutions and exposure times provided a unique evaluation of cytotoxicity among ophthalmic solutions. CVS50 was useful for comparison of the cell viability of the solutions. PMID:20823934

  1. Toxicity and genotoxicity of the quaternary ammonium compound benzalkonium chloride (BAC) using Daphnia magna and Ceriodaphnia dubia as model systems.

    Science.gov (United States)

    Lavorgna, Margherita; Russo, Chiara; D'Abrosca, Brigida; Parrella, Alfredo; Isidori, Marina

    2016-03-01

    The toxicity and genotoxicity of the cationic surfactant benzalkonium chloride (BAC) were studied using Daphnia magna and Ceriodaphnia dubia as model systems. Acute and chronic toxicity testing were performed according to the international standard guidelines and the genotoxicity was detected through the comet assay on cells from whole organisms in vivo exposed. Acute effects occurred at concentrations in the order of tens of μg/L in D. magna and hundreds of μg/L in C. dubia. Chronic effects were found at one order of magnitude less than short-term effects maintaining the same difference in sensitivity between D. magna and C. dubia. BAC induced relevant DNA damage, in both cladocerans; the lowest adverse effect levels were 0.4 and 4 ng/L for D. magna and C. dubia, respectively. As these effective concentrations are far lower than BAC occurrence in surface waters (units of μg/L) a concerning environmental risk cannot be excluded. The findings of this study showed that D. magna and C. dubia, could be used as model organisms to detect acute and chronic toxicity as well as genotoxicity at the whole organism level.

  2. Mechanism and toxicity research of benzalkonium chloride oxidation in aqueous solution by H2O2/Fe(2+) process.

    Science.gov (United States)

    Zhang, Qian; Xia, Yu-Feng; Hong, Jun-Ming

    2016-09-01

    As widely used disinfectants, the pollution caused by benzalkonium chloride (BAC) has attracted a lot of attention in recent years. Since it is not suitable for biodegradation, BAC was degraded firstly by Fenton advanced oxidation technologies (AOTs) in this research to enhance the biodegradability of the pollutions. The result revealed that the optimal molar ratio of H2O2/Fe(2+) for BAC degradation was 10:1, and the COD removal rate was 32 %. To clarify the pathway of degradation, the technique of GC-MS was implemented herein to identify intermediates and the toxicity of those BAC intermediates were also novelty tested through microbial fuel cells (MFC). The findings indicated that ten transformation products including benzyl dimethyl amine and dodecane were formed during the H2O2/Fe(2+) processes, which means the degradation pathway of BAC was initiated both on the hydrophobic (alkyl chain) and hydrophilic (benzyl and ammonium moiety) region of the surfactant. The toxicity of BAC before and after treated by Fenton process was monitored through MFC system. The electricity generation was improved 337 % after BAC was treated by H2O2/Fe(2+) oxidation processes which indicated that the toxicity of those intermediates were much lower than BAC. The mechanism and toxicity research in this paper could provide the in-depth understanding to the pathway of BAC degradation and proved the possibility of AOTs for the pretreatment of a biodegradation process.

  3. Mixed species biofilms of Listeria monocytogenes and Lactobacillus plantarum show enhanced resistance to benzalkonium chloride and peracetic acid

    NARCIS (Netherlands)

    Veen, van der S.; Abee, T.

    2011-01-01

    We investigated the formation of single and mixed species biofilms of Listeria monocytogenes strains EGD-e and LR-991, with Lactobacillus plantarum WCFS1 as secondary species, and their resistance to the disinfectants benzalkonium chloride and peracetic acid. Modulation of growth, biofilm formation,

  4. Effect of benzalkonium chloride on viability and energy metabolism in exponential- and stationary-growth-phase cells of Listeria monocytogenes

    NARCIS (Netherlands)

    Luppens, S.B.I.; Abee, T.; Oosterom, J.

    2001-01-01

    The difference in killing exponential- and stationary-phase cells of Listeria monocytogenes by benzalkonium chloride (BAC) was investigated by plate counting and linked to relevant bioenergetic parameters. At a low concentration of BAC (8 mg liter-1), a similar reduction in viable cell numbers was o

  5. Antibiotic susceptibility in benzalkonium chloride-resistant and -susceptible Listeria monocytogenes strains.

    Science.gov (United States)

    Ortiz, Sagrario; López, Pilar; López, Victoria; Martínez-Suárez, Joaquín V

    2014-07-01

    This study aimed to investigate whether Listeria monocytogenes strains with resistance to a commonly used biocide display any cross-resistance to antibiotics. Using pulsed-field gel electrophoresis (PFGE), 29 different PFGE types were previously identified in an Iberian pig abattoir and processing plant. Only three PFGE types were resistant to benzalkonium chloride (BAC), but they represented a significant proportion of the PFGE types surviving in the plant after 4 years. In the present study, a subset of 29 strains, representing the 29 different PFGE types, underwent antibiotic susceptibility testing. Antibiotic susceptibility was assessed by Etest, utilizing 12 commonly prescribed antibiotics. All of the 29 strains were susceptible to all of the antibiotics tested. The study revealed that this group of different PFGE types of L. monocytogenes, including those resistant to BAC, possesses uniform sensitivity to antibiotics.

  6. In vivo wound-healing effects of novel benzalkonium chloride-loaded hydrocolloid wound dressing.

    Science.gov (United States)

    Jin, Sung Giu; Yousaf, Abid Mehmood; Jang, Sun Woo; Son, Mi-Won; Kim, Kyung Soo; Kim, Dong-Wuk; Li, Dong Xun; Kim, Jong Oh; Yong, Chul Soon; Choi, Han-Gon

    2015-05-01

    The purpose of this study was to evaluate the wound-healing effects of a novel benzalkonium chloride (BC)-loaded hydrocolloid wound dressing (HCD). A BC-loaded HCD was prepared with various constituents using a hot melting method, and its mechanical properties and antimicrobial activities were assessed. The in vivo wound healings of the BC-loaded HCD in various would models were evaluated in rats compared with a commercial wound dressing, Duoderm™. This BC-loaded HCD gave better skin adhesion, swelling, mechanical strength, and flexibility compared with the commercial wound dressing. It showed excellent antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. In addition, as compared with the commercial wound dressing, it showed more improved wound healings and tissue restoration effect on the excision, infection, and abrasion wounds in rats. Thus, this novel BC-loaded HCD would be an excellent alternative to the commercial wound dressing for treatment of various wounds.

  7. Corrosive Esophagitis with Benzalkonium Chloride in a Two Days Old Neonate.

    Science.gov (United States)

    Civan, Hasret Ayyildiz; Gulcu, Didem; Erkan, Tulay

    2016-09-01

    Benzalkonium chloride (BAC) is a caustic agent which is used in farms, homes and hospitals for cleaning skin and wounds as an antiseptic solution. It may lead to digestive system injuries in case of ingestion. We present a two-days-old newborn case which was carried to the emergency unit with complaints of poor breastfeeding, uneasiness and crying for 4-6 hours. Her mom confessed that she had given a spoon of 10% BAC solution for her cough. Initial laboratory tests were in normal ranges. A gastroscopy performed in the second hour of her admission revealed an hyperemic and edematous mucosa in the middle third of esophagus and a circumferential ulceration followed in the distal portion. Hereupon, a conservative treatment for 10 days was administered and the control gastroscopy demonstrated that the damage was almost totally improved. She was the youngest case with this etiology and successfully treated with conservative approach.

  8. Reduced virulence of Pseudomonas aeruginosa grown in the presence of benzalkonium chloride.

    Science.gov (United States)

    Adair, F W; Liauw, H L; Geftic, S G; Gelzer, J

    1975-01-01

    Resistant cells of Pseudomonas aeruginosa ATCC 9027 which were grown in the presence of 1 mg of benzalkonium chloride (BC) per ml caused only a mild conjunctivitis when they were dropped onto the scratched corneas of rabbits. In contrast, cells of the BC-sensitive parent strain induced a severe keratoconjunctivitis. In addition, the BC-grown cells also had a reduced capacity to produce kidney infections in mice as compared to the parent strain. BC-grown cells acted as weak complex antigens which conferred slight protection against lethal doses of BC-grown cells. No cross-protection to cells of the parent strain occurred. The data indicate that growth in the presence of BC results in cells with reduced virulence. Images PMID:809470

  9. The toxicity of the quaternary ammonium compound benzalkonium chloride alone and in mixtures with other anionic compounds to bacteria in test systems with Vibrio fischeri and Pseudomonas putida.

    Science.gov (United States)

    Sütterlin, H; Alexy, R; Kümmerer, K

    2008-10-01

    Mixtures of chemicals are present in the aquatic environment but standard testing methods assess only single compounds. One aspect of this question is the importance of the formation of ionic pairs, for example from quaternary ammonium compounds with organic anions, and the significance of the ionic pairs for bacterial toxicity in the aquatic environment. The aim of the present study was to investigate the toxicity of the cationic quaternary ammonium compound benzalkonium chloride (BAC) against aquatic bacteria in the presence of substances commonly found in wastewater, such as the anionic surfactant linear alkylbenzene sulfonate (LAS), naphthalene sulfonic acid (NSA), sodium dodecylsulfonate (SDS), and benzene sulfonic acid (BSA). The growth inhibition test with Pseudomonas putida and the Vibrio fischeri luminescent inhibition test were used to determine the toxicity of single compounds and compound mixtures. The results found in this study indicate that ion pair formation is of minor significance under the test conditions applied here.

  10. Effects of Benzalkonium Chloride on THP-1 Differentiated Macrophages In Vitro

    Science.gov (United States)

    Michée, Sylvain; Brignole-Baudouin, Françoise; Riancho, Luisa; Rostene, William; Baudouin, Christophe; Labbé, Antoine

    2013-01-01

    Purpose To characterize the effects of benzalkonium chloride (BAK) in THP-1 differentiated cells in vitro. Methods Macrophages were obtained after differentiation of THP-1 cells, a human monocytic leukemia cell line. Macrophages were exposed for 24 h to 33 nM (10−5%) benzalkonium chloride (BAK), 10 nM dinitrochlorobenzene (DNCB), 100 ng/mL lipopolysaccharide (LPS), 5 ng/mL tumor necrosis factor alpha (TNF-α) or phosphate buffered saline (PBS) as controls. The expression of CD11b, CD11c, CD33 and CD54 was evaluated using immunohistochemistry and flow cytometry (FCM). Phagocytosis function was analyzed using carboxylate-modified fluorescent microspheres and quantified by FCM. Migration was evaluated in cocultures with conjunctival epithelial cells. Cytokine production was detected and quantified in culture supernatants using a human cytokine array. Results Stimulation of THP-1-derived macrophages with a low concentration of BAK increased CD11b and CD11c expression and decreased CD33. Macrophages exposed to BAK, LPS and TNF-α had increased phagocytosis. In contrast to LPS, BAK and TNF-α increased macrophage migration. Cytokines in supernatants of macrophages exposed to BAK revealed an increased release of CCL1, CCL4/MIP-1β, TNF-α, soluble CD54/ICAM-1 and IL-1β. Conclusion In vitro, BAK has a direct stimulating effect on macrophages, increasing phagocytosis, cytokine release, migration and expression of CD11b and CD11c. Long-term exposure to low concentrations of BAK should be considered as a stimulating factor responsible for inflammation through macrophage activation. PMID:23991114

  11. Effects of benzalkonium chloride on THP-1 differentiated macrophages in vitro.

    Directory of Open Access Journals (Sweden)

    Sylvain Michée

    Full Text Available PURPOSE: To characterize the effects of benzalkonium chloride (BAK in THP-1 differentiated cells in vitro. METHODS: Macrophages were obtained after differentiation of THP-1 cells, a human monocytic leukemia cell line. Macrophages were exposed for 24 h to 33 nM (10(-5% benzalkonium chloride (BAK, 10 nM dinitrochlorobenzene (DNCB, 100 ng/mL lipopolysaccharide (LPS, 5 ng/mL tumor necrosis factor alpha (TNF-α or phosphate buffered saline (PBS as controls. The expression of CD11b, CD11c, CD33 and CD54 was evaluated using immunohistochemistry and flow cytometry (FCM. Phagocytosis function was analyzed using carboxylate-modified fluorescent microspheres and quantified by FCM. Migration was evaluated in cocultures with conjunctival epithelial cells. Cytokine production was detected and quantified in culture supernatants using a human cytokine array. RESULTS: Stimulation of THP-1-derived macrophages with a low concentration of BAK increased CD11b and CD11c expression and decreased CD33. Macrophages exposed to BAK, LPS and TNF-α had increased phagocytosis. In contrast to LPS, BAK and TNF-α increased macrophage migration. Cytokines in supernatants of macrophages exposed to BAK revealed an increased release of CCL1, CCL4/MIP-1β, TNF-α, soluble CD54/ICAM-1 and IL-1β. CONCLUSION: In vitro, BAK has a direct stimulating effect on macrophages, increasing phagocytosis, cytokine release, migration and expression of CD11b and CD11c. Long-term exposure to low concentrations of BAK should be considered as a stimulating factor responsible for inflammation through macrophage activation.

  12. Cytotoxicity of prostaglandin analog eye drops preserved with benzalkonium chloride in multiple corneoconjunctival cell lines

    Directory of Open Access Journals (Sweden)

    Masahiko Ayaki

    2010-08-01

    Full Text Available Masahiko Ayaki1, Atsuo Iwasawa21Department of Ophthalmology, Saitama National Hospital, Wako, 2Department of Clinical Pathology, Showa University Fujigaoka Hospital, Yokohama, JapanPurpose: This study evaluated the cytotoxicity of five prostaglandin analog ophthalmic ­solutions on four ocular surface cell lines, ie, Chang (human conjunctiva, SIRC (rabbit cornea, RC-1 (rabbit cornea, and BCE C/D-1b (bovine cornea.Methods: Cell viability was measured by neutral red and MTT assays in cells treated for 10, 30, or 60 minutes with various doses of prostaglandins (undiluted, and 2- and 10-fold dilutions. The number of cell lines with viability ≥50% in the presence of selected dilution of the drug (CVS50 was used for comparison. In addition, 24 cell viability comparisons (four cell lines, two assays, and three exposure times were made between latanoprost (Xalatan® and each other solution at each dose. A comparison between the newly introduced tafluprost (Tapros® with 0.01% benzalkonium chloride was also made.Results: The order of cell viability determined by CVS50 was Travatan Z® (travoprost with the SofZia system> Tapros ≥ Travatan® (travoprost = Xalatan > Rescula® (unoproston. This was consistent with the results of direct comparisons between Xalatan and the other drugs. There was no clear difference in cell viability between Tapros and benzalkonium chloride.Conclusions: Use of two assays, multiple cell lines, and various dilutions and exposure times provided a unique evaluation of cytotoxicity among ophthalmic solutions. CVS50 was useful for comparison of the cell viability of the solutions.Keywords: glaucoma, cornea, cell viability score

  13. Antifungal activity of benzalkonium chloride, dettol , and chlorhexidine on opportunistic isolated fungi from the environment and operating rooms in private clinics of Tehran in 2011

    Directory of Open Access Journals (Sweden)

    Hossein Nowrozi

    2013-11-01

    Conclusion: Benzalkonium chloride and Dettol had a complete antifungal activity, but chlorhexidine was found to be the least effective agent.. Therefore, the tested concentrations give out their most fungicidal activity as disinfectants, if their durability is taken into account.

  14. Efficacy and tolerability of benzalkonium chloride-free travoprost in glaucoma patients switched from benzalkonium chloride-preserved latanoprost or bimatoprost

    Directory of Open Access Journals (Sweden)

    García-Feijoo J

    2016-10-01

    Full Text Available Julian García-Feijoo,1 Francisco J Muñoz-Negrete,2 Douglas A Hubatsch,3 Gemma C Rossi4 On behalf of the study investigators 1Department of Ophthalmology, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Universidad Complutense, OFTARED, 2Hospital UniversItario Ramón y Cajal, Universidad de Alcalá, IRYCIS, OFTARED, Madrid, Spain; 3Alcon Laboratories, Inc., Fort Worth, TX, USA; 4Department of Ophthalmology, University Eye Clinic, IRCCS Policlinico San Matteo Foundation, Pavia, Italy Introduction: The preservative benzalkonium chloride (BAK is used to preserve several topical, intraocular pressure (IOP-lowering glaucoma medications but can cause tolerability concerns that may lead to decreased adherence to treatment and ultimately diminish the effectiveness of IOP control. The study aimed to determine the efficacy and tolerability of BAK-free travoprost preserved with polyquaternium-1 in glaucoma patients switched from BAK-preserved latanoprost or bimatoprost.Methods: This 12-week, open-label study was conducted in Europe between December 2011 and February 2013. We enrolled adult patients with open-angle glaucoma or ocular hypertension who were receiving BAK-preserved latanoprost 0.005% or bimatoprost 0.01% and, in the opinion of the investigator, would benefit from transition to BAK-free travoprost 0.004% preserved with polyquaternium-1 because of tolerability concerns. Assessments included IOP, proportion of patients with IOP ≤18 mmHg, ocular surface status, hyperemia, patient treatment preference, and adherence. Adverse events were recorded throughout the study.Results: Of the 202 patients screened, 187 patients were included in the intent-to-treat population (mean age, 66.6 years; range, 19–90 years. The mean IOP significantly reduced from baseline (17.0 mmHg to week 6 (mean change, -1.17 mmHg; P<0.001 and week 12 (-1.16 mmHg; P<0.001. At week 12, more patients achieved IOP ≤18 mmHg (81.2% versus 73.3% at

  15. [Simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis].

    Science.gov (United States)

    Song, Baohua; Ding, Xiaojing; Li, Jia; Wang, Zhi

    2012-09-01

    Benzalkonium chloride (BAC) is a mixture of alkyl substituted benzyl dimethylammonium chloride homologs (C12-BAC, C14-BAC and C16-BAC). Chlorhexidine acetate is a widely used effective component in compound chemical disinfectants. A method for the simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis (CE) was established. The CE analysis was carried out using an uncoated capillary with 50 microm i. d. and 37 cm total length. The running buffer was 150 mmol/L NaH2PO4-62.5 mmol/L H3PO4 (pH 2.5) containing 40% (v/v) acetonitrile. The sample medium was 50 mmol/L acetic acid-acetonitrile (1:1, v/v). The detection wavelength was 214 nm. The factors such as the buffer concentration and pH, the content of acetonitrile, which influenced the separation and accurate assay of compound chemical disinfectants were investigated in detail. The intra-day and inter-day precisions of the method were below 3. 0% and 3.7%, respectively. The limits of detection (LOD, signal to noise ratio (S/N) = 3) for chlorhexidine acetate, C12-BAC, Cl4-BAC and C16-BAC were 0. 3, 0.5, 0.5 and 0.5 mg/L, respectively. The limits of quantification (LOQ, S/N = 10) were 1.0, 1.5, 1.5, and 1.5 mg/L, respectively. The corrected peak area and the mass concentration of the four components mentioned above showed good linear relationships within the ranges of 1.0 - 400 mg/L, 1. 5 - 200 mg/L, 1.5 - 200 mg/L and 1.5 - 200 mg/L, with linear correlation coefficients (r) of 0.9995, 0.9998, 0.999 7 and 0.9998, respectively. The established method was used for the determination of the four disinfectants in the compound chemical disinfectants. The results were in good agreement with those obtained by the high performance liquid chromatographic method.

  16. Technical Note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

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    J. Gloël

    2015-08-01

    Full Text Available Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2 is routinely used for such preservation, but its handling and subsequent disposal incur significant risks and expense. Benzalkonium chloride (BAC has been used previously for freshwater samples. Here, we assess BAC as a less hazardous alternative microbial inhibitor for marine samples prior to the measurement of oxygen-to-argon (O2/Ar ratios, as used for the determination of plankton net community production. BAC at a concentration of 50 mg dm−3 inhibited microbial activity for at least three days in seawater with chlorophyll a (Chl a concentrations up to 1 mg m−3, possibly longer when Chl a concentrations were lower. BAC concentrations of 100 and 200 mg dm−3 were no more effective than 50 mg dm−3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.

  17. Technical note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

    Science.gov (United States)

    Gloël, J.; Robinson, C.; Tilstone, G. H.; Tarran, G.; Kaiser, J.

    2015-12-01

    Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur environmental risks and significant expense. There is therefore a strong motivation to find less hazardous alternatives. Benzalkonium chloride (BAC) has been used previously as microbial inhibitor for freshwater samples. Here, we assess the use of BAC for marine samples prior to the measurement of oxygen-to-argon (O2 / Ar) ratios, as used for the determination of biological net community production. BAC at a concentration of 50 mg dm-3 inhibited microbial activity for at least 3 days in samples tested with chlorophyll a (Chl a) concentrations up to 1 mg m-3. BAC concentrations of 100 and 200 mg dm-3 were no more effective than 50 mg dm-3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.

  18. Efficacy and tolerability of benzalkonium chloride-free travoprost in glaucoma patients switched from benzalkonium chloride-preserved latanoprost or bimatoprost

    Science.gov (United States)

    García-Feijoo, Julian; Muñoz-Negrete, Francisco J; Hubatsch, Douglas A; Rossi, Gemma C

    2016-01-01

    Introduction The preservative benzalkonium chloride (BAK) is used to preserve several topical, intraocular pressure (IOP)-lowering glaucoma medications but can cause tolerability concerns that may lead to decreased adherence to treatment and ultimately diminish the effectiveness of IOP control. The study aimed to determine the efficacy and tolerability of BAK-free travoprost preserved with polyquaternium-1 in glaucoma patients switched from BAK-preserved latanoprost or bimatoprost. Methods This 12-week, open-label study was conducted in Europe between December 2011 and February 2013. We enrolled adult patients with open-angle glaucoma or ocular hypertension who were receiving BAK-preserved latanoprost 0.005% or bimatoprost 0.01% and, in the opinion of the investigator, would benefit from transition to BAK-free travoprost 0.004% preserved with polyquaternium-1 because of tolerability concerns. Assessments included IOP, proportion of patients with IOP ≤18 mmHg, ocular surface status, hyperemia, patient treatment preference, and adherence. Adverse events were recorded throughout the study. Results Of the 202 patients screened, 187 patients were included in the intent-to-treat population (mean age, 66.6 years; range, 19–90 years). The mean IOP significantly reduced from baseline (17.0 mmHg) to week 6 (mean change, −1.17 mmHg; P<0.001) and week 12 (−1.16 mmHg; P<0.001). At week 12, more patients achieved IOP ≤18 mmHg (81.2% versus 73.3% at baseline), and ocular surface disease severity improved from baseline to week 12. Most patients preferred BAK-free travoprost (74.9%) versus their previous medication and were very confident in their adherence (84.1%). Reduced visual acuity and eye pruritus were the most common adverse events (2.5% each). Conclusion BAK-free travoprost 0.004% preserved with polyquaternium-1 was efficacious and well tolerated and may be an advantageous prostaglandin analog option for patients with open-angle glaucoma or ocular hypertension

  19. Amniotic membrane extract ameliorates benzalkonium chloride-induced dry eye in a murine model.

    Science.gov (United States)

    Xiao, Xinye; Luo, Pingping; Zhao, Hui; Chen, Jingyao; He, Hui; Xu, Yuxue; Lin, Zhirong; Zhou, Yueping; Xu, Jianjiang; Liu, Zuguo

    2013-10-01

    Human amniotic membrane (AM) is avascular but contains various beneficial bioactive factors, its extract (AE) is also effective in treating many ocular surface disorders. In this study, we for the first time evaluated the therapeutic effects of AE on dry eye induced by benzalkonium chloride in a BALB/c mouse model. Topical application of AE (1.5 and 3 μg/eye/day) resulted in significantly longer tear break-up time on Day 3 and 6, lower fluorescein staining scores on Day 3, and lower inflammatory index on Day 6. AE reduced corneal epithelial K10 expression, inflammatory infiltration, and levels of TNF-α, IL-1β and IL-6 in BAC treated mice than that in the control mice. Moreover, decreased TUNEL positive cells in cornea and increased goblet cells in conjunctiva were also observed in AE treated corneas. Finally, AE induced more Ki-67 positive cells in corneal epithelium of dry eye mouse. Taken together, our data provide further support for BAC induced dry eye model as a valuable for dry eye study and suggest a great potential for AE as a therapeutic agent in the clinical treatment of dry eye.

  20. Preservation of resin-dentin interfaces treated with benzalkonium chloride adhesive blends.

    Science.gov (United States)

    Sabatini, Camila; Ortiz, Pilar A; Pashley, David H

    2015-04-01

    Reducing collagen degradation within hybrid layers may contribute to the preservation of adhesive interfaces. This study evaluated the stability of resin-dentin interfaces treated with benzalkonium chloride (BAC)-modified adhesive blends and assessed collagen degradation in dentin matrices treated with BAC. The etch-and-rinse adhesive, Adper Single Bond Plus, modified with 0.5% and 1.0% BAC, was evaluated for microtensile bond strength (μTBS) and nanoleakage (NL) after 24 h and 1 yr. Thirty completely demineralized dentin beams from human molars were dipped for 60 s in deionized water (DW; control), or in 0.5% or 1.0% BAC, and then incubated in simulated body fluid (SBF). Collagen degradation was assessed by quantification of the dry mass loss and the amount of hydroxyproline (HYP) released from hydrolyzed specimens after 1 or 4 wk. Although all groups demonstrated a significant increase in NL after 1 yr, adhesive modified with 0.5% BAC showed stable bond strength after 1 yr (9% decrease) relative to the control (44% decrease). Significantly less HYP release and dry mass loss were observed for both 0.5% and 1.0% BAC relative to the control. This in vitro study demonstrates that BAC contributes to the preservation of resin-dentin bonds for up to 1 yr by reducing collagen degradation.

  1. Conservation and distribution of the benzalkonium chloride resistance cassette bcrABC in Listeria monocytogenes.

    Science.gov (United States)

    Dutta, Vikrant; Elhanafi, Driss; Kathariou, Sophia

    2013-10-01

    Analysis of a panel of 116 Listeria monocytogenes strains of diverse serotypes and sources (clinical, environment of food processing plants, and food) revealed that all but one of the 71 benzalkonium chloride-resistant (BC(r)) isolates harbored bcrABC, previously identified on a large plasmid (pLM80) of the 1998-1999 hot dog outbreak strain H7858. In contrast, bcrABC was not detected among BC-susceptible (BC(s)) isolates. The bcrABC sequences were highly conserved among strains of different serotypes, but variability was noted in sequences flanking bcrABC. The majority of the BC(r) isolates had either the pLM80-type of organization of the bcrABC region or appeared to harbor bcrABC on the chromosome, adjacent to novel sequences. Transcription of bcrABC was induced by BC (10 μg/ml) in strains of different serotypes and diverse bcrABC region organization. These findings reveal widespread dissemination of bcrABC across BC(r) L. monocytogenes strains regardless of serotype and source, while also suggesting possible mechanisms of bcrABC dissemination across L. monocytogenes genomes.

  2. Role of Efflux Pumps in Adaptation and Resistance of Listeria monocytogenes to Benzalkonium Chloride

    Science.gov (United States)

    Romanova, N. A.; Wolffs, P. F. G.; Brovko, L. Y.; Griffiths, M. W.

    2006-01-01

    In this study, potential mechanisms underlying resistance and adaptation to benzalkonium chloride (BC) in Listeria monocytogenes were investigated. Two groups of strains were studied. The first group consisted of strains naturally sensitive to BC which could be adapted to BC. The second group consisted of naturally resistant strains. For all adapted isolates, there was a correlation between the resistance to BC and ethidium bromide, but this was not the case for the naturally resistant isolates. To investigate the role of efflux pumps in adaptation or resistance, reserpine, an efflux pump inhibitor, was added to the strains. Addition of reserpine to the sensitive and adapted strains resulted in a decrease in the MIC for BC, whereas no such decrease was observed for the resistant strains, indicating that efflux pumps played no role in the innate resistance of certain strains of L. monocytogenes to this compound. Two efflux pumps (MdrL and Lde) have been described in L. monocytogenes. Studies showed low and intermediate levels of expression of the genes encoding the efflux pumps for two selected resistant strains, H7764 and H7962, respectively. Adaptation to BC of sensitive isolates of L. monocytogenes resulted in significant increases in expression of mdrl (P < 0.05), but no such increase was observed for lde for two adapted strains of L. monocytogenes, LJH 381 (P = 0.91) and C719 (P = 0.11). This indicates that the efflux pump Mdrl is at least partly responsible for the adaptation to BC. PMID:16672496

  3. Effects of artificial tears on rabbit ocular surface healing after exposure to benzalkonium chloride.

    Science.gov (United States)

    Zhang, Yuqiu; Cao, Hong; Lin, Tong; Gong, Lan

    2016-10-01

    The aim of the study was to observe the effect of different artificial tears on healing the drug-induced keratopathy. To this aim, 64 rabbits received topical administration of 0.01% benzalkonium chloride to establish models and were divided into four groups. The control group received ocular saline solution (Saline), while the others were treated with Refresh Plus® (RF), Hycosan® (H) and Systane® Ultra (SU). Surface abnormalities were examined daily using slit-lamp. Fluorescein staining, histopathological and transmission electron microscopic (TEM) examination were performed at day 0, 2 weeks, and 1 and 2 months. A significant difference was observed between RF and SU, but not between H and SU at 2 weeks. TEM examination revealed new microvilli close to the cavity surface, and the number of microvilli in SU was greater than in H at 2 weeks and 1 month. Based on the results, the effect in the SU group was the most significant. Eye drops with nontoxic preservative such as SU are an alternative to treat drug-induced keratopathy.

  4. Removal of Listeria monocytogenes dual-species biofilms using combined enzyme-benzalkonium chloride treatments.

    Science.gov (United States)

    Rodríguez-López, Pedro; Carballo-Justo, Alba; Draper, Lorraine A; Cabo, Marta L

    2017-01-01

    The effects of pronase (PRN), cellulase (CEL) or DNaseI alone or combined with benzalkonium chloride (BAC) against Listeria monocytogenes-carrying biofilms were assayed. The best removal activity against L. monocytogenes-Escherichia coli biofilms was obtained using DNaseI followed by PRN and CEL. Subsequently, a modified logistic model was used to quantify the combined effects of PRN or DNaseI with BAC. A better BAC performance after PRN compared to DNaseI eradicating L. monocytogenes was observed. In E. coli the effects were the opposite. Finally, effects of DNaseI and DNaseI-BAC treatments were compared against two different L. monocytogenes-carrying biofilms. DNaseI-BAC was more effective against L. monocytogenes when co-cultured with E. coli. Nonetheless, comparing the removal effects after BAC addition, these were higher in mixed-biofilms with Pseudomonas fluorescens. However, a high number of released viable cells was observed after combined treatments. These results open new perspectives of enzymes as an anti-biofilm strategy for environmental pathogen control.

  5. Determination of Benzalkonium Chloride in Nasal Drops by High-Performance Liquid Chromatography

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    Danijela A. Kostić

    2012-01-01

    Full Text Available A high-performance liquid chromatography (HPLC system was used in the reversed phase mode for the determination of benzalkonium chloride (BKC in nosal drops. A Chromolit RP-18e, 100 x 4.6, (UM6077/035 column was used at 40 °C. The mobile phase, optimized through an experimental design, was a 70:30 (v/v mixture of 0.057M Na-heksansulphonate potassium, dihydrogen orthophosphate buffer (pH 2.9 and acetonitrile, pumped at a flow rate of 1.75 mL/min at maintaining column temperature at 40 °C. Maximum UV detection was achieved at 215 nm. The method was validated in terms of selectivity, linearity, repeatability, precision and accuracy. The method was successfully applied for the determination of BKC in a pharmaceutical formulation of nasal drop solution without any interference from common excipients and drug substance. All the validation parameters were within the acceptance range, concordant to ICH guidelines.

  6. Ultrastructural Alterations Associated with the Growth of Resistant Pseudomonas aeruginosa in the Presence of Benzalkonium Chloride

    Science.gov (United States)

    Hoffmann, Hans-Peter; Geftic, Sam G.; Gelzer, Justus; Heymann, Hans; Adair, Frank W.

    1973-01-01

    Cells of Pseudomonas aeruginosa resistant to benzalkonium chloride (BC) underwent unique ultrastructural reorganizations when they were grown in the presence of 1 mg of BC/ml. The resistant cells usually contained a single, centrally positioned pseudovacuole. The pseudovacuole was surrounded by a diffuse substance that spread irregularly throughout the cytoplasm. The presence of the pseudovacuole seemed to cause a physical compartmentalization of the cytoplasm into random pockets of ribosomes and nuclear material. Contained within the pseudovacuole was a horseshoe-shaped, electron-dense body which was bounded by a trilaminar membrane 5.2 nm in width. These bodies averaged 77 nm when measured through the long axis. The surfaces of resistant cells were covered by an additional layer not found in sensitive cells. Thin sections of sensitive cells which had been treated with 1 mg of BC/ml showed little or no lysis. The cytoplasm appeared to be deeply stained and coagulated. Ribosomes were no longer distinctly visible. Although the cell wall remained intact, the cell membrane was dissolved and fragmented. BC-grown resistant cells could not be successfully stained by standard techniques; however, details were demonstrated with the aid of a combination of 1.5% glutaraldehyde, 1% osmium tetroxide, and 1% phosphotungstic acid prepared in 0.1 m sodium dimethylarsonate buffer (pH 6.8). Images PMID:4120070

  7. Determination of benzalkonium chloride in viscous ophthalmic drops of azithromycin by high-performance liquid chromatography *

    Science.gov (United States)

    Shen, Yan; Xu, Sheng-jie; Wang, Shi-chun; Tu, Jia-sheng

    2009-01-01

    A high-performance liquid chromatography (HPLC) system was used in the reversed phase mode for the determination of benzalkonium chloride (BKC) in azithromycin viscous ophthalmic drops. A Venusil-XBP(L)-C18 (150 mm×4.6 mm, 5 μm) column was used at 50 °C. The mobile phase consisted of a mixture of methanol-potassium phosphate (16:5, v/v). Two sample preparation methods were compared. The results suggested that, compared with an extraction procedure, a deproteinization procedure was much quicker and more convenient. Using the deproteinization procedure for sample preparation, calibration curves were linear in the range 5.0~50 μg/ml. The within-day and inter-day coefficients of variation were less than 10%. The average recoveries were determined as 96.70%, 98.52%, and 97.96% at concentrations of 10.0, 30.0, and 50.0 μg/ml, respectively. Variability in precision did not exceed 5%. In conclusion, this HPLC method using a simple sample treatment procedure appears suitable for monitoring BKC content in azithromycin viscous ophthalmic drops. PMID:19946951

  8. Detection of benzalkonium chloride resistance in community environmental isolates of staphylococci.

    Science.gov (United States)

    He, Gui-Xin; Landry, Michael; Chen, Huizhong; Thorpe, Conner; Walsh, Dennis; Varela, Manuel F; Pan, Hongmiao

    2014-05-01

    We isolated a total of 653 strains from 64 community environmental samples in Massachusetts, USA. Among these isolates, 9.65 % (63 strains) were benzalkonium chloride (BC)-resistant staphylococci. All BC-resistant strains were collected from surfaces upon which antibacterial wipes or antibacterial sprays containing 0.02-0.12 % BC had frequently been used in the fitness centres. However, isolates from surfaces upon which antibacterial wipes or antibacterial sprays had not been used were all sensitive to BC. All BC-resistant strains were also resistant to erythromycin, penicillin and ampicillin. In addition, 51 strains showed resistance to cetyltrimethylammonium bromide (CTAB), 15 strains showed resistance to chloramphenicol, 12 strains showed resistance to ciprofloxacin and four strains showed resistance to meticillin. Resistance gene analysis demonstrated that 41 strains contained qacA/B, 30 strains had qacC, 25 strains contained qacG, 16 strains had qacH and eight strains contained qacJ. These data indicate that application of BC is associated with environmental staphylococcal antimicrobial resistance.

  9. Ion mobility spectrometry as a fast analytical tool in benzalkonium chloride homologs determination.

    Science.gov (United States)

    Gallart-Mateu, D; Armenta, S; Esteve-Turrillas, F A; de la Guardia, M

    2017-03-01

    A novel procedure is proposed for the determination by ion mobility spectrometry (IMS) of C12, C14 and C16 benzalkonium chloride (BAC) homologs. The proposed method requires minimum sample treatment and the measurement was made in less than one minute. A high sensitivity was obtained for BAC determination by IMS with limit of detection values from 37 to 69µgL(-1). Accuracy of the proposed methodology was evaluated through the analysis of aqueous and alcoholic samples spiked with BAC at concentration levels from 0.002% to 20% (w/v), providing recovery values from 91% to 104%. BAC was determined in sanitary alcohols, nasal sprays, postharvest products, algaecides, and treated swimming pool water. Results obtained by the proposed IMS methodology were statistically comparable to those provided by a liquid chromatography-ultraviolet (LC-UV) reference methodology. The Green Certificate evaluation of the proposed IMS methodology provided 91 score points in the Eco-Scale as compared with 77 for LC-UV method.

  10. Efflux pump-mediated benzalkonium chloride resistance in Listeria monocytogenes isolated from retail food.

    Science.gov (United States)

    Jiang, Xiaobing; Yu, Tao; Liang, Yu; Ji, Shengdong; Guo, Xiaowei; Ma, Jianmin; Zhou, Lijun

    2016-01-18

    In this study, efflux pump-mediated benzalkonium chloride (BC) resistance, including plasmid-encoded (Qac protein family and BcrABC) and chromosome-borne efflux pumps, was investigated in Listeria monocytogenes from retail food in China. Among the 59 L. monocytogenes strains, 13 (22.0%) strains were resistant to BC. The PCR results showed that bcrABC was harbored by 2 of 13 BC resistant strains. However, none of the qac genes were detected among the 59 strains. The bcrABC was absent in both of the plasmid cured strains, indicating that this BC resistance determinant was plasmid-encoded in the two bcrABC-positive strains. In the presence of reserpine, most of the bcrABC-negative strains had decreases in the MICs of BC, suggesting the existence of other efflux pumps and their role in BC resistance. After exposed to reserpine, the reduction in BC MICs was observed in the two cured strains, indicating that efflux pumps located on chromosome was also involved in BC resistance. Our findings suggest that food products may act as reservoirs for BC resistant isolates of L. monocytogenes and plasmid- and chromosome-encoded efflux pumps could mediate the BC resistance of L. monocytogenes, which is especially relevant to the adaption of this organism in food-related environments with frequent BC use.

  11. Hyperosmolarity and Benzalkonium Chloride Differently Stimulate Inflammatory Markers in Conjunctiva-Derived Epithelial Cells in vitro.

    Science.gov (United States)

    Warcoin, Elise; Clouzeau, Chloé; Roubeix, Christophe; Raveu, Anne-Laure; Godefroy, David; Riancho, Luisa; Baudouin, Christophe; Brignole-Baudouin, Françoise

    2016-12-10

    Tear hyperosmolarity is known to cause ocular surface inflammation in dry eye syndrome. Benzalkonium chloride (BAK), an eyedrop preservative, is known to induce dry eye in long-term-treated patients. Analyzing the modulation of the proinflammatory potential of hyperosmolarity in the presence of BAK on the conjunctiva could give new insights into the effect of this preservative on the disease. In a hyperosmolar model on a conjunctiva-derived cell line, and in the presence of BAK, we evaluated key inflammatory markers [CCL2, IL-8, IL-6, macrophage migration inhibitory factor (MIF) and intercellular adhesion molecule (ICAM)-1] as well as the osmoprotectant element nuclear factor of activated T cells (NFAT)5 using ELISA, RT-qPCR or immunofluorescence staining. Hyperosmolarity highly stimulated CCL2 and NFAT5 in these cells. BAK alone only increased IL-6 expression. The stress-combined condition stimulated CCL2, NFAT5, MIF and IL-8 secretion. ICAM-1 was not modulated by any of the conditions tested. In this model, hyperosmolarity and BAK induced the release of different proinflammatory mediators, and, when combined, they lead to the release of additional inflammatory cytokines. This in vitro study highlights the importance of avoiding long-term ophthalmic treatments containing BAK, as tear film hyperosmolarity can be a result of its detergent action.

  12. Study of the hormetic effect of disinfectants chlorhexidine, povidone iodine and benzalkonium chloride.

    Science.gov (United States)

    Morales-Fernández, L; Fernández-Crehuet, M; Espigares, M; Moreno, E; Espigares, E

    2014-01-01

    The study of the dose-response relationship of disinfectants is of great importance in treating infection, the objective being to use concentrations above the minimal bactericidal concentration (MBC). Below these concentrations, the bacteriostatic or bactericidal effect may be insufficient. Moreover, at low concentrations, a hormetic effect may be observed, producing a stimulation of growth instead of inhibitory action. Hormesis is not well known in the context of antimicrobial substances. This study investigates the possible existence of a hormetic effect in three commonly used antiseptics-chlorhexidine digluconate, povidone iodine and benzalkonium chloride-on strains of reference of Staphylococcus aureus and Pseudomonas aeruginosa. Growth curves were determined for different concentrations of the disinfectants. The variables studied-concentration of disinfectant, instantaneous growth rate and number of generations-were analysed using linear, quadratic and cubic models to adjust for the variables. The three disinfectants tested show a significant hormetic effect with P. aeruginosa and a less significant effect with S. aureus. These findings point to a dose-response effect that is not linear at low concentrations, while hormetic effects observed at some low concentrations result in greater bacterial growth. In infected wounds, materials or surfaces where microorganisms may occupy zones of difficult access for a disinfectant, the hormetic effect may have important consequences.

  13. Similar Microbial Consortia and Genes Are Involved in the Biodegradation of Benzalkonium Chlorides in Different Environments.

    Science.gov (United States)

    Ertekin, Emine; Hatt, Janet K; Konstantinidis, Konstantinos T; Tezel, Ulas

    2016-04-19

    Benzalkonium chlorides (BACs) are emerging pollutants. Identification of microorganisms and the genes involved in the biodegradation of BACs is crucial for better understanding the fate of BACs in the environment and developing treatment strategies. Four microbial communities degrading BACs were developed from sewage (SEW), activated sludge (AS), soil (SOIL) and sea sediment (SEA) samples. According to 16S rRNA pyrosequencing and shotgun metagenome sequencing analyses, the most abundant species represented uncharacterized members of the Pseudomonas and Achromobacter genera. BAC biotransformation rates of the enriched microbial communities were 2.8, 3.2, 17.8, and 24.3 μM hr(-1) for SEA, AS, SOIL, and SEW, respectively, and were positively correlated with the relative abundance of a particular Pseudomonas sp. strain, BIOMIG1. The strain BIOMIG1 mineralizes BACs at a rate up to 2.40 μmol hr(-1) 10(-11) cells. Genomes of four BAC degrading and nondegrading BIOMIG1 phenotypes were sequenced and differentially compared with each other. As a result, a gene cluster encoding for transporters, an integrase and a dioxygenase were involved in BAC biotransformation. Our results suggest that BIOMIG1 plays a key role on the fate of BACs in the environment and genes, other than those reported to date, are involved in BAC biotransformation in various habitats.

  14. Synthesis, Structure and Antimicrobial Properties of Novel Benzalkonium Chloride Analogues with Pyridine Rings.

    Science.gov (United States)

    Brycki, Bogumił; Małecka, Izabela; Koziróg, Anna; Otlewska, Anna

    2017-01-13

    Quaternary ammonium compounds (QACs) are a group of compounds of great economic significance. They are widely used as emulsifiers, detergents, solubilizers and corrosion inhibitors in household and industrial products. Due to their excellent antimicrobial activity QACs have also gained a special meaning as antimicrobials in hospitals, agriculture and the food industry. The main representatives of the microbiocidal QACs are the benzalkonium chlorides (BACs), which exhibit biocidal activity against most bacteria, fungi, algae and some viruses. However, the misuses of QACs, mainly at sublethal concentrations, can lead to an increasing resistance of microorganisms. One of the ways to avoid this serious problem is the introduction and use of new biocides with modified structures instead of the biocides applied so far. Therefore new BAC analogues P13-P18 with pyridine rings were synthesized. The new compounds were characterized by NMR, FT-IR and ESI-MS methods. PM3 semiempirical calculations of molecular structures and the heats of formation of compounds P13-P18 were also performed. Critical micellization concentrations (CMCs) were determined to characterize the aggregation behavior of the new BAC analogues. The antimicrobial properties of novel QACs were examined by determining their minimal inhibitory concentration (MIC) values against the fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The MIC values of N,N-dimethyl-N-(4-methylpyridyl)-N-alkylammonium chlorides for fungi range from 0.1 to 12 mM and for bacteria, they range from 0.02 to 6 mM.

  15. Synthesis, Structure and Antimicrobial Properties of Novel Benzalkonium Chloride Analogues with Pyridine Rings

    Directory of Open Access Journals (Sweden)

    Bogumił Brycki

    2017-01-01

    Full Text Available Quaternary ammonium compounds (QACs are a group of compounds of great economic significance. They are widely used as emulsifiers, detergents, solubilizers and corrosion inhibitors in household and industrial products. Due to their excellent antimicrobial activity QACs have also gained a special meaning as antimicrobials in hospitals, agriculture and the food industry. The main representatives of the microbiocidal QACs are the benzalkonium chlorides (BACs, which exhibit biocidal activity against most bacteria, fungi, algae and some viruses. However, the misuses of QACs, mainly at sublethal concentrations, can lead to an increasing resistance of microorganisms. One of the ways to avoid this serious problem is the introduction and use of new biocides with modified structures instead of the biocides applied so far. Therefore new BAC analogues P13–P18 with pyridine rings were synthesized. The new compounds were characterized by NMR, FT-IR and ESI-MS methods. PM3 semiempirical calculations of molecular structures and the heats of formation of compounds P13–P18 were also performed. Critical micellization concentrations (CMCs were determined to characterize the aggregation behavior of the new BAC analogues. The antimicrobial properties of novel QACs were examined by determining their minimal inhibitory concentration (MIC values against the fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The MIC values of N,N-dimethyl-N-(4-methylpyridyl-N-alkylammonium chlorides for fungi range from 0.1 to 12 mM and for bacteria, they range from 0.02 to 6 mM.

  16. Development and validation of a rapid ultra-high performance liquid chromatography method for the assay of benzalkonium chloride using a quality-by-design approach.

    Science.gov (United States)

    Mallik, Rangan; Raman, Srividya; Liang, Xiaoli; Grobin, Adam W; Choudhury, Dilip

    2015-09-25

    A rapid robust reversed-phase UHPLC method has been developed for the analysis of total benzalkonium chloride in preserved drug formulation. A systematic Quality-by-Design (QbD) method development approach using commercial, off the shelf software (Fusion AE(®)) has been used to optimize the column, mobile phases, gradient time, and other HPLC conditions. Total benzalkonium chloride analysis involves simple sample preparation. The method uses gradient elution from an ACE Excel 2 C18-AR column (50mm×2.1mm, 2.0μm particle size), ammonium phosphate buffer (pH 3.3; 10mM) as aqueous mobile phase and methanol/acetonitrile (85/15, v/v) as the organic mobile phase with UV detection at 214nm. Using these conditions, major homologs of the benzalkonium chloride (C12 and C14) have been separated in less than 2.0min. The validation results confirmed that the method is precise, accurate and linear at concentrations ranging from 0.025mg/mL to 0.075mg/mL for total benzalkonium chloride. The recoveries ranged from 99% to 103% at concentrations from 0.025mg/mL to 0.075mg/mL for total benzalkonium chloride. The validation results also confirmed the robustness of the method as predicted by Fusion AE(®).

  17. Reasoned opinion on the dietary risk assessment for proposed temporary maximum residue levels (MRLs of didecyldimethylammonium chloride (DDAC and benzalkonium chloride (BAC

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2014-04-01

    Full Text Available EFSA was requested by the European Commission to perform a dietary exposure assessment for the proposed temporary maximum residue levels (MRLs for didecyldimethylammonium chloride (DDAC and benzalkonium chloride (BAC (0.1 mg/kg, respectively, for all food commodities covered by the EU MRL legislation. Based on the information, EFSA did not identify potential consumer health risks for these proposed MRLs. Thus, the proposed MRLs are considered to be sufficiently protective. However, due to the limited data available, the risk assessments are affected by a high degree of uncertainty.

  18. Interactions between Surfactants in Solution and Electrospun Protein Fibers: Effects on Release Behavior and Fiber Properties

    DEFF Research Database (Denmark)

    Boutrup Stephansen, Karen; García-Díaz, María; Jessen, Flemming

    2016-01-01

    ), a cationic surfactant (benzalkonium chloride), and a neutral surfactant (Triton X-100) were studied. The anionic surfactants increased the insulin release in a concentration-dependent manner, whereas the neutral surfactant had no significant effect on the release. Interestingly, only minute amounts...... of insulin were released from the fibers when benzalkonium chloride was present. The FSP-Ins fibers appeared dense after incubation with this cationic surfactant, whereas high fiber porosity was observed after incubation with anionic or neutral surfactants. Contact angle measurements and staining...

  19. Resistance to benzalkonium chloride, peracetic acid and nisin during formation of mature biofilms by Listeria monocytogenes.

    Science.gov (United States)

    Saá Ibusquiza, P; Herrera, J J R; Cabo, M L

    2011-05-01

    Increase of resistance to the application of benzalkonium chloride (BAC), peracetic acid (PA) and nisin during biofilm formation at 25 °C by three strains of Listeria monocytogenes (CECT 911, CECT 4032, CECT 5873 and BAC-adapted CECT 5873) in different scenarios was compared. For this purpose, resistance after 4 and 11-days of biofilm formation was quantified in terms of lethal dose 90% values (LD(90)), determined according with a dose-response logistic mathematical model. Microscopic analyses after 4 and 11-days of L. monocytogenes biofilm formation were also carried out. Results demonstrated a relation between the microscopic structure and the resistance to the assayed biocides in matured biofilms. The worst cases being biofilms formed by the strain 4032 (in both stainless steel and polypropylene), which showed a complex "cloud-type" structure that correlates with the highest resistance of this strain against the three biocides during biofilm maturation. However, that increase in resistance and complexity appeared not to be dependent on initial bacterial adherence, thus indicating mature biofilms rather than planctonic cells or early-stage biofilms must be considered when disinfection protocols have to be optimized. PA seemed to be the most effective of the three disinfectants used for biofilms. We hypothesized both its high oxidizing capacity and low molecular size could suppose an advantage for its penetration inside the biofilm. We also demonstrated that organic material counteract with the biocides, thus indicating the importance of improving cleaning protocols. Finally, by comparing strains 5873 and 5873 adapted to BAC, several adaptative cross-responses between BAC and nisin or peracetic acid were identified.

  20. A Time-Limited and Partially Reversible Model of Hypoganglionosis Induced by Benzalkonium Chloride Treatment.

    Science.gov (United States)

    Yu, Hui; Pan, Weikang; Wang, HuaiJie; Gao, Ya

    2016-05-01

    Serosal application of benzalkonium chloride (BAC) has been previously applied to produce a model of aganglionosis; however, confusion remains regarding the extent of chemical ablation of enteric myenteric plexus after BAC treatment. The time sequence of BAC-induced effects on the myenteric plexus of the rat colon was determined and followed the morphologic changes. After sacrifice of animals 7, 14, 28, 56, 84 or 168 days postintervention, colonic tissue samples were removed, fixed in formalin, and cut into 5-μm longitudinal sections for histological analysis. The neural analysis was used to re-evaluate BAC treatments for the appropriate model. Compared with rats in sham groups, rats in 0.1 %-30-min BAC group maintained only 15.27 ± 4.80 % of ganglia per section in a 1-cm/5-μm slice and 11.76 ± 2.30 % of ganglionic cells after 28 days, the lower and stable number of ganglionic cells between Day 7 and 84 (from 11.67 ± 2.10 to 19.05 ± 5.10 %). Although an increase, ganglionic cell numbers did not recover at Day168 when compared with the numbers in sham groups. The results showed that characteristics of rats in the 0.1 %-30-min BAC group between Day 7 and 84 most closely kept in stable state, suggesting that these treatment parameters are ideal for producing a hypoganglia model of hypoganglionosis.

  1. A mouse dry eye model induced by topical administration of benzalkonium chloride

    Science.gov (United States)

    Lin, Zhirong; Liu, Xiaochen; Zhou, Tong; Wang, Yihui; Bai, Li; He, Hui

    2011-01-01

    Purpose To develop a dry eye model of mouse induced by topical administration of benzalkonium chloride (BAC) and investigate the possible mechanisms. Methods BAC at concentration of 0.2% was applied to the mouse ocular surface for 7 days. Phenol red thread tear test, tear break-up time (BUT) test, corneal inflammatory index scoring, fluorescein and rose bengal test were performed to evaluate the toxic effects of BAC on the ocular surface. Global specimens were collected on day (D) 7 and labeled with a series of antibodies including cytokeratin 10 (K10) and mucin 5AC (MUC5AC). Apoptosis of ocular surface epithelium was evaluated by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Histologic analysis and transmission electron microscopy (TEM) were performed on D7. Results BAC at a concentration of 0.2% successfully induced a dry eye condition with decreased tear volume and BUTs, increased corneal fluorescein and rose bengal scores. The Inflammatory index was increased in accompanyment with higher tumor necrosis factor-α (TNF-α) expression and more inflammatory infiltration in the cornea. Immunolabeling revealed positive K10 expression in BAC-treated corneal epithelium and fewer MUC5AC-positive cells in the BAC-treated conjunctival fornix. TUNEL assay showed more apoptotic cells in the corneal basal epithelium. TEM showed that the size and intervals of the microvillis were both reduced in the corneal epithelium. Conclusions Topical administration of 0.2% BAC in mouse induces changes resembling that of dry eye syndrome in humans, and thus, represents a novel model of dry eye. PMID:21283525

  2. Survival and susceptibility of Burkholderia cepacia complex in chlorhexidine gluconate and benzalkonium chloride.

    Science.gov (United States)

    Kim, Jeong Myeong; Ahn, Youngbeom; LiPuma, John J; Hussong, David; Cerniglia, Carl E

    2015-06-01

    The Burkholderia cepacia complex (BCC) includes opportunistic pathogenic bacteria that have occasionally been recovered from various pharmaceutical products, including antiseptics and disinfectants. Plausible reasons for the contamination include intrinsic sources, such as inadequate process controls, especially for water or equipment used during product manufacture, or extrinsic sources, such as improper handling and dilution or distribution in contaminated containers. Because the survival of BCC in antiseptics is a concern to the public health and pharmaceutical industry, we determined minimum inhibitory concentrations (MICs) of 36 BCC strains against the antiseptics, following exposure to chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) solutions (1-500 µg/ml for each chemical). Susceptibility to CHX and BZK varied across the BCC strains and was recorded as mean 90.3 and 111.1 µg/ml, respectively, at initial inoculation, which was significantly higher than the 46.4 and 61.1 µg/ml levels measured for BCC incubated in water for 40 days. After determining antiseptic MICs of individual BCC strains, BCC recovery was measured on Tryptic Soy Agar (TSA), Reasoner's Second Agar (R2A) and diluted preparations of these media under their sub-MICs. The survival of BCC was monitored for 14 days (336 h) in sub-MICs diluted to less than their antiseptic susceptible concentration value. Diluted TSA and R2A media exhibited greater efficiency of recovery for most BCC strains from the CHX and BZK solutions than full strength TSA or R2A. For BCC survival in antiseptic solutions, the cell number of BCC decreased rapidly within the first 20 min in both antiseptics, but after this, recovery remained constant in CHX and increased in BZK over the 14 day incubation period. The results indicate that BCC in water can remain viable with low susceptibility to antiseptics for 14 days, which suggests the necessity for improved detection methods and control measures to monitor

  3. Toxic effect in the lungs of rats after inhalation exposure to benzalkonium chloride

    Directory of Open Access Journals (Sweden)

    Radosław Świercz

    2013-08-01

    Full Text Available Background: Benzalkonium chloride (BAC is a quaternary ammonium compound (QAC toxic to microorganisms. Inhalation is one of the major possible routes of human exposure to BAC. Materials and Methods: Experiments were performed on female Wistar rats. The rats were exposed to aerosol of BAC water solution at the target concentration of 0 (control group and 35 mg/m3 for 5 days (6 h/day and, after a 2-week interval, the animals were challenged (day 21 with BAC aerosol at the target concentration of 0 (control group and 35 mg/m3 for 6 h. Results: Compared to the controls, the animals exposed to BAC aerosol were characterized by lower food intake and their body weight was significantly smaller. As regards BAC-exposed group, a significant increase was noted in relative lung mass, total protein concentration, and MIP-2 in BALF both directly after the termination of the exposure and 18 h afterwards. Significantly higher IL-6 and IgE concentrations in BALF and a decrease in the CC16 concentration in BALF were found in the exposed group immediately after the exposure. The leukocyte count in BALF was significantly higher in the animals exposed to BAC aerosol compared to the controls. In the lungs of rats exposed to BAC the following effects were observed: minimal perivascular, interstitial edema, focal aggregates of alveolar macrophages, interstitial mononuclear cell infiltrations, thickened alveolar septa and marginal lipoproteinosis. Conclusion: Inhalation of BAC induced a strong inflammatory response and a damage to the blood-air barrier. Reduced concentrations of CC16, which is an immunosuppressive and anti-inflammatory protein, in combination with increased IgE concentrations in BALF may be indicative of the immuno-inflammatory response in the animals exposed to BAC aerosol by inhalation. Histopathological examinations of tissue samples from the BAC-exposed rats revealed a number of pathological changes found only in the lungs.

  4. Corneal alternations induced by topical application of benzalkonium chloride in rabbit.

    Directory of Open Access Journals (Sweden)

    Wensheng Chen

    Full Text Available Benzalkonium chloride (BAC is the most common preservative in ophthalmic preparations. Here, we investigated the corneal alternations in rabbits following exposure to BAC. Twenty-four adult male New Zealand albino rabbits were randomly divided into three groups. BAC at 0.01%, 0.05%, or 0.1% was applied twice daily to one eye each of rabbits for 4 days. The contralateral untreated eyes were used as control. Aqueous tear production and fluorescein staining scores of BAC-treated eyes were compared with those of controls. The structure of the central cornea was examined by in vivo confocal microscopy. Expression of mucin-5 subtype AC (MUC5AC in conjunctiva was detected by immunostainig on cryosections. Corneal barrier function was assessed in terms of permeability to carboxy fluorescein (CF. The distribution and expression of ZO-1, a known marker of tight junction, and reorganization of the perijunctional actomyosin ring (PAMR were examined by immunofluorescence analysis. Although there were no significant differences between control and BAC-treated eyes in Schirmer scores, corneal fluorescein scores and the number of conjunctival MUC5AC staining cells, in vivo confocal microscopy revealed significant epithelial and stromal defects in all BAC-treated corneas. Moreover, BAC at 0.1% resulted in significant increases in central corneal thickness and endothelial CF permeability, compared with those in control eyes, and endothelial cell damage with dislocation of ZO-1 and disruption of PAMR. Topical application of BAC can quickly impair the whole cornea without occurrence of dry eye. A high concentration of BAC breaks down the barrier integrity of corneal endothelium, concomitant with the disruption of PAMR and remodeling of apical junctional complex in vivo.

  5. Corneal Alternations Induced by Topical Application of Benzalkonium Chloride in Rabbit

    Science.gov (United States)

    Chen, Wensheng; Li, Zhiyuan; Hu, Jiaoyue; Zhang, Zhenhao; Chen, Lelei; Chen, Yongxiong; Liu, Zuguo

    2011-01-01

    Benzalkonium chloride (BAC) is the most common preservative in ophthalmic preparations. Here, we investigated the corneal alternations in rabbits following exposure to BAC. Twenty-four adult male New Zealand albino rabbits were randomly divided into three groups. BAC at 0.01%, 0.05%, or 0.1% was applied twice daily to one eye each of rabbits for 4 days. The contralateral untreated eyes were used as control. Aqueous tear production and fluorescein staining scores of BAC-treated eyes were compared with those of controls. The structure of the central cornea was examined by in vivo confocal microscopy. Expression of mucin-5 subtype AC (MUC5AC) in conjunctiva was detected by immunostainig on cryosections. Corneal barrier function was assessed in terms of permeability to carboxy fluorescein (CF). The distribution and expression of ZO-1, a known marker of tight junction, and reorganization of the perijunctional actomyosin ring (PAMR) were examined by immunofluorescence analysis. Although there were no significant differences between control and BAC-treated eyes in Schirmer scores, corneal fluorescein scores and the number of conjunctival MUC5AC staining cells, in vivo confocal microscopy revealed significant epithelial and stromal defects in all BAC-treated corneas. Moreover, BAC at 0.1% resulted in significant increases in central corneal thickness and endothelial CF permeability, compared with those in control eyes, and endothelial cell damage with dislocation of ZO-1 and disruption of PAMR. Topical application of BAC can quickly impair the whole cornea without occurrence of dry eye. A high concentration of BAC breaks down the barrier integrity of corneal endothelium, concomitant with the disruption of PAMR and remodeling of apical junctional complex in vivo. PMID:22022526

  6. Bactericidal Property of the Benzalkonium Chloride in Industrial Circulating Water%洁儿灭在工业循环水中的杀菌性能研究

    Institute of Scientific and Technical Information of China (English)

    孙彩霞; 陈燕敏; 吴晋英; 黄长山

    2016-01-01

    In the thesis,the bactericidal property of benzalkonium chloride was tested by the method of plate counting. The bactericidal effciency was improved with increasing the concentration of benzalkonium chloride. At the same time the bacterial agent which prepared by the benzalkonium chloride had a better scale inbibtion effect , and could be sately applied to industrial circulating water pipeline system.%通过平板计数法考察了不同浓度的洁儿灭对工业循环水中异养菌的杀菌性能,结果显示,洁儿灭杀菌效率随着浓度的增加而增加,且由洁儿灭配制而成的杀菌剂阻垢性能较好,能安全地应用到工业循环水管道系统中。

  7. Evaluation of antibiofilm effect of benzalkonium chloride, iodophore and sodium hypochlorite against biofilm of Pseudomonas aeruginosa of dairy origin.

    Science.gov (United States)

    Pagedar, Ankita; Singh, Jitender

    2015-08-01

    The present study was undertaken with objectives of; a) to investigate and compare Pseudomonas aeruginosa isolates from two dairies for biofilm formation potential and, b) to compares three common biocides for biofilm eradication efficiencies. Amongst the isolates from commercial dairy, 70 % were strong and/or moderate biofilm former in comparison to 40 % isolates from small scale dairy. All isolates, irrespective of source, exhibited higher susceptibility to biocides in planktonic stage than in biofilm. Antibiofilm efficiencies of three biocides i.e. benzalkonium chloride, sodium hypochlorite and iodophore were determined in terms of their microbial biofilms eradicating concentration (MBEC). Our findings show that the three biocides were ineffective against preformed biofilms at recommended in-use concentrations. Biofilms were the most resistant to benzalkonium chloride and least against iodophore. A trend of decreasing MBECs was observed with extended contact time. The findings of present study warrant for a systematic approach for selecting types and concentrations of biocide for application as antibiofilm agent in food industry.

  8. Biopolymer-modified graphite oxide nanocomposite films based on benzalkonium chloride-heparin intercalated in graphite oxide

    Energy Technology Data Exchange (ETDEWEB)

    Meng Na; Zhou Ninglin; Shen Jian [Jiangsu Engineering Research Center for Biomedical Function Materials, Nanjing Normal University, Nanjing 210046 (China); Zhang Shuangquan, E-mail: zhouninglin@njnu.edu.cn, E-mail: jshen@njnu.edu.cn, E-mail: shuangquanz@yahoo.com [Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210046 (China)

    2010-05-07

    Heparin is a potent anticoagulant agent that interacts strongly with antithrombin III to prevent the formation of fibrin clots. In the present work, poly(dimethylsiloxane)(PDMS)/graphite oxide-benzalkonium chloride-heparin (PDMS/modified graphite oxide) nanocomposite films were obtained by the solution intercalation technique as a possible drug delivery system. The heparin-benzalkonium chloride (BAC-HEP) was intercalated into graphite oxide (GO) layers to form GO-BAC-HEP (modified graphite oxide). Nanocomposite films were characterized by XRD, SEM, TEM, ATR-FTIR and TGA. The modified graphite oxide was observed to be homogeneously dispersed throughout the PDMS matrix. The effect of modified graphite oxide on the mechanical properties of the nanocomposite film was investigated. When the modified graphite oxide content was lower than 0.2 wt%, the nanocomposites showed excellent mechanical properties. Furthermore, nanocomposite films become delivery systems that release heparin slowly to make the nanocomposite films blood compatible. The in vitro studies included hemocompatibility testing for effects on platelet adhesion, platelet activation, plasma recalcification profiles, and hemolysis. Results from these studies showed that the anticoagulation properties of PDMS/GO-BCA-HEP nanocomposite films were greatly superior to those for no treated PDMS. Cell culture assay indicated that PDMS/GO-BCA-HEP nanocomposite films showed enhanced cell adhesion.

  9. Biopolymer-modified graphite oxide nanocomposite films based on benzalkonium chloride-heparin intercalated in graphite oxide

    Science.gov (United States)

    Meng, Na; Zhang, Shuang-Quan; Zhou, Ning-Lin; Shen, Jian

    2010-05-01

    Heparin is a potent anticoagulant agent that interacts strongly with antithrombin III to prevent the formation of fibrin clots. In the present work, poly(dimethylsiloxane)(PDMS)/graphite oxide-benzalkonium chloride-heparin (PDMS/modified graphite oxide) nanocomposite films were obtained by the solution intercalation technique as a possible drug delivery system. The heparin-benzalkonium chloride (BAC-HEP) was intercalated into graphite oxide (GO) layers to form GO-BAC-HEP (modified graphite oxide). Nanocomposite films were characterized by XRD, SEM, TEM, ATR-FTIR and TGA. The modified graphite oxide was observed to be homogeneously dispersed throughout the PDMS matrix. The effect of modified graphite oxide on the mechanical properties of the nanocomposite film was investigated. When the modified graphite oxide content was lower than 0.2 wt%, the nanocomposites showed excellent mechanical properties. Furthermore, nanocomposite films become delivery systems that release heparin slowly to make the nanocomposite films blood compatible. The in vitro studies included hemocompatibility testing for effects on platelet adhesion, platelet activation, plasma recalcification profiles, and hemolysis. Results from these studies showed that the anticoagulation properties of PDMS/GO-BCA-HEP nanocomposite films were greatly superior to those for no treated PDMS. Cell culture assay indicated that PDMS/GO-BCA-HEP nanocomposite films showed enhanced cell adhesion.

  10. Effects of chronic exposure to benzalkonium chloride in Oncorhynchus mykiss: cholinergic neurotoxicity, oxidative stress, peroxidative damage and genotoxicity.

    Science.gov (United States)

    Antunes, S C; Nunes, B; Rodrigues, S; Nunes, R; Fernandes, J; Correia, A T

    2016-07-01

    Benzalkonium chloride (BAC) is one of the most used conservatives in pharmaceutical preparations. However, its use is limited to a small set of external use formulations, due to its high toxicity. Benzalkonium chloride effects are related to the potential exertion of deleterious effects, mediated via oxidative stress and through interaction with membrane enzymes, leading to cellular damage. To address the ecotoxicity of this specific compound rainbow trouts were chronically exposed to BAC at environmental relevant concentrations (ranging from 0.100 to 1.050mg/L), and the biological response of cholinergic neurotoxicity, modulation of the antioxidant defense, phase II metabolism, lipid peroxidation and genotoxicity was studied. The obtained results showed a dual pattern of antioxidant response, with significant alterations in catalase activity (starting at 0.180mg/L), and lipid peroxidation, for intermediate (0.180 and 0.324mg/L) concentrations. No significant alterations occurred for glutathione-S-transferases activity. An unexpected increased of the acetylcholinesterase activity was also recorded for the individuals exposed to higher concentrations of BAC (starting at 0.180mg/L). Furthermore, exposure to BAC resulted in the establishment of genotoxic alterations, observable (for the specific case of the comet assay results) for all tested BAC concentrations. However, and considering that the oxidative response was not devisable, other mechanisms may be involved in the genotoxic effects reported here.

  11. Reduction of cytotoxicity of benzalkonium chloride and octenidine by Brilliant Blue G.

    Science.gov (United States)

    Bartok, Melinda; Tandon, Rashmi; Alfaro-Espinoza, Gabriela; Ullrich, Matthias S; Gabel, Detlef

    2015-01-01

    The irritative effects of preservatives found in ophthalmologic solution, or of antiseptics used for skin disinfection is a consistent problem for the patients. The reduction of the toxic effects of these compounds is desired. Brilliant Blue G (BBG) has shown to meet the expected effect in presence of benzalkonium chloride (BAK), a well known preservative in ophthalmic solutions, and octenidine dihydrochloride (Oct), used as antiseptic in skin and wound disinfection. BBG shows a significant protective effect on human corneal epithelial (HCE) cells against BAK and Oct toxicity, increasing the cell survival up to 51 % at the highest BAK or Oct concentration tested, which is 0.01 %, both at 30 min incubation. Although BBG is described as a P2x7 receptor antagonist, other selective P2x7 receptor antagonists, OxATP (adenosine 5'-triphosphate-2',3'-dialdehyde) and DPPH (N'-(3,5-dichloropyridin-4-yl)-3-phenylpropanehydrazide), did not reduce the cytotoxicity of neither BAK nor Oct. Therefore we assume that the protective effect of BBG is not due to its action on the P2x7 receptor. Brilliant Blue R (BBR), a dye similar to BBG, was also tested for protective effect on BAK and Oct toxicity. In presence of BAK no significant protective effect was observed. Instead, with Oct a comparable protective effect was seen with that of BBG. To assure that the bacteriostatic effect is not affected by the combinations of BAK/BBG, Oct/BBG and Oct/BBR, bacterial growth inhibition was analyzed on different Gram-negative and Gram-positive bacteria. All combinations of BAK or Oct with BBG hinder growth of Gram-positive bacteria. The combinations of 0.001 % Oct and BBR above 0.025 % do not hinder the growth of B. subtilis. For Gram-negative bacteria, BBG and BBR reduce, but do not abolish, the antimicrobial effect of BAK nor of Oct. In conclusion, the addition of BBG at bacterial inhibitory concentrations is suggested in the ready-to-use ophthalmic preparations and antiseptic solutions.

  12. Tn6188 - a novel transposon in Listeria monocytogenes responsible for tolerance to benzalkonium chloride.

    Directory of Open Access Journals (Sweden)

    Anneliese Müller

    Full Text Available Controlling the food-borne pathogen Listeria (L. monocytogenes is of great importance from a food safety perspective, and thus for human health. The consequences of failures in this regard have been exemplified by recent large listeriosis outbreaks in the USA and Europe. It is thus particularly notable that tolerance to quaternary ammonium compounds such as benzalkonium chloride (BC has been observed in many L. monocytogenes strains. However, the molecular determinants and mechanisms of BC tolerance of L. monocytogenes are still largely unknown. Here we describe Tn6188, a novel transposon in L. monocytogenes conferring tolerance to BC. Tn6188 is related to Tn554 from Staphylococcus (S. aureus and other Tn554-like transposons such as Tn558, Tn559 and Tn5406 found in various Firmicutes. Tn6188 comprises 5117 bp, is integrated chromosomally within the radC gene and consists of three transposase genes (tnpABC as well as genes encoding a putative transcriptional regulator and QacH, a small multidrug resistance protein family (SMR transporter putatively associated with export of BC that shows high amino acid identity to Smr/QacC from S. aureus and to EmrE from Escherichia coli. We screened 91 L. monocytogenes strains for the presence of Tn6188 by PCR and found Tn6188 in 10 of the analyzed strains. These isolates were from food and food processing environments and predominantly from serovar 1/2a. L. monocytogenes strains harboring Tn6188 had significantly higher BC minimum inhibitory concentrations (MICs (28.5 ± 4.7 mg/l than strains without Tn6188 (14 ± 3.2 mg/l. Using quantitative reverse transcriptase PCR we could show a significant increase in qacH expression in the presence of BC. QacH deletion mutants were generated in two L. monocytogenes strains and growth analysis revealed that ΔqacH strains had lower BC MICs than wildtype strains. In conclusion, our results provide evidence that Tn6188 is responsible for BC tolerance in various L

  13. Toxicity of antiglaucoma drugs with and without benzalkonium chloride to cultured human corneal endothelial cells

    Directory of Open Access Journals (Sweden)

    Masahiko Ayaki

    2010-10-01

    Full Text Available Masahiko Ayaki1, Atsuo Iwasawa2, Yoichi Inoue31Department of Ophthalmology, Saitama National Hospital, Wako, Japan; 2Life Particle Interaction Engineering Creation, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan; 3Department of Ophthalmology, Olympia Eye Hospital, Tokyo, JapanPurpose: The toxicity of antiglaucoma medications to ocular surface cells has been evaluated extensively; however, the toxicity to corneal endothelial cells (CECs remains elusive. Our aim is to evaluate the toxicity of antiglaucoma medications to CECs using an in vitro toxicity assay.Methods: Primary cultures of human (H CECs derived from eye bank specimens were established. Following exposure of HCECs to test solutions for 10, 30, or 60 minutes, or 48 hours, we measured cell viability using a WST-1 assay. Test solutions were diluted in culture media and included 0.5% Timoptol®, preservative-free 0.5% timolol maleate, 1% Trusopt®, preservative-free 1% dorzolamide, Travatan®, Travatan Z®, Xalatan®, and benzalkonium chloride (BAK. To assess cell viability, the value of the test culture well after treatment was expressed as a percentage of that of the control well. Toxicity of each solution was compared using the cell viability score (CVS.Results: After exposure to 10-fold dilutions of test solutions for 48 hours, HCEC viabilities were 48.5% for 0.5% Timoptol, 80.9% for preservative-free 0.5% timolol maleate, 47.0% for 1% Trusopt, 71.7% for preservative-free 1% dorzolamide, 55.5% for Travatan, 88.5% for Travatan Z, and 52.5% for Xalatan. Exposure to test solutions diluted 100-fold or more resulted in HCEC viabilities > 80%, with the exception of preservative-free 1% dorzolamide, which resulted in a viability of 72.0% at a dilution of 100-fold. Based on CVS, the order of cell viability was Travatan Z ≥ preservative-free timolol maleate = preservative-free dorzolamide > 0.5% Timoptol = 1% Trusopt > Travatan ≥ Xalatan. Assessment of the

  14. Evaluation of Biomarkers of Inflammation in Response to Benzalkonium Chloride on Corneal and Conjunctival Epithelial Cells

    Science.gov (United States)

    Chen, Dongmei; Asbell, Penny A.

    2009-01-01

    Abstract Purpose Most eye drops contain preservatives; benzalkonium chloride (BAK) is most common. Recent data demonstrated BAK adding to toxicity. BAK is degraded into hydrogen peroxide (H2O2), which in even small amounts is known to be an irritant. Increased toxicity should cause localized inflammation with increased elaboration of inflammatory biomarkers. To evaluate the inflammation BAK causes to the ocular surface, enzyme linked immunosorbant assays (ELISAs) were utilized to quantify the levels of inflammatory biomarkers in response to BAK and/or H2O2. Methods Immortalized human conjunctival and corneal epithelial cells were exposed to: BAK (0.001%–0.1%), hydrogen peroxide (H2O2) (0.01%–0.1%), and cell media for 1 h. Cytokine quantification was performed via enzyme-linked immunosorbent assays [ELISAs]). Additional experimentation was performed in which testing solutions were replaced with media after 1 h and the resulting supernatants quantified after 24 h. Results BAK induced significant amounts of interleukin (IL-) 1 and tumor necrosis factor (TNF), but only moderate amounts of C-reactive protein (CRP), IL- 10 and 12, and H2O2. Lower concentrations of BAK induced proportionally less elaboration. Replacing the test solutions with media and providing 23 h for cytokine elaboration significantly increased TNF, but not IL-1. Lipopolysaccharide (LPS) positive controls induced substantial elaboration/release of both IL-1 and TNF as did in increasing the exposure to the full 24 h. Conclusions After 1 h of exposure, BAK increased quantities of all biomarkers. The biomarkers in decreasing order of induction/upregulation were: TNF ≥ IL-1 ≥ IL-12 ≥ IL-10 ≥ CRP. Even low concentrations caused some degree of inflammation. Replacing the testing solution with media and providing 23 h for cytokine elaboration, significantly increased the elaboration/release of TNF, but not IL-1, as compared to the 1-h BAK exposure. Whereas increasing the exposure to the full 24 h

  15. Corneal toxicity secondary to inadvertent use of benzalkonium chloride preserved viscoelastic material in cataract surgery

    Science.gov (United States)

    Eleftheriadis, H; Cheong, M; Sandeman, S; Syam, P P; Brittain, P; Klintworth, G K; Lloyd, A; Liu, C

    2002-01-01

    Aims: To study the long term toxic effects of intraocular benzalkonium chloride (BAC). Methods: 19 patients exposed to intraocular BAC preserved viscoelastic during cataract surgery in February 1999 developed severe striate keratopathy immediately postoperatively. 16 patients, including two who underwent penetrating keratoplasty, were studied in the period April to June 2000. Ocular symptoms, visual acuity, biomicroscopy, intraocular pressure, dilated funduscopy, specular endothelial microscopy, and corneal pachymetry findings were recorded. The corneal and iris specimens of the two patients who underwent keratoplasty were studied by light, transmission, and scanning electron microscopy. Results: Six males and 10 females, aged 64–98 years, were studied 14–16 months postoperatively. All patients were symptomatic. 12 patients had best corrected visual acuity of 6/12 or better and four patients of between 6/18 and 6/60. Five patients had corneal epithelial oedema and 11 had Descemet's membrane folds. The central corneal thickness, 620 (SD 71) μm, in affected eyes was significantly higher (p<0.005, two tailed paired t test) than that of the contralateral eyes, 563 (SD 48) μm. The endothelial cell density was significantly lower (p<0.0001, two tailed paired t test) in affected eyes: 830 (SD 280) cells/mm2v 2017 (SD 446) cells/mm2. The mean average cell area was significantly higher in the BAC treated eyes: 1317 (SD 385) μm2v 521 (SD 132) μm2. There was no significant difference in the coefficient of variation of cell size between the two eyes (p=0.3, two tailed paired t test). Two corneal specimens displayed morphological features of bullous keratopathy and other non-specific abnormalities. Extracellular melanosomes were present in a portion of the iris of one case. Conclusion: BAC is toxic to the corneal endothelium when used intraocularly, leading to severe striate keratopathy. This cleared in most cases but left varying degrees of residual stromal thickening

  16. Hyperosmolarity potentiates toxic effects of benzalkonium chloride on conjunctival epithelial cells in vitro

    Science.gov (United States)

    Godefroy, David; Riancho, Luisa; Rostène, William; Baudouin, Christophe; Brignole-Baudouin, Françoise

    2012-01-01

    Purpose Benzalkonium chloride (BAK), the most commonly used preservative in eye drops, is known to induce ocular irritation symptoms and dry eye in long-term treated patients and animal models. As tear film hyperosmolarity is diagnostic of some types of dry eye disease, we determined in vitro on conjunctival epithelial cells the cytoxicity of BAK in hyperosmolar conditions through cell viability, apoptosis, and oxidative stress assays. Methods The Wong Kilbourne derivative of Chang conjunctival epithelial cells were cultured for 24 h or 48 h either in NaCl-induced hyperosmolar conditions (400–425–500 mOsM), in low concentrations of BAK (10−4%, 3.10−4%, and 5.10−4%), or in combination of both. We investigated cell viability through lysosomal integrity evaluation, cell death (cell membrane permeability and chromatin condensation), and oxidative stress (reactive oxygen species, superoxide anion) using spectrofluorimetry. Immunohistochemistry was performed for cytoskeleton shrinkage (phalloidin staining), mitochondrial permeability transition pore (cytochrome c release), the apoptosis effector active caspase-3, and the caspase-independent apoptosis factor AIF. We also observed early effects induced by the experimental conditions on the conjunctival cell layers using phase contrast imaging of live cells. Results As compared to standard culture solutions, hyperosmolar stress potentiated BAK cytotoxicity on conjunctival cells through the induction of oxidative stress; reduction of cell viability; cell membrane permeability increase; cell shrinkage with cell blebbing, as shown in phase contrast imaging of live cells; and chromatin condensation. Like BAK, but to a much lesser extent, hyperosmolarity increased cell death in a concentration-dependent manner through a caspase-dependent apoptosis characterized by a release of cytochrome c in the cytoplasm from mitochondria and the activation of caspase-3. Moreover, the caspase-independent apoptosis factor AIF was

  17. Tn6188 - a novel transposon in Listeria monocytogenes responsible for tolerance to benzalkonium chloride.

    Science.gov (United States)

    Müller, Anneliese; Rychli, Kathrin; Muhterem-Uyar, Meryem; Zaiser, Andreas; Stessl, Beatrix; Guinane, Caitriona M; Cotter, Paul D; Wagner, Martin; Schmitz-Esser, Stephan

    2013-01-01

    Controlling the food-borne pathogen Listeria (L.) monocytogenes is of great importance from a food safety perspective, and thus for human health. The consequences of failures in this regard have been exemplified by recent large listeriosis outbreaks in the USA and Europe. It is thus particularly notable that tolerance to quaternary ammonium compounds such as benzalkonium chloride (BC) has been observed in many L. monocytogenes strains. However, the molecular determinants and mechanisms of BC tolerance of L. monocytogenes are still largely unknown. Here we describe Tn6188, a novel transposon in L. monocytogenes conferring tolerance to BC. Tn6188 is related to Tn554 from Staphylococcus (S.) aureus and other Tn554-like transposons such as Tn558, Tn559 and Tn5406 found in various Firmicutes. Tn6188 comprises 5117 bp, is integrated chromosomally within the radC gene and consists of three transposase genes (tnpABC) as well as genes encoding a putative transcriptional regulator and QacH, a small multidrug resistance protein family (SMR) transporter putatively associated with export of BC that shows high amino acid identity to Smr/QacC from S. aureus and to EmrE from Escherichia coli. We screened 91 L. monocytogenes strains for the presence of Tn6188 by PCR and found Tn6188 in 10 of the analyzed strains. These isolates were from food and food processing environments and predominantly from serovar 1/2a. L. monocytogenes strains harboring Tn6188 had significantly higher BC minimum inhibitory concentrations (MICs) (28.5 ± 4.7 mg/l) than strains without Tn6188 (14 ± 3.2 mg/l). Using quantitative reverse transcriptase PCR we could show a significant increase in qacH expression in the presence of BC. QacH deletion mutants were generated in two L. monocytogenes strains and growth analysis revealed that ΔqacH strains had lower BC MICs than wildtype strains. In conclusion, our results provide evidence that Tn6188 is responsible for BC tolerance in various L. monocytogenes

  18. The influence of subminimal inhibitory concentrations of benzalkonium chloride on biofilm formation by Listeria monocytogenes.

    Science.gov (United States)

    Ortiz, Sagrario; López, Victoria; Martínez-Suárez, Joaquín V

    2014-10-17

    Disinfectants, such as benzalkonium chloride (BAC), are commonly used to control Listeria monocytogenes and other pathogens in food processing plants. Prior studies have demonstrated that the resistance to BAC of L. monocytogenes was associated with the prolonged survival of three strains of molecular serotype 1/2a in an Iberian pork processing plant. Because survival in such environments is related to biofilm formation, we hypothesised that the influence of BAC on the biofilm formation potential of L. monocytogenes might differ between BAC-resistant strains (BAC-R, MIC≥10mg/L) and BAC-sensitive strains (BAC-S, MIC≤2.5mg/L). To evaluate this possibility, three BAC-R strains and eight BAC-S strains, which represented all of the molecular serotype 1/2a strains detected in the sampled plant, were compared. Biofilm production was measured using the crystal violet staining method in 96-well microtitre plates. The BAC-R strains produced significantly (p<0.05) less biofilm than the BAC-S in the absence of BAC, independent of the rate of planktonic growth. In contrast, when the biofilm values were measured in the presence of BAC, one BAC-R strain (S10-1) was able to form biofilm at 5mg/L of BAC, which prevented biofilm formation among the rest of the strains. A genetic determinant of BAC resistance recently described in L. monocytogenes (Tn6188) was detected in S10-1. When a BAC-S strain and its spontaneous mutant BAC-R derivative were compared, resistance to BAC led to biofilm formation at 5mg/L of BAC and to a significant (p<0.05) stimulation of biofilm formation at 1.25mg/L of BAC, which significantly (p<0.05) reduced the biofilm level in the parent BAC-S strain. Our results suggest that the effect of subminimal inhibitory concentrations of BAC on biofilm production by L. monocytogenes might differ between strains with different MICs and even between resistant strains with similar MICs but different genetic determinants of BAC resistance. For BAC-R strains similar

  19. Benzalkonium chloride and heavy-metal tolerance in Listeria monocytogenes from retail foods.

    Science.gov (United States)

    Xu, Dongyang; Li, Yanli; Zahid, M Shamim Hasan; Yamasaki, Shinji; Shi, Lei; Li, Jian-rong; Yan, He

    2014-11-03

    Phenotypic and genotypic tolerance in 71 Listeria monocytogenes isolates from different varieties of foods to benzalkonium chloride (BC) and cadmium were investigated by susceptibility test and molecular methods. To investigate the role of efflux pumps in BC tolerance, reserpine, an efflux pump inhibitor, was added to the BC tolerant strains. Tolerance to BC and cadmium were 26.8% (19/71) and 49.3% (35/71) respectively. Strains with BC tolerance were significantly more frequent among those of serotype 4b (100%, 6/6) than among those of serotype 1/2a (or 3a) (13.5%, 5/37), which represent the predominant number of strains (52.1%, 37/71). Tolerance to cadmium was encountered among 62.2% (23/37) and 50.0% (3/6) of the serotype 1/2a (or 3a) and 4b strains, respectively, and among 19.0% (4/21) of the strains of the serotype 1/2c. All of the 10 (14.1%) isolates found to be BC and cadmium co-tolerance were isolated from raw meat or quick-frozen food made of wheat flour and rice. Five multi-drug resistant strains were tolerant to cadmium as well. Among 71 isolates examined, one contained qacA and three contained qacEΔ1-sul. To the best of our knowledge, this is the first detection of qacA and qacEΔ1-sul in L. monocytogenes, an indication of the possible horizontal transfer of the two genes. Addition of reserpine to the tolerant strains resulted in the loss of tolerance among seven out of 19 BC strains, suggesting a certain role the efflux pump played in mediating BC tolerance. Of the three distinct cadA types known to date in L. monocytogenes, the cadA1 and cadA2 genes were detected among 24 (33.8%) and three (4.2%) isolates respectively. The presence of cadA1 and cadA2 largely corresponded to the susceptibility phenotype. A subset (9/35 [25.7%]) of the cadmium-tolerant isolates lacked the known cadmium resistance determinants. These findings suggest that food products could act as a reservoir for L. monocytogenes harboring tolerance to BC and cadmium and will further

  20. Toxicity of antiglaucoma drugs with and without benzalkonium chloride to cultured human corneal endothelial cells

    Science.gov (United States)

    Ayaki, Masahiko; Iwasawa, Atsuo; Inoue, Yoichi

    2010-01-01

    Purpose The toxicity of antiglaucoma medications to ocular surface cells has been evaluated extensively; however, the toxicity to corneal endothelial cells (CECs) remains elusive. Our aim is to evaluate the toxicity of antiglaucoma medications to CECs using an in vitro toxicity assay. Methods Primary cultures of human (H) CECs derived from eye bank specimens were established. Following exposure of HCECs to test solutions for 10, 30, or 60 minutes, or 48 hours, we measured cell viability using a WST-1 assay. Test solutions were diluted in culture media and included 0.5% Timoptol®, preservative-free 0.5% timolol maleate, 1% Trusopt®, preservative-free 1% dorzolamide, Travatan®, Travatan Z®, Xalatan®, and benzalkonium chloride (BAK). To assess cell viability, the value of the test culture well after treatment was expressed as a percentage of that of the control well. Toxicity of each solution was compared using the cell viability score (CVS). Results After exposure to 10-fold dilutions of test solutions for 48 hours, HCEC viabilities were 48.5% for 0.5% Timoptol, 80.9% for preservative-free 0.5% timolol maleate, 47.0% for 1% Trusopt, 71.7% for preservative-free 1% dorzolamide, 55.5% for Travatan, 88.5% for Travatan Z, and 52.5% for Xalatan. Exposure to test solutions diluted 100-fold or more resulted in HCEC viabilities >80%, with the exception of preservative-free 1% dorzolamide, which resulted in a viability of 72.0% at a dilution of 100-fold. Based on CVS, the order of cell viability was Travatan Z ≥ preservative-free timolol maleate = preservative-free dorzolamide > 0.5% Timoptol = 1% Trusopt > Travatan ≥ Xalatan. Assessment of the combined effect of drug and BAK revealed that latanoprost reduced the toxicity of BAK. Conclusion Antiglaucoma eye drops produced HCEC toxicity that appeared to depend on the presence of BAK. Because dilution of the antiglaucoma solutions resulted in markedly lower HCEC toxicity, HCEC damage due to antiglaucoma medication may

  1. Enhanced microbial biomass assay using mutant luciferase resistant to benzalkonium chloride.

    Science.gov (United States)

    Hattori, Noriaki; Sakakibara, Tatsuya; Kajiyama, Naoki; Igarashi, Toshinori; Maeda, Masako; Murakami, Seiji

    2003-08-15

    In a biomass assay based on adenosine 5(')-triphosphate (ATP) bioluminescence, extracellular ATP is removed; then intracellular ATP is extracted from the microorganism by an ATP extractant and subsequently reacted with luciferase. To provide a highly sensitive assay, the concentration of benzalkonium chloride (BAC) in the ATP extractant was optimized by using a mutant luciferase resistant to BAC. The use of 0.2% BAC, which was acceptable for the luciferase, simultaneously achieved the maximum extraction of intracellular ATP from microorganisms and the inactivation of the ATP-eliminating enzymes for removal of extracellular ATP. The detection limit (blank+3 SD) for ATP was 1.8x10(-14)M (1.8x10(-18)mol/assay) in the presence of the ATP extractant with coefficients of variation of 0.7 to 6.3%. The reagent system coupled with the ATP-eliminating enzymes allowed for the detection of 93 colony-forming units (CFU)/ml of Escherichia coli ATCC 25922, 170CFU/ml of Pseudomonas aeruginosa ATCC 27853, 170CFU/ml of Proteus mirabilis ATCC 29906, 68CFU/ml of Staphylococcus aureus ATCC 25923, and 7.7CFU/ml of Bacillus subtilis ATCC 6051. The yeast cell of Saccharomyces cerevisiae IFO 10217 could be detected at 1CFU/ml. With 54 kinds of microorganisms, the average ATP extraction efficiency compared to the trichloroacetic acid extraction method was 81.0% in 24 strains among gram-negative bacteria, 99.4% in 13 strains among gram-positive bacteria, and 97.0% in 17 strains among yeast. The ATP contents of the gram-negative bacteria, gram-positive bacteria, and yeasts ranged from 0.40 to 2.70x10(-18)mol/CFU (mean=1.5x10(-18)mol/CFU), from 0.41 to 16.7x10(-18)mol/CFU (mean=5.5x10(-18)mol/CFU), and from 0.714 to 54.6x10(-16)mol/CFU (mean=8.00x10(-16)mol/CFU), respectively.

  2. Effects of Benzalkonium Chloride, Proxel LV, P3 Hypochloran, Triton X-100 and DOWFAX 63N10 on anaerobic digestion processes

    DEFF Research Database (Denmark)

    Flores, German Antonio Enriquez; Fotidis, Ioannis; Karakashev, Dimitar Borisov

    2015-01-01

    In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch and conti...

  3. Inactivation of human norovirus surrogates by benzalkonium chloride, potassium peroxymonosulfate, tannic acid, and gallic acid.

    Science.gov (United States)

    Su, Xiaowei; D'Souza, Doris H

    2012-09-01

    Novel methods to effectively disinfect contact surfaces and prevent human norovirus transmission are essential. The effect of benzalkonium chloride (BAC), potassium peroxymonosulfate (KPMS), tannic acid (TA), and gallic acid (GA) on enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), and bacteriophage MS2 was studied. Viruses at high (∼7 log₁₀ PFU/mL) or low (∼5 log₁₀ PFU/mL) titers were mixed with equal volumes of BAC (0.2, 0.5, and 1 mg/mL), KPMS (5, 10, and 20 mg/mL), TA (0.02 and 0.2 mg/mL), GA (0.2, 0.4, and 0.8 mg/mL), or water and incubated for 2 h at room temperature. Viral infectivity after triplicate treatments was evaluated using plaque assays in duplicate. Low titers of FCV-F9 and MNV-1 were completely reduced, while low-titer MS2 was reduced by 1.7-1.8 log₁₀ PFU/mL with BAC at all three concentrations. High-titer FCV-F9 was reduced by 2.87, 3.08, and 3.25 log₁₀ PFU/mL, and high-titer MNV-1 was reduced by 1.55, 2.32, and 2.75 log₁₀ PFU/mL with BAC at 0.1, 0.25, and 0.5 mg/mL, respectively. High-titer MS2 was reduced by ∼2 log₁₀ PFU/mL with BAC at all three concentrations. KPMS at all three concentrations reduced high and low titers of FCV-F9 and MS2 and low-titer MNV-1 to undetectable levels, while high-titer MNV-1 was reduced by 0.92 and 3.44 log₁₀ PFU/mL with KMPS at 2.5 and 5 mg/mL, respectively. TA at 0.2 mg/mL only reduced high-titer FCV-F9 by 0.98 log₁₀ PFU/mL and low-titer FCV-F9 by 1.95 log₁₀ PFU/mL. GA at 0.1, 0.2, and 0.4 mg/mL reduced low-titer FCV-F9 by 2.50, 2.36, and 0.86 log₁₀ PFU/mL, respectively with negligible effects against high-titer FCV-F9. BAC and KPMS show promise to be used as broad-spectrum contact surface disinfectants for prevention of noroviral surrogate contamination.

  4. Effect of benzalkonium chloride-free latanoprost ophthalmic solution on ocular surface in patients with glaucoma

    Directory of Open Access Journals (Sweden)

    Walimbe T

    2016-05-01

    Full Text Available Tejaswini Walimbe,1 Vidya Chelerkar,2 Purvi Bhagat,3 Abhijeet Joshi,4 Atul Raut4 1Walimbe Eye Clinic, 2PBMA’s H.V. Desai Eye Hospital, Pune, 3Glaucoma Clinic, M and J Western Regional Institute of Ophthalmology, Civil Hospital, Ahmedabad, 4Clinical Research Department, Sun Pharma Advanced Research Company Ltd., Mumbai, India Introduction: Benzalkonium chloride (BAK, included as a preservative in many topical treatments for glaucoma, induces significant toxicity and alters tear breakup time (TBUT. BAK-containing latanoprost, an ester prodrug of prostaglandin F2a, can cause ocular adverse events (AEs associated with BAK. The purpose of this study was to evaluate the efficacy and safety of BAK-free latanoprost. Patients and methods: A prospective, open-label, single-arm, multicenter, 8-week study in patients with primary open-angle glaucoma or ocular hypertension taking BAK-containing latanoprost for ≥12 months was performed. Patients were switched to BAK-free latanoprost ophthalmic solution 0.005% administered once daily, and eyes were assessed after 28 and 56 days. Primary efficacy and safety variables were TBUT and treatment-emergent AEs, respectively. Results: At day 56, 40 eyes were evaluable. Mean TBUT increased significantly from baseline (3.67±1.60 seconds to 5.03±2.64 and 6.06±3.39 seconds after 28 and 56 days of treatment with BAK-free latanoprost (P<0.0001. Ocular Surface Disease Index© (OSDI© score also decreased significantly to 12.06±13.40 and 7.06±10.75 at 28 and 56 days, respectively, versus baseline (18.09±18.61, P<0.0001. In addition, inferior corneal staining score decreased significantly to 0.53 from baseline (0.85, P=0.0033. A reduction in conjunctival hyperemia and intraocular pressure was observed at both time points. No treatment-related serious AEs were evident and 12 (26.08% treatment-emergent AEs occurred in seven patients, with eye pain and irritation being the most frequent. No clinically significant changes

  5. Comparative Phenotypic and Genotypic Analysis of Swiss and Finnish Listeria monocytogenes Isolates with Respect to Benzalkonium Chloride Resistance.

    Science.gov (United States)

    Meier, Anja B; Guldimann, Claudia; Markkula, Annukka; Pöntinen, Anna; Korkeala, Hannu; Tasara, Taurai

    2017-01-01

    Reduced susceptibility of Listeria monocytogenes to benzalkonium chloride (BC), a quaternary ammonium compound widely used in food processing and hospital environments, is a growing public health and food safety concern. The minimal inhibitory concentration of BC on 392 L. monocytogenes strains from Switzerland (CH) and Finland (FIN) was determined. Within this strain collection, benzalkonium chloride resistance was observed in 12.3% (24/195) of Swiss and 10.6% (21/197) of Finnish strains. In both countries, the highest prevalence of BC-resistant strains (CH: 29.4%; FIN: 38.9%) was detected among serotype 1/2c strains. Based on PCR analysis, genes coding for the qacH efflux pump system were detected for most of the BC-resistant strains (CH: 62.5%; FIN: 52.4%). Some Swiss BC-resistant strains harbored genes coding for the bcrABC (16.7%) efflux pump system, while one Finnish BC-resistant strain harbored the emrE gene previously only described among BC-resistant L. monocytogenes strains from Canada. Interestingly, a subset of BC-resistant strains (CH: 5/24, 20.8%; FIN: 9/21, 42.8%) lacked genes for efflux pumps currently known to confer BC resistance in L. monocytogenes. BC resistance analysis in presence of reserpine showed that the resistance was completely or partially efflux pump dependent in 10 out of the 14 strains lacking the known BC resistance genes. Sequence types 155 and ST403 were over-representated among these strains suggesting that these strains might share similar but yet unknown mechanisms of BC resistance.

  6. Benzalkonium chloride exposure in cats: a retrospective analysis of 245 cases reported to the Veterinary Poisons Information Service (VPIS).

    Science.gov (United States)

    Bates, N; Edwards, N

    2015-02-28

    Benzalkonium chloride is commonly found in household products. This retrospective study examined 245 cases of feline exposure to benzalkonium chloride-containing products reported to the Veterinary Poisons Information Service (VPIS). A single route of exposure was reported in 188 cats (ingestion 126, skin 58, buccal 4); 57 cats had multiple routes. The common products involved were household antibacterial cleaners (43.6 per cent), household disinfectants (22.3 per cent) and patio cleaners (17.5 per cent). The most common signs were hypersalivation/drooling (53.9 per cent), tongue ulceration (40.4 per cent), hyperthermia (40.4 per cent) and oral ulceration (22.9 per cent). The mean time recorded for onset of the first clinical sign was 6.4 hours (range five minutes to 48 hours, median 4.5 hours, n=60), however, the VPIS was not contacted until 14.0 ± 13.2 hours after exposure (n=120). This figure also reflects the time of presentation. The most common treatments given were antibiotics (82.0 per cent), fluids (50.2 per cent), analgesia (45.3 per cent), gastroprotectants (31.0 per cent), dermal decontamination (24.1 per cent) and steroids (22.7 per cent). 13 cats (5.3 per cent) received syringe or nasogastric feeding. Of 245 cats, 12 (4.9 per cent) remained asymptomatic, 230 (93.9 per cent) recovered and three died (1.2 per cent). The time to recovery ranged from 1 to 360 hours (n=67) with a mean of 100.4 ± 82.0 hours (4.2 ± 3.4 days, median 72 hours).

  7. Preservative toxicity in glaucoma medication: clinical evaluation of benzalkonium chloride-free 0.5% timolol eye drops

    Directory of Open Access Journals (Sweden)

    Rosin LM

    2013-10-01

    Full Text Available Lauren M Rosin,1 Nicholas P Bell1,2 1Ruiz Department of Ophthalmology and Visual Science, The University of Texas Medical School at Houston, 2Robert Cizik Eye Clinic, Houston, TX, USA Abstract: Timolol (generic name is a frequently used medication for the control of glaucoma. Benzalkonium chloride (BAK is a commonly used preservative in ophthalmic solutions with a broad range of antimicrobial activity; however, this nonspecificity can result in toxicity. Adverse effects attributed to BAK, including conjunctival inflammation and fibrosis, tear film instability, corneal cytotoxicity, anterior chamber inflammation, trabecular meshwork cell apoptosis, cataract development, macular edema, and even systemic effects, have been well documented. These effects can lead to ocular discomfort, poor intraocular pressure control, glaucoma surgery failure, and decreased patient compliance. BAK use in topical medications has decreased recently as newer and less toxic preservatives have become available. Yet these preservatives still exert some toxic effects, especially in patients with chronic eye disease who use multiple drops over extended periods of time. Thus, attempts to reduce overall preservative loads for patients are important, whether it be decreasing the amount of preservative, decreasing the total number of drops patients use, or eliminating preservatives entirely. A preservative-free formulation of timolol, TIMOPTIC® in OCUDOSE®, is available in unit-dose vials. Preservative-free unit-dose vials minimize toxic adverse effects and are a good option for patients with ocular surface disease, on long-term multidrop therapy, or who simply do not tolerate the effects of preservatives due to discomfort. Keywords: glaucoma, ocular toxicity, benzalkonium chloride, preservative-free timolol

  8. In Vitro and in Vivo Experimental Studies on Trabecular Meshwork Degeneration Induced by Benzalkonium Chloride (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Baudouin, Christophe; Denoyer, Alexandre; Desbenoit, Nicolas; Hamm, Gregory; Grise, Alice

    2012-01-01

    Purpose: Long-term antiglaucomatous drug administration may cause irritation, dry eye, allergy, subconjunctival fibrosis, or increased risk of glaucoma surgery failure, potentially due to the preservative benzalkonium chloride (BAK), whose toxic, proinflammatory, and detergent effects have extensively been shown experimentally. We hypothesize that BAK also influences trabecular meshwork (TM) degeneration. Methods: Trabecular specimens were examined using immunohistology and reverse transcriptase–polymerase chain reaction. A trabecular cell line was stimulated by BAK and examined for apoptosis, oxidative stress, fractalkine and SDF-1 expression, and modulation of their receptors. An experimental model was developed with BAK subconjunctival injections to induce TM degeneration. Mass spectrometry (MS) imaging assessed BAK penetration after repeated instillations in rabbit eyes. Results: Trabecular specimens showed extremely low densities of trabecular cells and presence of cells expressing fractalkine and fractalkine receptor and their respective mRNAs. Benzalkonium in vitro induced apoptosis, oxidative stress, and fractalkine expression and inhibited the protective chemokine SDF-1 and Bcl2, also inducing a sustained intraocular pressure (IOP) increase, with dramatic apoptosis of trabecular cells and reduction of aqueous outflow. MS imaging showed that BAK could access the TM at measurable levels after repeated instillations. Conclusion: BAK enhances all characteristics of TM degeneration typical of glaucoma—trabecular apoptosis, oxidative stress, induction of inflammatory chemokines—and causes degeneration in acute experimental conditions, potentially mimicking long-term accumulation. BAK was also shown to access the TM after repeated instillations. These findings support the hypothesis that antiglaucoma medications, through toxicity of their preservative, may cause further long-term trabecular degeneration and therefore enhance outflow resistance, reducing the

  9. 双氯芬酸钠滴眼液中苯扎氯铵的测定%Determination of benzalkonium chloride in diclofenac sodium eye drops

    Institute of Scientific and Technical Information of China (English)

    李玮玲

    2013-01-01

    Objective To develop a method to determine benzalkonium chloride in diclofenac sodium eye drops. Methods Separation was performed on a CNW column (150 mmX4.6 mm, 5 urn). The mobile phase consisted of acetonitrile: 5 mmol · L-1 ammonium acetate-1% triethylamine (adjusting pH to 5.0 ± 0.5 by acetic acid) = 65 : 35 (v/v). The UV detection was 214 nm. Results Benzalkonium chloride had a good linearity at 12.50 - 125.00 μg · mL-1, the average recovery of benzalkonium chloride was 99.0% and the RSD was 1.3%. Conclusion The method is simple, rapid and sensitive, and it could be applied to determine benzalkonium chloride in diclofenac sodium eye drops.%目的 采用HPLC双氯芬酸钠滴眼液中苯扎氯铵的含量.方法 乙腈-5mmol·L-1醋酸铵溶液(含1%三乙胺,用冰醋酸调节pH值至5.0±0.5)(65:35)为流动相,CNW色谱柱(150 mm×4.6 mm,5 μm),检测波长为214 nm.结果 苯扎氯铵的测定在12.50~125.00 μg·mL-1与峰面积线性关系良好,苯扎氯铵的平均回收率为99.0%,RSD为1.3%.结论 方法简单、灵敏度高,可用于双氯芬酸钠滴眼液中苯扎氯铵的测定.

  10. Long‐term recovery of the human corneal endothelium after toxic injury by benzalkonium chloride

    Science.gov (United States)

    Hughes, E H; Pretorius, M; Eleftheriadis, H; Liu, C S C

    2007-01-01

    Introduction The inadvertent intra‐ocular administration of benzalkonium chloride‐preserved hydroxypropyl methylcellulose during cataract surgery at another hospital in 1999 resulted in toxic corneal endothelial injury and profound postoperative corneal oedema as a result of endothelial decompensation. The long‐term effect of this adverse event was assessed. Methods All 19 patients were invited to return for examination including corneal endothelial specular microscopy and pachymetry seven years after the incident. Results were compared with data from one year after the incident. Results Five patients attended for examination, one had received a penetrating keratoplasty and was, therefore, excluded. Ten patients had died and four had moved out of the region and were unable to attend. All four study patients were pain free and achieved 6/12 or better. Mean central corneal thickness reduced by 13% from 652.6 μm at one year to 563.4 μm. Mean central corneal endothelial cell density (n  =  3) increased 28% from 663.7 cells/mm2 at one year to 835.7 cells/mm2 (p<0.05). Conclusions After toxic injury, corneal endothelial function may have a remarkable capacity for recovery even after the first postoperative year. The rise in central endothelial cell density may represent cell migration from less affected areas or cellular proliferation. Should this unfortunate event recur, clinicians may expect continued recovery beyond one year. PMID:17504856

  11. UV/chlorine as an advanced oxidation process for the degradation of benzalkonium chloride: Synergistic effect, transformation products and toxicity evaluation.

    Science.gov (United States)

    Huang, Nan; Wang, Ting; Wang, Wen-Long; Wu, Qian-Yuan; Li, Ang; Hu, Hong-Ying

    2017-05-01

    Benzalkonium chlorides (BACs), as typical cationic surfactants and biocides widely applied in household and industrial products, have been frequently detected as micropollutants in many aquatic environments. In this study, the combination of UV irradiation and chlorine (UV/chlorine), a newly interested advanced oxidation process, was used to degrade dodecylbenzyldimethylammonium chloride (DDBAC). UV/chlorine showed synergistic effects on DDBAC degradation comparing to UV irradiation or chlorination alone. Radical quenching experiments indicated that degradation of DDBAC by UV/chlorine involved both UV photolysis and radical species oxidation, which accounted for 48.4% and 51.6%, respectively. Chlorine dosage and pH are essential parameters affecting the treatment efficiency of UV/chlorine. The pseudo first order rate constant (kobs, DDBAC) increased from 0.046 min(-1) to 0.123 min(-1) in response to chlorine dosage at 0-150 mg/L, and the degradation percentage of DDBAC within 12 min decreased from 81.4% to 56.6% at pH 3.6-9.5. Five main intermediates were identified and semi-quantified using HPLC-MS/MS and a possible degradation pathway was proposed. The degradation mechanisms of DDBAC by UV/chlorine included cleavage of the benzyl-nitrogen bond and hydrogen abstraction of the alkyl chain. Trichloromethane (TCM), chloral hydrate (CH), trichloropropanone (TCP), dichloropropanone (DCP) and dichloroacetonitrile (DCAN) were detected using GC-ECD. The formation of chlorinated products increased rapidly initially, then decreased (TCM, TCP, DCP and DCAN) or remained stable (CH) with extended treatment. The actual formation of TCM peaked at 30 min (50.3 μg/L), while other chlorinated products did not exceed 10 μg/L throughout the process. Based on the luminescent bacterial assay, DDBAC solution underwent almost complete detoxification subjected to UV/chlorine treatment for 120 min, which is more effective than UV irradiation or chlorination alone.

  12. Long-term exposure to benzalkonium chloride disinfectants results in change of microbial community structure and increased antimicrobial resistance.

    Science.gov (United States)

    Tandukar, Madan; Oh, Seungdae; Tezel, Ulas; Konstantinidis, Konstantinos T; Pavlostathis, Spyros G

    2013-09-03

    The effect of benzalkonium chlorides (BACs), a widely used class of quaternary ammonium disinfectants, on microbial community structure and antimicrobial resistance was investigated using three aerobic microbial communities: BACs-unexposed (DP, fed a mixture of dextrin/peptone), BACs-exposed (DPB, fed a mixture of dextrin/peptone and BACs), and BACs-enriched (B, fed only BACs). Long-term exposure to BACs reduced community diversity and resulted in the enrichment of BAC-resistant species, predominantly Pseudomonas species. Exposure of the two microbial communities to BACs significantly decreased their susceptibility to BACs as well as three clinically relevant antibiotics (penicillin G, tetracycline, ciprofloxacin). Increased resistance to BACs and penicillin G of the two BACs-exposed communities is predominantly attributed to degradation or transformation of these compounds, whereas resistance to tetracycline and ciprofloxacin is largely due to the activity of efflux pumps. Quantification of several key multidrug resistance genes showed a much higher number of copies of these genes in the DPB and B microbial communities compared to the DP community. Collectively, our findings indicate that exposure of a microbial community to BACs results in increased antibiotic resistance, which has important implications for both human and environmental health.

  13. Suppression of c-Kit signaling induces adult neurogenesis in the mouse intestine after myenteric plexus ablation with benzalkonium chloride

    Science.gov (United States)

    Tamada, Hiromi; Kiyama, Hiroshi

    2016-01-01

    Adult neurogenesis rarely occurs in the enteric nervous system (ENS). In this study, we demonstrated that, after intestinal myenteric plexus (MP) ablation with benzalkonium chloride (BAC), adult neurogenesis in the ENS was significantly induced in c-kit loss-of-function mutant mice (W/Wv). Almost all neurons and fibers in the MP disappeared after BAC treatment. However, 1 week after ablation, substantial penetration of nerve fibers from the non-damaged area was observed in the MP, longitudinal muscle and subserosal layers in both wildtype and W/Wv mice. Two weeks after BAC treatment, in addition to the penetrating fibers, a substantial number of ectopic neurons appeared in the subserosal and longitudinal muscle layers of W/Wv mice, whereas only a few ectopic neurons appeared in wildtype mice. Such ectopic neurons expressed either excitatory or inhibitory intrinsic motor neuron markers and formed ganglion-like structures, including glial cells, synaptic vesicles and basal lamina. Furthermore, oral administration of imatinib, an inhibitor of c-Kit and an anticancer agent for gastrointestinal stromal tumors, markedly induced appearance of ectopic neurons after BAC treatment, even in wildtype mice. These results suggest that adult neurogenesis in the ENS is negatively regulated by c-Kit signaling in vivo. PMID:27572504

  14. Preparation of microfibrillated cellulose/chitosan-benzalkonium chloride biocomposite for enhancing antibacterium and strength of sodium alginate films.

    Science.gov (United States)

    Liu, Kai; Lin, Xinxing; Chen, Lihui; Huang, Liulian; Cao, Shilin; Wang, Huangwei

    2013-07-03

    The nonantibacterial and low strength properties of sodium alginate films negatively impact their application for food packaging. In order to improve these properties, a novel chitosan-benzalkonium chloride (C-BC) complex was prepared by ionic gelation using tripolyphosphate (TPP) as a coagulant, and a biocomposite obtained through the adsorption of C-BC complex on microfibrillated cellulose, MFC/C-BC, was then incorporated into a sodium alginate film. The TEM image showed that the C-BC nanoparticles were spherical in shape with a diameter of about 30 nm, and the adsorption equilibrium time of these nanoparticles on the surface of MFC was estimated to be 6 min under the driving forces of hydrogen bonds and electrostatic interactions. According to the disc diffusion method, the MFC/C-BC biocomposite-incorporated sodium alginate film exhibited remarkable antibacterial activity against Staphylococcus aureus and certain antibacterial activity against Escherichia coli . The strength tests indicated that the tensile strength of the composite sodium alginate film increased about 225% when the loading of MFC/C-BC biocomposite was 10 wt %. These results suggested that the MFC/C-BC biocomposite-incorporated sodium alginate film with excellent antibacterial and strength properties would be a promising material for food packaging, and the MFC/C-BC may also be a potential multifunctional biocomposite for other biodegradable materials.

  15. Genoprotective effect of hyaluronic acid against benzalkonium chloride-induced DNA damage in human corneal epithelial cells

    Science.gov (United States)

    Wu, Han; Zhang, Huina; Wang, Changjun; Wu, Yihua; Xie, Jiajun; Jin, Xiuming; Yang, Jun

    2011-01-01

    Purpose The aim of this study was to investigate hyaluronic acid (HA) protection on cultured human corneal epithelial cells (HCEs) against benzalkonium chloride (BAC)-induced DNA damage and intracellular reactive oxygen species (ROS) increase. Methods Cells were incubated with different concentrations of BAC with or without the presence of 0.2% HA for 30 min. DNA damage to HCEs was examined by alkaline comet assay and by immunofluorescence microscopic detection of the phosphorylated form of histone variant H2AX (γH2AX) foci. ROS production was assessed by the fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). Cell apoptosis was determined with annexin V staining by flow cytometry. Results HA significantly reduced BAC-induced DNA damage as indicated by the tail length (TL) and tail moment (TM) of alkaline comet assay and by γH2AX foci formation, respectively. Moreover, HA significantly decreased BAC-induced ROS increase and cell apoptosis. However, exposure to HA alone did not produce any significant change in DNA damage, ROS generation, or cell apoptosis. Conclusions BAC could induce DNA damage and cell apoptosis in HCEs, probably through increasing oxidative stress. Furthermore, HA was an effective protective agent that had antioxidant properties and could decrease DNA damage and cell apoptosis induced by BAC. PMID:22219631

  16. Decrease in Corneal Damage due to Benzalkonium Chloride by the Addition of Mannitol into Timolol Maleate Eye Drops.

    Science.gov (United States)

    Nagai, Noriaki; Yoshioka, Chiaki; Tanino, Tadatoshi; Ito, Yoshimasa; Okamoto, Norio; Shimomura, Yoshikazu

    2015-01-01

    We investigated the protective effects of mannitol on corneal damage caused by benzalkonium chloride (BAC), which is used as a preservative in commercially available timolol maleate eye drops, using rat debrided corneal epithelium and a human cornea epithelial cell line (HCE-T). Corneal wounds were monitored using a fundus camera TRC-50X equipped with a digital camera; eye drops were instilled into rat eyes five times a day after corneal epithelial abrasion. The viability of HCE-T cells was calculated by TetraColor One; and Escherichia coli (ATCC 8739) were used to measure antimicrobial activity. The reducing effects on transcorneal penetration and intraocular pressure (IOP) of the eye drops were determined using rabbits. The corneal wound healing rate and rate constant (kH), as well as cell viability, were higher following treatment with 0.005% BAC solution containing 0.5% mannitol than in the case BAC solution alone; the antimicrobial activity was approximately the same for BAC solutions with and without mannitol. In addition, the kH for rat eyes instilled with commercially available timolol maleate eye drops containing 0.5% mannitol was significantly higher than that for eyes instilled with timolol maleate eye drops without mannitol, and the addition of mannitol did not affect the corneal penetration or IOP reducing effect of the timolol maleate eye drops. A preservative system comprising BAC and mannitol may provide effective therapy for glaucoma patients requiring long-term treatment with anti-glaucoma agents.

  17. Transcorneal permeation of diclofenac as a function of temperature from film formulation in presence of triethanolamine and benzalkonium chloride.

    Science.gov (United States)

    Mohapatra, Rajaram; Senapati, Sibananda; Sahoo, Chinmaya; Mallick, Subrata

    2014-11-01

    The objective of this report was to evaluate the transcorneal permeation of diclofenac potassium (DCP) as a function of temperature from hydroxypropyl methylcellulose (HPMC) matrix film containing triethanolamine (TEM) as plasticizer and benzalkonium chloride (BKC) as preservative. Activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) of permeation, diffusion and partition were evaluated to understand the underlying mechanism of permeation. Permeation improved with the presence of both the plasticizer and preservative compared to preservative alone. Further, increased amount of TEM in the film increased drug transport across the cornea. Decreased Ea value of the film supported the fact. Rise of temperature from 26 to 30, 34 and 40 °C increased permeation in all the films. Ocular residence of the film in vivo in the rabbit revealed that the film swelled by pronounced lachrymal fluid uptake and traces of hydrogel remained still at the end of 6 h of application. Absence of characteristic exothermic peak of the drug in the thermogram of film formulations indicated the molecular dispersion of drug in polymer matrix. Scanning electron microscopy indicated that the drug crystal size decreased with increasing concentration of TEM in presence of BKC due to effective wetting of drug particles by the polymer.

  18. Benzalkonium chloride (BAK induces apoptosis or necrosis, but has no major influence on the cell cycle of Jurkat cells

    Directory of Open Access Journals (Sweden)

    Piotr Pozarowski

    2011-07-01

    Full Text Available Benzalkonium chloride (BAK is a cationic detergent with a very slow turnover. Because of its strong antibacterial activities, BAK is widely used especially in dentistry and ophthalmology. It is the most commonly used preservative in topical ophthalmic medications. Due to chronicity and widespread use of such treatments, BAK’s side effects are of great importance. BAK toxicity for adherent cells, probably related to its pro-oxidative activities, is time- and dose-dependent. Although lymphocytes often infiltrate superficial eye tissues, the BAK influence on them is yet to be established. The aim of this study was to check BAK cytotoxicity on T lymphocytic Jurkat line cells and to verify the suggestion that BAK can induce G2M cell blocks. A dose- and time-dependent cytotoxic effect of BAK on lymphoid cells in relatively low concentrations was shown in this study. In lower concentrations, it shows a moderate apoptotic and minimal antiproliferative effect on Jurkat cells, while in higher concentrations it shows a rapid necrotic effect. No G2M cell blocks were observed. Our findings could suggest lymphoid dysfunction during intensive, prolonged topical BAK treatment, even at dosages relatively non-toxic to epithelial eye cells. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 225–230

  19. Meta analysis about the efficacy and safety of anti-ocular hypertension eye drops without benzalkonium chloride

    Institute of Scientific and Technical Information of China (English)

    Yan-Qing Wang; Xin Wang; Ping Liu

    2013-01-01

    Objective:To explore the safety and efficacy of eye drops without benzalkonium chloride(BAK) in treating glaucoma and ocular hypertension.Methods:The clinical case-control literatures about eye drops withoutBAK treating glaucoma and ocular hypertension were retrieved in PubMed,EMBASE,Cochrane andChineseBiological andMedical database.Meta5.0 software was used to analyze the literatures.Results:Five clinicalcontrol studies were included.The results indicated both eye drops could lower the intraocular pressure, and the intraocular pressure-lowering difference between two eye drops was0.07 mmHg(95%CI:0.04,0.19)(P>0.05).Two adverse reactions occurred more were conjunctival injection(10.78%) and allergic conjunctivitis (4.78%).The odd ratio of two eye drops occurring conjunctival injection and allergic conjunctivitis was0.67(95%CI,0.25,1.10) and0.82(95%CI,0.09,1.54), respectively(P<0.05) in fixed effect model.Conclusions:There is no difference between the eye drops with or withoutBAK in lowering intraocular pressure, but the latter is of higher safety.In consideration of the relatively small sample size of this research, more high-quality clinical research contrasts are needed as evidence.

  20. Control of Listeria monocytogenes contamination in an Iberian pork processing plant and selection of benzalkonium chloride-resistant strains.

    Science.gov (United States)

    Ortiz, Sagrario; López, Victoria; Martínez-Suárez, Joaquín V

    2014-05-01

    The aims of this study were to characterize the different strains of Listeria monocytogenes collected at an Iberian pork processing plant and to investigate whether their specific characteristics were associated with prolonged survival in the plant. Using pulsed-field gel electrophoresis (PFGE), 29 PFGE types were previously identified during a three-year period. Eight of these PFGE types persisted in the plant during that period. In the present study, a subset of 29 PFGE type strains, which represented the 29 different PFGE types, was further characterized by assessing the potential virulence, and using motility, surface attachment, and antimicrobial susceptibility tests. After changing the disinfection procedures in the plant, the isolation rate of L. monocytogenes decreased, and only four of the 29 PFGE types, including three of the eight persistent PFGE types, were found the following year. These four "surviving" PFGE types included three from PCR serogroup IIa that were characterized by their low virulence mutations and low-level resistance to benzalkonium chloride (BAC). Furthermore, these PFGE types comprised the only BAC-resistant isolates found in the study, and they appear to have been selected due to the control of Listeria contamination. The resistance to increased sublethal concentrations of disinfectants may lead to prolonged survival of L. monocytogenes in food plants.

  1. Suppression of c-Kit signaling induces adult neurogenesis in the mouse intestine after myenteric plexus ablation with benzalkonium chloride.

    Science.gov (United States)

    Tamada, Hiromi; Kiyama, Hiroshi

    2016-08-30

    Adult neurogenesis rarely occurs in the enteric nervous system (ENS). In this study, we demonstrated that, after intestinal myenteric plexus (MP) ablation with benzalkonium chloride (BAC), adult neurogenesis in the ENS was significantly induced in c-kit loss-of-function mutant mice (W/W(v)). Almost all neurons and fibers in the MP disappeared after BAC treatment. However, 1 week after ablation, substantial penetration of nerve fibers from the non-damaged area was observed in the MP, longitudinal muscle and subserosal layers in both wildtype and W/W(v) mice. Two weeks after BAC treatment, in addition to the penetrating fibers, a substantial number of ectopic neurons appeared in the subserosal and longitudinal muscle layers of W/W(v) mice, whereas only a few ectopic neurons appeared in wildtype mice. Such ectopic neurons expressed either excitatory or inhibitory intrinsic motor neuron markers and formed ganglion-like structures, including glial cells, synaptic vesicles and basal lamina. Furthermore, oral administration of imatinib, an inhibitor of c-Kit and an anticancer agent for gastrointestinal stromal tumors, markedly induced appearance of ectopic neurons after BAC treatment, even in wildtype mice. These results suggest that adult neurogenesis in the ENS is negatively regulated by c-Kit signaling in vivo.

  2. Prolonged exposure of mixed aerobic cultures to low temperature and benzalkonium chloride affect the rate and extent of nitrification.

    Science.gov (United States)

    Yang, Jeongwoo; Tezel, Ulas; Li, Kexun; Pavlostathis, Spyros G

    2015-03-01

    The combined effect of benzalkonium chloride (BAC) and prolonged exposure to low temperature on nitrification was investigated. Ammonia oxidation at 22-24°C by an enriched nitrifying culture was inhibited at increasing BAC concentrations and ceased at 15 mg BAC/L. The non-competitive inhibition coefficient was 1.5±0.9 mg BAC/L. Nitrification tests were conducted without and with BAC at 5mg/L using an aerobic, mixed heterotrophic/nitrifying culture maintained at a temperature range of 24-10°C. Maintaining this culture at 10°C for over one month in the absence of BAC, resulted in slower nitrification kinetics compared to those measured when the culture was first exposed to 10°C. BAC was degraded by the heterotrophic population, but its degradation rate decreased significantly as the culture temperature decreased to 10°C. These results confirm the negative impact of quaternary ammonium compounds on the nitrification process, which is further exacerbated by prolonged, low temperature conditions.

  3. Preservative toxicity in glaucoma medication: clinical evaluation of benzalkonium chloride-free 0.5% timolol eye drops

    Science.gov (United States)

    Rosin, Lauren M; Bell, Nicholas P

    2013-01-01

    Timolol (generic name) is a frequently used medication for the control of glaucoma. Benzalkonium chloride (BAK) is a commonly used preservative in ophthalmic solutions with a broad range of antimicrobial activity; however, this nonspecificity can result in toxicity. Adverse effects attributed to BAK, including conjunctival inflammation and fibrosis, tear film instability, corneal cytotoxicity, anterior chamber inflammation, trabecular meshwork cell apoptosis, cataract development, macular edema, and even systemic effects, have been well documented. These effects can lead to ocular discomfort, poor intraocular pressure control, glaucoma surgery failure, and decreased patient compliance. BAK use in topical medications has decreased recently as newer and less toxic preservatives have become available. Yet these preservatives still exert some toxic effects, especially in patients with chronic eye disease who use multiple drops over extended periods of time. Thus, attempts to reduce overall preservative loads for patients are important, whether it be decreasing the amount of preservative, decreasing the total number of drops patients use, or eliminating preservatives entirely. A preservative-free formulation of timolol, TIMOPTIC® in OCUDOSE®, is available in unit-dose vials. Preservative-free unit-dose vials minimize toxic adverse effects and are a good option for patients with ocular surface disease, on long-term multidrop therapy, or who simply do not tolerate the effects of preservatives due to discomfort. PMID:24204115

  4. Development of Calcitonin Salmon Nasal Spray: similarity of peptide formulated in chlorobutanol compared to benzalkonium chloride as preservative.

    Science.gov (United States)

    Costantino, Henry R; Culley, Heather; Chen, Lishan; Morris, Daniel; Houston, Michael; Roth, Sharin; Phoenix, Mary Jo; Foerder, Chuck; Philo, John S; Arakawa, Tsutomu; Eidenschink, Lisa; Andersen, Niels H; Brandt, Gordon; Quay, Steven C

    2009-10-01

    The similarity of an intranasal salmon calcitonin (sCT) employing chlorobutanol as preservative (Calcitonin Salmon Nasal Spray) was compared to the reference listed drug (RLD) employing benzalkonium chloride as preservative (Miacalcin Nasal Spray). Various orthogonal methods assessed peptide structuring, dynamics, and aggregation state. Mass spectrometry, amino acid analysis, and N-terminal sequencing all demonstrated similarity in primary structure. Near- and far-UV circular dichroism (CD) data supported similarity in secondary and tertiary sCT structure. Nuclear magnetic resonance studies further supported similarity of three-dimensional structure and molecular dynamics of the peptide. Other methods, such as sedimentation velocity and size exclusion chromatography, demonstrated similarity in peptide aggregation state. These latter methods, in addition to reversed phase chromatography, were also employed for monitoring stability under forced degradation, and at the end of recommended shelf storage and patient use conditions. In all cases and for all methodologies employed, similarity to the RLD was observed with respect to extent of aggregation and other degradation processes. Finally, ELISA and bioassay data demonstrated similarity in biological properties. These investigations comprehensively demonstrate physicochemical similarity of Calcitonin Salmon Nasal Spray and the RLD, and should prove a useful illustration to pharmaceutical scientists developing alternative and/or generic peptide or protein products.

  5. Assessment of corneal epithelial integrity after acute exposure to ocular hypotensive agents preserved with and without benzalkonium chloride.

    Science.gov (United States)

    Whitson, Jess T; Cavanagh, H Dwight; Lakshman, Neema; Petroll, W Matthew

    2006-01-01

    The corneal toxicity of 2 intraocular pressure-lowering agents was compared in a rabbit cornea model with New Zealand White rabbits. Corneal epithelial morphology and cell size were assessed by in vivo confocal microscopy. Baseline microscopic examinations were performed on 1 eye of each animal. Two weeks later, the eyes were bathed for 3 min in travoprost 0.004% preserved without benzalkonium chloride (BAK( or latanoprost 0.005% preserved with 0.02% BAK; the eyes were then rinsed with balanced salt solution, and the corneas were again examined by confocal microscopy (n=4/group). A second group of animals was exposed to the medications through a dosing regimen of 1 drop/min (lpar3 drops total) (n=4/group). In eyes treated with travoprost without BAK (3-min bath), superficial epithelial cells were similar to baseline, as indicated by their visible cell borders and bright nuclei. In contrast, the surface cells in eyes treated with latanoprost were significantly smaller and brighter and had less distinct borders. Surface cell size was significantly smaller as compared with baseline size and as compared with rabbits treated with travoprost without BAK for 3 min. Similar effects on corneal epithelial cell morphology were observed with the 1-drop/min dosing regimen. In this rabbit model, travoprost 0.004% preserved without BAK did not cause corneal epithelial toxicity; latanoprost 0.005% induced superficial cell loss, most likely caused by the presence of a relatively high concentration of BAK (0.02%).

  6. Subminimal Inhibitory Concentrations of the Disinfectant Benzalkonium Chloride Select for a Tolerant Subpopulation of Escherichia coli with Inheritable Characteristics

    Directory of Open Access Journals (Sweden)

    Solveig Langsrud

    2012-03-01

    Full Text Available Exposure of Escherichia coli to a subminimal inhibitory concentration (25% below MIC of benzalkonium chloride (BC, an antimicrobial membrane-active agent commonly used in medical and food-processing environments, resulted in cell death and changes in cell morphology (filamentation. A small subpopulation (1–5% of the initial population survived and regained similar morphology and growth rate as non-exposed cells. This subpopulation maintained tolerance to BC after serial transfers in medium without BC. To withstand BC during regrowth the cells up regulated a drug efflux associated gene (the acrB gene, member of the AcrAB-TolC efflux system and changed expression of outer membrane porin genes (ompFW and several genes involved in protecting the cell from the osmotic- and oxidative stress. Cells pre-exposed to osmotic- and oxidative stress (sodium chloride, salicylic acid and methyl viologen showed higher tolerance to BC. A control and two selected isolates showing increased BC-tolerance after regrowth in BC was genome sequenced. No common point mutations were found in the BC- isolates but one point mutation in gene rpsA (Ribosomal protein S1 was observed in one of the isolates. The observed tolerance can therefore not solely be explained by the observed point mutation. The results indicate that there are several different mechanisms responsible for the regrowth of a tolerant subpopulation in BC, both BC-specific and general stress responses, and that sub-MIC of BC may select for phenotypic variants in a sensitive E. coli culture.

  7. Subminimal Inhibitory Concentrations of the Disinfectant Benzalkonium Chloride Select for a Tolerant Subpopulation of Escherichia coli with Inheritable Characteristics

    Science.gov (United States)

    Moen, Birgitte; Rudi, Knut; Bore, Erlend; Langsrud, Solveig

    2012-01-01

    Exposure of Escherichia coli to a subminimal inhibitory concentration (25% below MIC) of benzalkonium chloride (BC), an antimicrobial membrane-active agent commonly used in medical and food-processing environments, resulted in cell death and changes in cell morphology (filamentation). A small subpopulation (1–5% of the initial population) survived and regained similar morphology and growth rate as non-exposed cells. This subpopulation maintained tolerance to BC after serial transfers in medium without BC. To withstand BC during regrowth the cells up regulated a drug efflux associated gene (the acrB gene, member of the AcrAB-TolC efflux system) and changed expression of outer membrane porin genes (ompFW) and several genes involved in protecting the cell from the osmotic- and oxidative stress. Cells pre-exposed to osmotic- and oxidative stress (sodium chloride, salicylic acid and methyl viologen) showed higher tolerance to BC. A control and two selected isolates showing increased BC-tolerance after regrowth in BC was genome sequenced. No common point mutations were found in the BC- isolates but one point mutation in gene rpsA (Ribosomal protein S1) was observed in one of the isolates. The observed tolerance can therefore not solely be explained by the observed point mutation. The results indicate that there are several different mechanisms responsible for the regrowth of a tolerant subpopulation in BC, both BC-specific and general stress responses, and that sub-MIC of BC may select for phenotypic variants in a sensitive E. coli culture. PMID:22605968

  8. Short term comparative study of topical 2% carteolol with and without benzalkonium chloride in healthy volunteers

    Science.gov (United States)

    Baudouin, C.; de Lunardo, C.

    1998-01-01

    AIM—A crossover, randomised double blind study was undertaken in 30 healthy volunteers, in order to compare the tolerance of 2% carteolol with and without preservative in short term use.
METHODS—Complete ophthalmic examinations were performed before and 30, 60, and 180 minutes after instillation of one drop of the solution, and after 3 days of preservative treatment. After a 5 day washout, the same examinations were done with the second drug.
RESULTS—Results showed good general tolerance for both formulations. No significant difference in subjective tolerance, corneal aesthesiometry, punctuate keratitis, Schirmer's test, intraocular pressure (IOP) decrease (about 25% in the two groups at 3 hours, 10% after 3 days of treatment), resting cardiac frequency, or blood pressure was observed. However, break up time was significantly reduced from baseline by preserved carteolol both at 3 hours (10.40 (5.9) seconds to 6.15 (3.9) seconds, p=0.001) and after 3 days (7.72 (5.5) seconds, p=0.04). Preservative free carteolol did not significantly change the break up time (baseline 9.08 (5.7) seconds; 3 hours = 7.88 (5.5) seconds, not significant; day 3 = 8.35 (5.8), non-significant).
CONCLUSIONS—These results confirm that carteolol is well tolerated, either with or without preservative. The preservative free group showed better stability of the tear film, without loss of effect on IOP. This difference, although mild in the healthy young subjects in the present study could be much more relevant in those patients treated long term, older patients, and/or those suffering from ocular surface disorders. In such instances, preservative free drugs could be of potential benefit to protect the lacrimal fluid integrity and corneoconjunctival surface.

 Keywords: glaucoma; carteolol; benzalkonium; preservatives; β blockers PMID:9536878

  9. Research on Quality Differences in Benzalkonium Chloride from Domestic and Abroad%国内外苯扎氯铵质量差异的研究

    Institute of Scientific and Technical Information of China (English)

    熊亚群; 刘雁鸣; 龙海燕; 彭琳; 艾俊涛

    2016-01-01

    目的::比较国内外苯扎氯铵的质量差异,为我国苯扎氯铵质量标准的修订提供参考。方法:采用《美国药典》2015年版(USP 38)中苯扎氯铵项下HPLC法测定国内外样品的烷基组成比率。分别照《中国药典》2015年版、USP 38中苯扎氯铵项下化学滴定法测定总含量。结果:烷基组成比率结果表明,国产与进口样品的不合格率分别为100%和50%。按两国药典方法计算含量的差值显示,国产与进口样品的总含量变化分别为3.86%~4.15%和1.15%~3.90%。结论:国内外苯扎氯铵的质量存在较大差异,建议我国药典参照USP 38增订烷基组成比率的测定,修正苯扎氯铵总含量的计算公式,提高该品种的质量标准。%Objective:To compare the quality differences in benzalkonium chloride samples from domestic and abroad to provide references for the quality standard revision for benzalkonium chloride in Chinese pharmacopoeia. Methods: The ratio of alkyl compo-nents was determined according to the method described in USP 38, and the total content of benzalkonium chloride was determined ac-cording to the method recorded in Chinese Pharmacopoeia (2015 edition) and USP 38, respectively. Results:According to the results of composition ratio of alkyl, the fraction defective of domestic samples and imported samples was 100% and 50%, respectively. The content difference between the values calculated by the methods in the two pharmacopoeias showed that the total content of domestic samples changed from 3. 86% to 4. 15%, and that of imported samples changed from 1. 15% to 3. 90%. Conclusion:There are sig-nificant differences in the quality of benzalkonium chloride between domestic samples and imported samples. It is recommended that the ratio of alkyl components should be supplemented in our pharmacopoeia referring to the method in USP 38 and the total content calcula-tion formula for benzalkonium chloride should be revised to improve

  10. Coselection of cadmium and benzalkonium chloride resistance in conjugative transfers from nonpathogenic Listeria spp. to other Listeriae.

    Science.gov (United States)

    Katharios-Lanwermeyer, S; Rakic-Martinez, M; Elhanafi, D; Ratani, S; Tiedje, J M; Kathariou, S

    2012-11-01

    Resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) may be an important contributor to the ability of Listeria spp. to persist in the processing plant environment. Although a plasmid-borne disinfectant resistance cassette (bcrABC) has been identified in Listeria monocytogenes, horizontal transfer of these genes has not been characterized. Nonpathogenic Listeria spp. such as L. innocua and L. welshimeri are more common than L. monocytogenes in food processing environments and may contribute to the dissemination of disinfectant resistance genes in listeriae, including L. monocytogenes. In this study, we investigated conjugative transfer of resistance to BC and to cadmium from nonpathogenic Listeria spp. to other nonpathogenic listeriae, as well as to L. monocytogenes. BC-resistant L. welshimeri and L. innocua harboring bcrABC, along with the cadmium resistance determinant cadA2, were able to transfer resistance to other nonpathogenic listeriae as well as to L. monocytogenes of diverse serotypes, including strains from the 2011 cantaloupe outbreak. Transfer among nonpathogenic Listeria spp. was noticeably higher at 25°C than at 37°C, whereas acquisition of resistance by L. monocytogenes was equally efficient at 25 and 37°C. When the nonpathogenic donors were resistant to both BC and cadmium, acquisition of cadmium resistance was an effective surrogate for transfer of resistance to BC, suggesting coselection between these resistance attributes. The results suggest that nonpathogenic Listeria spp. may behave as reservoirs for disinfectant and heavy metal resistance genes for other listeriae, including the pathogenic species L. monocytogenes.

  11. [Preservative substances - the daily dose of benzalkonium chloride in glaucoma treatment from the patients point of view].

    Science.gov (United States)

    Výborný, P; Sičáková, S; Veselá Flórová, Z

    2014-06-01

    The author calculated the daily dose of Benzalkonium Chloride (BAC) in eye drops used in glaucoma treatment from the patients point of view, which means the real amount of BAC applied in the conjunctival sac. The information about BAC concentration in 1 milliliter (mL) do not offer sufficient picture about real circumstances, because the size of the drop, especially after the introducing of the use of generic products in clinical practice in specific anti-glaucomatic drugs, differs significantly. The daily dose of BAC may have substantial significance in the patients treatment tolerance. The overview of BAC daily dose in single therapeutic groups and drugs follows: betablockers: Timo-COMOD 0, Arutimol 2.6, Vistagan 2.8, Timolol-POS 3.0, Arteoptic 3.7, Betoptic S 4.8, Timoptol MSD 6.3, Betoptic 10.0; alpha-mimetics: Alphagan 3.5, Luxfen 3.5, Aruclonin 7.1; derivates of prostaglandine, prostamides: Taflotan 0, Monopost 0, Lumigan 1.4, Unilat 3.1, Travatan 3.9, Latanoprost Apotex 4.3, Rescula 5.8, Latanoprost POS 5.9, Xalatan 6.0, Latanoprost Ratiopharm 6.0, Latanoprost Actavis 6.0, Latanoprost Arrow 6.0, Arulatan 5.4, Latalux 6.0, Glaucotens 6.0, Xaloptic 6.0, Solusin 6.1; carboanhydrase inhibitors: Batidor 3.8, Azopt 4.8, Trusopt 5.4, Oftidor 8.1; fixed combinations: Ganfort 1.4, Dorzolamid/timolol TEVA 2.8, Combigan 3.2, Duotrav 4.3, Cosopt 5.6, Xalacom 6.0, Glaucotima 6.0, Latanoprost/timolol Apotex 6.3, Azarga 6.4, Dorzogen Combi 6.5, and Dozotima 8.8 µl.

  12. Heavy-Metal and Benzalkonium Chloride Resistance of Listeria monocytogenes Isolates from the Environment of Turkey-Processing Plants▿ †

    Science.gov (United States)

    Mullapudi, S.; Siletzky, R. M.; Kathariou, S.

    2008-01-01

    The resistance of Listeria monocytogenes to cadmium and arsenic has been used extensively for strain subtyping. However, limited information is available on the prevalence of such resistance among isolates from the environment of food-processing plants. In addition, it is not known whether the resistance of such isolates to heavy metals may correlate with resistance to quaternary ammonium compounds extensively used as disinfectants in the food-processing industry. In this study, we characterized 192 L. monocytogenes isolates (123 putative strains) from the environment of turkey-processing plants in the United States for resistance to cadmium and arsenic and to the quaternary ammonium disinfectant benzalkonium chloride (BC). Resistance to cadmium was significantly more prevalent among strains of serotypes 1/2a (or 3a) and 1/2b (or 3b) (83% and 74%, respectively) than among strains of the serotype 4b complex (19%). Resistance to BC was encountered among 60% and 51% of the serotype 1/2a (or 3a) and 1/2b (or 3b) strains, respectively, and among 7% of the strains of the serotype 4b complex. All BC-resistant strains were also resistant to cadmium, although the reverse was not always the case. In contrast, no correlation was found between BC resistance and resistance to arsenic, which overall was low (6%). Our findings suggest that the processing environment of turkey-processing plants may constitute a reservoir for L. monocytogenes harboring resistance to cadmium and to BC and raise the possibility of common genetic elements or mechanisms mediating resistance to quaternary ammonium disinfectants and to cadmium in L. monocytogenes. PMID:18192428

  13. Coselection of Cadmium and Benzalkonium Chloride Resistance in Conjugative Transfers from Nonpathogenic Listeria spp. to Other Listeriae

    Science.gov (United States)

    Katharios-Lanwermeyer, S.; Rakic-Martinez, M.; Elhanafi, D.; Ratani, S.; Tiedje, J. M.

    2012-01-01

    Resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) may be an important contributor to the ability of Listeria spp. to persist in the processing plant environment. Although a plasmid-borne disinfectant resistance cassette (bcrABC) has been identified in Listeria monocytogenes, horizontal transfer of these genes has not been characterized. Nonpathogenic Listeria spp. such as L. innocua and L. welshimeri are more common than L. monocytogenes in food processing environments and may contribute to the dissemination of disinfectant resistance genes in listeriae, including L. monocytogenes. In this study, we investigated conjugative transfer of resistance to BC and to cadmium from nonpathogenic Listeria spp. to other nonpathogenic listeriae, as well as to L. monocytogenes. BC-resistant L. welshimeri and L. innocua harboring bcrABC, along with the cadmium resistance determinant cadA2, were able to transfer resistance to other nonpathogenic listeriae as well as to L. monocytogenes of diverse serotypes, including strains from the 2011 cantaloupe outbreak. Transfer among nonpathogenic Listeria spp. was noticeably higher at 25°C than at 37°C, whereas acquisition of resistance by L. monocytogenes was equally efficient at 25 and 37°C. When the nonpathogenic donors were resistant to both BC and cadmium, acquisition of cadmium resistance was an effective surrogate for transfer of resistance to BC, suggesting coselection between these resistance attributes. The results suggest that nonpathogenic Listeria spp. may behave as reservoirs for disinfectant and heavy metal resistance genes for other listeriae, including the pathogenic species L. monocytogenes. PMID:22904051

  14. Localization and Expression of Zonula Occludins-1 in the Rabbit Corneal Epithelium following Exposure to Benzalkonium Chloride

    Science.gov (United States)

    Zhang, Zhenhao; Chen, Lelei; Xie, Hui; Dong, Nuo; Chen, Yongxiong; Liu, Zuguo

    2012-01-01

    Preservatives are a major component of the ophthalmic preparations in multi-dose bottles. The purpose of this study was to investigate the acute effect of benzalkonium chloride (BAC), a common preservative used in ophthalmic preparations, on the localization and expression of zonula occludens (ZO)-1 in the rabbit corneal epithelium in vivo. BAC at 0.005%, 0.01%, or 0.02% was topically applied to one eye each of albino rabbits at 5 min intervals for a total of 3 times. The contralateral untreated eyes served as controls. The following clinical indications were evaluated: Schirmer test, tear break-up time (BUT), fluorescein and rose Bengal staining. The structure of central cornea was examined by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance and permeability to carboxy fluorescein. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of ZO-1, 2, occludin, claudin-1, Ki67 and cell apoptosis in the epithelium. The expression of ZO-1 in the corneal epithelium was also examined by western blot and reverse transcription-polymerase chain reaction analyses. Exposure to BAC resulted in higher rose Bengal staining scores while no significant changes in BUT, Schirmer and corneal florescein scores. It also induced corneal epithelial cell damage, dispersion of ZO-1 and ZO-2 from their normal locus at the superficial layer and disruption of epithelial barrier function. However, the amounts of ZO-1 mRNA and protein in the corneal epithelium were not affected by BAC treatment. Exposure to BAC can quickly impair the corneal epithelium without tear deficiency. BAC disrupts the tight junctions of corneal epithelium between superficial cells in the rabbit corneal epithelium in vivo. PMID:22815857

  15. Localization and expression of zonula occludins-1 in the rabbit corneal epithelium following exposure to benzalkonium chloride.

    Directory of Open Access Journals (Sweden)

    Wensheng Chen

    Full Text Available Preservatives are a major component of the ophthalmic preparations in multi-dose bottles. The purpose of this study was to investigate the acute effect of benzalkonium chloride (BAC, a common preservative used in ophthalmic preparations, on the localization and expression of zonula occludens (ZO-1 in the rabbit corneal epithelium in vivo. BAC at 0.005%, 0.01%, or 0.02% was topically applied to one eye each of albino rabbits at 5 min intervals for a total of 3 times. The contralateral untreated eyes served as controls. The following clinical indications were evaluated: Schirmer test, tear break-up time (BUT, fluorescein and rose Bengal staining. The structure of central cornea was examined by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance and permeability to carboxy fluorescein. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of ZO-1, 2, occludin, claudin-1, Ki67 and cell apoptosis in the epithelium. The expression of ZO-1 in the corneal epithelium was also examined by western blot and reverse transcription-polymerase chain reaction analyses. Exposure to BAC resulted in higher rose Bengal staining scores while no significant changes in BUT, Schirmer and corneal florescein scores. It also induced corneal epithelial cell damage, dispersion of ZO-1 and ZO-2 from their normal locus at the superficial layer and disruption of epithelial barrier function. However, the amounts of ZO-1 mRNA and protein in the corneal epithelium were not affected by BAC treatment. Exposure to BAC can quickly impair the corneal epithelium without tear deficiency. BAC disrupts the tight junctions of corneal epithelium between superficial cells in the rabbit corneal epithelium in vivo.

  16. Benzalkonium chloride (BAC) and dimethyldioctadecyl-ammonium bromide (DDAB), two common quaternary ammonium compounds, cause genotoxic effects in mammalian and plant cells at environmentally relevant concentrations.

    Science.gov (United States)

    Ferk, F; Misík, M; Hoelzl, C; Uhl, M; Fuerhacker, M; Grillitsch, B; Parzefall, W; Nersesyan, A; Micieta, K; Grummt, T; Ehrlich, V; Knasmüller, S

    2007-11-01

    Quaternary ammonium compounds (QACs) are cationic surfactants that are widely used as disinfectants. In the present study, we tested two important representatives, namely, benzalkonium chloride (BAC) and dimethyldioctadecyl-ammonium bromide (DDAB) in four genotoxicity tests, namely, in the Salmonella/microsome assay with strains TA 98, TA 100 and TA 102, in the single-cell gel electrophoresis (SCGE) assay with primary rat hepatocytes and in micronucleus (MN) assays with peripheral human lymphocytes and with root tip cells of Vicia faba. In the bacterial experiments, consistently negative results were obtained in the dose range between 0.001 and 110 microg per plate in the presence and absence of metabolic activation while significant induction of DNA migration was detected in the liver cells. With BAC, a moderate but significant effect was found with an exposure concentration of 1.0 mg/l while DDAB caused damage at lower doses (0.3 mg/l). The effects were not altered when the nuclei were treated with formamidopyridine glycosylase, indicating that they are not due to formation of oxidized purines. The MN assays with blood cells were carried out under identical conditions to the SCGE experiments and a significant increase was seen at the highest dose levels (BAC: 1.0 and 3.0 mg/l; DDAB: 1 mg/l). Both compounds also caused significant induction of MN as well as inhibition of cell division in plant cells, the lowest effective levels were 1.0 and 10 mg/l for DDAB and BAC, respectively. Our findings show that both chemicals induce moderate but significant genotoxic effects in eukaryotic cells at concentrations which are found in wastewaters and indicate that their release into the environment may cause genetic damage in exposed organisms. Furthermore, the direct contact of humans to QAC-containing detergents and pharmaceuticals that contain substantially higher concentrations than those which were required to cause effects in eukaryotic cells in the present study should

  17. Development and Validation of a Precise and Stability Indicating LC Method for the Determination of Benzalkonium Chloride in Pharmaceutical Formulation Using an Experimental Design

    Directory of Open Access Journals (Sweden)

    Harshal K. Trivedi

    2010-01-01

    Full Text Available A simple, precise, shorter runtime and stability indicating reverse-phase high performance liquid chromatographic method has been developed and validated for the quantification of benzalkonium chloride (BKC preservative in pharmaceutical formulation of sparfloxacin eye drop. The method was successfully applied for determination of benzalkonium chloride in various ophthalmic formulations like latanoprost, timolol, dexametasone, gatifloxacin, norfloxacin, combination of moxifloxacin and dexamethasone, combination of nepthazoline HCl, zinc sulphate and chlorpheniramine maleate, combination of tobaramycin and dexamethasone, combination of phenylephrine HCl, naphazoline HCl, menthol and camphor. The RP-LC separation was achieved on an Purospher Star RP-18e 75 mm × 4.0 mm, 3.0 μ in the isocratic mode using buffer: acetonitrile (35: 65, v/v, as the mobile phase at a flow rate of 1.8 mL/min. The methods were performed at 215 nm; in LC method, quantification was achieved with PDA detection over the concentration range of 50 to 150 μg/mL. The method is effective to separate four homologs with good resolution in presence of excipients, sparfloxacin and degradable compound due to sparfloxacin and BKC within five minutes. The method was validated and the results were compared statistically. They were found to be simple, accurate, precise and specific. The proposed method was validated in terms of specificity, precision, recovery, solution stability, linearity and range. All the validation parameters were within the acceptance range and concordant to ICH guidelines.

  18. Antimicrobial properties of titanium soaked with benzalkonium chloride solution%纯钛经苯扎氯铵浸泡后的抗菌性能的研究

    Institute of Scientific and Technical Information of China (English)

    李佳; 廉云敏; 高岚

    2015-01-01

    Objective:To study the antibacterial properties of pure titanium treated with benzalkonium chloride solution.Meth-ods:10 mm ×10 mm ×1 mm titanium specimens were processed by the benzalkonium chloride solution at 1%,0.5% and 0.1%respectively followed by treatment in the cultured bacterial suspension,and then the antibacterial properties of the titanium plates were examined.Additionally,the thermal cycling test was carried out for the 1% benzalkonium chloride-treated titanium plates, and subsequently put the plates into cultured bacterial suspension,the duration of antibacterial properties was observed.Results:0.5% and 1% benzalkonium chloride solution-treated titanium plates significantly inhibited the growth of candida albicans(P <0. 05),1% solution was more effective than 0.5% solution.After 1 000 and 2 500 thermal cycling,the pure titanium still retained the antibacterial ability,but the plates treated by 5 000 cycling showed no antibacterial effect.Conclusion:A certain concentration of benzalkonium chloride can make the pure titanium obtain antibacterial properties.The treated plates may maintain the antibacte-rial properties for a minimum of 3 months.%目的:通过用苯扎氯铵溶液浸泡处理钛片,了解该方法能否使纯钛具有抗菌性及抗菌性持续的时间。方法:制作10 mm ×10 mm ×1 mm 的钛片试件,用不同浓度的苯扎氯铵溶液浸泡处理,菌悬液浸泡培养,检测有无抗菌性。用1%的苯扎氯铵溶液浸泡处理试件,进行冷热循环实验后再进行细菌培养,检测抗菌性的持续时间。结果:不同浓度的苯扎氯铵溶液处理纯钛后对白色念珠菌生长的抑制效果不同,0.5%和1%的苯扎氯铵溶液浸泡纯钛可使其产生抗菌性(均有显著差异,P <0.05),1%的苯扎氯铵溶液效果更佳。冷热循环1000次和2500次后纯钛仍具有抗菌性,5000次时与未进行抗菌处理效果相同。结论:一定浓度的苯扎氯铵

  19. Research on the Stability of a Rabbit Dry Eye Model Induced by Topical Application of the Preservative Benzalkonium Chloride

    Science.gov (United States)

    Luan, Shaohong; Wan, Pengxia; Li, Naiyang; Tang, Jing; Han, Yu; Xiong, Cuiju; Wang, Zhichong

    2012-01-01

    Background Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC) and determined the valid time of this model. Methods and Findings Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2), 3 weeks (Group BAC-W3), 4 weeks (Group BAC-W4), or 5 weeks (Group BAC-W5). Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal) and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE) staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05). Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001). Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21. Conclusions A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye) or for at least 3 weeks (for mucin-deficient dry eye). PMID:22438984

  20. Therapeutic Effects of Sodium Hyaluronate on Ocular Surface Damage Induced by Benzalkonium Chloride Preserved Anti-glaucoma Medications

    Institute of Scientific and Technical Information of China (English)

    Xing Liu; Fen-Fen Yu; Yi-Min Zhong; Xin-Xing Guo; Zhen Mao

    2015-01-01

    Background:Long-term use of benzalkonium chloride (BAC)-preserved drugs is often associated with ocular surface toxicity.Ocular surface symptoms had a substantial impact on the glaucoma patients' quality of life and compliance.This study aimed to investigate the effects of sodium hyaluronate (SH) on ocular surface toxicity induced by BAC-preserved anti-glaucoma medications treatment.Methods:Fifty-eight patients (101 eyes),who received topical BAC-preserved anti-glaucoma medications treatment and met the severe dry eye criteria,were included in the analysis.All patients were maintained the original topical anti-glaucoma treatment.In the SH-treated group (56 eyes),unpreserved 0.3% SH eye drops were administered with 3 times daily for 90 days.In the control group (55 eyes),phosphate-buffered saline were administered with 3 times daily for 90 days.Ocular Surface Disease Index (OSDI) questionnaire,break-up time (BUT) test,corneal fluorescein staining,corneal and conjunctival rose Bengal staining,Schirmer test,and conjunctiva impression cytology were performed sequentially on days 0 and 91.Results:Compared with the control group,SH-treated group showed decrease in OSDI scores (Kruskal-Wallis test:H =38.668,P < 0.001),fluorescein and rose Bengal scores (Wilcoxon signed-ranks test:z =-3.843,P< 0.001,and z =-3.508,P < 0.001,respectively),increase in tear film BUT (t-test:t =-10.994,P < 0.001) and aqueous tear production (t-test:t =-10.328,P < 0.001) on day 91.The goblet cell density was increased (t-test:t =-9.981,P < 0.001),and the morphology of the conjunctival epithelium were also improved after SH treatment.Conclusions:SH significantly improved both symptoms and signs of ocular surface damage in patients with BAC-preserved anti-glaucoma medications treatment.SH could be proposed as a new attempt to reduce ocular surface toxicity,and alleviate symptoms of ocular surface damage in BAC-preserved anti-glaucoma medications treatment.

  1. Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

    Science.gov (United States)

    Khoh-Reiter, Su; Jessen, Bart A

    2009-01-01

    Background Benzalkonium chloride (BAC) is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D) corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC) and olopatadine (0.01% BAC) was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T) cell cultures, expression levels (mRNA and protein) of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year) in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC) and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC contained in ophthalmic

  2. Effects of benzalkonium chloride- or polyquad-preserved fixed combination glaucoma medications on human trabecular meshwork cells

    Science.gov (United States)

    Ammar, David A.

    2011-01-01

    Purpose We investigated the potential short and long-term effects in cultured human trabecular meshwork (TM) cells of various topical glaucoma formulations containing different preservatives. Methods We tested the fixed combination medications 0.004% travoprost plus 0.5% timolol preserved with either 0.015% benzalkonium chloride (BAK; DuoTrav®), or with 0.001% polyquad (PQ; DuoTrav® BAK-free); and 0.005% latanoprost plus 0.5% timolol preserved with 0.020% BAK (Xalacom®). Also tested was a range of BAK concentrations (0.001%–0.020%) in balanced salt solution (BSS). Cells were treated for 25 min at 37 °C with solutions diluted 1:10 and 1:100 to mimic the reduced penetration of topical preparations to the anterior chamber. The percentage of live cells was determined immediately after treatment through the uptake of the fluorescent vital dye calcein-AM. To determine any long-term effects, we assayed release of matrix metalloproteinase 9 (MMP-9) and apoptosis 24 h after treatments. Results BAK demonstrated a dose-dependent reduction in TM cell viability, ranging from 71±5% live cells at 0.001% BAK (diluted 1:10) to 33±3% live cells at 0.020% BAK (diluted 1:10). Travoprost (0.004%) plus 0.5% timolol preserved with 0.015% BAK had statistically fewer live TM cells (79±7%) than the same preparation preserved with 0.001% polyquad® (PQ; 93±1%; p<0.001). Latanoprost plus timolol preserved with 0.020% BAK (29±9% live cells) was similar to the 0.020% BAK (33±3%) treatment. However, travoprost plus timolol preserved in 0.015% BAK had significantly more live cells (83±12%) than the 1:10 dilution of 0.015% BAK (49±10%). We also found 0.020% BAK (diluted 1:100) resulted in elevated levels of extracellular MMP-9 at 24 h. Conclusions These results demonstrate that the substitution of the preservative BAK from topical ophthalmic drugs results in greater in vitro viability of TM cells. Travoprost with timolol, but not latanoprost with timolol, countered some of the toxic

  3. Research on the stability of a rabbit dry eye model induced by topical application of the preservative benzalkonium chloride.

    Directory of Open Access Journals (Sweden)

    Chaoyang Li

    Full Text Available BACKGROUND: Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC and determined the valid time of this model. METHODS AND FINDINGS: Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2, 3 weeks (Group BAC-W3, 4 weeks (Group BAC-W4, or 5 weeks (Group BAC-W5. Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05 and in Group BAC-W5 on day 14 (P<0.05. Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001. Decreased levels of mucin-5 subtype AC (MUC5AC, along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21. CONCLUSIONS: A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye or for at least 3 weeks (for mucin-deficient dry eye.

  4. Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

    Directory of Open Access Journals (Sweden)

    Jessen Bart A

    2009-07-01

    Full Text Available Abstract Background Benzalkonium chloride (BAC is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC and olopatadine (0.01% BAC was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T cell cultures, expression levels (mRNA and protein of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC

  5. SANS study of surfactant ordering in kappa-carrageenan/cetylpyridinium chloride complexes

    DEFF Research Database (Denmark)

    Evmenenko, G.; Theunissen, E.; Mortensen, K.

    2001-01-01

    Small-angle neutron scattering using contrast variation by H2O/D2O has been applied for the structural investigation of kappa -carrageenan/cetylpyridinium chloride (CPC) complexes. interaction of kappa -carrageenan with an ionic surfactant involves self-assembly of the surfactant molecules...

  6. Safety and acceptability of vaginal disinfection with benzalkonium chloride in HIV infected pregnant women in west Africa: ANRS 049b phase II randomized, double blinded placebo controlled trial. DITRAME Study Group

    Science.gov (United States)

    Msellati, P.; Meda, N.; Leroy, V.; Likikouet, R.; Van de Perre, P.; Cartoux, M.; Bonard, D.; Ouangre, A.; Combe, P.; Gautier-Charpenti..., L.; Sylla-Koko, F.; Lassalle, R.; Dosso, M.; Welffens-Ekra, C.; Dabis, F.; Mandelbrot, L.

    1999-01-01

    OBJECTIVES: To study the tolerance and acceptability in Africa of a perinatal intervention to prevent vertical HIV transmission using benzalkonium chloride disinfection. DESIGN: A randomized, double blinded phase II trial. SETTING: Prenatal care units in Abidjan (Cote d'Ivoire) and Bobo-Dioulasso (Burkina Faso). PATIENTS: Women accepting testing and counselling who were seropositive for HIV-1 and under 37 weeks of pregnancy were eligible. A total of 108 women (54 in each group) enrolled from November 1996 to April 1997, with their informed consent. INTERVENTION: Women self administered daily a vaginal suppository of 1% benzalkonium chloride or matched placebo from 36 weeks of pregnancy, and a single intrapartum dose. The neonate was bathed with 1% benzalkonium chloride solution or placebo within 30 minutes after birth. MAIN OUTCOME MEASURES: Adverse events were recorded weekly, with a questionnaire and speculum examination in women through delivery, and examination of the neonate through day 30. The incidence of genital signs and symptoms in the women and cutaneous or ophthalmological events in newborns were compared between groups on an intent to treat basis. RESULTS: The median duration of prepartum treatment was 21 days (range 0-87 days). Compliance was 87% for prepartum and 69% for intrapartum treatment, and 88% for the neonatal bath, without differences between the two groups. In women, the most frequent event was leucorrhoea; the incidence of adverse events did not differ between treatment groups. In children, the incidence of dermatitis and conjunctivitis did not differ between the benzalkonium chloride and placebo groups (p = 0.16 and p = 0.29, respectively). CONCLUSION: Vaginal disinfection with benzalkonium chloride is a feasible and well tolerated intervention in west Africa. Its efficacy in preventing vertical HIV transmission remains to be demonstrated. 


 PMID:10754950

  7. Binding of alkylpyridinium chloride surfactants to sodium polystyrene sulfonate

    NARCIS (Netherlands)

    Ishiguro, M.; Koopal, L.K.

    2009-01-01

    Binding of cationic surfactants to anionic polymers is well studied. However, the surfactant binding characteristics at very low concentration near the start of binding and at high concentration, where charge compensation may Occur. are less well known. Therefore, the binding characteristics of

  8. Microwave corneosurfametry and the short-duration dansyl chloride extraction test for rating concentrated irritant surfactants.

    Science.gov (United States)

    Goffin, V; Piérard, G E

    2001-01-01

    There are ethical concerns to conduct in vivo tests in the animal and human to provide evidence that cosmetics and other topical products are safe. To compare two methods, namely the short-duration dansyl chloride extraction test and the microwave corneosurfametry bioassay, to test the irritation potential of concentrated surfactant systems. Five surfactants and water were tested using the in vivo test and the bioassay. A significant linear correlation was found between data yielded by the two procedures. The short-duration dansyl chloride extraction test and the microwave corneosurfametry bioassay provide similar information. The latter has the advantage of being safe.

  9. Effect of the hand antiseptic agents benzalkonium chloride, povidone-iodine, ethanol, and chlorhexidine gluconate on atopic dermatitis in NC/Nga mice.

    Science.gov (United States)

    Sadakane, Kaori; Ichinose, Takamichi

    2015-01-01

    Antiseptic agents can cause skin irritation and lead to severe problems, especially for individuals with atopic diatheses. We investigated the effect of 4 different antiseptic agents using an atopic dermatitis (AD) model mouse. NC/Nga mice were subcutaneously injected with mite allergen (Dp) to induce AD-like skin lesions (ADSLs), and an application of 0.2% (w/v) benzalkonium chloride (BZK), 10% (w/v) povidone-iodine (PVP-I), 80% (v/v) ethanol (Et-OH), or 0.5% (v/v) chlorhexidine gluconate (CHG) was applied to the ear envelope. BZK induced a significant increase in the severity of the clinical score, infiltration of inflammatory cells, local expression of inflammatory cytokines in subcutaneous tissue, and total serum immunoglobulin (Ig) E. PVP-I increased the clinical score, number of mast cells, and production of inflammatory cytokines, and total serum IgE. Et-OH increased the clinical score and number of inflammatory cells, but showed no effect on serum IgE levels. No differences in any parameters were observed between CHG and the vehicle. Collectively, the results suggest the severity of the ADSL was related in part to the strength of the immunoreaction. These findings suggest that CHG could offer the lowest risk of inducing ADSL in individuals with atopic dermatitis and that medical staff and food handlers with AD could benefit from its use.

  10. Development and Validation of a Precise Method for Determination of Benzalkonium Chloride (BKC Preservative, in Pharmaceutical Formulation of Latanoprost Eye Drops

    Directory of Open Access Journals (Sweden)

    J. Mehta

    2010-01-01

    Full Text Available A simple and precise reversed phase high performance liquid chromatographic method has been developed and validated for the quantification of benzalkonium chloride (BKC preservative in pharmaceutical formulation of latanoprost eye drops. The analyte was chromatographed on a Waters Spherisorb CN, (4.6×250 mm column packed with particles of 5 μm. The mobile phase, optimized through an experimental design, was a 40:60 (v/v mixture of potassium dihydrogen orthophosphate buffer (pH 5.5 and acetonitrile, pumped at a flow rate of 1.0 mL/min at maintaining column temperature at 30 °C. Maximum UV detection was achieved at 210 nm. The method was validated in terms of linearity, repeatability, intermediate precision and method accuracy. The method was shown to be robust, resisting to small deliberate changes in pH, flow rate and composition (organic ratio of the mobile phase. The method was successfully applied for the determination of BKC in a pharmaceutical formulation of latanoprost ophthalmic solution without any interference from common excipients and drug substance. All the validation parameters were within the acceptance range, concordant to ICH guidelines.

  11. Effects of Benzalkonium Chloride, Proxel LV, P3 Hypochloran, Triton X-100 and DOWFAX 63N10 on anaerobic digestion processes.

    Science.gov (United States)

    Flores, German Antonio Enriquez; Fotidis, Ioannis A; Karakashev, Dimitar Borisov; Kjellberg, Kasper; Angelidaki, Irini

    2015-10-01

    In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch and continuous (up-flow anaerobic sludge blanket, UASB) reactors with biochemical-industrial wastewater, as substrate. In batch experiments, half-maximal inhibitory concentrations (IC50) for the tested xenobiotics were found to be 13.1, 1003, 311.5 and 24.3 mg L(-1) for BKC, PRX, DWF and TRX, respectively while HPC did not affect the AD process. Furthermore, the xenobiotics mixture tested did not present any synergistic inhibitory effect on the AD process. In continuous experiments, BKC and xenobiotics' mixture induced even stronger (more than 85%) of inhibition, expressed as IC50, compared to the levels observed from the batch reactors. Oppositely, TRX showed no inhibition in continuous mode, while inhibition was detected at batch mode.

  12. Genetic Characterization of Plasmid-Associated Benzalkonium Chloride Resistance Determinants in a Listeria monocytogenes Strain from the 1998-1999 Outbreak ▿

    Science.gov (United States)

    Elhanafi, Driss; Dutta, Vikrant; Kathariou, Sophia

    2010-01-01

    Quaternary ammonium compounds such as benzalkonium chloride (BC) are widely used as disinfectants in both food processing and medical environments. BC-resistant strains of Listeria monocytogenes have been implicated in multistate outbreaks of listeriosis and have been frequently isolated from food processing plants. However, the genetic basis for BC resistance in L. monocytogenes remains poorly understood. In this study, we have characterized a plasmid (pLM80)-associated BC resistance cassette in L. monocytogenes H7550, a strain implicated in the 1998-1999 multistate outbreak involving contaminated hot dogs. The BC resistance cassette (bcrABC) restored resistance to BC (MIC, 40 μg/ml) in a plasmid-cured derivative of H7550. All three genes of the cassette were essential for imparting BC resistance. The transcription of H7550 BC resistance genes was increased under sublethal (10 μg/ml) BC exposure and was higher at reduced temperatures (4, 8, or 25°C) than at 37°C. The level of transcription was higher at 10 μg/ml than at 20 or 40 μg/ml. In silico analysis suggested that the BC resistance cassette was harbored by an IS1216 composite transposon along with other genes whose functions are yet to be determined. The findings from this study will further our understanding of the adaptations of this organism to disinfectants such as BC and may contribute to the elucidation of possible BC resistance dissemination in L. monocytogenes. PMID:20971860

  13. Conjunctival and corneal reactions in rabbits following short- and repeated exposure to preservative-free tafluprost, commercially available latanoprost and 0.02% benzalkonium chloride

    Science.gov (United States)

    Liang, H; Baudouin, C; Pauly, A; Brignole-Baudouin, F

    2008-01-01

    Aim: To compare the conjunctival and corneal reactions of commercially available solution of latanoprost (Xalatan) and preservative-free (PF) tafluprost in rabbits. Methods: The rabbits received 50 μl of phosphate-buffered saline (PBS), PF-tafluprost 0.0015%, latanoprost 0.005% or benzalkonium chloride (BAK) 0.02%; all solutions were applied at 5 min intervals for a total of 15 times. The ocular surface toxicity was investigated using slit-lamp biomicroscopy examination, flow cytometry (FCM) and on imprints for CD45 and tumour necrosis factor-receptor 1 (TNFR1) conjunctival impression cytology (CIC) and corneal in vivo confocal microscopy (IVCM). Standard immunohistology also assessed inflammatory/apoptotic cells. Results: Clinical observation and IVCM images showed the highest ocular surface toxicity with latanoprost and BAK, while PF-tafluprost and PBS eyes presented almost normal corneoconjunctival aspects. FCM showed a higher expression of CD45+ and TNFR1+ in latanoprost- or BAK-instilled groups, compared with PF-tafluprost and PBS groups. Latanoprost induced fewer positive cells for inflammatory marker expressions in CIC specimens compared with BAK-alone, both of which were higher than with PF-tafluprost or PBS. Immunohistology showed the same tendency of toxic ranking. Conclusion: The authors confirm that rabbit corneoconjunctival surfaces presented a better tolerance when treated with PF-tafluprost compared with commercially available latanoprost or BAK solution. PMID:18723745

  14. Accelerated solvent extraction followed by on-line solid-phase extraction coupled to ion trap LC/MS/MS for analysis of benzalkonium chlorides in sediment samples

    Science.gov (United States)

    Ferrer, I.; Furlong, E.T.

    2002-01-01

    Benzalkonium chlorides (BACs) were successfully extracted from sediment samples using a new methodology based on accelerated solvent extraction (ASE) followed by an on-line cleanup step. The BACs were detected by liquid chromatography/ion trap mass spectrometry (LC/MS) or tandem mass spectrometry (MS/MS) using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the high sensitivity offered by the ion trap MS/MS. The effects of solvent type and ASE operational variables, such as temperature and pressure, were evaluated. After optimization, a mixture of acetonitrile/water (6:4 or 7:3) was found to be most efficient for extracting BACs from the sediment samples. Extraction recoveries ranged from 95 to 105% for C12 and C14 homologues, respectively. Total method recoveries from fortified sediment samples, using a cleanup step followed by ASE, were 85% for C12BAC and 79% for C14-BAC. The methodology developed in this work provides detection limits in the subnanogram per gram range. Concentrations of BAC homologues ranged from 22 to 206 ??g/kg in sediment samples from different river sites downstream from wastewater treatment plants. The high affinity of BACs for soil suggests that BACs preferentially concentrate in sediment rather than in water.

  15. Epidermal Hyperplasia and Elevated HB-EGF are More Prominent in Retinoid Dermatitis Compared with Irritant Contact Dermatitis Induced by Benzalkonium Chloride

    Science.gov (United States)

    Lee, Jung Eun; Chang, Jae Yong; Lee, Sang Eun; Kim, Moon Young; Lee, Jeong Seon; Lee, Min Geol

    2010-01-01

    Background 'Retinoid dermatitis' is a retinoid-induced irritant contact dermatitis (ICD). The mechanism of retinoid dermatitis may be different from that of other ICDs. However, it remains uncertain how topical retinoid induce ICD. Objective We compared several aspects of contact dermatitis induced by topical retinol and benzalkonium chloride (BKC) on hairless mice skin. Methods 2% retinol or 2.5% BKC was applied to hairless mice and transepidermal water loss (TEWL), ear thickness, histologic and immunohistochemical findings were compared. We also compared mRNA expression of inflammatory cytokines, epidermal differential markers, cyclooxygenases (COXs) and heparin binding epidermal growth factor like growth factor (HB-EGF). Results Topical application of 2% retinol and 2.5% BKC increased TEWL and ear thickness in similar intensity. Epidermal hyperplasia was more prominent in retinol treated skin. Proliferating cell nuclear antigen, involucrin and loricrin expression were higher in retinol-treated skin than in BKC-treated skin. Filaggrin, however, was more expressed in BKC-treated skin. The mRNA expression of IL-8, TNF-α, COX-2, involucrin, loricrin and filaggrin were increased in both retinol- and BKC-treated skin in similar intensity. HB-EGF was more significantly increased in retinol-treated skin. Conclusion Elevated HB-EGF and epidermal hyperplasia are more prominent features of retinoid dermatitis than in BKC-induced ICD. PMID:20711265

  16. Tolerance development in Listeria monocytogenes-Escherichia coli dual-species biofilms after sublethal exposures to pronase-benzalkonium chloride combined treatments.

    Science.gov (United States)

    Rodríguez-López, Pedro; Cabo, Marta López

    2017-10-01

    This study was designed to assess the effects that sublethal exposures to pronase (PRN) and benzalkonium chloride (BAC) combined treatments have on Listeria monocytogenes-Escherichia coli dual-species biofilms grown on stainless steel in terms of tolerance development (TD) to these compounds. Additionally, fluorescence microscopy was used to observe the changes of the biofilm structure. PRN-BAC exposure was carried out using three different approaches and TD was evaluated treating biofilms with a final 100 μg/ml PRN followed by 50 μg/ml BAC combined treatment. Results showed that exposure to PRN-BAC significantly decreased the number of adhered L. monocytogenes (P monocytogenes compared to E. coli. Additionally, microscopy images showed an altered morphology produced by sublethal PRN-BAC in exposed L. monocytogenes-E. coli dual-species biofilms compared to control samples. Results also demonstrated that L. monocytogenes-E. coli dual-species biofilms are able to develop tolerance to PRN-BAC combined treatments depending on way they have been previously exposed. Moreover, they suggest that the generation of bacterial tolerance should be included as a parameter for sanitation procedures design. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Comparison of the Related Substances in Benzalkonium Chloride at Home and Abroad%国内外苯扎氯铵的有关物质比较

    Institute of Scientific and Technical Information of China (English)

    彭琳; 刘雁鸣; 龙海燕; 熊亚群

    2016-01-01

    目的::对药用辅料苯扎氯铵中的有关物质进行测定并比较国内外样品的内在质量。方法:采用高效液相色谱梯度洗脱法,色谱柱:ODS-HYPERSIL C18柱(250 mm ×4.6 mm,5μm);检测波长:210 nm和257 nm(采用PDA检测器);流速:1.0 ml· min-1;柱温:30℃;进样体积:20μl;流动相:A(取己烷磺酸钠1.09 g及磷酸二氢钠6.9 g加水稀释至1000 ml,摇匀,用磷酸调节pH至3.5)-B(甲醇)。结果:国内外样品的苯甲醛残留均较低;国外样品中苯甲醇残留合格,但明显高于国内样品;国内样品中氯化苄含量较高。结论:该方法快速、简便,可用于比较国内外样品中的有关物质,同时为企业合理选择苯扎氯铵提供依据。%Objective:To determine the related substances in benzalkonium chloride used as a pharmaceutical adjuvant, and com-pare the quality at home and abroad. Methods:An HPLC method was used with an ODS-HYPERSIL C18 column(250 mm × 4. 6 mm, 5 μm). The detection wavelength was 210 nm and 257 nm. The flow rate was 1. 0 ml· min-1 and the column temperature was 30℃. The injection volume was 20 ml. The mobile phase was A ( dissolving 1. 09 g sodium1-hexanesulfonate and 6. 9 g sodium dihydrogen phosphate in water, adjusting pH to 3. 5 with phosphoric acid and diluting to 1 000. 0 ml) and B ( methanol) with gradient elution. Results:The content of benzaldehyde in the samples at home and abroad was low. The content of benzyl alcohol in the samples from a-broad was qualified, which was significantly higher than that in the domestic samples. The content of benzyl chloride in the domestic samples was higher than that in the samples from abroad. Conclusion:The method is simple and fast, which is suitable for comparing the related substances of domastic and imported samples. At the same time, the study provides basis for enterprises to choose benzalko-nium chloride rationally.

  18. Efficacy and safety of benzalkonium chloride-free fixed-dose combination of latanoprost and timolol in patients with open-angle glaucoma or ocular hypertension

    Directory of Open Access Journals (Sweden)

    Bhagat P

    2014-06-01

    Full Text Available Purvi Bhagat,1 Kalyani Sodimalla,2 Chandrima Paul,3 Surinder S Pandav,4 Ganesh V Raman,5 Rengappa Ramakrishnan,6 Abhijeet Joshi,7 Atul Raut7 1Glaucoma Clinic, M & J Western Regional Institute of Ophthalmology, Civil Hospital, Ahmedabad, Gujarat, India; 2Glaucoma Department, PBMA’s H.V. Desai Eye Hospital, Maharashtra, India; 3Glaucoma Service, B B Eye Foundation, Kolkata, India; 4Advanced Eye Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 5Glaucoma Clinic, Aravind Eye Hospital, Coimbatore, Tamilnadu, India; 6Glaucoma Clinic, Aravind Eye Hospital, Tirunelveli, Tamilnadu, India; 7Clinical Research Department, Sun Pharma Advanced Research Company Ltd, Mumbai, Maharashtra, India Background: Benzalkonium chloride (BAK is a common preservative in topical ocular preparations; however, prolonged use may lead to deleterious effects on the ocular surface, affecting quality of life and reducing adherence to treatment and overall outcomes. This study compared the intraocular pressure (IOP-lowering efficacy and safety of a novel once-daily, BAK-free, fixed-dose combination of latanoprost plus timolol with latanoprost or timolol administered as monotherapy or concomitantly. Methods: This was a 6-week, randomized, open-label, parallel-group, active-controlled study in patients aged ≥18 years with open-angle glaucoma or ocular hypertension. A total of 227 patients were randomized to either a once-daily, BAK-free, fixed-dose combination of latanoprost 0.005%/timolol 0.5% ophthalmic solution or concomitant administration of once-daily latanoprost 0.005% plus twice-daily timolol 0.5% or once-daily latanoprost 0.005% monotherapy, or twice-daily timolol 0.5% monotherapy. Efficacy end points were assessed at three time points on visits at weeks 1, 2, 4, and 6 versus baseline. Results: The IOP-lowering efficacy of the fixed-dose combination of latanoprost/timolol was similar to that of latanoprost plus timolol administered

  19. A new safety concern for glaucoma treatment demonstrated by mass spectrometry imaging of benzalkonium chloride distribution in the eye, an experimental study in rabbits.

    Directory of Open Access Journals (Sweden)

    Françoise Brignole-Baudouin

    Full Text Available We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety

  20. Comparative study on the cytotoxic effects of benzalkonium chloride on the Wong-Kilbourne derivative of Chang conjunctival and IOBA-NHC cell lines

    Science.gov (United States)

    Brasnu, E.; Brignole-Baudouin, F.; Riancho, L.; Warnet, J.-M.

    2008-01-01

    Purpose The Wong-Kilbourne derivative of Chang conjunctiva-derived cell line has been widely used for toxicological and functional in vitro studies on the ocular surface. The common reserve to this cell line is the reported contamination with HeLa cells. Thus, the IOBA-NHC spontaneously immortalized conjunctival epithelial cell line has been recently developed and did not show other cell type contamination. Our purpose was to determine whether both cell lines would be equally suitable for in vitro toxicological studies. Therefore, we compared in these two cell types the toxic effects of the preservative, benzalkonium chloride (BAC); its toxicity has been often reported on conjunctival in vivo and in vitro models. Methods The necrotic, apoptotic, and oxidative effects of BAC were evaluated on Chang and IOBA-NHC cell lines using microplate cytofluorometry tests (neutral red, 2,7- dichlorofluorescein diacetate dye [H2DCF-DA], hydroethidine, and Yopro-1), flow cytometry (Annexin V/7-AAD and DNA content tests), and standard immunofluorescence stainings. Cells were exposed to five concentrations of BAC (10−2%, 5.10−3%, 10−3%, 10−4%, and 10−5%) for two incubation times: 15 min of treatment and 15 min of treatment followed by 24 h of cell recovery in complete medium. Results All parameters of toxicity increased in a BAC dose-dependent manner on both cell lines. Conclusions The comparison of BAC toxicity on both cell lines supported the use of IOBA-NHC and Chang cells for toxicological in vitro studies. Drawbacks of both cell lines have to be known and considered in studies performed on these cell lines. PMID:18334956

  1. Co-culture with Listeria monocytogenes within a dual-species biofilm community strongly increases resistance of Pseudomonas putida to benzalkonium chloride.

    Directory of Open Access Journals (Sweden)

    Efstathios Giaouris

    Full Text Available Biofilm formation is a phenomenon occurring almost wherever microorganisms and surfaces exist in close proximity. This study aimed to evaluate the possible influence of bacterial interactions on the ability of Listeria monocytogenes and Pseudomonas putida to develop a dual-species biofilm community on stainless steel (SS, as well as on the subsequent resistance of their sessile cells to benzalkonium chloride (BC used in inadequate (sub-lethal concentration (50 ppm. The possible progressive adaptability of mixed-culture biofilms to BC was also investigated. To accomplish these, 3 strains per species were left to develop mixed-culture biofilms on SS coupons, incubated in daily renewable growth medium for a total period of 10 days, under either mono- or dual-species conditions. Each day, biofilm cells were exposed to disinfection treatment. Results revealed that the simultaneous presence of L. monocytogenes strongly increased the resistance of P. putida biofilm cells to BC, while culture conditions (mono-/dual-species did not seem to significantly influence the resistance of L. monocytogenes biofilm cells. BC mainly killed L. monocytogenes cells when this was applied against the dual-species sessile community during the whole incubation period, despite the fact that from the 2nd day this community was mainly composed (>90% of P. putida cells. No obvious adaptation to BC was observed in either L. monocytogenes or P. putida biofilm cells. Pulsed field gel electrophoresis (PFGE analysis showed that the different strains behaved differently with regard to biofilm formation and antimicrobial resistance. Such knowledge on the physiological behavior of mixed-culture biofilms could provide the information necessary to control their formation.

  2. Cytotoxicity of five fluoroquinolone and two nonsteroidal anti-inflammatory benzalkonium chloride-free ophthalmic solutions in four corneoconjunctival cell lines

    Science.gov (United States)

    Ayaki, Masahiko; Iwasawa, Atsuo; Soda, Mitsutaka; Yaguchi, Shigeo; Koide, Ryohei

    2010-01-01

    Purpose: Epithelial disorders after eye surgery can result in visual deterioration and patient discomfort. Such disorders may be caused by drug toxicity. In the present study, we evaluated the toxicity of ophthalmic solutions, with or without benzalkonium chloride (BAK) as the preservative, used for postoperative care. Methods: A range of commercially available antibiotic and anti-inflammatory ophthalmic solutions used postoperatively (ie, levofloxacin, moxifloxacin, gatifloxacin, norfloxacin, tosufloxacin, dibekacin, cefmenoxime, diclofenac, bromfenac, pranoprofen, betamethasone, and fluoromethorone) were assessed in three corneal cell lines and one conjunctival cell line. All antibiotic solutions were BAK free. Cell viability was determined with the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay after cells had been exposed to the drugs for 48 h. The effects of preservatives on cell viability were also determined. Toxicity was compared using the cell viability score (CVS). Results: Based on results of the MTT assay and CVS, the order of cell viability after exposure to the antibiotic solutions was cefmenoxime ≥ tosufloxicin ≥ dibekacin ≥ levofloxacin ≥ norfloxacin = gatifloxacin = moxifloxacin. For the anti-inflammatory solutions, the order of cell viability was betamethasone ≥ betamethasone + fradiomycin > preservative-free diclofenac ≥ preservative-free bromfenac >> 0.02% fluoromethorone ≥ 0.1% fluoromethorone = diclofenac + preservative = bromfenac + preservative = pranoprofen. The anti-inflammatory drugs were more toxic than the antibiotics. The toxicity of antibiotic drugs against ocular surface cells was dependent on the pharmaceutical components of the solution, whereas that of the anti-inflammatory drugs was dependent on both the pharmaceutical components and the preservatives. Conclusion: Postoperative drug-induced epitheliopathy may be caused primarily by anti-inflammatory drugs. CVS is useful in comparing the

  3. A Comparison of the Effects of Benzalkonium Chloride on Ocular Surfaces between C57BL/6 and BALB/c Mice

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    Qian Yang

    2017-02-01

    Full Text Available Models of benzalkonium chloride (BAC-induced ocular disruption have been created and are widely used in various animals. This study aimed to compare the effects of BAC on the ocular surfaces of C57BL/6 and BALB/c mice. C57BL/6 and BALB/c mice were treated separately with BAC eye-drops at different concentrations. Eyes were evaluated by scoring epithelial disruption, corneal opacity and neovascularization in vivo, and by histological assays with hematoxylin/eosin (H/E and periodic acid-Schiff stainings and by determining the expression of inflammatory factors in vitro on Days 7 and 14. The in vivo corneal epithelial disruption, corneal edema/opacity and neovascularization, which were in accordance with the results of the H/E staining and peaked at Day 7, were observed in a dose-dependent manner in the BAC-treated mice, with more severe signs in the C57BL/6 mice than the BALB/c mice. The loss of conjunctival goblet cells in the conjunctivas and the increasing expression of monocyte chemoattractant protein 1 (MCP-1, growth-regulated protein alpha (GROa and macrophage inflammatory protein-1 alpha (MIP-1a in the corneas were found in a dose-dependent manner in both strains of mice. Topical application of BAC can dramatically disrupt the ocular surfaces of C57BL/6 and BALB/c mice, and the disruptions were much more severe in the C57BL/6 mice that received high doses of BAC.

  4. 15 Month follow up of African children following vaginal cleansing with benzalkonium chloride of their HIV infected mothers during late pregnancy and delivery

    Science.gov (United States)

    Mandelbrot, L; Msellati, P; Meda, N; Leroy, V; Likikouet, R; Van de Perre, P; Dequae-Merchadoux, L; Sylla-Koko, F; Ouangre, A; Ouassa, T; Ramon, R; Gautier-Charpenti..., L; Cartoux, M; Dosso, M; Dabis, F; Welffens-Ekra, C

    2002-01-01

    Objectives: To study mother to child HIV-1 transmission (MTCT) and infant mortality following benzalkonium chloride (BC) disinfection. Methods: A randomised, double blind phase II placebo controlled trial. Women testing positive for HIV-1 infection in prenatal care units in Abidjan, Côte d'Ivoire, and Bobo-Dioulasso, Burkina Faso, from November 1996 to April 1997 were eligible, with their informed consent. Women self administered daily a vaginal suppository of 1% BC (53) or matched placebo (54) from 36 weeks of pregnancy, plus a single dose during labour. The neonate was bathed with 1% BC solution or placebo within 30 minutes after birth. MTCT rate was assessed based on repeated polymerase chain reaction (PCR) and serology results. For the present analysis, children were followed up to 15 months. Results: A total of 107 women were enrolled. Of 103 eligible liveborn children, 23 were HIV infected, 75 uninfected, and five of indeterminate status. MTCT transmission rate was 24.2% overall (95% confidence interval (CI): 14.3% to 30.4%). On an intent to treat basis, the transmission rate did not differ between the two groups (23.5%, CI 13.8 to 38.5, in the BC group and 24.8%, CI 15.0 to 39.6, in the placebo group at 15 months). Similarly, there was no difference in mortality at 15 months (22.9%, CI 13.7 to 36.9, in the BC group and 16.5%, CI 9.0 to 29.4, in the placebo group). Conclusion: This analysis failed to suggest any benefit of BC disinfection on mother to child HIV transmission or perinatal and infant mortality. PMID:12181464

  5. Toxicity research status of benzalkonium chloride on ocular surface%苯扎氯铵的眼表毒性研究现状

    Institute of Scientific and Technical Information of China (English)

    黄彩虹; 陈文生; 陈永雄; 刘祖国

    2014-01-01

    苯扎氯铵是滴眼液中最常用的防腐剂.至今有大量临床及实验研究表明,使用含苯扎氯铵的滴眼液会引起包括细胞凋亡在内的一系列眼表损伤.但最近有临床研究表明眼表正常的患者使用含苯扎氯铵的滴眼液后引起的眼表毒性与苯扎氯铵并无明显联系.有学者认为研究本身的局限性导致了人们对苯扎氯铵的毒性认识存在夸大之嫌.在此,我们总结了近年来有关苯扎氯铵临床及实验研究的众多资料,将对苯扎氯铵的眼表毒性研究现状作一综述.%Benzalkonium chloride (BAC) is the most commonly used preservative in ophthalmic preparations.So far large bodies of clinical and experimental studies have shown that use of topical drugs containing BAC can induce a series of ocular surface diseases,such as apoptosis.However,recently,some clinical studies have shown that ocular toxicity in patients treated with eye drops containing BAC has not apparent correlated with BAC.Some scholars consider that the limitations of the research lead people to recognize the BAC toxicity exaggeratedly.Here we summarize numerous clinical and experimental studies of BAC in the past few years,and focus on reviewing recent researches of the toxic effect of BAC on ocular surfface.

  6. Co-culture with Listeria monocytogenes within a dual-species biofilm community strongly increases resistance of Pseudomonas putida to benzalkonium chloride.

    Science.gov (United States)

    Giaouris, Efstathios; Chorianopoulos, Nikos; Doulgeraki, Agapi; Nychas, George-John

    2013-01-01

    Biofilm formation is a phenomenon occurring almost wherever microorganisms and surfaces exist in close proximity. This study aimed to evaluate the possible influence of bacterial interactions on the ability of Listeria monocytogenes and Pseudomonas putida to develop a dual-species biofilm community on stainless steel (SS), as well as on the subsequent resistance of their sessile cells to benzalkonium chloride (BC) used in inadequate (sub-lethal) concentration (50 ppm). The possible progressive adaptability of mixed-culture biofilms to BC was also investigated. To accomplish these, 3 strains per species were left to develop mixed-culture biofilms on SS coupons, incubated in daily renewable growth medium for a total period of 10 days, under either mono- or dual-species conditions. Each day, biofilm cells were exposed to disinfection treatment. Results revealed that the simultaneous presence of L. monocytogenes strongly increased the resistance of P. putida biofilm cells to BC, while culture conditions (mono-/dual-species) did not seem to significantly influence the resistance of L. monocytogenes biofilm cells. BC mainly killed L. monocytogenes cells when this was applied against the dual-species sessile community during the whole incubation period, despite the fact that from the 2nd day this community was mainly composed (>90%) of P. putida cells. No obvious adaptation to BC was observed in either L. monocytogenes or P. putida biofilm cells. Pulsed field gel electrophoresis (PFGE) analysis showed that the different strains behaved differently with regard to biofilm formation and antimicrobial resistance. Such knowledge on the physiological behavior of mixed-culture biofilms could provide the information necessary to control their formation.

  7. A Comparison of the Effects of Benzalkonium Chloride on Ocular Surfaces between C57BL/6 and BALB/c Mice.

    Science.gov (United States)

    Yang, Qian; Zhang, Yafang; Liu, Xiuping; Wang, Nan; Song, Zhenyu; Wu, Kaili

    2017-02-26

    Models of benzalkonium chloride (BAC)-induced ocular disruption have been created and are widely used in various animals. This study aimed to compare the effects of BAC on the ocular surfaces of C57BL/6 and BALB/c mice. C57BL/6 and BALB/c mice were treated separately with BAC eye-drops at different concentrations. Eyes were evaluated by scoring epithelial disruption, corneal opacity and neovascularization in vivo, and by histological assays with hematoxylin/eosin (H/E) and periodic acid-Schiff stainings and by determining the expression of inflammatory factors in vitro on Days 7 and 14. The in vivo corneal epithelial disruption, corneal edema/opacity and neovascularization, which were in accordance with the results of the H/E staining and peaked at Day 7, were observed in a dose-dependent manner in the BAC-treated mice, with more severe signs in the C57BL/6 mice than the BALB/c mice. The loss of conjunctival goblet cells in the conjunctivas and the increasing expression of monocyte chemoattractant protein 1 (MCP-1), growth-regulated protein alpha (GROa) and macrophage inflammatory protein-1 alpha (MIP-1a) in the corneas were found in a dose-dependent manner in both strains of mice. Topical application of BAC can dramatically disrupt the ocular surfaces of C57BL/6 and BALB/c mice, and the disruptions were much more severe in the C57BL/6 mice that received high doses of BAC.

  8. A New Safety Concern for Glaucoma Treatment Demonstrated by Mass Spectrometry Imaging of Benzalkonium Chloride Distribution in the Eye, an Experimental Study in Rabbits

    Science.gov (United States)

    Brignole-Baudouin, Françoise; Desbenoit, Nicolas; Hamm, Gregory; Liang, Hong; Both, Jean-Pierre; Brunelle, Alain; Fournier, Isabelle; Guerineau, Vincent; Legouffe, Raphael; Stauber, Jonathan; Touboul, David; Wisztorski, Maxence; Salzet, Michel; Laprevote, Olivier; Baudouin, Christophe

    2012-01-01

    We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK) chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining) and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation) and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety-first principle for

  9. Determination of benzalkonium chloride in Dextran 70and glycerol eye drops%右旋糖酐70甘油滴眼液中苯扎氯铵含量测定方法研究

    Institute of Scientific and Technical Information of China (English)

    朱样根; 龚楚良

    2012-01-01

    Objective: To determine the content of benzalkonium chloride in Dextran 70 and glycerol eye drops by HPLC. Methods; The chromatographic conditions were as follows; the column was Kromasil C18 (250 mm x 4. 6 mm,5 (um)column;the mobile phase consisted of acetonitrile -0. 03 mol · L-1 sodium dihydrogen phosphate (pH 7. 0 ) ( 43: 57 ) ; the flow rate was 2. 0 mL · min -; the column temperature was 35℃; the detection wavelength was at 214 nm;the injection volume was 20 uX;the separable degree of benzalkonium chloride between C12,C14, C16,should meet rules. Results;The calibration curve of benzalkonium chloride ranged from 1.28-3.00 u,g had good linearity with peak area (r = 0. 9999, n = 7 ) ; The recovery ( n = 6) was 100. 9% ; RSD = 0. 9%. Conclusion: The method is simple, fast, and accurate, with high sensitivity and good repeatability, and can be used for content determination of benzalkonium chloride in Dextran 70 and glycerol eye drops.%目的:建立高效液相色谱法测定右旋糖酐70甘油滴眼液中苯扎氯铵的含量.方法:以氰基硅烷键合硅胶为填充剂;以乙腈-0.03 mol·L-1磷酸二氢钠溶液(用1 mol·L-1氢氧化钠溶液调pH至7.0)(43∶ 57)为流动相;流速:2.0 mL·min -1;柱温:35℃;检测波长214 nm.苯扎氯铵C12、C14、C16之间的分离度应符合规定.结果:苯扎氯铵在1.28~3.00 μg范围内与峰面积线性关系良好(r =0.9999,n=7);平均回收率(n=6)为100.9%,RSD=0.9%.结论:该法操作简便,快速、准确,灵敏度高,重复性好,可用于右旋糖酐70甘油滴眼液中苯扎氯铵含量测定.

  10. Determination of benzalkonium chloride in compound tropicamide eye drops by HPLC%HPLC法测定复方托吡卡胺滴眼液中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    何丹; 杨林

    2013-01-01

    Objective :To establish an HPLC method for detecting the content of Benzalkonium Chloride in Compound Tropicamide Eye Drops .Methods :A Alltech Alltima -CN column (250cm × 4 .6mm ,5μm) was used ,and the mobile phase was 0 .1mol・L -1 NaAc solution -acetonitrile (60 :40) ,HAc was used to adjust pH to 5 ,column temperature was 30℃ ,at a flow rate of 2 .0ml・min -1 and detection wavelength of 254 nm .Results :The linear range of Benzalkonium Chloride was 0 .02~0 .5mg・mL -1 ;The correlation coefficient was 0 .9999 .The average recovery of Benzalkonium Chloride was 98 .91% (RSD=0 .44% ,n=9 ) .Conclusion :The method is accurate ,simple ,rapid and suitable for the quality control of Benzalkonium Chloride in Compound Tropicamide eye drops .%目的:建立超高效液相色谱法测定复方托吡卡胺滴眼液中苯扎氯铵的含量测定方法。方法:色谱柱为Alltech Alltima -CN(250cm ×4.6mm ,5μm),流动相为0.1mol・L -1醋酸钠溶液(用冰醋酸调节pH值至5.0)-乙腈(60:40),检测波长254nm ,流速为2.0ml・min -1,柱温30℃,进样体积50μL。结果:苯扎氯铵在0.02至0.5mg・mL -1浓度范围内线性关系良好(r=0.9999);平均回收率为98.91%,RSD=0.44%(n=9)。结论:该方法准确、简便、快速、可靠,能有效控制复方托吡卡胺滴眼液中苯扎氯铵的含量。

  11. El cloruro de benzalconio: inaceptable para esterilizar o desinfectar instrumental médico o dental Benzalkonium chloride is unacceptable to sterilize or disinfect medical or dental instruments

    Directory of Open Access Journals (Sweden)

    Enrique Acosta-Gío

    2001-12-01

    Full Text Available Objetivo. Comparar la actividad esporicida del cloruro de benzalconio (CB con la del glutaraldehído. Material y métodos. Estudio comparativo, hecho en el Laboratorio de Microbiología de la Facultad de Odontología, Universidad Nacional Autónoma de México (UNAM. Se expusieron esporas de Bacillus subtilis ATCC 9372 a estos germicidas (1 espora x µl sobre un filtro de 0.22 µm. Al completarse el tiempo de contacto, se lavaron las esporas y los filtros fueron incubados sobre agar nutritivo por 72 h a 37ºC. Resultados. El CB no eliminó las esporas de B. subtilis a la concentración de uso, ni aun al incrementar a 15 h su exposición (900 veces el tiempo recomendado. El glutaraldehído al 2% destruyó las esporas después de 10 h. La urea y el cloruro de sodio no mostraron actividad esporicida. Conclusiones. Los resultados confirman que el CB carece de actividad esporicida y ratifican que este compuesto cuaternario de amonio no tiene aplicación como agente esterilizante o como desinfectante de instrumental médico y dental. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.htmlObjective. To compare the sporicidal activity of benzalkonium chloride (BKC with that of glutaraldehyde. Material and Methods. A comparative study was conducted at the microbiology laboratory of Facultad de Odontología, Universidad Nacional Autónoma de México. Bacillus subtilis ATCC 9372 spores were exposed to these germicides (1 spore x mL on a 0.22 mm filter. After completing the contact time the spores were washed and the filters were incubated on nutrient agar for 72 h at 37ºC. Results. BKC did not eliminate B. subtilis spores at the concentration used, not even after increasing contact time to 15 h (900-fold the recommended time. Two percent glutaraldehyde destroyed spores only after 10 h of contact. Urea and sodium chloride showed no sporicidal activity. Conclusions. The results confirm that BKC lacks sporicidal

  12. Studies on Toxicity of Combination of Borneol and Benzalkonium Chloride to Red Blood Cells and Corneal Epithelial Cells in Vitro%冰片与苯扎氯铵合用对红细胞及角膜上皮细胞的损伤效应

    Institute of Scientific and Technical Information of China (English)

    廖南英; 伍海涛; 梁小雯; 刘启德; 宓穗卿; 王宁生

    2014-01-01

    目的:考察冰片与苯扎氯铵合用对红细胞及角膜上皮细胞的毒性。方法实验分为溶剂对照组、冰片组、苯扎氯铵组、冰片+苯扎氯铵组,分别测定各组红细胞半数溶血浓度(HC50)和角膜上皮细胞半数抑制浓度(IC50),根据等辐射分析法和响应面分析法判断联合作用类型和趋势,并观察二者合用对眼角膜上皮细胞增殖的影响。结果苯扎氯铵对红细胞及角膜上皮细胞的毒性作用呈明显的量效关系,加入冰片后能降低其HC50和IC50值。结论冰片与苯扎氯铵对红细胞的溶血效应表现为协同作用,冰片能增强苯扎氯铵对角膜上皮细胞的毒性作用,受损一定程度内的细胞可恢复。%Objective The in vitro hemolytic test and cytotoxicity test were used to study the toxicity of the combination of borneol and benzalkonium chloride to red blood cells and corneal epithelial cells. Methods Suspension of rabbit red blood cells and corneal epithelial cells were treated with different concentrations of borneol , benzalkonium chloride and combination of borneol-benzalkonium. Dose-response assays were firstly carried out to obtain the 50%hemolysis concentration(HC50) of the individual drug group. Then isobolographic analysis and response surface analysis were used to define the type and tendency of interaction between borneol and benzalkonium chloride. The effects of the combination on the proliferation of corneal epithelial cells were also observed. Results The toxicity of benzalkonium chloride to red blood cells and corneal epithelial cells was dose-dependent. The curve of dose-effect showed that HC 50 and IC50 of benzalkonium chloride were decreased after borneol was added. Conclusion Borneol and benzalkonium chloride have synergistic action on the hemolytic effect, and borneol can enhance the toxicity of benzalkonium chloride on corneal epithelial cells. The corneal epithelial cells with certain degrees of

  13. Novel Highly Flexible Wormlike Micelles Formed by Cetylpyridinium Chloride and Trioxyethylene Monododecyl Ether Surfactants

    Directory of Open Access Journals (Sweden)

    Firoz Kapadia

    2014-06-01

    Full Text Available The impact of small nonionic hydrophobic molecule, trioxyethylene monododecyl ether (C12EO3, on the viscoelastic properties of aqueous solutions of cetylpyridinium chloride (CPC is studied. As the C12EO3 concentration increases, the viscosity passes through a maximum. Dynamic rheological measurements revealed a comprehensive picture of how C12EO3 affects the different length scales in the entangled wormlike micelles. Increase in the viscosity can normally be caused by insertion of amphiphilic C12EO3 molecules into the cationic surfactant (CPC layer, or micellar swelling, caused by solubilization of very hydrophobic molecules in the micellar core. The partial phase behavior and rheology of this mixed surfactant systems is studied.

  14. Comparative study on bactericidal activity of benzalkonium chloride and dodecyl two propylene triamine%苯扎氯铵与十二烷基二亚丙三胺杀菌活性比较研究

    Institute of Scientific and Technical Information of China (English)

    张丽蓉; 陈维; 邓金花; 宋金武

    2016-01-01

    Objective To compare bactericidal activity of benzalkonium chloride and dodecyl two propylene triamine.Methods Suspension quantitative germicidal test and antibacterial ring test were used to study bactericidal activity of benzalkonium chloride and dodecyl two propylene triamine.Results The average killing logarithm values of Pseudomonas aeruginosa,Escherichia coli and Staphylococcus aureus exposed to the concentration of 500 mg/L of the benzalkonium chloride for 1 min were 5.18,7.02 and 7.13 respectively,the average killing logarithm value of Candida albicans was 4.48.The average killing logarithm values of P.aeruginosa,E.coli and S.aureus exposed to the concentration of 500 mg/L of the dodecyl two propylene triamine for 1 min were 5.84,7.32 and 7.13 respectively,the average killing logarithm value of C.albicans was 4.94.Concentration was 50 mg/L,the antibacterial ring diameters of benzalkonium chloride and dodecyl two propylene triamine were 8.3 mm and 8.2 mm respectively.Conclusion The bactericidal effect of dodecyl two propylene triamine is better than that of benzalkonium chloride,there was no significant difference in antibacterial effect.%目的 比较苯扎氯铵与十二烷基二亚丙三胺的杀菌活性.方法 采用悬液定量杀菌试验和抑菌环试验方法,对苯扎氯铵和十二烷基二亚丙三胺的杀菌活性进行比较研究.结果 用含500 mg/L的苯扎氯铵作用1 min,对铜绿假单胞菌、大肠杆菌和金黄色葡萄球菌的平均杀灭对数值分别为5.18、7.02和7.13,对白色念珠菌的平均杀灭对数值为4.48.用含500 mg/L的十二烷基二亚丙三胺作用1 min,对铜绿假单胞菌、大肠杆菌和金黄色葡萄球菌的平均杀灭对数值分别为5.84、7.32和7.13,对白色念珠菌的平均杀灭对数值为4.94.浓度为50 mg/L时,苯扎氯铵与十二烷基二亚丙三胺的抑菌环直径分别为8.3 mm和8.2 mm.结论 十二烷基二亚丙三胺的杀菌效果优于苯扎氯铵,抑菌效果无显著差异.

  15. Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

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    Lovelace Cherie

    2011-04-01

    Full Text Available Abstract Background Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system. Methods Each product was tested for antimicrobial effectiveness by European Pharmacopoeia A (EP-A standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours not required by the United States Pharmacopeia or Japanese Pharmacopoeia. Aliquots were inoculated with between 105 and 106 colony-forming units of the test organisms: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus brasiliensis. Sampling and enumeration were conducted at protocol-defined time points through 28 days. Results BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against Staphylococcus aureus. Both products satisfied United States and Japanese pharmacopoeial criteria. Conclusions Latanoprost with 0

  16. In vitro cytotocity of Benzalkonium Chloride%苯扎氯铵对人结膜上皮细胞毒性的研究

    Institute of Scientific and Technical Information of China (English)

    刘扬; 刘祖国; 许传超; 陈小平; 李朝阳

    2008-01-01

    目的 探讨苯扎氯铵(BAC)对无血清培养法培养的人结膜上皮细胞的细胞毒性.方法 采用无血清培养的3-5代人结膜上皮细胞,将不同浓度的BAC(O.01%,0.005%,0.001%,0.0005%,0.0001%)单次作用于结膜上皮细胞15min,分别于处理细胞后6,12,24,48hMTT法检测细胞活力,于处理细胞后48h固定,扫描电镜观察拍照.结果 自BAC处理后6h起,与对照组相比,各浓度BAC均使细胞活力下降(P<0.01).经过48小时的恢复期,细胞活力未见恢复.随BAC浓度增高,细胞表面微绒毛消失,细胞出现不同程度收缩至脱落至大部分溶解坏死.结论 BAC对于培养的人结膜上皮细胞具有细胞毒性,其毒性作用呈剂量依赖性.%Objective To investigate the cytotoxic effects of benzalkonium chloride (BAC), a preservative used in many ophthalmic topical solutions, on human conjunctival epithelial cells in vitro.Methods Cultured epithelial cells obtained from human conjunctiva were exposed to medium containing BAC solutions at 0.01%, 0.005%, 0.001%, 0.0005% and 0.0001% concentrations for a period of 15 min. Cell were examined before treatment and 6,12, 24, 48 hours later, cell viability was assessed with methyl thiazolyl tetrazolium(MTT) assay, and scanning electron microscopy was used to evaluate the cytotoxic effect 48 hours after treatment.Results Cell viability decreased significantly in a dose-dependent manner after a single 15-minute treatment with BAC at various concentrations (P<0.01 at all points after treatment). Cells treated with BAC at different concentrations showed loss of micromilli, cell exfoliation, even death. Conclusions These results suggest that BAC induces cytotoxicity at a concentration as low as 0.0001%. The mode of BAC-induced cytotoxicity is dose-dependent.

  17. Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

    Science.gov (United States)

    2011-01-01

    Background Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK) in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system. Methods Each product was tested for antimicrobial effectiveness by European Pharmacopoeia A (EP-A) standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours) not required by the United States Pharmacopeia or Japanese Pharmacopoeia. Aliquots were inoculated with between 105 and 106 colony-forming units of the test organisms: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus brasiliensis. Sampling and enumeration were conducted at protocol-defined time points through 28 days. Results BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against Staphylococcus aureus. Both products satisfied United States and Japanese pharmacopoeial criteria. Conclusions Latanoprost with 0.02% BAK exhibited more

  18. Cytotoxicity of five fluoroquinolone and two nonsteroidal anti-inflammatory benzalkonium chloride-free ophthalmic solutions in four corneoconjunctival cell lines

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    Masahiko Ayaki

    2010-09-01

    Full Text Available Masahiko Ayaki1, Atsuo Iwasawa2, Mitsutaka Soda3, Shigeo Yaguchi3, Ryohei Koide41Department of Ophthalmology, Saitama National Hospital, Saitama, Japan; 2Department of Clinical Pathology, Showa University Fujigaoka Hospital, Yokohama, Japan; 3Department of Ophthalmology, Showa University Fujigaoka Rehabilitation Hospital, Yokohama, Japan; 4Department of Ophthalmology, Showa University School of Medicine, Tokyo, JapanPurpose: Epithelial disorders after eye surgery can result in visual deterioration and patient discomfort. Such disorders may be caused by drug toxicity. In the present study, we evaluated the toxicity of ophthalmic solutions, with or without benzalkonium chloride (BAK as the preservative, used for postoperative care.Methods: A range of commercially available antibiotic and anti-inflammatory ophthalmic solutions used postoperatively (ie, levofloxacin, moxifloxacin, gatifloxacin, norfloxacin, tosufloxacin, dibekacin, cefmenoxime, diclofenac, bromfenac, pranoprofen, betamethasone, and fluoromethorone were assessed in three corneal cell lines and one conjunctival cell line. All antibiotic solutions were BAK free. Cell viability was determined with the 3-(4,5-dimethyl-2 thiazoyl-2,5-diphenyl-2H-tetrazolium bromide (MTT assay after cells had been exposed to the drugs for 48 h. The effects of preservatives on cell viability were also determined. Toxicity was compared using the cell viability score (CVS.Results: Based on results of the MTT assay and CVS, the order of cell viability after exposure to the antibiotic solutions was cefmenoxime ≥ tosufloxicin ≥ dibekacin ≥ levofloxacin ≥ norfloxacin = gatifloxacin = moxifloxacin. For the anti-inflammatory solutions, the order of cell viability was betamethasone ≥ betamethasone + fradiomycin > preservative-free diclofenac ≥ preservative-free bromfenac >> 0.02% fluoromethorone ≥ 0.1% fluoromethorone = diclofenac + preservative = bromfenac + preservative = pranoprofen. The anti

  19. Travoprost 0.004%/timolol 0.5%-fixed combination with and without benzalkonium chloride: a prospective, randomized, doubled-masked comparison of safety and efficacy

    Science.gov (United States)

    Kitazawa, Y; Smith, P; Sasaki, N; Kotake, S; Bae, K; Iwamoto, Y

    2011-01-01

    Purpose The purpose of this study is to compare the safety and intraocular pressure (IOP)-lowering efficacy of travoprost/timolol in a benzalkonium chloride (BAK)-free fixed combination preserved with polyquaternium-1 (TRA/TIM BAK-free), with travoprost/timolol-fixed combination preserved with BAK (TRA/TIM), in patients with open-angle glaucoma or ocular hypertension. Methods In this prospective randomized controlled trial, subjects with IOP of at least 22 mm Hg in one or both eyes at 0900 h, and IOP of at least 21 mm Hg in one or both eyes at 1100 h and 1600 h at two eligibility visits were randomly assigned to receive either TRA/TIM BAK-free (n=195) or TRA/TIM (n=193), dosed once daily in the morning (0900 h) for 6 weeks. IOP was assessed at 0900 h, 1100 h, and 1600 h at each scheduled visit (baseline, 2 and 6 weeks after randomization). Results Mean IOP reduction across all visits and time points was 8.0 mm Hg in the TRA/TIM BAK-free group and 8.4 mm Hg in the TRA/TIM group (P=0.0943). The difference in mean IOP between groups ranged from 0.2 to 0.7 mm Hg across visits and time points, with a mean pooled difference of 0.4 mm Hg (95% CI: −0.1 to 0.8), demonstrating equivalence of the two formulations. The most common drug-related adverse event was hyperemia of the eye (ocular hyperemia and conjunctival hyperemia combined), occurring in 11.8% of the TRA/TIM BAK-free group and 13.0% of the TRA/TIM group. Conclusion Travoprost/timolol BAK-free demonstrated equivalence to travoprost/timolol preserved with BAK in efficacy. No clinically relevant differences in the safety profiles of travoprost/timolol BAK-free and travoprost/timolol preserved with BAK were identified. PMID:21701528

  20. Influence of surfactant on dynamics of photoinduced motions in a dye-doped deoxyribonucleic acid

    Science.gov (United States)

    Mysliwiec, Jaroslaw; Parafiniuk, Kacper; Miniewicz, Andrzej; Rau, Ileana; Kajzar, Francois; Niziol, Jacek; Hebda, Edyta; Pielichowski, Jan; Sahraoui, Bouchta

    2012-10-01

    Pure deoxyribonucleic acid (DNA) is known to be soluble in water only and exhibits poor temperature stability. In contrary, it is well known that the complex of DNA - with cetyltrimethyl ammonium (CTMA) is soluble in alcohols and can be processed into very good optical quality thin films by solution casting and spin deposition. Despite the success of DNA-CTMA, there is still need for new cationic surfactants which would extend the range of available solvents for DNA complex. We test and present experimental results of influence of new surfactants based on benzalkonium chloride (BA), and didecyldimethylammonium chloride (DDCA) for applications in all optical switching.

  1. Micellar-enhanced ultrafiltration membrane (MEUF) of Batik wastewater using Cetylpyridinium chloride surfactant

    Science.gov (United States)

    Aryanti, Nita; Pramudono, Bambang; Prawira, Christ Nadya P.; Renardi, Rheza; Fatikhatul K. Ika, S.

    2015-12-01

    In batik production, reactive dyes such as remazol, indigosol, naphtol and rapid are used in the dying process. Batik wastewater contains high level of reactive dyes, wax and sodium salts and is characterized with high Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) as well as high concentration of phenol and Ammonia. Micellar-Enhanced Ultrafiltration Membrane (MEUF) is one of promising technology to separate low molecular weight substances such as dyes. The MEUF process involves combination of ultrafiltration membrane and surfactant at concentration higher than surfactant's Critical Micelle Concentration (CMC). This technique combines high selectivity of reverse osmosis membrane and high flux of ultrafiltration membrane but with lower pressure. Ultrafiltration of batik waste water without surfactant (UF) and with addition of surfactant (MEUF) were studied in order to compare the performance of both systems. The Batik wastewater were obtained from batik industry in Semarang and Surakarta, Central Java, Indonesia. Cetyl Pyridinium Chloride at concentration of 2 and 4 times of its CMC were used. Flatsheet ultrafiltration membrane was made from Polyethersulphone (12% w/w), N-methyl Pyrrolidone (83% w/w) and Polyethylene Glycol (5% w/w). The performance of the UF and MEUF were evaluated based on flux profiles and rejections (COD, TSS, concentration of Ammonia). The results showed that the MEUF had superior performance than the UF. Concentration of COD, TSS, phenol and ammonia were reduced significantly. The rejection of COD were 92.74% and 94.15%. Moreover, the MEUF was capable to reduce the TSS with the rejection of 86.26% and 65%. The concentration of ammonia in permeate were 0.43 ppm and below 0.01 ppm.

  2. Determination of Benzalkonium Chloride in Besifloxacin Hydrochloride Eye Drops by HPLC%盐酸贝西沙星滴眼液中苯扎氯铵的HPLC法测定

    Institute of Scientific and Technical Information of China (English)

    陈再新; 朱峰; 王勇军

    2013-01-01

    An HPLC method was established for the determination of benzalkonium chloride in besifloxacin hydrochloride eye drops.A Kromasil C18 column was used,with the mobile phase of 5 mmol/L ammonium acetate (containing 1% triethylamine,adjust pH to 5.2±0.5 with glacial acetic acid)-acetonitrile (29 ∶ 71),at the detection wavelength of 215 nm.The flow rate was 1.0 ml/min.The calibration curve of benzalkonium chloride was linear in the concentration range of 5-15 μg/ml (R2=0.998 3).The average recovery was 99.4 % with RSD of 0.42 %.%建立了高效液相色谱法测定盐酸贝西沙星滴眼液中苯扎氯铵的含量.采用Kromasil C18柱,5 mmol/L乙酸铵溶液(含1%三乙胺,用冰乙酸调至pH 5.2±0.5)-乙腈(29∶71)为流动相,检测波长为215nm,流速1.0 ml/min.苯扎氯铵在5~15 μg/ml浓度范围内线性关系良好(R2=0.998 3),平均回收率为99.4% (RSD=-0.42%).

  3. Determination of Benzalkonium Chloride in Glutathione Eye Drops by HPLC%高效液相色谱法测定谷胱甘肽滴眼液中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    欧嘉娜

    2012-01-01

      Objective:To establish a HPLC method For the determination of Benzalkonium Chloride in Glutathione eye drops. Methods:The sample was analyzed on an Agilent Zorbax SB-CN column (4.6mm ×250mm,5μm) with mobile phase consisting of 0.1%phosphoric acid and acetonitrile and tetrahydrofuran (52∶38∶10) and the detection wavelength was 214nm. Results:The Calibration curves of Benzalkonium Chloride was linear in the range of 50~250μg/ml and the linear equation was Y=20674X-79747(r=0.99979). The average recoveries was 100.9% with RSD 0.19%. Conclusion :This method is simple, rapid, accurate and with good repeatability and recovery, it cab be used as a quality control method for this preparation.%  目的:建立测定谷胱甘肽滴眼液中苯扎氯铵含量的方法.方法:采用Agilent Zorbax SB-CN柱(4.6mm×250mm,5μm);流动相:0.1%磷酸水溶液-乙腈-四氢呋喃(52∶38∶10);检测波长:214nm.结果:苯扎氯铵的线性范围为50~250μg/ml,线性回归方程为Y=20674X-79747(r=0.99979).平均回收率分别为100.9%,RSD为0.19%.结论:该方法简便、快速、准确,具有良好的重复性和回收率,可作为该制剂的质量控制标准.

  4. Determination of Benzalkonium Chloride in Compound Aspartate, Vitamin B6 and Dipotassium Glycyrrhe-tate Eye Drops%复方门冬维甘滴眼液中苯扎氯铵的测定

    Institute of Scientific and Technical Information of China (English)

    董超琪

    2014-01-01

    目的::建立测定复方门冬维甘滴眼液中苯扎氯铵含量的方法。方法:采用Agilent Zorbax C18色谱柱(150 mm ×4.6 mm,5μm),以乙腈-5 mmol·L-1醋酸铵溶液(含1%三乙胺,用冰醋酸调节pH至5.0±0.5)(65∶35)为流动相,流速为1.0 ml·min-1,检测波长为214 nm。结果:苯扎氯铵在50.00~150.00μg·ml-1范围内与峰面积线性关系良好,r=0.9980;平均回收率为99.1%,RSD为0.6%。结论:该方法简便,迅速,灵敏度高,具有良好的重复性及回收率,可用于复方门冬维甘滴眼液中苯扎氯铵的测定。%Objective:To develop a method to determine benzalkonium chloride in compound aspartate, vitamin B6 and dipotassi-umglycyrrhetateeyedrops.Methods:TheseparationwasperformedonanAgilentZorbaxC18(150mm×4.6mm,5μm)column. The mobile phase consisted of acetonitrile-5 mmol·L-1 ammonium acetate ( in which 1% triethylamine was added, then the pH value was adjusted to 5. 0 ± 0. 5 by acetic acid) 65∶35(v/v). The flow rate was 1. 0 ml·min-1 and the detection wavelength was 214nm. Re-sults:Benzalkonium chloride had a good linearity within the range of 50. 00-150. 00μg·ml-1(r=0. 998 0), and the average recovery was 99. 1%(RSD=0. 6%). Conclusion:The method is simple, rapid and sensitive with good repeatability and recovery. It can be used to determine benzalkoinum chloride in compound aspartate, vitamin B6 and dipotassium glycyrrhetate eye drops.

  5. 苯扎氯铵溶液在慢性创面及感染肉芽肿的临床应用及观察%The Clinical Application and Observation of Benzalkonium Chloride used in Chronic Wound and Infectious Granuloma

    Institute of Scientific and Technical Information of China (English)

    王本峰; 张振信; 朱秀梅

    2014-01-01

    Objective:To observe the benzalkonium chloride disinfectant on sterilization of chronic wound infection and promote healing. Methods: we used Benzalkonium chloride disinfectant in Chronic wounds and granuloma after debridement,and then observe the sterilization ef ect of Staphylococcus aureus,bacil us,Acinetobacter bactericidal action Escherichia coli that is drug resistant. Results: 0.1% benzalkonium chloride solution has obvious ef ect on kil ing high resistant bacteria from chronic wound and infectious granuloma and educeing scar formation obviously. Conclusion:0.1% benzalkonium chloride solution has obvious ef ect on kil ing high resistant bacteria from chronic wound and infectious granuloma,Short ing the time of wound healing and improving the quality of wound healing.%目的:观察苯扎氯铵消毒液对慢性感染性创面的杀菌及促使修复作用。方法对慢性创面及感染性肉芽肿扩创后外用苯扎氯铵消毒液,观察其对耐药的金黄色葡萄球菌、不动杆菌、大肠埃希菌的灭菌作用。结果0.1%苯扎氯铵溶液对慢性创面及感染性肉芽肿的高耐药细菌有明显的灭菌、减少瘢痕形成。结论0.1%苯扎氯铵溶液对慢性创面及感染性肉芽肿的高耐药细菌有明显的灭菌,缩短创面愈合时间,提高创面愈合质量。

  6. Determination of Benzalkonium Chloride Homologs in Complex Chemical Disinfectant by High-Performance Liquid Chromatography%复方化学消毒剂中苯扎氯铵的高效液相色谱测定

    Institute of Scientific and Technical Information of China (English)

    刘雯雯; 张瑾; 乔俊琴; 练鸿振

    2011-01-01

    建立了一种测定复方化学消毒剂中苯扎氯铵成分十二烷基二甲基苄基氯化铵、十四烷基二甲基苄基氯化铵和十六烷基二甲基苄基氯化铵的反相离子对高效液相色谱法.色谱柱为Platisil ODS(5 μm,250 mm×4.6 mm),流动相为甲醇-0.2 mol/L己烷磺酸钠(含1%三乙胺,V/V,用高氯酸调节至pH=6.0,体积比85∶15),紫外220 nm检测.用己烷磺酸钠作为离子对试剂,增强了苯扎氯铵成分的保留,三乙胺作为扫尾剂,通过抑制固定相表面残存的硅羟基对苯扎氯铵成分的吸附,减少了色谱峰拖尾.3种苯扎氯铵成分分离良好,标准曲线的线性范围分别为0.002~5 mg/mL、0.005~10 mg/mL和0.005~10 mg/mL,检测限分别为0.0005 mg/mL、0.001 mg/mL和0.001 mg/mL.方法具有良好的准确度和精密度,在测定低浓度样品时优势明显.实际用于测定苯扎氯铵消毒液和医用消毒纸巾中3种苯扎氯铵成分的含量,回收率为99.3%~104.1%,日内和日间测定相对标准偏差(RSD)均小于2.0%.%An ion pair reversed phase High-Performance Liquid Chromatography ( HPLC ) method has been developed for the simultaneous determination of benzalkonium chloride ( BAC ) homologues, dodecyl dimethyl benzyl ammonium chloride ( C12 ), tetradecyl dimethyl benzyl ammonium chloride ( C14 ) and cetyl dimethyl benzyl ammonium chloride ( C16 ), in complex chemical disinfectant. Separation was carried out on Platisil ODS column ( 5 μm, 250 mm ×4. 6 mm ), using methanol and 200 mmol/L hexane sulfonate sodium aqueous solution consisting of 1 % triethylamine ( V/V), adjusted with perchloric acid to pH 6. 0 ( 85 : 15, V/V) as the mobile phase in an isocratic elution. The detection wavelength was 220 nm. In the experiment, sodium hexanesulfonate was used as the ion-pair reagent to enhance the retention of benzalkonium chloride, and triethylamine was used as the tailing-suppressor to restrain the adsorption of benzalkonium chloride to the residual silanols

  7. Effect of surfactants on the performance of tubular and spherical micromotors – a comparative study†

    Science.gov (United States)

    Sanchez, Samuel; Chokmaviroj, Sarocha; Ruiz-Molina, Daniel; Baeza, Alejandro; Schmidt, Oliver G.

    2014-01-01

    The development of artificial micromotors is one of the greatest challenges of modern nanotechnology. Even though many kinds of motors have been published in recent times, systematic studies on the influence of components of the fuel solution are widely missing. Therefore, the autonomous movement of Pt-microtubes and Pt-covered silica particles is comparatively observed in the presence and absence of surfactants in the medium. One representative of each of the three main surfactant classes – anionic (sodium dodecyl sulfate, SDS), cationic (benzalkonium chloride, BACl) and non-ionic (Triton X) – has been chosen and studied. PMID:25364501

  8. Antibiotic Washing Therapy of Maxillofacial Abscess: Comparison of Benzalkonium Chloride versus Povidone Iodine%苯扎氯铵溶液与碘伏溶液冲洗治疗颌面部脓肿疗效比较

    Institute of Scientific and Technical Information of China (English)

    王建国; 李可来; 李庆隆

    2013-01-01

    Objectives:To compare the treatment efficacy of benzalkonium chloride solution versus povidone iodine solution in maxillofacial abscess washing therapy.Methods:59 cases of maxillofacial abscess patients were randomly divided into experiment group A (29 cases) and comparative group B (30 cases).In group A,maxillofacial abscess was partly incised and drainged,then rinsed daily with 0.01% benzalkonium chloride solution.In group B,patients' abscess partly incised and drainged,then rinsed daily with 0.25% povidone iodine solution.In both groups,bacterial culture of the pus were undertaken before incision and drainage and every 3 days after washing therapy.Results:Three days after dressing,the positive rate of bacterial culture in experimental group A and comparative group B were 7 cases and 15 cases respectively.6 days after,positive culture cases were 0 in group A and 7 in group B.The average dressing time in experimental group A and comparative group B were 3.34 days and 5.87 days respectively.Conclusion:The treatment efficiency of abscess by benzalkonium chloride solution is much better than by povidone iodine solution.%目的:对比苯扎氯铵溶液及碘伏溶液在冲洗治疗颌面部脓肿中的效果.方法:颌面部脓肿患者59例,随机分为实验组29例,对照组30例.实验组行脓肿切开引流后每天用0.01%苯扎氯铵溶液冲洗;对照组行脓肿切开引流后每天用0.25%碘伏溶液冲洗.两组病例均在脓肿切开前取脓液送细菌培养,切开后每3d取脓液送细菌培养1次.并记录每例患者治愈脓肿的换药天数.结果:换药3d后实验组细菌培养阳性为7例,对照组细菌培养阳性为15例;换药6d后实验组细菌培养阳性为0例,对照组细菌培养阳性为7例.实验组平均换药天数为3.34 d,对照组平均换药天数为5.87d.结论:用苯扎氯胺溶液冲洗治疗颌面部脓肿比用碘伏溶液冲洗更为有效,并可以减少脓肿切开后到治愈的换药天数.

  9. 苯扎氯铵溶液用于烧伤创面的初步临床观察%Preliminary Clinical Observation of Benzalkonium Chloride on Burn Wounds

    Institute of Scientific and Technical Information of China (English)

    李峰; 柴家科; 杨红明

    2012-01-01

    目的 观察苯扎氯铵溶液对烧伤创面的抑菌作用及对创面愈合的影响.方法 2007年10月-2008年8月共观察30名成年住院烧伤患者,按自身对照分别使用苯扎氯铵和碘伏溶液换药,在第1、第7天换药前行细菌培养观察长期抑菌作用;10例在消毒后3 min再次行细菌培养,观察其即时消毒效果;第7天观察创面愈合率.结果 苯扎氯铵组和碘伏组的长期、即时抑菌作用基本类似,用药第7天创面愈合率苯扎氯铵组高于碘伏组,差异有统计学意义.两组在换药时患者感觉均有疼痛感,未见伤口周围皮肤瘙痒和皮疹.结论 苯扎氯铵溶液用于烧伤创面的抑菌作用与碘伏类似,但是苯扎氯铵溶液是阳离子表面活性剂,可清洁创面血污及有机物,有利于创面愈合,有可能替代碘伏成为烧伤创面基本用药.%Objective To observe the bacteriostasis of benzalkonium chloride solution(BZK) on bum wounds. Methods From October 2007 to August 2008 in our hospital,30 adult burned patients were enrolled in the study. BZK or povidone iodine ( PVP-iodine) were used on the wounds by self-control. Wounds culture was performed on the 1st and 7 th day before dressing exchange to observe the long term bacteriostasis. In order to observe the immediate bacteriostasis, wounds bacterial culture were conducted 3 min later after the disinfection was performed in 10 of them. The healing rate was observed on the 7th day. Results The long term or immediate bacteriostasis was similarly, however, the wounds healing rate in BZK group was significantly higher than that PVP-iodine group. The patients in both groups felt pain when dressed; there was no itching or rashes of the skin around the wound. Conclusion Benzalkonium chloride solution has a similar bacteriostasis for burn wounds with povidone-iodine. Benzalkonium chloride solution is also a cationic surface active agent,it can clean the wounds bloodstained and organic matter,is conducive to

  10. 高效液相色谱法同时测定化妆品中的3种苯扎氯铵同系物%Simultaneous determination of 3 benzalkonium chloride homologsin cosmetics by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    刘艳琴; 王浩; 杨红梅; 史海良; 郭启雷

    2011-01-01

    建立了采用高效液相色谱-二极管阵列检测器(HPLC-DAD)同时检测化妆品中3种苯扎氯铵同系物(n-CH-CHNCl、n-CH-CHNCl、n-CH-CHNCl)的方法.采用含0.5%甲酸的甲醇超声提取样品,以CAPCELL PAK SCX色谱柱(250 mm×4.6 mm,5 μm)分离,流动相为40 mmol/L乙酸铵水溶液(含0.1%三乙胺,pH 4.0)和乙腈,梯度洗脱,流速1.0 mL/min,检测波长260 nm,柱温25℃,进样量20 μL.该方法的检出限50.0 mg/kg,定量限200.0 mg/kg,线性范围5.0~3 000.0 mg/L,加标回收率92.5%~102.1%.相对标准偏差为3.81%~6.66%.结果表明,该方法快速、准确,能够同时测定化妆品中3种苯扎氯铵同系物.%An analytical method based on high performance liquid chromatography with a diode array detector (HPLC-DAD) has been established for the simultaneous determination of 3 benzalkonium chloride homologs (n-C12H25-C9H13NCl, n-C14H29-C9H13NCI, n-C16H33-C9H13NCl) in cosmetics.The sample was extracted with methanol ( including 0.5% formic acid) under ultrasonic operation, the HPLC separation was carried out on a CAPCELL PAK SCX column (250 mm × 4.6 mm, 5 μm), the mobile phases were 40 mmol/L ammonium acetate solution (including 0.1% triethylamine) and acetonitrile with gradient elution, the flow rate was 1.0 mL/min, the detection wavelength was 260 nm, the column temperature was 25 ℃, and the injection volume was 20 μL.The limit of detection was 50.0 mg/kg and the quantitation limit was 200.0 mg/kg for 3 benzalkonium chloride homologs in cosmetics.The linear plots were obtained between 5.0 mg/L and 3 000.0 mg/L.Overall recoveries were between 92.5% and 102.1% with the relative standard deviations (RSDs) between 3.81% and 6.66%.The method is simple, rapid, accurate and suitable for the determination of 3 benzalkonium chloride homologs in cosmetics.

  11. Biodegradable surfactant stabilized nanoscale zero-valent iron for in situ treatment of vinyl chloride and 1,2-dichloroethane

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yu-Ting; Wu, Shian-chee; Yang, Shi-Wei; Che, Choi-Hong [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan, ROC (China); Lien, Hsing-Lung, E-mail: lien.sam@nuk.edu.tw [Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung, Taiwan, ROC (China); Huang, De-Huang [Chinese Petroleum Corporation, Kaohsiung, Taiwan, ROC (China)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Biodegradable surfactant stabilized nanoscale zero-valent iron (NZVI) is tested. Black-Right-Pointing-Pointer Vinyl chloride and 1,2-dichloroethane are remediated by NZVI in the field. Black-Right-Pointing-Pointer Multiple functions of biodegradable surfactants are confirmed. Black-Right-Pointing-Pointer Biodegradable surfactants stabilize NZVI and facilitate the bioremediation. Black-Right-Pointing-Pointer NZVI creates reducing conditions beneficial to an anaerobic bioremediation. - Abstract: Nanoscale zero-valent iron (NZVI) stabilized with dispersants is a promising technology for the remediation of contaminated groundwater. In this study, we demonstrated the use of biodegradable surfactant stabilized NZVI slurry for successful treatment of vinyl chloride (VC) and 1,2-dichloroethane (1,2-DCA) in a contaminated site in Taiwan. The biodegradable surfactant stabilized NZVI was coated with palladium and synthesized on-site. From monitoring the iron concentration breakthrough and distribution, it was found that the stabilized NZVI is capable of transporting in the aquifer at the test plot (200 m{sup 2}). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth.

  12. Effect of varying nonwoven cotton substrate and the properties of the surfactant solution upon the adsorption of aqueous solutions of alkyl-dimethyl-benzyl-ammonium chloride

    Science.gov (United States)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  13. HPLC法测定磷酸钠盐灌肠液中防腐剂苯扎氯铵的含量%Deternination of Preservative Benzalkonium Chloride in Sodium Phos-phate Rectal Solution by HPLC

    Institute of Scientific and Technical Information of China (English)

    傅素华; 叶兴法; 韩鹏; 田利洪

    2015-01-01

    目的:建立测定磷酸钠盐灌肠液中防腐剂苯扎氯铵的含量。方法采用高效液相色谱法。色谱柱为 Ultimate AQ-C18柱(5μm,4.6×250mm);流动相:乙腈-5mmoL醋酸铵溶液(含1%三乙胺,用冰醋酸调节pH值至5.0±0.5)(65∶35);流速:1.0mL· min -1;柱温:35℃;检测波长214nm。结果苯扎氯铵n-C12H25取代同系物在0.1839μg~0.5517μg范围内线性关系良好。(r=0.9999,n =5);平均回收率为100.5%, RSD为1.45%(n=9)。结论该方法简便快速,结果准确,可用于测定磷酸钠盐灌肠液中防腐剂苯扎氯铵的含量。%OBJECTIVE To establish a method for the the Deternination of preservative benzalkonium chloride in Sodium Phosphate Rectal Solution.METHODS HPLC, Liquid chromatography column was Ultimate AQ-C18 (5μm,4.6 ×250mm);mobile phase was acetonitrile-5mmol· L-1 ammonium acetate solution (Containing 1%three triethylamine;dilute Glacial aceticacld pH 5.0 ±0.5 ) ( 65∶35 );flow rate was 1.0 mL · min-1;column temperature was 35℃;detection wavelength was 214 nm.RESULTS The calibration curve of n-C12 H2 5 substituted congeners in benzalkonium chloride was linear in the sample volume range of 0.1839μg~0.5517μg ( r=0.9999 ).The average recovery was 100.5%(RSD=1.45%,n=9).CONCLUSION The method is simple,rapid and accurate,can be the product quality control methods.

  14. Determination of Benzalkonium Chloride in Loteprednol and Tobramycin Ophthalmic Suspension by HPLC%高效液相色谱法测定复方混悬滴眼液中苯扎氯铵含量

    Institute of Scientific and Technical Information of China (English)

    杨龙华; 宿洁; 陈涛; 卢京光

    2016-01-01

    Objective To establish an HPLC method for the determination of benzalkonium chloride in Loteprednol and Tobramycin Ophthalmic Suspension. Methods After being filtrated,samples were separated by HPLC on a Waters Spherisorb S5 CN column(250 mm × 4. 6 mm,5 μm). The mobile phase was 0. 1% phosphoric acid water solution- acetonitrile- tetrahydrofuran(52 :39 :15). The detec-tion wavelength was 216 nm. The flowing speed was 1. 5 mL/min. The column temperature was 30 ℃. Results The mass concentration of benzalkonium chloride was in good linear relationship with the peak area in the range of 0. 04-0. 20 g/L ( r=0. 999 9,n=5), and the average recovery rate was 100. 22%,RSD=0. 59%( n=9). Conclusion The method is sensitive,accurate and convenient with good resolution,it can be applied to control the quality of Loteprednol and Tobramycin Ophthalmic Suspension.%目的:建立测定氯替泼诺妥布霉素复方混悬滴眼液中防腐剂苯扎氯铵含量的高效液相色谱(HPLC)法。方法色谱柱为Waters Spherisorb S5 CN柱(250 mm ×4.6 mm,5μm),流动相为0.1%磷酸溶液-乙腈-四氢呋喃(52:39:15),流速为1.5 mL/min,检测波长为216 nm,柱温为30℃。结果苯扎氯铵质量浓度在0.04~0.20 g/L( r=0.9999,n=5)范围内与峰面积线性关系良好,平均回收率为100.22%,RSD为0.59%( n=9)。结论该方法简便、灵敏,色谱峰分离度良好,结果准确、可靠,可用于氯替泼诺妥布霉素混悬滴眼液的质量控制。

  15. Determination of benzalkonium chloride in ambroxol hydrochloride inhalation solution by RP-HPLC%反相液相色谱法测定盐酸氨溴素吸入溶液中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    卜宇倩; 蒋宇丹; 邵佶祥

    2015-01-01

    目的:建立盐酸氨溴素吸入溶液中苯扎氯铵含量的反相液相色谱测定方法。方法:采用Agilent Zorbax SB-C18色谱柱(4.6 mm×250 mm,5mm);以0.02 mol/L庚烷磺酸钠(含0.1%三乙胺,用磷酸调节pH至3.0±0.1)-乙腈(35∶65)为流动相;检测波长208 nm;进样体积20ml。结果:苯扎氯铵浓度在3.32~7.74mg/ml范围内线性关系良好,平均回收率为99.2%。结论:该方法快速、简便、准确、专属性强、重复性好,可适用于盐酸氨溴索吸入溶液中苯扎氯铵的含量测定。%Objective:To establish a RP-HPLC method for the quantitative analysis of benzalkonium chloride in ambroxol hydrochloride inhalation solution.Methods: RP-HPLC was performed on a column of an Agilent Zorbax SB- C18 (4.6 mm × 250 mm,5mm) with a mobile phase of 0.02 mol/L sodium 1-heptanesulfate solution (containing 0.1% triethylamine, adjusted pH to 3.0±0.1 by phosphate)-acetonitrile (35∶65) and at UV detection wavelength of 208 nm. Results:The standard curve was linear over the range of 3.32~7.74mg/ml with the average recovery 99.2% (n=9).Conclusion:This method is fast, simple, accurate, sensitive with good reproducibility and can be applied in the determination of benzalkonium chloride in ambroxol hydrochloride inhalation solution.

  16. 高效液相色谱法测定消毒湿巾中苯扎氯铵的含量%HPLC Determination of Benzalkonium Chloride in Disinfectant Wet Wipes

    Institute of Scientific and Technical Information of China (English)

    黄银波; 李兴根; 乔勇升; 胡慧

    2012-01-01

    A method for determination of benzalkonium chloride in disinfectant wet wipes by HPLC was proposed. The sample was extracted ultrasonically with the mobile phase, and then separated on Eclipse XDB-C18 (150 min×4. 6 mm, 5 μm) column, using a mixture of acetonitrile and 70 mmol · L^-1 ammonium acetate solution (containing 1% by vol. of triethylamine, adjusted with acetic acid to pH 5.0) in the ratio of 70 to 30 as mobile phase. Photodiode array detections were made at 262 nm. Linear relationships between values of peak areas and mass concentration of benzalkonium chloride was obtained in the range of 100--500 mg· L^-1 ,with limit of detection (3S/N) of 10. 2 mg · L^-1. The proposed method was used in the analysis of sample of disinfectant wet wipes, values of recovery found by standard addition method were in range of 95.3%-97.8% with RSD's (n=5) in the range of 2.5 %- 4.0%.%提出了高效液相色谱法测定消毒湿巾中苯扎氯铵含量的方法。样品经流动相超声提取,以Eclipse XDB-C18色谱柱(150 mm×4.6 mm,5μm)为分离柱,以乙腈-70 mmol.L-1乙酸铵(含1%三乙胺,冰乙酸调pH至5.0)按体积比70比30混合液为流动相,用二极管阵列检测器于波长262 nm处测定。苯扎氯铵的质量浓度在100~500 mg.L-1范围内与其峰面积呈线性关系,检出限(3S/N)为10.2mg.L-1。应用此法测定消毒湿巾中苯扎氯铵,回收率在95.3%~97.8%之间,相对标准偏差(n=5)在2.5%~4.0%之间。

  17. Paradoxical bronchospasm from benzalkonium chloride (BAC) preservative in albuterol nebulizer solution in a patient with acute severe asthma. A case report and literature review of airway effects of BAC.

    Science.gov (United States)

    George, Mathew; Joshi, Saumya Vinod; Concepcion, Emily; Lee, Haesoon

    2017-01-01

    Nebulized bronchodilator solutions are available in the United States as both nonsterile and sterile-filled products. Sulfites, benzalkonium chloride (BAC), or chlorobutanol are added to nonsterile products to prevent bacterial growth. Bronchoconstriction from inhaled BAC is cumulative, prolonged, and correlates directly with basal airway responsiveness. The multi-dose dropper bottle of albuterol sulfate solution contains 50 μg BAC per/2.5 mg of albuterol, which may be below or at the lower limit of the threshold dose for bronchoconstriction. However, with repeated albuterol nebulization, the effect can be additive and cumulative, often exceeding the bronchoconstriction threshold. We report a case of a 17 years old patient, who received 32 mg of BAC via nebulization over a period of 3.5 days that probably caused persistent bronchospasm evidenced by failure to improve clinically and to increase peak expiratory flow rate (PEFR) from 125 L/min (27% of predicted value) to 300 L/min (68% of predicted value) within 2 hours of withdrawing BAC. The patient's respiratory status and PEFR improved dramatically once the nebulization solution was switched to BAC free lev-albuterol solution. The pediatric providers, particularly the emergency department physicians, intensivists and pulmonologists need to be aware of this rare albeit possible toxicity to the respiratory system caused by BAC used as a preservative in albuterol nebulizer solution.

  18. Paradoxical bronchospasm from benzalkonium chloride (BAC preservative in albuterol nebulizer solution in a patient with acute severe asthma. A case report and literature review of airway effects of BAC

    Directory of Open Access Journals (Sweden)

    Mathew George, MD

    2017-01-01

    Full Text Available Nebulized bronchodilator solutions are available in the United States as both nonsterile and sterile-filled products. Sulfites, benzalkonium chloride (BAC, or chlorobutanol are added to nonsterile products to prevent bacterial growth. Bronchoconstriction from inhaled BAC is cumulative, prolonged, and correlates directly with basal airway responsiveness. The multi-dose dropper bottle of albuterol sulfate solution contains 50 μg BAC per/2.5 mg of albuterol, which may be below or at the lower limit of the threshold dose for bronchoconstriction. However, with repeated albuterol nebulization, the effect can be additive and cumulative, often exceeding the bronchoconstriction threshold. We report a case of a 17 years old patient, who received 32 mg of BAC via nebulization over a period of 3.5 days that probably caused persistent bronchospasm evidenced by failure to improve clinically and to increase peak expiratory flow rate (PEFR from 125 L/min (27% of predicted value to 300 L/min (68% of predicted value within 2 hours of withdrawing BAC. The patient's respiratory status and PEFR improved dramatically once the nebulization solution was switched to BAC free lev-albuterol solution. The pediatric providers, particularly the emergency department physicians, intensivists and pulmonologists need to be aware of this rare albeit possible toxicity to the respiratory system caused by BAC used as a preservative in albuterol nebulizer solution.

  19. Ocular Inflammation and Corneal Permeability Alteration by Benzalkonium Chloride in Rats: A Protective Effect of a Myosin Light Chain Kinase Inhibitor

    Science.gov (United States)

    Droy-Lefaix, Marie Thérèse; Bueno, Lionel; Caron, Philippe; Belot, Eric; Roche, Olivier

    2013-01-01

    Purpose. The aim of this study was to evaluate the interest of an ophthalmic eyedrop preparation containing a myosin light chain kinase (MLCK) inhibitor, ML-7, in the treatment of ocular surface. The local protective effect on the inflammation and the increase of corneal permeability induced by benzalkonium (BAK) was evaluated. Methods. An ocular instillation of 10 μL BAK at a concentration of 0.1% in PBS was performed on rats. The eyes were rinsed with sterilized water, 10 minutes after BAK preceded by instillation at T −24, −12, and −0.5 hours of 10 μL of ML-7: 100 μg (10 μL) into a gel form vehicle. All animals were sacrificed 6 hours after BAK instillation. The eyes were isolated for study in a masked manner. The ocular surface inflammation was assessed by measuring the inflammatory cell infiltration by a histologic quantitative analysis and for total ocular myeloperoxidase (MPO) activity. The tight junction permeability was tested. Results. Instillation of 0.1% BAK increased the inflammation of the eye. The quantitative analysis showed an increase in the number of eosinophil and neutrophil polynuclears, and MPO activity. Pretreatment with ML-7 reduced inflammation (P < 0.05). The vehicle alone produced no notable effects. BAK instillation also thickened the fluorescent corneal front on frozen sections, indicating an increase of tight junction permeability. Pretreatment with ML-7 suppressed BAK-induced alterations of paracellular permeability while the vehicle had no visible effects. Conclusions. Our study indicates that the inhibition of corneal cytoskeleton contraction by an MLCK inhibitor prevents BAK-induced ocular inflammatory response, and that ML-7 may be a new and original preparation in the treatment of ocular surface pathologies. PMID:23518768

  20. Interactions between Surfactants in Solution and Electrospun Protein Fibers: Effects on Release Behavior and Fiber Properties.

    Science.gov (United States)

    Stephansen, Karen; García-Díaz, María; Jessen, Flemming; Chronakis, Ioannis S; Nielsen, Hanne M

    2016-03-07

    Intermolecular interaction phenomena occurring between endogenous compounds, such as proteins and bile salts, and electrospun compounds are so far unreported, despite the exposure of fibers to such biorelevant compounds when applied for biomedical purposes, e.g., tissue engineering, wound healing, and drug delivery. In the present study, we present a systematic investigation of how surfactants and proteins, as physiologically relevant components, interact with insulin-loaded fish sarcoplasmic protein (FSP) electrospun fibers (FSP-Ins fibers) in solution and thereby affect fiber properties such as accessible surface hydrophilicity, physical stability, and release characteristics of an encapsulated drug. Interactions between insulin-loaded protein fibers and five anionic surfactants (sodium taurocholate, sodium taurodeoxycholate, sodium glycocholate, sodium glycodeoxycholate, and sodium dodecyl sulfate), a cationic surfactant (benzalkonium chloride), and a neutral surfactant (Triton X-100) were studied. The anionic surfactants increased the insulin release in a concentration-dependent manner, whereas the neutral surfactant had no significant effect on the release. Interestingly, only minute amounts of insulin were released from the fibers when benzalkonium chloride was present. The FSP-Ins fibers appeared dense after incubation with this cationic surfactant, whereas high fiber porosity was observed after incubation with anionic or neutral surfactants. Contact angle measurements and staining with the hydrophobic dye 8-anilino-1-naphthalenesulfonic acid indicated that the FSP-Ins fibers were hydrophobic, and showed that the fiber surface properties were affected differently by the surfactants. Bovine serum albumin also affected insulin release in vitro, indicating that also proteins may affect the fiber performance in an in vivo setting.

  1. Ion-pair hollow-fiber liquid-phase microextraction of the quaternary ammonium surfactant dicocodimethylammonium chloride.

    Science.gov (United States)

    Hultgren, Sofie; Larsson, Niklas; Nilsson, Bo F; Jönsson, Jan Ake

    2009-02-01

    A two-phase hollow-fiber (HF) liquid-phase microextraction (LPME) method was developed for determination of a quaternary ammonium compound surfactant, dicocodimethylammonium chloride, in aqueous samples. The porous HF was fixed on a metal rod support and was impregnated with approximately 6.6 microL of organic extractant, which was immobilized in the HF pores. Surfactant extraction was facilitated by addition of carboxylic acid to the sample forming neutral ion pairs with the quaternary ammonium compound. After extraction, the analyte was transferred from the organic extractant in the fiber pores by dissolving the 1-octanol into 100 microL methanol. The methanol extract was analyzed by liquid chromatography-mass spectrometry. The method was optimized (with optimized parameters in brackets) with regard to type of organic extractant (1-octanol), fiber length (2 cm), choice and concentration of anionic carrier (600 microg L(-1) octanoate), procedure of transfer to methanol (15-min sonication), sample volume (250 mL), extraction time (17 h), pH (10), and ionic strength (50 mM carbonate). Aspects influencing repeatability in LPME of (quaternary ammonium) surfactants are discussed. The enrichment factor achieved in 250-mL carbonate buffer was around 400. Due to matrix effects, the enrichment factors achieved when industrial process water was analyzed were 120 or about 30% of that in carbonate buffer. Detection limits of 0.3 microg L(-1) in carbonate buffer and 0.9 microg L(-1) in industrial process water were obtained. If the studied compound is seen as a model substance representing quaternary dialkylated dimethylated ammonium surfactants in general, the developed method may be applied to other quaternary ammonium surfactants.

  2. [The influence of an isotonic solution containing benzalkonium chloride and a hypertonic seawater solution on the function of ciliary epithelium from the nasal cavity in vitro].

    Science.gov (United States)

    Laberko, E L; Bogomil'sky, M R; Soldatsky, Yu L; Pogosova, I E

    2016-01-01

    The objective of the present study was to evaluate the influence of an isotonic saline solution containing benzalconium chloride and of a hypertonic seawater solution on the function of ciliary epithelium in the nasal cavity in vitro. To this effect, we investigated the cytological material obtained from 35 children presenting with adenoid tissue hypertrophy. The tissue samples were taken from the nasal cavity by the standard method. A cellular biopsy obtained from each patient was distributed between three tubes that contained isotonic saline solution supplemented by benzalconium chloride (0.1 mg/ml), a hypertonic seawater solution, and a standard physiological saline solution. It was shown that the number of the viable cells in both isotonic solutions was statistically comparable and significantly higher than in the hypertonic solution (p<0.05). The ciliary beat frequency of the cells embedded in the two isotonic solutions was not significantly different but considerably exceeded that in the hypertonic seawater solution (p<0.05). Thus, the present study has demonstrated the absence of the ciliotoxic influence of isotonic saline solution containing benzalconium chloride at a concentration of 0.1 mg/ml and the strong ciliotoxic effect of the hypertonic seawater solution. This finding gives reason to recommend isotonic solutions for the regular application whereas hypertonic solutions can be prescribed only during infectious and/or inflammatory ENT diseases.

  3. 苯扎氯铵对食管下端肌间神经毁损效果的研究%The effect of benzalkonium chloride in the damage of the myenteric plexus of lower esophagus in rats

    Institute of Scientific and Technical Information of China (English)

    赵艳民; 梁振; 李仲荣; 朱利斌; 刘征吉; 陈肖鸣

    2009-01-01

    目的 观察苯扎氯铵(BAC)毁损食管下端括约肌肌间神经的效果及毁损后不同时间神经组织的改变,为建立合适的贲门失迟缓症动物模型奠定基础.方法 80只健康的雄性SD大鼠随机分为二组:BAC组和生理盐水对照组各40只;开腹手术将0.4%BAC脑棉敷于大鼠食管下端30 min,术后1、2、4、8周分别处死大鼠,观察食管下端肌间神经组织的变化.结果 术后1周BAC组食管下端出现部分肌间神经元、神经纤维变性坏死;术后第二周肌间神经元密度为(1.25±1.58)个/横切面,与对照组(5.38±2.33)个/横切面相比,明显减少(P<0.01);术后4周和术后8周肌间神经元进一步减少,但这种减少与术后第二周的差异无统计学意义(P>0.05).BAC对不同神经递质的神经元毁损为非选择性的.结论 0.4BAC能成功毁损大鼠食管下端肌间神经元,肌间神经元毁损的动物玎丁用于贲门失弛缓症实验研究.%Objective To establish the appropriate animal model of achalasia in the cardia and to observe the effect of Benzalkonium Chloride(BAC) in the damag of the myenteric plexus of lower esophagus in rats and the changes of neurons at different time points.Methods Eighty male SD rats were randomly divided into two experimental groups (40 rats respectively in the BAC group and control groups).The 0.4% benzalkonium chloride was applied on the lower esophagus for 30 minutes during the laparotomy on rats.The changes of the neuron in lower esophagus were observed under microscope after sacrifice of rats at 1,2,4 and 8 weeks respectively.Results One week after the operation,degeneration and necrosis were observed in parts of the neurons and the nerve fibers in the myenteric plexus of lower esophagus in the BAc group.Two weeks after the operation,density of neurons in BAC group was 1.25±0.71 neurons per cross section,which was significantly lower than that in the control group (5.38±2.33 neurons per cross section

  4. Silver Nanoparticles-Based Nano-drop Spectrophotometric Determination of Cationic Surfactants Coupled with Hydrophobic Interaction; An Application to Pharmaceuticals and Environmental

    Directory of Open Access Journals (Sweden)

    Ashima Sharma

    2016-10-01

    Full Text Available The proposed work describes the nanodrop spectrophotometric determination of cationic surfactants using citrate-modified silver nanoparticles based on the aggregation of silver nanoparticles induced by cationic surfactants due to the hydrophobic effect. The visible color change in the solution of silver nanoparticle includes a red shift with the quenching of the absorption spectra. The maximum absorbance was measured at wavelength,λmax400 nm. The concentrations of cationic surfactants were determined using a nanodrop spectrophotometer with limits of detection of 15.0, 8.0, 6.0, 5.8, and 13.0 µM for dodecyl trimethyl ammonium bromide, myristiltrimethyl ammonium bromide, cetrimoniumtrimethyl ammonium bromide, cetylpyridinium chloride and benzalkonium chloride, respectively. The proposed method was successfully applied for the determination of cetylpyridinium chloride in commercial mouthwasher, gum astringent and nasal spray pharmaceuticals and environmental samples.

  5. 高效液相色谱法测定化妆品中苯扎氯铵%Determination of benzalkonium chloride in cosmetics by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    张鹏祥; 曹蕊; 高晓譞; 尹家振; 张明明; 赵华

    2012-01-01

    采用高效液相色谱法测定化妆品中苯扎氯铵的含量.色谱条件为:Agilent Zorbax CN柱(250 mm×4.6 mm i.d.,5μm),流动相为V(乙腈)∶V(0.1 mol· L-1醋酸铵缓冲溶液(冰醋酸调pH =5.0))=70∶30的混合溶液,流速1.0 mL·min-1,检测波长260 nm,柱温25℃,进样量20 μL.结果表明,该方法的检出限为130μg·g-1,线性范围为5~100 mg ·L-1,回收率为92.0%~110.6%,RSD为0.32%~2.10%.%A high performance liquid chromatographic method was established for the determination of benzalkonium chloride in cosmetics. Chromatography separation was carried out on a Agilent Zorbax CN column (250 mm × 4. 6 mm i. d. ,5 μm), using acetonitrile with 0. 1 mol · L-1 ammonium acetate (70: 30 volume ratio and pH adjusted to 5.0 by glacial acetic acid) as mobile phase. The flow rate was 1.0 mL · min-1 and the column temperature was 25℃. Detection was carried out at 260 nm. The limit of detection is 130 μg · g-1. Linear plot ranges between 5 ~ 100 mg · L-1. Average recoveries are 92.0% -110.6% with relative standard deviations of 0. 32% ~2. 10%.

  6. Ultrastructural effects of acetone and benzalkonium chloride on the stratum corneum lipids in murine epidermis%丙酮和氯化苯甲烃铵对角质层脂质超微结构的影响

    Institute of Scientific and Technical Information of China (English)

    姜少军; 周晓军

    2003-01-01

    本文用裸鼠作为实验动物对化学刺激性物质导致角质层脂态的变化进行超微结构的研究.裸鼠表皮经丙酮和氯化苯甲烃铵处理后,样品用四氧化钌固定.超微结构观察表明由于丙酮和氯化苯甲烃铵的刺激作用导致角质层脂质形态的变化、角质层脂质的抽提以及在角质细胞之间形成腔隙.结果表明四氧化钌对角质层脂质有良好的固定作用,并清晰地展示出丙酮和氯化苯甲烃铵对角质层脂质的影响.%To gain a better understanding of the interaction of chemically different irritants with the stratum corneum lipids, the morphological changes of the stratum corneum lipids resulting from the chemical irritants in murine epidermis were investigated. Node mice were treated topically with either acetone or 2% benzalkonium chloride, the visualization of the stratum corneum was carried out using a special fixation method utilizing 0.25% ruthenium tetroxide as the post-fixative. Ultrastructural observation demonstrated obvious distortions within the intercellular domains of the stratum corneum, including disorganization of lipid bilayers, lipid extraction, and lacunae formation. The results of this study indicated that ruthenium tetroxide is a preferable post-fixative for the study of the stratum corneum lipids, and provide evidence that different irritants induce distinct alterations within the stratum corneum to reflect the specific interaction with the stratum corneum lipids.

  7. 高效液相色谱法测定重组人干扰素α1b滴眼液中苯扎氯铵的含量%Determination of benzalkonium chloride content in recombinant human interferon a1b eye drops by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    牛晓霞; 曹艳; 吴美英

    2013-01-01

    Objective To determine the benzalkonium chloride content in recombinant human interferon α1b (rhIFNα1b) eye drops by high performance liquid chromatography (HPLC).Methods The benzalkonium chloride content in rhIFNα1b eye drops was determined by HPLC.A Waters Symmetry C18 column was used with the mobile phase of V(A):V(B) =65:35 [A:acetonitrile; B:5 mmol/L ammonium acetate containing 1% triethylamine,adjusted with acetic acid to pH(5.0 ± 0.2)] at a flow rate of 1.0 ml/min.The detection wavelength,sample load and column temperature were 262 nm,20 μl and room temperature,respectively.The method was verified,and used for determination of benzalkonium chloride contents in three batches of rhIFNα1b eye drops.Results The method showed good specificity and suitability in determination of benzalkonium chloride content,of which the minimum detection limit and minimum quantitation limit were 0.53 and 1.48 μg/ml respectively.The standard curve showed good linearity within a benzlkonium chloride concentration range of 10 ~ 50 μg/ml (R2 =0.9991).The RSD of peak areas of six samples loaded were 1.78%.The mean recovery rate of samples at theoretical benzalkonium chloride concentrations of 22,24 and 26 μg/ml was 97.90%,with a RSD of 0.96%.The relative benzalkonium chloride contents in three batches of rIFNα1b eye drops were 19.27,19.89 and 19.76 μg/ml,which were 96.34%,94.46% and 98.80% of stated amounts,respectively.Conclusion The developed HPLC method was simple,sensitive and accurate,which might be used for determinatioin of benzalkonium chloride content in recombinant human interferon α1b eye drops.%目的 采用高效液相色谱法(high performance liquid chromatography,HPLC)测定重组人干扰素α1b(recombinant human interferon α1b,rhIFNα1b)滴眼液中苯扎氯铵(benzalkonium chloride)的含量.方法 采用HPLC法测定rhIFNα1b滴眼液中苯扎氯铵含量,色谱条件:流动相:乙腈:5 mmol/L醋酸铵[含1%三乙胺

  8. Non-covalent bonding interaction of surfactants with functionalized carbon nanotubes in proton exchange membranes for fuel cell applications.

    Science.gov (United States)

    Sayeed, M Abu; Kim, Young Ho; Park, Younjin; Gopalan, A I; Lee, Kwang-Pill; Choi, Sang-June

    2013-11-01

    Dispersion of functionalized multiwalled carbon nanotubes (MWCNTs) in proton exchange membranes (PEMs) was conducted via non-covalent bonding between benzene rings of various surfactants and functionalized MWCNTs. In the solution casting method, dispersion of functionalized MWCNTs in PEMs such as Nafion membranes is a critical issue. In this study, 1 wt.% pristine MWCNTs (p-MWCNTs) and oxidized MWCNTs (ox-MWCNTs) were reinforced in Nafion membranes by adding 0.1-0.5 wt.% of a surfactant such as benzalkonium chloride (BKC) as a cationic surfactant with a benzene ring, Tween-80 as a nonanionic surfactant without a benzene ring, sodium dodecylsulfonate (SDS) as an anionic surfactant without a benzene ring, or sodium dodecylben-zenesulfonate (SDBS) as an anionic surfactant with a benzene ring and their effects on the dispersion of nanocomposites were then observed. Among these surfactants, those with benzene rings such as BKC and SDBS produced enhanced dispersion via non-covalent bonding interaction between CNTs and surfactants. Specifically, the surfactants were adsorbed onto the surface of functionalized MWCNTs, where they prevented re-aggregation of MWCNTs in the nanocomposites. Furthermore, the prepared CNTs reinforced nanocomposite membranes showed reduced methanol uptake values while the ion exchange capacity values were maintained. The enhanced properties, including thermal property of the CNTs reinforced PEMs with surfactants, could be applicable to fuel cell applications.

  9. Evidence of self-aggregation of cationic surfactants in a choline chloride+glycerol deep eutectic solvent.

    Science.gov (United States)

    Pal, Mahi; Singh, Ranjan K; Pandey, Siddharth

    2015-08-24

    Based on fluorescence probe, electrical conductivity, surface tension, small-angle X-ray/dynamic light scattering, and transmission electron microscopy experiments, we present the first clear lines of evidence for self-aggregation of cationic surfactants of the n-alkyltrimethylammonium family within an archetypical deep eutectic solvent comprised of a 1:2 molar mixture of choline chloride and glycerol. Estimated thermodynamic parameters suggest this self-aggregation process to be less entropically driven than that in water. These novel water-free self-assemblies might serve as dynamic soft templates to direct the growth of size- or shape-tailored nanoparticles within water-restricted media. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Clinical Observation of Benzalkonium Chloride and Povidone-Iodine in Treatment of 56 Cases with Large Area of Skin Defect and Infection in Limbs%苯扎氯铵与碘伏治疗肢体大面积皮肤缺损并感染56例临床观察

    Institute of Scientific and Technical Information of China (English)

    孙鲁; 刘恒平; 王明喜

    2012-01-01

    Objective To observe the effect of benzalkonium chloride and povidone-iodine in the treatment of patients with large area of skin defect and infection in limbs. Methods Total 56 cases with large area of skin defects and infection in limbs in our hospital from September 2008 to November 2010 were randomly divided into two groups. After the debridement surgery and skin flap or skin graft surgery, benzalkonium chloride and povidone-iodine irrigation treatment were performed, the efficacy of two disinfectants and local adverse reactions were observed. Results The total effective rate was 96. 43% in the benzalkonium chloride group and 85. 71% in the povidone-iodine group. The growth of granulation,elongation of skin,effect of internal fixation materials on wound and the incidence of complication in the benzalkonium chloride group were better as compared to the povidone-iodine group. There was statistically significance,P <0. 05. Conclusion The benzalkonium chloride can accelerate wound healing, it has a strong bactericidal control on the local infection, and has non-irritating to the skin. It is the first choice for the treatment of antibacterial drugs for clinical disinfection.%目的 观察苯扎氯铵与碘伏治疗肢体大面积皮肤缺损并感染的效果.方法 将我院收治的56例肢体大面积皮肤缺损并感染患者随机分为两组,在清创手术及皮瓣转移术或皮肤移植术后分别采用苯扎氯铵与碘伏冲洗治疗,观察两种消毒剂的疗效、并发症、肉芽生长速度、皮肤爬行速度及内固定材料对创面的影响.结果 苯扎氯铵组总有效率96.43%,碘伏组总有效率为85.71%,苯扎氯铵组的肉芽生长速度、皮肤爬行速度、内固定材料对创面的影响、并发症发生率方面均明显优于碘伏组,上述指标组间差异均具有统计学意义(P值均<0.05).结论 苯扎氯铵能加速创面的愈合,有较强的杀菌、控制局部感染作用,且对皮肤无刺激性,临床

  11. Surfactive and antibacterial activity of cetylpyridinium chloride formulations in vitro and in vivo

    NARCIS (Netherlands)

    Busscher, Hendrik; White, Don J; Atema-Smit, Jelly; Geertsema-Doornbusch, Geessien; de Vries, Jacob; van der Mei, Henderina

    2008-01-01

    Aim: To compare effects of three cetylpyridinium chloride (CPC) formulations with and without alcohol and Tween80 on physico-chemical properties of salivary pellicles, bacterial detachment in vitro and bacterial killing in vivo. Material and Methods: Adsorption of CPC to salivary pellicles in vitro

  12. Determination of benzalkonium chloride concentration in tobramycin in-situ forming eye gel by high performance liquid chromatography%高效液相色谱法测定妥布霉素眼用即用型凝胶中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    刘修树; 汤国平

    2012-01-01

    目的:建立高效液相色谱(HPLC)法测定妥布霉素眼用即用型凝胶中苯扎氯铵的含量.方法:HPLC法色谱柱为Kromasil C18(250.0 mm×4.6 mm,5 μm),0.07 mol/L乙酸铵溶液(含1%三乙胺,冰乙酸调节pH值至5.0)-乙腈(70:30)为流动相;检测波长215 nm,柱温35 ℃,流速0.8 ml/min.结果:苯扎氯铵在16.22~81.10 μg/ml范围内呈良好的线性关系(r=0.999 8,n=5),回归方程为Y ∧=6 091.9X+10 114,平均回收率为99.85%,RSD为1.07%.结论:该法简便、灵敏、准确、重复性好,可用于妥布霉素眼用即用型凝胶中的苯扎氯铵的含量控制.%Objective: To establish a high performance liquid chromatography ( HPLC ) method for the determination of benzalkonium chloride in tobramycin in-situ forming eye gel. Methods:HPLC,the chromatographic column was Kromasil C18(250. 0 mm ×4. 6 mm, 5 (j,m) ,the mobile phase 0.07 mol/L ammonium acetate solution(including 1% triethylamine,adjusting with glacial acetic acid to pH 5. 0) -acetonitrile(70: 30). The detection wavelength 215 nm,the column temperature 35 ℃ ,the flow rate was 0. 8 ml/min. Results: The calibration curve was linear in the range of 16. 22 —81. 10 μg/ml for benzalkonium chloride ( r = 0. 999 8, n = 5 ) , the regression equation was Y =6 091. 9X + 10 114,the average recovery was 99. 85% ,RSD was 1. 07%. Conclusions: The method is convenient, sensitive and accurate with a good repeatability for the determination of benzalkonium chloride in tobramycin in-situ forming eye gel.

  13. Effects of benzalkonium chloride on MUC1 in human conjunctival epithelial cells%苯扎氯铵对人结膜上皮细胞黏蛋白MUC1表达的影响

    Institute of Scientific and Technical Information of China (English)

    刘扬; 刘祖国; 许传超; 李朝阳; 陈小平; 虞东芳

    2010-01-01

    目的 探讨防腐剂苯扎氯铵(BAC)对体外培养的人结膜上皮细胞黏蛋白MUC1表达的影响及毒性作用.方法 采用培养的3~5代人结膜上皮细胞,将不同浓度(0.0100%、0.0050%、0.0010%、0.0005%、0.0001%)的BAC单次作用于结膜上皮细胞15 min,分别于处理细胞后0、6、12、24、48、72 h提取RNA及蛋白,采用RT-PCR及Western杂交方法检测MUC1表达水平.结果 0.0100%和0.0050%BAC作用后12~72 h可观察到结膜上皮细胞MUC1基因表达下调,0.0010%和0.0005%BAC作用后,24~48 h出现MUC1基因表达的下调,72 h恢复.0.0100%BAC作用后6~72 h检测到MUC1蛋白表达下降,而0.0050%BAC作用后12~72 h MUC1蛋白表达下降,0.0010%BAC作用后72 h MUC1蛋白表达减少.结论 BAC具有下调人结膜上皮细胞MUC1表达的作用,其下调作用具有时间依赖性和剂量依赖性.%Objective To investigate the effects of benzalkonium chloride ( BAC), a preservative used in many ophthalmic topical solutions, on mucinl ( MUC1 ) in human conjunctival epithelial cells in vitro.Methods Cultured epithelial cells obtained from human conjunctiva were exposed to medium containing BAC solutions at 0.0100% , 0.0050% , 0.0010% , 0.0005% and 0.0001% concentrations for a period of 15 min.Cells were examined after treatment and 6,12, 24, 48 and 72 h later.The relative expression of the MUC1 mucin gene was determined by conventional reverse transcription-polymerase chain reaction (RT-PCR).Monoclonal antibody for MUC1 was used in Western blot analysis to detect MUC1.Results Cell exposure to 0.0100% and 0.0050% BAC decreased the expression of MUC1 at gene level between 12 and 72 h after treatment Cells treated with 0.0010% and 0.0005% BAC decreased the expression of MUC1 between 24 and 48 h after treatment,recovered 72 h after treatment.At protein level, cells exposed to 0.0100% BAC decreased MUC1 between 24 and 72 h, 0.0050% BAC between 12 and 72 h, 0.0010% BAC 72 h later.Conclusions These results suggest

  14. 利用小鼠炎症模型评价苯扎氯铵的黏膜毒性%Determination of mucosal toxicity of benzalkonium chloride by using an inflammatory factor mice model

    Institute of Scientific and Technical Information of China (English)

    袁松华; 贲银银; 李亮助

    2012-01-01

    Objective To determine mucosal toxicity of benzalkonium chloride (BZK) by using an inflammatory factor mice model, so as to reveal the safety and application prospect of BZK. Methods BZK gel at the concentrations of 0. 02% ,0. 2% and 2% were intra-vaginally administered to the mice for 3 consecutive days, and vaginal washes of each mouse were collected daily. Six inflammatory cytokines in vaginal washes, including interleukin (IL-2, IL-4, IL-6 , IL-17A, tumor necrosis factor (TNF)- a and interferon (IFN)- y, were detected by a cytometric bead array (CBA) assay. Hematoxylin-eosin (HE) stain was also used in the present study to verify histopathological damages caused by different concentrations of BZK. Results Compared to the placebo group, BZK at 2% induced obvious disruptions on vaginal epithelium, while the groups treated with BZK at 0. 02% and 0. 2% had little histopathological change. However, BZK at 0. 2% significantly upregulated secretions of IL-6 and TNF-ain in vaginal washes, while BZK at both 0. 02% and 2% had no much impact on the expressions of these six cytokines. Conclusions BZK at 2% and 0. 2% caused toxicity on topical mucosal sites; BZK at 0. 02% displayed good tolerability for vaginal mucosa of the mice and BZK' s ability of inhibiting infections of pathogens needs further testing.%目的 利用小鼠黏膜炎症因子模型,研究不同浓度苯扎氯铵(BZK)对生殖道黏膜的刺激毒性,以探究BZK作为黏膜用药物的安全性和应用前景.方法 连续三天用浓度为0.02%、0.2%和2%的BZK凝胶处理小鼠阴道黏膜,每天收集小鼠阴道灌洗液,用多指标流式蛋白定量技术(Cytometric Bead Array,CBA)检测其中的6种炎症因子[白介素(Interleukin,IL)-2、IL-4、IL-6、IL-17A和肿瘤坏死因子(Tumor necrosis factor,TNF)-α、γ干扰素(Interferon γ,IFN)-γ]的表达情况;利用苏木紫-伊红(Hematoxylin-Eosin,HE)染色法对小鼠阴道黏膜的病理学损伤情况进行观察.结果 2%

  15. Influence of surfactant on dynamics of photoinduced motions and light emission of a dye-doped deoxyribonucleic acid

    Science.gov (United States)

    Sznitko, Lech; Parafiniuk, Kacper; Miniewicz, Andrzej; Rau, Ileana; Kajzar, Francois; Niziol, Jacek; Hebda, Edyta; Pielichowski, Jan; Sahraoui, Bouchta; Mysliwiec, Jaroslaw

    2013-10-01

    Pure deoxyribonucleic acid (DNA) is known to be soluble in water only and exhibits poor temperature stability. In contrary, it is well known that the complex of DNA - with cetyltrimethyl ammonium (CTMA) is insoluble in water but soluble in alcohols and can be processed into very good optical quality thin films by solution casting or spin deposition. Despite the success of DNA-CTMA, there is still need for new cationic surfactants which would extend the range of available solvents for DNA complex. We test and present experimental results of influence of new surfactants replacing CTMA in the DNA complex and based on benzalkonium chloride (BA) and didecyldimethylammonium chloride (DDCA) on their optical properties. Particularly, we were interested in all optical switching and light generation in amplified spontaneous emission process in these materials.

  16. Identification of co-existing cationic surfactants with preliminary separation on silica HPTLC plates using mixed aqueous sodium chloride-ethanol as eluent

    Directory of Open Access Journals (Sweden)

    Ali Mohammad

    2015-12-01

    Full Text Available A new high-performance thin-layer chromatographic system comprising of silica gel 60 HPTLC plates as stationary phase and ethanol-5% aqueous sodium chloride (8:2 as mobile phase has been identified as most suitable for separation of quaternary mixture of cationic surfactants. Separation efficacy of developed method has been established by obtaining well-resolved densitogram of separated spots. To check the versatility, effects of presence of metal cations, inorganic anions, amino acids, vitamins and non-ionic surfactants as impurities were also examined. The chromatographic parameters like ΔRF, separation factor (α, resolution (RS and limit of detection were also calculated. The proposed method is applicable for the identification of surfactants in eye drops and Colgate Plax mouthwash.

  17. A Fourier transform infrared spectroscopic study of dodecyltrimethylammonium chloride/sodium dodecyl sulfate surfactant mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Scheuing, D.R.; Weers, J.G. (Clorox Technical Center, Pleasanton, CA (USA))

    1990-03-01

    The utility of FT-IR in characterizing the composition-dependent changes in packing of DTAC and SDS in mixed micelles is demonstrated. As the mixed micelle composition becomes equimolar, the micelle aggregation number is known to increase, indicating a spherical to nonspherical micelle shape change. The frequency of the composite CH{sub 2} stretching bands decreases as the composition becomes equimolar, suggesting a decrease in the gauche/trans conformer ratio in the tails of the surfactants, which is a result of the increased crowding of the methylene chains accompanying the shape change. The use of SDS-d{sub 25} allows confirmation of this trend through the inspection of the shifts in the CH{sub 2} stretching bands (DTAC tails) and the CD{sub 2} stretching bands (SDS-d{sub 25} tails). Electrostatic interactions between the headgroups of DTAC and SDS can also be monitored spectroscopically. The shifts in the asymmetric and symmetric S-O stretching bands with micelle composition indicate an increase in SDS headgroup ordering in SDS-rich mixed micelles and a dominance of interactions with DTA{sup +} ions in DTAC-rich micelles.

  18. 聚乙二醇滴眼液对拉坦前列腺素眼表毒性的中和作用%Neutralization of polyethylene glycol on ocular surface toxicity induced by benzalkonium chloride-preserved latanoprost

    Institute of Scientific and Technical Information of China (English)

    余芬芬; 钟毅敏; 李媚; 毛真; 郭歆星; 杨莎莎; 曹丹; 肖辉; 刘杏

    2013-01-01

    Background Reducing ocular surface toxicity induced by topical antiglaucoma medications,and thus improving the therapeutic compliance of glaucomatous patients to treating drug become an urgent issue in the long-term antiglaucomatous therapies.Whether polyethylene glycol,a new type of artificial tear,can play a protective role from ocular surface toxicity induced by topical antiglaucoma medications remains further study.Objective The present study was to investigate the protective effect of polyethylene glycol on ocular surface toxicity induced by prolonged use of benzalkonium chloride-preserved latanoprost eye drops.Methods Thirty adult female New Zealand rabbits were randomly divided into normal control group,phosphate buffer solution (PBS) group and polyethylene glycol eye drops group.PBS with 0.005% latanoprost was topically administered for consequent 60 days in the PBS group,and 0.005% latanoprost with polyethylene glycol eye drops was used at the same way in the polyethylene glycol group.Schirmer Ⅰ test,fluorescein and rose bengal staining of cornea and conjunctiva,conjunctiva impression cytology specimens collecting were performed before experiment as well as 31 and 61 days after administration of drug.Histomorphological and ultrastructural changes of cornea and conjunctiva were observed under the light microscopy,scanning and transmission electron microscopy on day 61.Results The score of corneal fluorescine staining was significantly different among the control group,PBS group and polyethylene glycol group (H =25.265,P<0.001 ;H=29.426,P<0.001) on day 31 and day 61.Significant difference also was found in the score of rose bengal staining of cornea and conjunctiva (H=26.167,P<0.001 ;H =29.212,P<0.001),Schirmer Ⅰ test value (F=4.746,P<0.05) and conjunctival goblet cell density (F=18.055,P<0.001).Compared with the control group,corneal fluorescein scores [0(0,1.0) vs.3 (2.0,3.0)] and rose bengal scores [0(0,1) vs.2(2,3)] were significantly

  19. Giant extracellular Glossoscolex paulistus Hemoglobin (HbGp) upon interaction with cethyltrimethylammonium chloride (CTAC) and sodium dodecyl sulphate (SDS) surfactants: Dissociation of oligomeric structure and autoxidation.

    Science.gov (United States)

    Santiago, Patricia S; Moreira, Leonardo M; de Almeida, Erika V; Tabak, Marcel

    2007-04-01

    The effects of two ionic surfactants on the oligomeric structure of the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) in the oxy - form have been studied through the use of several spectroscopic techniques such as electronic optical absorption, fluorescence emission, light scattering, and circular dichroism. The use of anionic sodium dodecyl sulphate (SDS) and cationic cethyltrimethyl ammonium chloride (CTAC) has allowed to differentiate the effects of opposite headgroup charges on the oligomeric structure dissociation and hemoglobin autoxidation. At pH 7.0, both surfactants induce the protein dissociation and a significant oxidation. Spectral changes occur at very low CTAC concentrations suggesting a significant electrostatic contribution to the protein-surfactant interaction. At low protein concentration, 0.08 mg/ml, some light scattering within a narrow CTAC concentration range occurs due to protein-surfactant precipitation. Light scattering experiments showed the dissociation of the oligomeric structure by SDS and CTAC, and the effect of precipitation induced by CTAC. At higher protein concentrations, 3.0 mg/ml, a precipitation was observed due to the intense charge neutralization upon formation of ion pair in the protein-surfactant precipitate. The spectral changes are spread over a much wider SDS concentration range, implying a smaller electrostatic contribution to the protein-surfactant interactions. The observed effects are consistent with the acid isoelectric point (pI) of this class of hemoglobins, which favors the intense interaction of HbGp with the cationic surfactant due to the existence of excess acid anionic residues at the protein surface. Protein secondary structure changes are significant for CTAC at low concentrations while they occur at significantly higher concentrations for SDS. In summary, the cationic surfactant seems to interact more strongly with the protein producing more dramatic spectral changes as compared to the

  20. 维生素A治疗苯扎氯铵诱导的小鼠干眼的实验研究%Therapeutic effects of Vitamin A on mouse dry eye induced by benzalkonium chloride topical medication

    Institute of Scientific and Technical Information of China (English)

    何欢; 刘祖国; 肖辛野; 林志荣; 周彤; 何卉

    2012-01-01

    Objective To investigate the therapeutic effect of Vitamin A on the recovery of dry eye that was induced by benzalkonium chloride (BAC) topical medication in the mouse.Methods In this randomized controlled experimental study,50 BALB/c mice were treated with the topical administration of 0.25% BAC to establish the dry eye condition.Based on the consistency of tear film break-up time (BUT),corneal fluorescein staining scores and inflammation index,the eyes were re-selected and 30 mice were randomly divided into three groups on day 21 after the BAC treatment,with 10 mice (20 eyes) in each group.Group C was set up as a blank control,while groups A and B were treated with 5000 IU/(g·ml) Vitamin A eye drops and microemulsion solvent drops,respectively.BUTs,corneal fluorescein staining scores,inflammation index and tear volumes were evaluated in each group on days 0,1,3,5 and 7 after the therapeutic treatment.Global specimens were collected on day 7.Sections were stained with hematoxylin and eosin (HE) or by periodic acid-Schiff (PAS) assay,and labeled with cytokeratin 10 (K10) antibody.The expression of K10 in the cornea and conjunctiva was quantified by Western Blot.The data were analyzed by one-way ANOVAs.Results On days 0,1,3 and 5,no clinical differences were observed among the groups.On day 7,the BUT values were (4.20±0.89)s,(3.32±1.01)s and (3.28±0.74)s in groups A,B and C,respectively.The BUT in group A was significantly longer than those in groups B and C (F=6.852,P=0.002).The corneal fluorescein staining scores were 3.74±1.31,5.47±1.81 and 5.83±1.54 in groups A,B and C,respectively.The scores in group A were significantly lower than those in groups B and C (F=8.853,P<0.01).No significant differences were found in the corneal inflammatory index or tear volume among the groups.Corneal morphology showed a loosened corneal epithelium feature in groups B and C,but comeal integrity in group A.PAS assay revealed similar goblet cell numbers between group A

  1. Benzalkonium tolerance genes and outcome in Listeria monocytogenes meningitis.

    Science.gov (United States)

    Kremer, P H C; Lees, J A; Koopmans, M M; Ferwerda, B; Arends, A W M; Feller, M M; Schipper, K; Valls Seron, M; van der Ende, A; Brouwer, M C; van de Beek, D; Bentley, S D

    2017-04-01

    Listeria monocytogenes is a food-borne pathogen that can cause meningitis. The listerial genotype ST6 has been linked to increasing rates of unfavourable outcome over time. We investigated listerial genetic variation and the relation with clinical outcome in meningitis. We sequenced 96 isolates from adults with listerial meningitis included in two prospective nationwide cohort studies by whole genome sequencing, and evaluated associations between bacterial genetic variation and clinical outcome. We validated these results by screening listerial genotypes of 445 cerebrospinal fluid and blood isolates from patients over a 30-year period from the Dutch national surveillance cohort. We identified a bacteriophage, phiLMST6 co-occurring with a novel plasmid, pLMST6, in ST6 isolates to be associated with unfavourable outcome in patients (p 2.83e-05). The plasmid carries a benzalkonium chloride tolerance gene, emrC, conferring decreased susceptibility to disinfectants used in the food-processing industry. Isolates harbouring emrC were growth inhibited at higher levels of benzalkonium chloride (median 60 mg/L versus 15 mg/L; p <0.001), and had higher MICs for amoxicillin and gentamicin compared with isolates without emrC (both p <0.001). Transformation of pLMST6 into naive strains led to benzalkonium chloride tolerance and higher MICs for gentamicin. These results show that a novel plasmid, carrying the efflux transporter emrC, is associated with increased incidence of ST6 listerial meningitis in the Netherlands. Suggesting increased disease severity, our findings warrant consideration of disinfectants used in the food-processing industry that select for resistance mechanisms and may, inadvertently, lead to increased risk of poor disease outcome. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. The Role of Surfactants in the Stability of NiO Nanofluids: An Experimental and DFT Study.

    Science.gov (United States)

    Sánchez-Coronilla, Antonio; Navas, Javier; Aguilar, Teresa; Martín, Elisa I; Gallardo, Juan Jesús; Gómez-Villarejo, Mr Roberto; Carrillo-Berdugo, Mr Iván; Alcántara, Rodrigo; Fernández-Lorenzo, Concha; Martín-Calleja, Joaquín

    2017-02-17

    This study shows an analysis of the stability of nanofluids based on a eutectic mixture of diphenyl oxide and biphenyl, which is used as a heat transfer fluid (HTF) in concentrating solar energy, and NiO nanoparticles. Two surfactants are used to analyse the stability of the nanofluids: benzalkonium chloride (BAC) and 1-octadecanethiol (ODT). From an experimental perspective, the stability is analysed by means of UV/Vis spectroscopy, particle size measurements through the dynamic light-scattering technique, and ζ-potential measurements. The results show that the stability of the nanofluids improves with the use of BAC. DFT calculations are performed to understand the role played by the surfactants. The interaction of the surfactants with both the fluid and the NiO (100) surface is studied. Quantum theory of atoms in molecules (QTAIM) analysis shows that hydrogen bridge interactions favour the stability of the fluid-surfactant mixture. The more stabilising NiO-surfactant interaction involves the Ni-H interaction of the -SH and -CH3 groups of ODT and BAC. Also, nanofluids with BAC are favoured over those with ODT, which is in agreement with experimental results. The structural and electronic effects of incorporating the surfactant onto the NiO (100) surface are shown by using electron localisation function analysis, the non-covalent interaction index and projected density of states.

  3. Benzalkonium Chloride Solution Combined with Calcium Alginate Dressings in Elderly Diabetic Foot Wounds:A Series of Clinical Studies%苯扎氯铵溶液联合藻酸钙敷料治疗老年糖尿病患者足部病变的效果

    Institute of Scientific and Technical Information of China (English)

    闫雅凤; 侯惠如; 杨晶; 刘志英; 曹春玲; 郝亚静; 邱振瑜; 李瑾竹

    2012-01-01

    Objective To evaluate the treatment results and nursing effects of benzalkonium chloride solution combined with calcium alginate dressings used in elderly diabetic foot wounds. Methods From January 2009 to September 2011,62 elderly diabetic patients with wounds in our hospital were randomly divided into observational group(n= 31) and control group(n = 31). The control group adopted the conventional iodophor disinfection and used a small dose of insulin and gentamicin to wash the wound with yarn ball isolation and gauze dressing method. Based on the conventional sterilization, the observational group used benzalkonium chloride solution for 5-10 min,and took calcium alginate dressing to cover the wound isolation. Comparisons were conducted on healing time, healing effect, the time and number of dressing of skin lesions and patient satisfaction with care. Results Significant differences were observed on healing time,healing effect, the number of dressing changes, patient care and overall satisfaction (satisfied, more satisfied,dissatisfied) between the two kinds of foot care methods(P<0. 01). Conclusion Benzalkonium chloridesolution in combination with calcium alginate dressings for elderly patients with diabetes care in the early foot lesions can effectively shorten the healing time and improve wound healing effect, to reduce the total dressing number of nursing staff and significantly improve patient satisfaction, which is a suitable early efficient method for elderly patients with diabetic foot wounds .%目的 探讨苯扎氯铵溶液联合藻酸钙敷料应用于老年糖尿病患者足部病变的治疗与护理效果.方法 便利抽样法选择2009年1月至2011年9月在解放军总医院住院的老年糖尿病足部病变患者62例,采用随机数字表法将其分为对照组和观察组各31例,对照组采用常规聚维酮碘消毒后使用硫酸庆大霉素加入小剂量普通胰岛素冲洗伤口、纱球隔离、纱布包扎的方法 ;观察组则

  4. Therapeutic effects of Pranoprofen on the mouse dry eye induced by topical medication of Benzalkonium Chloride%普拉洛芬治疗苯扎氯铵诱导小鼠干眼的研究

    Institute of Scientific and Technical Information of China (English)

    何欢; 刘祖国; 林志荣; 刘晓琛; 何卉; 肖启国

    2012-01-01

    ,联合用药组上皮规整;PAS染色示普拉洛芬组及氟米龙组的杯状细胞数量相当,均多于人工泪液组及空白对照组.普拉洛芬组及氟米龙组的角膜上皮层均几乎不表达K10,而人工泪液组及空白对照组仍阳性表达.普拉洛芬组及氟米龙处理组角膜中的TNF-α水平均有下降.结论 普拉洛芬具有抑制苯扎氯铵溶液局部点眼诱导干眼眼表炎症的作用,有望用于干眼眼表炎症的临床治疗.%Objective Randomized controlled experimental study to investigate the therapeutic effect and the possible mechanism of Pranoprofen on the recovery of dry eye induced by topical medication of Benzalkonium Chloride (BAC) in mouse.Methods It was an experimental study.Seventy BALB/c mice were treated with topical administration of 0.25% BAC to establish the dry eye condition.Based on the consistency of break-up time of tear-film ( BUT ),corneal fluorescein staining scores and inflammation index,the eyes were re-selected and randomly divided into four groups on day (D) 21 after the BAC treatment.Group A was set up as blank control,while group B,C and D were treated respectively with 0.1% sodium hyaluronate eye drops,0.1% fluorometholone eye drops plus 0.1% sodium hyaluronate eye drops,0.1% pranoprofen eye drops plus 0.1% sodium hyaluronate eye drops.BUTs,tear volumes,corneal fluorescein staining scores and inflammation index were evaluated in each group on DO,1,3 and 5 after the therapeutic treatment.Global specimens were collected on D6.Sections were stained with hematoxylin and eosin (HE) or by periodic acid-schiff (PAS) assay,and labeled with cytokeratin 10 (K10) antibody.The expression of tumor necrosis factor-α (TNF-α) in the cornea and conjunctiva was quantified by western blot.Results 72 eyes were included in the sequential experiment,18 eyes for each group.On DO,1 and 3,no clinical differences were observed among the groups.On D5,the BUT was (2.933 ± 0.320),(2.900 ±0

  5. 苯扎氯铵溶液膀胱冲洗预防留置导尿患者尿路感染的实效性评价%Effectiveness of bladder irrigation with benzalkonium chloride solution in prevention of urinary tract infections in indwelling catheterization patients

    Institute of Scientific and Technical Information of China (English)

    黄达飞; 周青英; 孙学斌; 郑定钦; 徐乃奋

    2015-01-01

    目的:评价苯扎氯铵溶液膀胱冲洗预防长期留置导尿患者尿路感染的实效性,探讨苯扎氯铵对尿路感染的预防效果。方法选择2013年5月-2014年5月在医院治疗需要长期留置导尿患者76例,按照膀胱冲洗方式的不同将其随机分为A、B组,每组各38例;A组患者采用0.0025%苯扎氯铵溶液进行膀胱冲洗,B组患者采用0.9%生理盐水溶液进行膀胱冲洗,观察并比较两组患者尿路感染情况。结果膀胱冲洗第1周和第2周后A组患者尿液细菌培养阳性率分别为15.79%和21.05%,明显低于B组的52.63%和71.05%,两组比较差异有统计学意义(P<0.05);A组患者尿液中白细胞计数分别为(6.7±3.0)个/HP和(8.7±4.0)个/HP ,均低于相应B组的(11.5±4.4)个/HP和(16.7±6.7)个/HP ,两组比较差异有统计学意义(P<0.05);A组中段尿中总细菌数少于B组,其各类菌株构成比差异有统计学意义(P<0.05)。结论苯扎氯铵溶液膀胱冲洗在预防长期留置导尿患者下尿路感染方面具有很好的效果,冲洗后细菌阳性率低,值得临床推广应用。%OBJECTIVE To evaluate the effectiveness of bladder irrigation with benzalkonium chloride solution in prevention of lower urinary tract infections in patients undergoing long‐term indwelling catheterization and observe the effect of benzalkonium chloride on prevention of the urinary tract infections .METHODS A total of 76 patients who needed to be treated with long‐term indwelling catheterization from May 2013 to May 2014 were enrolled in the study and randomly divided into the group A and group B according to the approach of bladder irrigation ,with 38 cases in each group .The group A was treated with bladder irrigation with 0 .0025% benzalkonium chloride so‐lution ,while the group B was given the bladder irrigation with 0 .9% normal saline solution .The

  6. Synthesis, surface-active properties, and antimicrobial activities of new double-chain gemini surfactants.

    Science.gov (United States)

    Murguía, Marcelo C; Vaillard, Victoria A; Sánchez, Victoria G; Conza, José Di; Grau, Ricardo J

    2008-01-01

    A novel series of neutral and cationic dimeric surfactants were prepared involving ketalization reaction, Williamson etherification, and regioselective oxirane ring opening with primary and tertiary alkyl amines. The critical micelle concentration (CMC), effectiveness of surface tension reduction (gamma(CMC)), surface excess concentration (Gamma), and area per molecule at the interface (A) were determined and values indicate that the cationic series is characterized by good surface-active and self-aggregation properties. For the first time, we reported the antimicrobial activities against representative bacteria and fungi for dimeric compounds. The antimicrobial activity was found to be dependent on the target microorganism (Gram-positive bacteria > fungi > Gram-negative bacteria), as well as both the neutral or ionic nature (cationic > neutral) and alkyl chain length (di-C(12) > di-C(18) > di-C(8)) of the compounds. The cationic di-C(12) derivative was found to have equipotent activity to that of benzalkonium chloride (BAC) used as standard.

  7. Chemically modified carbon paste and membrane sensors for the determination of benzethonium chloride and some anionic surfactants (SLES, SDS, and LABSA): Characterization using SEM and AFM.

    Science.gov (United States)

    Issa, Yousry M; Mohamed, Sabrein H; Baset, Mohamed Abd-El

    2016-08-01

    Chemically modified carbon-paste (CMCP) and membrane- sensors based on incorporating benzothonium-tetraphenylborate (BT-TPB) were constructed for the analysis of benzethonium chloride, and some other surfactants such as sodium lauryl ether sulphate (SLES), sodium dodecyl sulphate (SDS), and linear alkylbenzene sulphonic acid (LABSA). All sensors showed good sensitivity and reverse wide linearity over a concentration range of 5.97×10(-7) to 1.00×10(-3) and 5.96×10(-7) to 3.03×10(-3)molL(-1) with limit of detection of 3.92×10(-7)and 3.40×10(-7)molL(-1) for membrane and chemically modified carbon paste sensors, respectively, with respect to benzethonium chloride (BT.Cl). They could be used over a wide pH range of 2.0-10.0. The thermal coefficients of membrane and CMCP sensors are 5.40×10(-4), 1.17×10(-4)V/°C, respectively. The sensors indicated a wide selectivity over different inorganic cations. The effect of soaking on the surface morphology of the membrane sensor was studied using EDX-SEM and AFM techniques. The response time was <10s The freshly prepared, exhausted membrane, and CMCP sensors were successfully applied for the potentiometric determination of the pure BT.Cl solution. They were also used for the determination of its pharmaceutical formulation Dermoplast(®) antibacterial spray (20% benzocaine+0.2% benzethonium chloride) with recovery values ranging from 97.54±1.70 to 101.25±1.12 and from 96.32±2.49 to 101.23±2.15%. The second goal of these sensors is the potentiometric determination of different surfactants such as SLES, SDS, and LABSA with good recovery values using BT.Cl as a titrant in their pure forms, and in samples containing one of them (shampoo, Touri(®) dishwashing liquid, and waste water). The statistical analysis of the obtained data was studied.

  8. HPLC determination of alkyl components in benzalkonium chloride and comparison between domestic and foreign products%高效液相色谱法测定苯扎氯铵中烷基组成的比例并比较国内外样品的差异

    Institute of Scientific and Technical Information of China (English)

    熊亚群; 刘雁鸣; 龙海燕; 彭琳; 艾俊涛

    2016-01-01

    Objective To determine the alkyl components in benzalkonium chloride by RP-HPLC method and compare domestic and foreign products.Methods Inertsil CN-3 chromatographic column (4.6 mm × 250 mm,5 μm) was used.The mobile phase was 0.1 mol · L-1 sodium acetate solution (using acetic acid to adjust pH to 5.0)-acetonitrile (53:47).The flow rate was 2.0 mL · min-1,the detection wavelength was 254 ran.The column temperature was 35 ℃.Results n-C12,n-C14 and n-C16 showed good linearity at 0.252-25.20 mg·mL-1,0.121-12.11 mg · mL-1and 0.018-1.844 mg · mL-1,respectively.The detection limits were 109.6,172.9 and 120.0ng,respectively.Recoveries of 3 homologs at different levels were at 97.8%-102.4% and the RSD was at 0.16%-1.2%.Conclusion This method can be used to the determine the alkyl compositions in benzalkonium chloride quickly and accurately.%目的 采用高效液相色谱法对苯扎氯铵中烷基组成的比例进行测定,并比较国内外样品的差异.方法 采用Inertsil CN-3色谱柱(4.6 mm×250 mm,5μm),以0.1 mol·L-醋酸钠溶液(醋酸调节pH至5.0)-乙腈(53∶47)为流动相,流速为2.0 mL·min-1,检测波长为254 nm,柱温为35℃.结果 n-C12、n-C14、n-C16分别在0.252~25.20、0.121~12.11、0.018~1.844 mg·mL-1与峰面积呈良好的线性关系,检出限分别为109.6、172.9、120.0 ng,3种单体的3个不同浓度的回收率在97.8%~102.4%,RSD 在0.16%~1.2%.结论 经方法学验证,本方法能快速、准确测定苯扎氯铵中烷基组成比例.

  9. Effect of the salt-induced micellar microstructure on the nonlinear shear flow behavior of ionic cetylpyridinium chloride surfactant solutions

    Science.gov (United States)

    Gaudino, D.; Pasquino, R.; Kriegs, H.; Szekely, N.; Pyckhout-Hintzen, W.; Lettinga, M. P.; Grizzuti, N.

    2017-03-01

    The shear flow dynamics of linear and branched wormlike micellar systems based on cetylpyridinium chloride and sodium salicylate in brine solution is investigated through rheometric and scattering techniques. In particular, the flow and the structural flow response are explored via velocimetry measurements and rheological and rheometric small-angle neutron scattering (SANS) experiments, respectively. Although all micellar solutions display a similar shear thinning behavior in the nonlinear regime, the experimental results show that shear banding sets in only when the micelle contour length L ¯ is sufficiently long, independent of the nature of the micellar connections (either linear or branched micelles). Using rheometric SANS, we observe that the shear banding systems both show very similar orientational ordering as a function of Weissenberg number, while the short branched micelles manifest an unexpected increase of ordering at very low Weissenberg numbers. This suggests the presence of an additional flow-induced relaxation process that is peculiar for branched systems.

  10. Simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis%毛细管电泳法同时测定复方化学消毒剂中醋酸洗必泰和苯扎氯铵

    Institute of Scientific and Technical Information of China (English)

    宋宝花; 丁晓静; 李佳; 王志

    2012-01-01

    Benzalkonium chloride (BAC) is a mixture of alkyl substituted benzyl dimethylam-monium chloride homologs (C12-BAC, C14-BAC and C,6-BAC). Chlorhexidine acetate is a widely used effective component in compound chemical disinfectants. A method for the simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis (CE) was established. The CE analysis was carried out using an uncoated capillary with 50 |xm i. d. and 37 cm total length. The running buffer was 150 mmol/L NaH2PO4-62. 5 mmol/L H3PO4(pH 2.5) containing 40% (v/v) acetonitrile. The sample medium was 50 mmol/L acetic acid-acetonitrile (is I, v/v). The detection wavelength was 214 nm. The factors such as the buffer concentration and pH, the content of acetonitrile, which influenced the separation and accurate assay of compound chemical disinfectants were investigated in detail. The intra-day and inter-day precisions of the method were below 3. 0% and 3. 7%, respectively. The limits of detection (LOD, signal to noise ratio (S/N) =3) for chlorhexidine acetate, C12-BAC, C14-BAC and CI6-BAC were 0.3, 0.5, 0.5 and 0.5 mg/L, respectively. The limits of quantification (LOQ, S/N = 10) were 1.0, 1.5, 1.5, and 1. 5 mg/L, respectively. The corrected peak area and the mass concentration of the four components mentioned above showed good linear relationships within the ranges of 1. 0 - 400 mg/L ,1.5- 200 mg/L, 1. 5 -200 mg/L and 1. 5 -200 mg/L, with linear correlation coefficients (r) of 0. 999 5,0. 999 8 , 0. 999 7 and 0. 999 8, respectively. The established method was used for the determination of the four disinfectants in the compound chemical disinfectants. The results were in good agreement with those obtained by the high performance liquid chromatographic method.%建立了复方化学消毒剂中常用有效成分醋酸洗必泰和苯扎氯铵(C12-BAC、C14-BAC及C16-BAC)同时分离测定的毛细管电泳(CE)方法.以37 cm×50 μm未涂

  11. Optimized Benzalkonium Chloride Gel: A Potential Vaginal Microbicides

    Institute of Scientific and Technical Information of China (English)

    Xun-cheng DING; Wei-hua LI; Jie-fei LI; Qiang-yi WANG

    2007-01-01

    Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa.Methods Four methods as below were used to research the spermicidal activity of BZK gel: 1)in vitro spermicidal test; 2) in vivo spermicidal test in rabbits; 3) anti-fertility test in rabbits; 4)contraceptive test in rabbits. Mucosal irritation test was used in rats to evaluate the safety of optimized BZK gel. Microbiological assessments were used to research anti-STI pathogens (including treponema pallidum, neisseria gonorrhoeae, trichomona vaginalis, candida albicans,ureaplama urealyticum, herpes simplex virus type-2, chlamydiae trachomatis) effect of optimized BZK gel.Results In vitro spermicidal test, EC50 of BZK gel was 0.029 mg/ml, a little higher than that of N-9 (0.019 mg/ml). The MIC of BZK gel was 0.25 mg/ml, similar to that of N-9 (0.20 mg/ml).The vaginal mucosal irritation test in rats showed that 0.429% BZK gel showed only minimal vaginal irritation, and did not damage the vaginal epithelium or cause local inflammation in rats. Microbiological assessments showed that optimized BZK gel could inhibit or inactivate common STI pathogens even after 3-fold or 5-fold dilution.Conclusion Optimized BZK gel was an effective microbicides.

  12. Surfactant-assisted sol gel preparation of high-surface area mesoporous TiO{sub 2} nanocrystalline Li-ion battery anodes

    Energy Technology Data Exchange (ETDEWEB)

    Casino, S. [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Di Lupo, F., E-mail: francesca.dilupo@polito.it [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Francia, C. [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Tuel, A. [IRCELYON, Institut de Recherches sur la Catalyse et l’environnement de Lyon, UMR 5256, CNRS-Université de Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France); Bodoardo, S. [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Gerbaldi, C., E-mail: claudio.gerbaldi@polito.it [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy)

    2014-05-01

    Highlights: • Mesoporous TiO{sub 2} nanocrystalline lithium battery anodes with tunable morphology. • Simple sol–gel technique using different cationic surfactants is adopted. • Textural/morphological characteristics define the electrochemical behaviour. • TiO{sub 2} anatase using C16TAB exhibits stable performance after 200 cycles. • It shows promising prospects as high-voltage safe Li-ion battery anode. - Abstract: We here investigate the physico-chemical/morphological characteristics and cycling behaviour of several kinds of nanocrystalline TiO{sub 2} Li-ion battery anodes selectively prepared through a simple sol–gel strategy based on a low-cost titanium oxysulfate precursor, by mediation of different cationic surfactants having different features (e.g., chain lengths, counter ion, etc.): i.e., cetyl-trimethylammonium bromide (CTAB), cetyl-trimethylammonium chloride (CTAC), benzalkonium chloride (BC) or octadecyl-trimethyl ammonium bromide (C{sub 18}TAB). X-ray diffraction profiles reveal single phase anatase having good correspondence with the reference pattern when using short chain CTAB, while in the other cases the presence of chloride and/or an increased chain length affect the purity of the samples. FESEM analysis reveal nanosized particles forming cauliflower-like aggregates. TiO{sub 2} materials demonstrate mesoporous characteristics and large specific surface area ranging from 250 to 30 m{sup 2} g{sup −1}. Remarkably stable electrode performance are achieved by appropriately selecting the cationic surfactant and the surfactant/precursor ratio. Detailed analysis is provided on the effect of the reaction conditions upon the formation of mesoporous crystalline titania enlightening new directions for the development of high performing lithium storage electrodes by a simple and low cost sol–gel strategy.

  13. Surfactant recovery from water using foam fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Tharapiwattananon, N.; Osuwan, S. [Chulalongkorn Univ., Bangkok (Thailand); Scamehorn, J.F. [Inst. of Oklahoma, Norman, OK (United States)] [and others

    1996-05-01

    The purpose of this study was to investigate the use of foam fractionation to recover surfactant from water. A simple continuous mode foam fractionation was used and three surfactants were studied (two anionic and one cationic). The effects of air flow rate, foam height, liquid height, liquid feed surfactant concentration, and sparger porosity were studied. This technique was shown to be effective in either surfactant recovery or the reduction of surfactant concentration in water to acceptable levels. As an example of the effectiveness of this technique, the cetylpyridinium chloride concentration in water can be reduced by 90% in one stage with a liquid residence time of 375 minutes. The surfactant concentration in the collapsed foam is 21.5 times the feed concentration. This cationic surfactant was easier to remove from water by foam fractionation than the anionic surfactants studied.

  14. Synthesis and Properties of Novel Cationic Maleic Diester Polymerizable Surfactants

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Three new cationic polymerizable surfactants are synthesized by the reaction of alkylmaleic hemiester with glycidyltrimethylammonium chloride. Their structures are confirmed by 1H NMR, IR and elements analysis. The values of CMC and gCMC of these surfactants have been measured. One can obtain nearly monodisperse polystyrene latex by emulsion polymerization using the polymerizable surfactant.

  15. Protection effect of sodium hyaluronate on ocular surface toxicity induced by Benzalkonium chloride-preserved brimonidine in rabbits%透明质酸钠对兔含苯扎氯铵溴莫尼定眼表毒性保护作用的研究

    Institute of Scientific and Technical Information of China (English)

    余芬芬; 刘杏; 钟毅敏; 毛真; 郭歆星; 李媚; 曹丹; 陈翔熙

    2013-01-01

    Objective To investigate the protective effects of sodium hyaluronate on ocular surface toxicity induced by a prolonged use of benzalkonium chloride-preserved Brimonidine eye drops.Methods Experimental study.Thirty adult female New Zealand rabbits were divided into three groups with randomized numbers design.Ten rabbits were treated with 0.2% Brimonidine eye drops and PBS (PBS group),the other ten rabbits with 0.2% Brimonidine combined with sodium hyaluronate eye drops (SH group),and control group received no treatment for 60 days.Schirmer test,fluorescein (FL) and Rose Bengal (RB) staining,conjunctival impression cytology specimens collecting were performed on day 0,31,and 61.Apoptosis of conjunctival epithelium was detected by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay on day 61.Conjunctival inflammation was observed by hematoxylin eosin staining.Histomorphological changes of cornea and conjunctiva were observed by light microscopy,and scanning and transmission electron microscopy at day 61.Fluorescein and Rose Bengal scores were analysed by Kruskal-Wallis test.Schirmer scores,goblet cell density and inflammatory cells infiltration were analysed by repeated measures analysis of variance.Results There were significant differences in fluorescein and Rose bengal (H =22.031,15.303,P < 0.01) staining among the groups on day 61.Compared with the control group (FL:0,0-1,RB:0,0-1),fluorescein and Rose Bengal scores were significantly (P < 0.001) increased in PBS group (FL:1.5,1-2,RB:1,1-2),whereas was significantly (P < 0.001) decreased in SH group (FL:0,0-1 RB:1,0-1) when compared to PBS group.There were significant differences in aqueous tear production and goblet cell density (F =7.980,14.545,both P < 0.01) among the groups on day 61.Compared with the control group [(9.43 ± 0.57) mm,(87.73 ± 2.34/HP)],Schirmer scores and goblet cell density were significantly (P < 0.01) reduced in PBS-treated group [(6.61 ± 0

  16. An anionic surfactant for EOR applications

    Science.gov (United States)

    Sagir, Muhammad; Tan, Isa M.; Mushtaq, Muhammad

    2014-10-01

    This work is to investigate the new anionic surfactants for the Enhanced Oil Recovery (EOR) application. Sulfonated anionic surfactant was produced by attaching SO3 to an ethoxylated alcohol to increase the performance of the surfactant. Methallyl chloride and ethoxylated alcohol was reacted followed by the reaction with sodium bisulfite to produce anionic sulfonated surfactant in 80.3 % yield. The sulfonation reaction parameters such as reactants mole ratio, reaction temperature and catalyst amount were optimized. The generation and stability of foam from the synthesized surfactant is also tested and results are reported. The synthesized novel surfactant was further investigated for the effect on the CO2 mobility in porous media and the findings are presented here. This in house developed surfactant has a great potential for CO2- EOR applications.

  17. Vapor pressure studies of the solubilization of hydrocarbons by surfactant micelles. Final report, April 1, 1984-December 31, 1984. [Solubilization data for system benzene/sodium octylsulfate/sodium chloride/water at 15/sup 0/, 25/sup 0/, 35/sup 0/ and 45/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Christian, S.D.; Tucker, E.E.

    1985-04-01

    This final report describes vapor pressure studies of the solubilization of hydrocarbons and hydrocarbon derivatives by aqueous micellar solutions. An automated vapor pressure apparatus and a manual apparatus incorporating a mercury-covered sintered-glass disk inlet valve were used to obtain highly precise data for the solubilization of hydrocarbons and aliphatic alcohols into aqueous solutions of the ionic surfactants sodium octylsulfate and n-hexadecylpyridinium chloride (cetylpyridinium chloride). A mass-action model based on a modification of the Poisson distribution equations has been developed and applied to data for the system benzene/sodium octylsulfate/sodium chloride/water at 15/sup 0/, 25/sup 0/, 35/sup 0/, and 45/sup 0/C. An excellent goodness of fit is achieved with the model. Tabulated experimental results (485 sets of activity and concentration data) are included in this report. 12 references, 2 figures.

  18. Switchable Surfactants

    National Research Council Canada - National Science Library

    Yingxin Liu; Philip G. Jessop; Michael Cunningham; Charles A. Eckert; Charles L. Liotta

    2006-01-01

    .... We report that long-chain alkyl amidine compounds can be reversibly transformed into charged surfactants by exposure to an atmosphere of carbon dioxide, thereby stabilizing water/alkane emulsions...

  19. Secondary oil recovery process. [two separate surfactant slugs

    Energy Technology Data Exchange (ETDEWEB)

    Fallgatter, W.S.

    1969-01-14

    Oil recovery by two separate surfactant slugs is greater than for either one alone. One slug contains a surfactant(s) in either oil or water. The other slug contains surfactant(s) in thickened water. The surfactants are sodium petroleum sulfonate (Promor SS20), polyoxyethylene sorbitan trioleate (Tween 85), lauric acid diethanolamide (Trepoline L), and sodium tridecyl sulfate polyglycol ether (Trepenol S30T). The thickener is carboxymethyl cellulose (Hercules CMC 70-S Medium thickener) or polyvinyl alcohol (Du Pont Elvanol 50-42). Consolidated sandstone cores were flooded with water, followed with Hawes crude, and finally salt water (5 percent sodium chloride) which recovered about 67 percent of the crude. A maximum of 27.5 percent of the residual oil was recovered by surfactant(s) in oil or water followed by fresh water, then surfactant(s) plus thickener in water followed by fresh water. Either surfactant slug may be injected first. Individually, each of the surfactant slugs can recover from about 3 to 11 percent less residual oil than their total recovery when used consecutively.

  20. Interactions in Calcium Oxalate Hydrate/Surfactant Systems.

    Science.gov (United States)

    Sikiric; Filipovic-Vincekovic; Babic-Ivancić Vdović Füredi-Milhofer

    1999-04-15

    Phase transformation of calcium oxalate dihydrate (COD) into the thermodynamically stable monohydrate (COM) in anionic (sodium dodecyl sulfate (SDS)) and cationic (dodecylammonium chloride) surfactant solutions has been studied. Both surfactants inhibit, but do not stop transformation from COD to COM due to their preferential adsorption at different crystal faces. SDS acts as a stronger transformation inhibitor. The general shape of adsorption isotherms of both surfactants at the solid/liquid interface is of two-plateau-type, but differences in the adsorption behavior exist. They originate from different ionic and molecular structures of crystal surfaces and interactions between surfactant headgroups and solid surface. Copyright 1999 Academic Press.

  1. A study of surfactant-assisted waterflooding

    Energy Technology Data Exchange (ETDEWEB)

    Scamehorn, J F; Harwell, J H

    1990-09-01

    In surfactant-assisted waterflooding, a surfactant slug is injected into a reservoir, followed by a brine spacer, followed by second surfactant slug. The charge on the surfactant in the first slug has opposite sign to that in the second slug. When the two slugs mix in the reservoir, a precipitate or coacervate is formed which plugs the permeable region of the reservoir. Subsequently injected water or brine is forced through the low permeability region of the reservoir, increasing sweep efficiency of the waterflood, compared to a waterflood not using surfactants. In this part of the work, two major tasks are performed. First, core floods are performed with oil present to demonstrate the improvement in incremental oil production, as well as permeability modification. Second, a reservoir simulation model will be proposed to further delineate the optimum strategy for implementation of the surfactant-assisted waterflooding, as well as indicate the reservoir types for which it would be most effective. Surfactants utilized were sodium dodecyl sulfate and dodecyl pyridinium chloride. 44 refs., 17 figs., 3 tabs.

  2. Synthesis and properties evaluation of sulfobetaine surfactant with double hydroxyl

    Science.gov (United States)

    Zhou, Ming; Luo, Gang; Zhang, Ze; Li, Sisi; Wang, Chengwen

    2017-09-01

    A series of sulfobetaine surfactants {N-[(3-alkoxy-2-hydroxyl)propoxy] ethyl-N,N-dimethyl-N-(2-hydroxyl)propyl sulfonate} ammonium chloride were synthesized with raw materials containing linear saturated alcohol, N,N-dimethylethanolamine, sodium 3-chloro-2-hydroxyl propane sulfonic acid and epichlorohydrin. The molecule structures of sulfobetaine surfactants were characterized by FTIR, 1HNMR and elemental analysis. Surface tension measurements can provide us information about the surface tension at the CMC (γCMC), pC20, Γmax and Amin. The pC20 values of sulfobetaine surfactants increase with the hydrophobic chain length increasing. Amin values of the surfactants decrease with increasing hydrophobic chain length from 10 to 14. The critical micelle concentration (CMC) and surface tension (γCMC) values of the sulfobetaine surfactants decrease with increasing hydrophobic chain length from 10 to 16. The lipophilicity of surfactant was enhanced with the increase of the carbon chain, however, the ability of anti-hard water was weakened. The minimum oil/water interfacial tension of four kinds of sulfobetaine surfactants is 10-2-10-3 mN/m magnitude, which indicates that the synthesized bis-hydroxy sulfobetaine surfactants have a great ability to reduce interfacial tension in the surfactant flooding system. The surface tension (γCMC) values of synthesized surfactants were lower compared with conventional anionic surfactant sodium dodecyl sulfonate.

  3. Study on performance of anion Gemini surfactant derived from cyanuric chloride%含三嗪环阴离子Gemini表面活性剂的性能研究

    Institute of Scientific and Technical Information of China (English)

    赵家乐; 胡志勇; 曹端林; 李鹏飞; 陈啟虎; 王虎山; 李晨

    2011-01-01

    研究了含三嗪环阴离子Gemini表面活性剂增溶、流变、溶致液晶、囊泡等性能.结果表明:增溶量随Gemini表面活性剂疏水链长度的增长而增大,C8-n-C8(n=2,3,4,6)的增溶量随联接基长度增加而增加,C12 -2-C12与SDS的复配体系比SDS的增溶量大,C12 -2-C12与CTAB的复配体系比这2种表面活性剂单独使用时的增溶量小;Gemini表面活性剂溶液分子结构(疏水基和联接基长度)对其水溶液的黏度有相同的影响;C6 -2-C6、C8 -2-C8、C8 -3-C8、C8-4-C8、C8 -6-C8、C12 -2-C12在质量分数分别为42.3%,37.8%,33.5%,30.4%,27.6%,20.3%时均产生层状的溶致液晶;0.01 mol/L的单一Gemini表面活性剂水溶液均不能形成囊泡,而当n( C12-2-C12)∶n(CATB)为8:2或9:1时,复配体系的水溶液形成了大量的囊泡结构.%The properties such as solubilization,viscosity,lyotropic liquid crystals and vesicle of Gemini surfactants are studied in this paper. The results show that the solubilization increases with the increase of the hydrophobic chains of Gemini surfactants. The longer spacer length of Gemini surfactants C8 -n-C8 (n =2,3,4,6) leads to the higher solubilization ability. Compared with SDS,the mixed C,2-2-C12/SDS system shows higher solubilization ability. However, the solubilization ability of the mixed C,2-2-C12/CTAB is lower than that of C12-2-C12 or CTAB alone. The nature of surfactant molecules ( hydrophobic and the spacer groups parts) has the same influence on the viscosity of aqueous Gemini surfactant solution. The aqueous solution of Gemini surfactants, such as C6-2-C6 ,Cg-2-C8 ,C8-3-C8 ,C8-4-C8 ,C8-6-C8 and C12-2-C12 can form lyotropic liquid crystals when their mass fraction is 42. 3% ,37. 8% ,33. 5% ,30.4% , 27. 6% ,20. 3% respectively. 0. 01 mol/L aqueous solution of Gemini surfactants, such as C6-2-C6, C8-2-C8, C8-3-C8, Cg-4-C8,Cg-6-C8 and Cl2-2-C12 alone,can not form vesicles. However,when n(C12-2-C12)/ra(CATB) is 8/2 or9/1,the

  4. Isolation and characterization of resistant variants from Salmonella Typhimurium cell cultures treated with benzalkonium chloride

    NARCIS (Netherlands)

    Castelijn, G.A.A.; Veen, van der S.; Moezelaar, H.R.; Abee, T.; Zwietering, M.H.

    2014-01-01

    An efficient disinfection strategy within the food industry is needed to ensure food safety and prevent the spreading of foodborne pathogens such as Salmonella Typhimurium. However, several factors affect the efficiency of disinfection treatments resulting in low level exposure of the bacterial flor

  5. Adaptive Resistance and Differential Protein Expression of Salmonella enterica Serovar Enteritidis Biofilms Exposed to Benzalkonium Chloride▿

    Science.gov (United States)

    Mangalappalli-Illathu, Anil K.; Korber, Darren R.

    2006-01-01

    The development of adaptive resistance of Salmonella enterica serovar Enteritidis ATCC 4931 biofilms following exposure to benzalkonium chloride (BC) either continuously (1 μg ml−1) or intermittently (10 μg ml−1 for 10 min daily) was examined. Biofilms adapted to BC over a 144-h period could survive a normally lethal BC challenge (500 μg ml−1 for 10 min) and then regrow, as determined by increases in biofilm thickness, total biomass, and the ratio of the viable biomass to the nonviable biomass. Exposure of untreated control biofilms to the lethal BC challenge resulted in biofilm erosion and cell death. Proteins found to be up-regulated following BC adaptation were those involved in energy metabolism (TpiA and Eno), amino acid and protein biosynthesis (WrbA, TrxA, RplL, Tsf, Tuf, DsbA, and RpoZ), nutrient binding (FruB), adaptation (CspA), detoxification (Tpx, SodB, and a probable peroxidase), and degradation of 1,2-propanediol (PduJ and PduA). A putative universal stress protein (YnaF) was also found to be up-regulated. Proteins involved in proteolysis (DegQ), cell envelope formation (RfbH), adaptation (UspA), heat shock response (DnaK), and broad regulatory functions (Hns) were found to be down-regulated following adaptation. An overall increase in cellular protein biosynthesis was deduced from the significant up-regulation of ribosomal subunit proteins, translation elongation factors, and amino acid biosynthesis protein and down-regulation of serine endoprotease. The cold shock response, stress response, and detoxification are suggested to play roles in the adaptive resistance of Salmonella serovar Enteritidis biofilms to BC. PMID:16940079

  6. Surface-enhanced Raman spectroscopy of surfactants on silver electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Soncheng; Birke, R.L.; Lombardi, J.R. (City Univ. of New York, NY (USA))

    1990-03-08

    Surface-enhanced Raman spectroscopy (SERS) has been used to study different kinds of surfactants (cationic, anionic, and nonionic surfactants) adsorbed on a roughened Ag electrode. Spectral assignments are made for the SERS spectrum of cetylpyridinium chloride (CPC), and it is shown that the molecule is oriented with its pyridinium ring end-on at the electrode surface at potentials positive to the point of zero charge (pzc) on Ag.

  7. Thermally cleavable surfactants

    Science.gov (United States)

    McElhanon, James R.; Simmons, Blake A.; Zifer, Thomas; Jamison, Gregory M.; Loy, Douglas A.; Rahimian, Kamyar; Long, Timothy M.; Wheeler, David R.; Staiger, Chad L.

    2006-04-04

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  8. Thermally cleavable surfactants

    Energy Technology Data Exchange (ETDEWEB)

    McElhanon, James R. (Manteca, CA); Simmons, Blake A. (San Francisco, CA); Zifer, Thomas (Manteca, CA); Jamison, Gregory M. (Albuquerque, NM); Loy, Douglas A. (Albuquerque, NM); Rahimian, Kamyar (Albuquerque, NM); Long, Timothy M. (Urbana, IL); Wheeler, David R. (Albuquerque, NM); Staiger, Chad L. (Albuquerque, NM)

    2009-09-29

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  9. Thermally cleavable surfactants

    Energy Technology Data Exchange (ETDEWEB)

    McElhanon, James R. (Manteca, CA); Simmons, Blake A. (San Francisco, CA); Zifer, Thomas (Manteca, CA); Jamison, Gregory M. (Albuquerque, NM); Loy, Douglas A. (Albuquerque, NM); Rahimian, Kamyar (Albuquerque, NM); Long, Timothy M. (Urbana, IL); Wheeler, David R. (Albuquerque, NM); Staiger, Chad L. (Albuquerque, NM)

    2009-11-24

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  10. Micellization of monomeric and poly-ω-methacryloyloxyundecyltrimethylammonium surfactants.

    Science.gov (United States)

    FitzGerald, Paul A; Chatjaroenporn, Khwanrat; Zhang, Xiaoli; Warr, Gregory G

    2011-10-04

    We have used small-angle neutron scattering to study how micelle morphology of the tail-polymerizable surfactants MUTAB and MUTAC (ω-methacryloyloxyundecyltrimethylammonium bromide and chloride) is affected by classic self-assembly modifiers such as temperature changes, salt addition, and counterion exchange, as a function of their conversion from monomer into polymer amphiphile in aqueous solution. Contrary to common assumptions about polymerized surfactants, these systems remain in dynamic equilibrium under all conditions examined and at all conversions (except for a small amount of high-molecular-weight precipitation by MUTAC). Counterintuitively, the polymerized methacrylate backbone has little influence on aggregate morphology, except for the formation of rod-like mixed micelles of polymerized and unpolymerized surfactant at intermediate conversions. The addition of salt produces a transition to rod-like micelles at all conversions except in the unpolymerized surfactant, which has some characteristics of an asymmetric bolaform surfactant and retains its spheroidal geometry under almost all conditions.

  11. A Study on the Optimization of Physical and Chemical Parameters for the Precipitate of Sodium Alkylsulfate with Cetylpyridinium Chloride

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sun Wha; Moon, Sung Doo; Lee, Don Keun; Lee, Dong Jae; Kang, Young Soo [Pukyong National University, Busan (Korea, Republic of)

    2004-02-15

    The optimum conditions for the most effective precipitate of surfactant complex of sodium alkylsulfate with cetylpyridinium chloride were studied in the aqueous solution. The parameters such as the alkyl chain length of anionic surfactants, molar ratio of two surfactants, temperature and the concentration of added NaCl in the aqueous solution were correlatively studied for the productivity of the precipitate formation. By the productivity, the optimum conditions to produce complex of anionic surfactant with cationic surfactant were the longer alkyl chain, equivalent molar ratio between anionic and cationic surfactants, 0 .deg. C and 1.5 M NaCl

  12. Analysis of benzalkonium bromide and benzalkonium chloride by liquid chromatography%苯扎溴铵、苯扎氯铵的液相色谱分析

    Institute of Scientific and Technical Information of China (English)

    赵文英; 张青; 武智强; 范志先

    2015-01-01

    建立了苯扎溴铵、苯扎氯铵的高效液相色谱定量和离子色谱定性鉴别的分析方法.定量采用HPLC-DAD,Elite SinoChrom ODS-BP色谱柱,流动相为甲醇:2.4 mmol/L三氟乙酸水溶液=77∶23(V/V);定性采用IEC-CD鉴别C1-或Br-.以十二烷基二甲基苄基溴化铵为标样,在10~800 mg/L浓度范围内,线性关系良好(r=0.9998);2个质量浓度添加水平的平均回收率为100.17%和99.94%.8次平行测定的样品RSD为0.50%.对市场上的3个苯扎溴铵样品进行了检测,有2个不合有溴离子.

  13. Surfactant recovery from water using foam fractionation: Effect of temperature and added salt

    Energy Technology Data Exchange (ETDEWEB)

    Kumpabooth, K.; Osuwan, S. [Chulalongkorn Univ., Bangkok (Thailand). Petroleum and Petrochemical Coll.; Scamehorn, J.F.; Harwell, J.H. [Univ. of Oklahoma, Norman, OK (United States). Inst. for Applied Surfactant Research

    1999-01-01

    The purpose of this study was to investigate the use of foam fractionation to recover surfactant present at low concentrations in aqueous streams. A simple continuous mode foam fractionation was used, and three surfactants were chosen for this study: sodium dodecyl sulfate, cetylpyridinium chloride, and sodium n-hexadecyl diphenyloxide disulfonate. In a previous study the effects of surfactant concentration, air flow rate, liquid- and vapor-phase heights, and sparger type were investigated for these surfactants. Here, the effects of temperature and added salt are studied. It is found that the foam flow rate and enrichment ratio increase whereas the foam wetness and the rate of surfactant recovery decrease with increasing temperature. Increasing the concentration of added salt decreases the CMC of the surfactants. The foam flow rate, foam wetness, and the rate of surfactant recovery increase, while the enrichment ratio decreases with increasing concentration of salt.

  14. Impact of surfactant type for ionic liquid pretreatment on enhancing delignification of rice straw.

    Science.gov (United States)

    Chang, Ken-Lin; Chen, Xi-Mei; Wang, Xiao-Qin; Han, Ye-Ju; Potprommanee, Laddawan; Liu, Jing-Yong; Liao, Yu-Ling; Ning, Xun-An; Sun, Shui-Yu; Huang, Qing

    2017-03-01

    This work describes an environmentally friendly method for pretreating rice straw by using 1-Allyl-3-methylimidazolium chloride ([AMIM]Cl) as an ionic liquid (IL) assisted by surfactants. The impacts of surfactant type (including nonionic-, anionic-, cationic- and bio-surfactant) on the ionic liquid pretreatment were investigated. The bio-surfactant+IL-pretreated rice straw showed significant lignin removal (26.14%) and exhibited higher cellulose conversion (36.21%) than the untreated (16.16%) rice straw. The cellulose conversion of the rice straw pretreated with bio-surfactant+IL was the highest and the lowest was observed for pretreated with cationic-surfactant+IL. Untreated and pretreated rice straw was thoroughly characterized through SEM and AFM. In conclusion, the results provided an effective and environmental method for pretreating lignocellulosic substrates by using green solvent (ionic liquid) and biodegradable bio-surfactant.

  15. Solubilization of pentanol by cationic surfactants and binary mixtures of cationic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, M.E.

    1993-12-31

    The research reported here has included studies of the solubilization of pentanol in hexadecylpyridinium chloride (CPC), trimethyletetradecylammonium chloride (C{sub 14}Cl), benzyldimethyltetradecylammonium chloride (C{sub 14}BzCl), benzyldimethylhexadecylpyridinium chloride (C{sub 16}BzCl), hexadecyltrimethylammonium bromide (CTAB), and binary mixtures of CPC + C{sub 16}BzCl and C{sub 14}Cl + C{sub 14}BzCl. Rather than using calorimetric methods, this project will employ headspace chromatography to measure solubilization of pentanol over a wide range of solute concentrations. While not yielding as much thermodynamic data as calorimetry, headspace chromatography is a more direct measure of the extent of solubilization. Using headspace chromatography, is a more direct measure of the extent of solubilization. Using headspace chromatography, this study will seek to determine whether strongly synergistic mixture ratios exist in the case of binary cationic surfactant systems. There are two equilibria in the pentanol-water-surfactant system: (1) The pentanol solubilized in micelles is in equilibrium with the monomeric pentanol in solution, and (2) the monomeric pentanol is in equilibrium with the pentanol in the vapor above the solution. To establish the link between the two equilibria, a sample of the vapor above pure liquid pentanol must be collected, in order to find the activity of pentanol in solution. Also, a calibration curve for various concentrations of pentanol in solution. From this type of data it is possible to infer both the concentration of pentanol solubilized in micelles and the concentrations of pentanol in the ``bulk`` solution outside the micelles. The method is equally applicable to systems containing a single surfactant as well as mixtures of surfactants.

  16. Viscoelasticity Enhancement of Surfactant Solutions Depends on Molecular Conformation: Influence of Surfactant Headgroup Structure and Its Counterion.

    Science.gov (United States)

    Lutz-Bueno, Viviane; Pasquino, Rossana; Liebi, Marianne; Kohlbrecher, Joachim; Fischer, Peter

    2016-05-03

    During the anisotropic growth from globular to wormlike micelles, the basic interactions among distinct parts of the surfactant monomer, its counterion, and additives are fundamental to tune molecular self-assembly. We investigate the addition of sodium salicylate (NaSal) to hexadecyltrimethylammonium chloride and bromide (CTAC and CTAB), 1-hexadecylpyridinium chloride and bromide (CPyCl and CPyBr), and benzyldimethylhexadecylammonium chloride (BDMC), which have the same hydrophobic tail. Their potential to enhance viscoelasticity by anisotropic micellar growth upon salt addition was compared in terms of (i) the influence of the headgroup structure, and (ii) the influence of surfactant counterion type. Employing proton nuclear magnetic resonance ((1)H NMR), we focused on the molecular conformation of surfactant monomers in the core and polar shell regions of the micelles and their interactions with increasing concentration of NaSal. The viscoelastic response was investigated by rotational and oscillatory rheology. We show that micellar growth rates can be tuned by varying the flexibility and size of the surfactant headgroup as well as the dissociation degree of the surfactant counterion, which directly influences the strength of headgroup-counterion pairing. As a consequence, the morphological transitions depend directly on charge neutralization by electrostatic screening. For example, the amount of salt necessary to start the rodlike-to-wormlike micelle growth depends directly on the number of dissociated counterions in the polar shell.

  17. 苯扎溴铵溶液防治皮肤创伤愈合瘢痕的临床观察%Clinical observation on benzalkonium bromide solution preventing skin wound healing and scar treatment

    Institute of Scientific and Technical Information of China (English)

    顾家富; 晋继忠

    2011-01-01

    AIM: To observe 0.1 % benzalkonium bromide solution on the prevention and treatment of skin wound healing and scar treatment. METHODS: 974 cases of trauma were randomly divided into treatment group and control group each for 487 cases. 0.5% of the complex with iodine solution was used for skin disinfection. 3% hydrogen peroxide solution, 0.9% sodium chloride injection, 0.1% benzalkonium bromide solution were continuously used to clean the wound. The 0.1 % benzalkonium bromide solution was wet compressed after suture with bandage wounds, once every 2 days to wound healing in treatment group. 3 % hydrogen peroxide solution and 0.9% sodium chloride injection were used to clear the wound in the control group, then bandage usually. The long-term healing scar of two groups were observed. RESULTS: The Vancouver scar scale of two groups had significantly difference in 12 months after skin wound healing, the treatment group was lower. CONCLUSION: 0.1 % benzalkonium bromide solution has preventive effect on the skin and scar formation after wound healing.%目的:观察0.1%苯扎溴铵溶液对皮肤创伤愈合瘢痕的防治疗效.方法:将974例创伤患者随机分为治疗组及对照组各487例,用0.5%的络合碘溶液消毒皮肤,治疗组用3%过氧化氢溶液、0.9%氯化钠注射液、0.1%苯扎溴铵溶液依次清创伤口,缝合后用0.1%苯扎溴铵溶液湿敷包扎伤口,每2 d一次,至伤口愈合,对照组用3%过氧化氢溶液和0.9%氯化钠注射液清创伤口,缝合后常规包扎,观察两组远期皮肤愈合瘢痕的形成.结果:皮肤创伤愈合12月后两组的温哥华瘢痕量表评分差异显著,治疗组低于对照组的评分.结论:0.1%苯扎溴铵溶液对皮肤创伤愈合后的瘢痕形成有防治疗效.

  18. Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on differently pretreated nonwoven cotton substrate

    Science.gov (United States)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  19. Surfactants in tribology

    CERN Document Server

    Biresaw, Girma

    2014-01-01

    Surface science and tribology play very critical roles in many industries. Manufacture and use of almost all consumer and industrial products rely on the application of advanced surface and tribological knowledge. The fourth in a series, Surfactants in Tribology, Volume 4 provides an update on research and development activities connecting surfactants and tribological phenomena. Written by renowned subject matter experts, the book demonstrates how improved design of surfactants can be harnessed to control tribological phenomena. Profusely illustrated and copiously referenced, the chapters also

  20. Preparation and evaluation of sulphonamide nonionic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, M. H. M.

    2010-07-01

    Alkyl (octyl, decyl and dodecyl; C{sub 8}, C{sub 1}0 and C{sub 1}2) benzene sulphonyl chloride was used in the preparation of a novel series of nonionic surfactants (IV-VI)a-c, (VII-IX) a-c and (X-XII)a-c. The preparations were completed by reacting each alkyl (C{sub 8}, C{sub 1}0 and C{sub 1}2) benzene sulphonyl chloride with ethanolamine to give (I-III) respectively. The resulting products were reacted separately with ethylene oxide in the presence of different (base KOH, Lewis acid SnCl4 and k10 clay) catalysts to produce different moles of nonionic surfactants (5, 7 and 9) in sequence corresponding to (IV-VI)a-c, (VII-IX) a-c and (X-XII)a-c respectively. The chemical structures of prepared nonionic surfactants were elucidated by IR and 1HNMR spectra. The surface activity, biodegradability and biological activities of the prepared compounds were investigated. The obtained data show that these compounds have good surface and biological activities as well as reasonable biodegradability properties. (Author) 30 refs.

  1. POLYMERIC SURFACTANT STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    P.M. Saville; J.W. White

    2001-01-01

    Polymeric surfactants are amongst the most widespread of all polymers. In nature, proteins and polysaccharides cause self organization as a result of this surfactancy; in industry, polymeric surfactants play key roles in the food, explosives and surface coatings sectors. The generation of useful nano- and micro-structures in films and emulsions as a result of polymer amphiphilicity and the application of mechanical stress is discussed. The use of X-ray and neutron small angle scattering and reflectivity to measure these structures and their dynamic properties will be described. New results on linear and dendritic polymer surfactants are presented.

  2. Dendrimer-surfactant interactions.

    Science.gov (United States)

    Cheng, Yiyun; Zhao, Libo; Li, Tianfu

    2014-04-28

    In this article, we reviewed the interactions between dendrimers and surfactants with particular focus on the interaction mechanisms and physicochemical properties of the yielding dendrimer-surfactant aggregates. In order to provide insight into the behavior of dendrimers in biological systems, the interactions of dendrimers with bio-surfactants such as phospholipids in bulk solutions, in solid-supported bilayers and at the interface of phases or solid-states were discussed. Applications of the dendrimer-surfactant aggregates as templates to guide the synthesis of nanoparticles and in drug or gene delivery were also mentioned.

  3. MODIFIKASI KAOLIN DENGAN SURFAKTAN BENZALKONIUM KLORIDA DAN KARAKTERISASINYA MENGGUNAKAN SPEKTROFOTOMETER INFRA MERAH

    OpenAIRE

    Nelly Wahyuni

    2010-01-01

    Modifikasi kaolin Capkala dengan surfaktan benzalkonium klorida telah dilakukan dengan mereaksikan kaolin dalam surfaktan selama 8 jam dengan pengadukan pada kecepatan 150 rpm. Modifikasi dilakukan dalam berbagai variasi konsentrasi surfaktan dan suhu aktivasi. Kaolin termodifikasi dikarakterisasi menggunakan Spektrometer Infra Merah. Kaolin termodifikasi menunjukkan adanya serapan C-H simetri dari gugus CH2 yang merupakan indikasi adanya surfaktan pada kaolin. Berdasarkan uji adsorpsi terhad...

  4. Chloride transference during electrochemical chloride extraction process

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chemical titration method and lab-made chloride probes were jointly adopted to investigate the effects of water-to-cement (W/C) ratio and the impressed current density on chloride transport for cement-based materials during electrochemical chloride extraction (ECE) process.The dissolution of bound chlorides and the effect of current density on dissolution were analyzed.The variations of chloride concentration at different depths and the chloride transference process were monitored.Test results show that W/C ratios adopted have slight influence on chloride extraction,while chloride extraction efficiency is mainly determined by the impressed current density.During ECE process a portion of bound chloride ions dissolved and the amount of bound chlorides released is directly proportional to current density.

  5. Surfactant Sector Needs Urgent Readjustment

    Institute of Scientific and Technical Information of China (English)

    Huang Hongzhou

    2007-01-01

    @@ Surfactant industrial system has been basically established After 50 years' development, China has already established a surfactant industrial system with a relatively complete product portfolio and can produce 4714 varieties of surfactants in cationic,anionic, nonionic and amphoteric categories.

  6. Compatibilization of HDPE/agar biocomposites with eutectic-based ionic liquid containing surfactant

    OpenAIRE

    Shamsuri, AA; Daik, R; Zainudin, ES; Tahir, PM

    2014-01-01

    In this research, eutectic-based ionic liquid specifically choline chloride/glycerol was prepared at a 1:2 mole ratio. The choline chloride/glycerol was added with the different content of surfactant (hexadecyltrimethylammonium bromide). The choline chloride/glycerol-hexadecyltrimethylammonium bromide was introduced into high-density polyethylene/agar biocomposites through melt mixing. The mechanical testing results indicated that the impact strength and tensile extension of the biocomposites...

  7. Influence of water concentrations on the phase transformation of a model surfactant/co-surfactant/water system

    Science.gov (United States)

    Lunkad, Raju; Srivastava, Arpita; Debnath, Ananya

    2017-02-01

    The influence of water concentrations on phase transformations of a surfactant/co-surfactant/water system is investigated by using all atom molecular dynamics simulations. At higher water concentrations, where surfactant (behenyl trimethyl ammonium chloride, BTMAC) to co-surfactant (stearyl alcohol, SA) ratio is fixed, BTMAC and SA self-assemble into spherical micelles, which transform into strongly interdigitated one dimensional rippled lamellar phases upon decreasing water concentrations. Fragmentation or fusions of spherical micelles of different sizes are evident from the radial distribution functions at different temperatures. However, at lower water concentrations rippled lamellar phase transforms into an LβI phase upon heating. Our simulations reveal that the concentrations of water can influence available space around the head groups which couple with critical thickness to accommodate the packing fraction required for respective phases. This directs towards obtaining a controlling factor to design desired phases important for industrial and medical applications in the future.

  8. SURFACTANTS IN LUBRICATION

    Science.gov (United States)

    Surfactants are one of the most widely applied materials by consumers and industry. The application areas for surfactants span from everyday mundane tasks such as cleaning, to highly complex processes involving the formulation of pharmaceuticals, foods, pesticides, lubricants, etc. Even though sur...

  9. Dynamic covalent surfactants

    NARCIS (Netherlands)

    Minkenberg, C.B.

    2012-01-01

    In this thesis the development of surfactant aggregates with fast exchange dynamics between the aggregated and non-aggregated state is described. Dynamic surfactant exchange plays an important role in natural systems, for instance in cell signaling, cell division, and uptake and release of cargo. Re

  10. Surfactant aggregation and its application to drag reduction

    Energy Technology Data Exchange (ETDEWEB)

    Harwigsson, I.

    1995-09-01

    A number of different drag-reducing (DR) surfactants: nonionics, zwitterionics and ampholytics suitable for use in both cool and hot water solution are described. These surfactants have been tested under various conditions common in district energy distribution. The surfactants described are environmentally more acceptable than the organic salts of quaternary ammonium compounds which have so far dominated as DR surfactants. The micellar phase formed in water by the surfactant system cetylpyridinium chloride/sodium salicylate has been investigated with surfactant self-diffusion (NMR) measurements and cryo-transmission electron microscopy. Results from this study support the hypothesis that worm-like micellar systems form a network before the phase boundary, when the first liquid crystalline phase formed is a bicontinuous cubic phase. A series of surfactants similar to the one used in the DR experiments has been examined in dilute solutions. Critical micellar concentration and the size of these micelles are investigated as a function of the amphiphile concentration, the pH and salt concentration. Adsorption properties on silica of zwitterionic dodecyl-N,N-dimethylammonio alkanoates, with polymethylene interchange arms of different lengths, have been investigated with an in situ ellipsometry technique. The use of two-tone frequency modulation spectroscopy as a general method for the determination of water activity has been initiated. 173 refs, 6 figs

  11. Surface tension method for determining binding constants for cyclodextrin inclusion complexes of ionic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Dharmawardana, U.R.; Christian, S.D.; Tucker, E.E.; Taylor, R.W.; Scamehorn, J.F. (Univ. of Oklahoma, Norman, OK (United States))

    1993-09-01

    A new method has been developed for determining binding constants of complexes of cyclodextrins with surface-active compounds, including water-soluble ionic surfactants. The technique requires measuring the change in surface tension caused by addition of a cyclodextrin (CD) to aqueous solutions of the surfactant; the experimental results lead directly to inferred values of the thermodynamic activity of the surfactant. Surface tension results are reported for three different surfactants sodium dodecyl sulfate (SDS), cetylpyridinium chloride (CPC), and cetyltrimethylammonium bromide (CTAB) in the presence and in the absence of added [beta]-CD. Data for CPC have been obtained at surfactant concentrations below and above the critical micelle concentration. Correlations between surface tension and surfactant activity are expressed by the Szyszkowski equation, which subsumes the Langmuir adsorption model and the Gibbs equation. It is observed that the surface tension increases monotonically as [beta]-cyclodextrin is added to ionic surfactant solutions. At concentrations of CD well in excess of the surfactant concentration, the surface tension approaches that of pure water, indicating that neither the surfactant-CD complexes nor CD itself are surface active. Binding constants are inferred from a model that incorporates the parameters of the Szyszkowski equation and mass action constants relating to the formation of micelles from monomers of the surfactant and the counterion. Evidence is given that two molecules of CD can complex the C-16 hydrocarbon chain of the cetyl surfactants. 30 refs., 5 figs., 1 tab.

  12. Structure and Conformational Dynamics of DMPC/Dicationic Surfactant and DMPC/Dicationic Surfactant/DNA Systems

    Directory of Open Access Journals (Sweden)

    Maciej Kozak

    2013-04-01

    Full Text Available Amphiphilic dicationic surfactants, known as gemini surfactants, are currently studied for gene delivery purposes. The gemini surfactant molecule is composed of two hydrophilic “head” groups attached to hydrophobic chains and connected via molecular linker between them. The influence of different concentrations of 1,5-bis (1-imidazolilo-3-decyloxymethyl pentane chloride (gemini surfactant on the thermotropic phase behaviour of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC bilayers with and without the presence of DNA was investigated using Fourier transformed infrared (FTIR and circular dichroism (CD spectroscopies, small angle scattering of synchrotron radiation and differential scanning calorimetry. With increasing concentration of surfactant in DMPC/DNA systems, a disappearance of pretransition and a decrease in the main phase transition enthalpy and temperature were observed. The increasing intensity of diffraction peaks as a function of surfactant concentration also clearly shows the ability of the surfactant to promote the organisation of lipid bilayers in the multilayer lamellar phase.

  13. Tribenzylammonium chloride

    Directory of Open Access Journals (Sweden)

    Waly Diallo

    2014-05-01

    Full Text Available Single crystals of the title salt, C21H21NH+·Cl−, were isolated as a side product from the reaction involving [(C6H5CH23NH]2[HPO4] and Sn(CH33Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetrahedral environment, with angles ranging from 107.7 to 111.16 (10°. In the crystal, the tribenzylammonium cations and chloride anions are linked through N—H...Cl and C—H...Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin.

  14. Differential Adaptive Response and Survival of Salmonella enterica Serovar Enteritidis Planktonic and Biofilm Cells Exposed to Benzalkonium Chloride▿

    Science.gov (United States)

    Mangalappalli-Illathu, Anil K.; Vidović, Sinisa; Korber, Darren R.

    2008-01-01

    This study examined the adaptive response and survival of planktonic and biofilm phenotypes of Salmonella enterica serovar Enteritidis adapted to benzalkonium chloride (BC). Planktonic cells and biofilms were continuously exposed to 1 μg ml−1 of BC for 144 h. The proportion of BC-adapted biofilm cells able to survive a lethal BC treatment (30 μg ml−1) was significantly higher (4.6-fold) than that of BC-adapted planktonic cells. Similarly, there were 18.3-fold more survivors among the BC-adapted biofilm cells than among their nonadapted (i.e., without prior BC exposure) cell counterparts at the lethal BC concentration, and this value was significantly higher than the value for BC-adapted planktonic cells versus nonadapted cells (3.2-fold). A significantly higher (P < 0.05) proportion of surviving cells was noticed among BC-adapted biofilm cells relative to BC-adapted planktonic cells following a 10-min heat shock at 55°C. Fatty acid composition was significantly influenced by phenotype (planktonic cells or biofilm) and BC adaptation. Cell surface roughness of biofilm cells was also significantly greater (P < 0.05) than that of planktonic cells. Key proteins upregulated in BC-adapted planktonic and biofilm cells included CspA, TrxA, Tsf, YjgF, and a probable peroxidase, STY0440. Nine and 17 unique proteins were upregulated in BC-adapted planktonic and biofilm cells, respectively. These results suggest that enhanced biofilm-specific upregulation of 17 unique proteins, along with the increased expression of CspA, TrxA, Tsf, YjgF, and a probable peroxidase, phenotype-specific alterations in cell surface roughness, and a shift in fatty acid composition conferred enhanced survival to the BC-adapted biofilm cell population relative to their BC-adapted planktonic cell counterparts. PMID:18663028

  15. The leaves of Diospyros kaki exert beneficial effects on a benzalkonium chloride–induced murine dry eye model

    Science.gov (United States)

    Kim, Kyung-A; Hyun, Lee Chung; Jung, Sang Hoon

    2016-01-01

    Purpose In this study, the beneficial effects of the oral administration of ethanol extract of Diospyros kaki (EEDK) were tested on a mouse dry eye model induced by benzalkonium chloride (BAC). Methods A solution of 0.2% BAC was administered topically to mouse eyes for 14 days, twice daily, to induce dry eye. Various concentrations of EEDK were administrated daily by oral gavage for 14 days after BAC treatment. Preservative-free eye drops were instilled in the positive-control group. The tear secretion volume (Schirmer’s test), tear break-up time (BUT), and fluorescein score were measured on the ocular surface. BAC-induced corneal damage was tested with hematoxylin-eosin staining. Moreover, apoptotic cell death in the corneal epithelial layer was investigated with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. The protein expression level of interleukin-1alpha (IL-1α), IL-1β, IL-6, tumor necrosis factor- alpha (TNF-α), and monocyte chemotactic protein-1 (MCP-1) was determined with western blot analysis. Furthermore, squamous metaplasia in the corneal epithelial layer was detected with immunofluorescent staining for cytokeratine-10. The cellular proliferation in the cornea was examined with immunohistochemical staining for Ki-67. Results EEDK treatment resulted in prolonged BUT, decreased fluorescein score, increased tear volume, and smoother epithelial cells compared with BAC treatment alone in the cornea. Moreover, EEDK treatment inhibited the inflammatory response and corneal epithelial cell death in a BAC-induced murine dry eye model, and changes in squamous cells were inhibited. Proliferative activity in the corneal epithelium cells was improved with EEDK. Conclusions EEDK could be a potential therapeutic agent in the clinical treatment of dry eye. PMID:27110091

  16. Surfactants in the environment.

    Science.gov (United States)

    Ivanković, Tomislav; Hrenović, Jasna

    2010-03-01

    Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products. After use, residual surfactants are discharged into sewage systems or directly into surface waters, and most of them end up dispersed in different environmental compartments such as soil, water or sediment. The toxic effects of surfactants on various aquatic organisms are well known. In general, surfactants are present in the environment at levels below toxicity and in Croatia below the national limit. Most surfactants are readily biodegradable and their amount is greatly reduced with secondary treatment in wastewater treatment plants. The highest concern is the release of untreated wastewater or wastewater that has undergone primary treatment alone. The discharge of wastewater polluted with massive quantities of surfactants could have serious effects on the ecosystem. Future studies of surfactant toxicities and biodegradation are necessary to withdraw highly toxic and non-biodegradable compounds from commercial use and replace them with more environmentally friendly ones.

  17. Pulmonary surfactant and lung transplantation

    NARCIS (Netherlands)

    Erasmus, Michiel Elardus

    1997-01-01

    Pulmonary surfactant lowers the surface tension at the air-water interface inside the alveolus. This is achieved by adsorption of surfactant phospholipids at the air-water interface, a process controlled by surfactant-associated proteins, such as SP-A. In this way, surfactant prevents collapse of th

  18. Metathesis depolymerizable surfactants

    Science.gov (United States)

    Jamison, Gregory M.; Wheeler, David R.; Loy, Douglas A.; Simmons, Blake A.; Long, Timothy M.; McElhanon, James R.; Rahimian, Kamyar; Staiger, Chad L.

    2008-04-15

    A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and/or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.

  19. Phosphine oxide surfactants revisited.

    Science.gov (United States)

    Stubenrauch, Cosima; Preisig, Natalie; Laughlin, Robert G

    2016-04-01

    This review summarizes everything we currently know about the nonionic surfactants alkyl dimethyl (C(n)DMPO) and alkyl diethyl (C(n)DEPO) phosphine oxide (PO surfactants). The review starts with the synthesis and the general properties (Section 2) of these compounds and continues with their interfacial properties (Section 3) such as surface tension, surface rheology, interfacial tension and adsorption at solid surfaces. We discuss studies on thin liquid films and foams stabilized by PO surfactants (Section 4) as well as studies on their self-assembly into lyotropic liquid crystals and microemulsions, respectively (Section 5). We aim at encouraging colleagues from both academia and industry to take on board PO surfactants whenever possible and feasible because of their broad variety of excellent properties.

  20. Solubilization isotherms of aromatic solutes in surfactant aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Gadelle, F.; Koros, W.J.; Schechter, R.S. (Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering)

    1995-03-01

    Several factors affecting solubilization of aromatic solutes in surfactant micelles have been investigated. Solubilization isotherms of benzene, toluene, and chlorobenzene in various aqueous micellar solutions were determined using head space gas chromatography. Cationic surfactants such as cetylpyridinium chloride or cetyltrimethylammonium bromide present high solubilization capacities. Comparable anionic surfactants exhibit lower solubilization and a greater tendency to precipitate. It was observed that nonionic surfactants show high solubilization on a molar basis. Solubilization in mixed cationic-anionic micelles was also investigated. It also appears that the molecular size of the solute determines the extent of the solubilization. Finally, the shape of the different isotherms indicates that knowing the amount solubilized at saturation of the micellar solution is not sufficient to estimate solubilization at solute concentrations lower than the solute aqueous solubility. Solubilization of organics in surfactant micelles is of major importance in many applications. One new application is micellar-enhanced ultrafiltration. Another application of interest is the surfactant-enhanced aquifer remediation, a process in which a micellar aqueous solution is flushed into contaminated groundwaters to enhance recovery of pollutants by micellar solubilization.

  1. Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, David

    2002-07-01

    the CSC have been determined for mixtures of cationically modified guar gums (of varying charge density) with two anionic surfactants: sodium lauryl (or dodecyl) ether sulfate [SLES] and sodium dodecyl sulfate [SDS], for various concentrations of the polyelectrolyte and added sodium chloride, at room temperature. The addition of sodium chloride has only a minor net effect on the CFC, but increases the CSC significantly. The interactions between the cationic polyelectrolyte and the surfactant have been studied in the one-phase regions, i.e. below the CFC and above the CSC, using different techniques. Surface tension, electrophoresis, light scattering and viscosimetry have been employed. In the two-phase region, the sedimented floe phase has been analysed and the flocculation has been investigated. Rheology of the floe phase has been studied, after a mild compression by centrifugation. The initial rate of flocculation has been determined, using stop-flow equipment. The growth and the structure of the flocs have been investigated by light scattering. The open-network flocs of polyelectrolyte-surfactant particles grow to {approx}10's {mu}m in size, prior to their eventual settling out. Other colloidal particles can be trapped within these large flocs, and the flocs can be used to transport these particles to a macroscopic surface. The deposition and the removal of such composite flocs on glass surfaces, under flow, have been studied using a flow cell device coupled with an optical microscope. Scanning electron microscopy and atomic force microscopy have also been employed. (author)

  2. Solubilization and separation of p-tert-butylphenol using polyelectrolyte/surfactant complexes in colloid-enhanced ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Hirotaka; Christian, S.D.; Tucker, E.E.; Scamehorn, J.F. (Univ. of Oklahoma, Norman, OK (United States))

    1994-03-15

    Water-soluble polyelectrolyte/surfactant complexes, involving oppositely charged species, can form at quite low thermodynamic activities of the surfactant. This fact can be exploited in colloid-enhanced ultrafiltration separations, where both molecular organic pollutants and toxic ions are to be removed from contaminated aqueous streams. Investigations have been made of (a) the solubilization and ultrafiltration of solutions of organic solutes in polymer/surfactant solutions, for comparison with studies of micellar surfactant solutions in the absence of added polymers; (b) the penetration of surfactant through the membrane (leakage of monomer) in dialysis and ultrafiltration experiments; and (c) the utility of polyelectrolytes as scavengers'' for surfactant species that-enter the permeate or filtrate in colloid-enhanced ultrafiltration separations. The polyelectrolyte chosen for the studies is sodium poly(styrenesulfonate) and the surfactant is cetylpyridinium chloride (hexadecylpyridinium chloride). A detailed study has been made of the solubilization and separation of p-tert-butylphenol in aqueous mixtures of sodium poly(styrenesulfonate) and cetylpyridinium chloride, at polyelectrolyte to surfactant mole ratios of two to one and three to one.

  3. Combination of surfactant solubilization with permanganate oxidation for DNAPL remediation.

    Science.gov (United States)

    Li, Zhaohui; Hanlie, Hong

    2008-02-01

    A combination of surfactant solubilization with permanganate oxidation of trichloroethylene (TCE) was studied in batch, flow-through column, and three-dimensional (3-D) tank tests. Batch results showed that chloride production, an indication of TCE degradation, followed a pseudo-first-order reaction kinetics with respect to KMnO4 in the presence of free-phase TCE. A higher chloride production rate was achieved when anionic surfactants were present. The observed pseudo-first-order reaction rate constant increased as the concentrations of anionic surfactants Ninate 411 and Calfax increased from 0% to 0.1%, 0.3%, and 1.0%. Column experiments on TCE reduction by permanganate in the presence and absence of surfactants were carried out using well-sorted coarse Ottawa sand. The peak effluent TCE concentration reached 1700 mg/L due to enhanced solubilization when both sodium dodecyl sulfate (SDS) and permanganate were used, in contrast to less than 300 mg/L when only permanganate solution was used. In addition, the effluent TCE concentration decreased much faster when SDS was present in the permanganate solution, compared with the case when SDS was absent. With an initial 1 mL of TCE emplaced in the columns, the effluent TCE concentration dropped to breakthrough occurred after 21-25 h of injection when SDS was present compared with 45-70 h later when SDS was absent. A slightly higher chloride concentration was observed in the earlier stage of the column experiment and the chloride concentration decreased quickly once KMnO4 was seen in the effluent. The 3-D tank test showed that the MnO2 precipitation front formed more quickly when 1% SDS was present, which further confirmed the observation from the column study.

  4. The effect of selected surfactants on the structure of a bicellar system (DMPC/DHPC) studied by SAXS

    Science.gov (United States)

    Kozak, Maciej; Domka, Ludwik; Jurga, Stefan

    2007-11-01

    The stabilizing or disturbing effect of different surfactants on the bicellar phase of phospholipids significantly depends on their type. The effect of different surfactants on the bicellar structure made of a mixture of phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphocholine and 1,2-dihexanoyl-sn-glycero-3-phospho-choline (DMPC/DHPC) has been studied by the small angle scattering of synchrotron radiation. The study has been performed for three surfactants: dodecyldimethyl-(hexyloxymethyl)ammonium chloride, n-undecylammonium chloride and t-octylphenoxypolyethoxyethanol (Triton X-100) introduced into a bicellar solution of DMPC/DHPC (2.8:1). The bicellar phase has been disturbed in the shortest time in the presence of dodecyldimethyl-(hexyloxymethyl)ammonium chloride in this system a transition from the bicellar to lamellar structure has been directly visible. The changes have been less pronounced in the presence of undecylammonium chloride and practically not noted in the presence of Triton X-100.

  5. Surfactant-Amino Acid and Surfactant-Surfactant Interactions in Aqueous Medium: a Review.

    Science.gov (United States)

    Malik, Nisar Ahmad

    2015-08-01

    An overview of surfactant-amino acid interactions mainly in aqueous medium has been discussed. Main emphasis has been on the solution thermodynamics and solute-solvent interactions. Almost all available data on the topic has been presented in a lucid and simple way. Conventional surfactants have been discussed as amphiphiles forming micelles and amino acids as additives and their effect on the various physicochemical properties of these conventional surfactants. Surfactant-surfactant interactions in aqueous medium, various mixed surfactant models, are also highlighted to assess their interactions in aqueous medium. Finally, their applied part has been taken into consideration to interpret their possible uses.

  6. 苯扎溴铵酊处方改进及苯扎溴铵的含量测定%Improvement of prescription on Benzalkonium Bromide Tincture and de-termination of benzalkonium bromide

    Institute of Scientific and Technical Information of China (English)

    吴海伟; 王晓青; 刘皈阳; 马建丽

    2015-01-01

    Objective To improve prescription of Benzalkonium Bromide Tincture and establish a titration method in determination for content of benzalkonium bromide in Benzalkonium Bromide Alcoholic Solution (eosin was removed from Benzalkonium Bromide Tincture). Methods The content of benzalkonium bromide was detected by setting up capacity analysis method, and found eosin can affect the result of content determination at different degree, therefore eosin com-position was removed from the prescription. The content of benzalkonium bromide in Benzalkonium Bromide Alcoholic Solution was detected by titration method with tetraphenylboron sodium volumetric solution (0.02 mol/L). Results Ben-zalkonium Bromide Tincture changed to Benzalkonium Bromide Alcohol Solution, in content determination, the change of titration end point was obvious and easy to judge. Within the range from 0.4 mg/mL to 1.4 mg/mL, benzalkonium bromide presented a good linear relationship with the consumption volume of tetraphenylboron sodium volumetric solu-tion (r=0.9995), and the equation of linear regression was V=18.3C-0.32. The average recovery of benzalkonium bro-mide in low, middle and high dose was 99.12%, and RSD was 0.84%. Conclusion The method is simple, fast and ac-curate, it can be used for the quality control of Benzalkonium Bromide Alcoholic Solution.%目的:改进苯扎溴铵酊处方,并建立容量分析法测定苯扎溴铵醇溶液(苯扎溴铵酊去除曙红成分)中苯扎溴铵的含量。方法在建立容量分析法测定苯扎溴铵的含量时,发现曙红在不同程度上均能影响含量测定结果,故将曙红成分从处方中删去。采用四苯硼钠(0.02 mol/L)为滴定液,滴定苯扎溴铵醇溶液中苯扎溴铵的含量。结果苯扎溴铵酊制剂更改为苯扎溴铵醇溶液,在含量测定中,滴定终点变化明显,易于判断。苯扎溴铵在浓度0.4~1.4 mg/mL的范围内与消耗四苯硼钠滴定液体积呈良好线性关系,r=0

  7. Solubilization of trichloroethylene by polyelectrolyte/surfactant complexes

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Hirotaka; Christian, S.D.; Tucker, E.E.; Scamehorn, J.F. (Univ. of Oklahoma, Norman, OK (United States))

    1994-12-01

    An automated vapor pressure method is used to obtain solubilization isotherms for trichloroethylene (TCE) in polyelectrolyte/surfactant complexes throughout a wide range of solute activities at 20 and 25 C. The polyelectrolyte chosen is sodium poly(styrenesulfonate), PSS< and the surfactant is cetylpyridinium chloride or N-hexadecylpyridinium chloride, CPC. Data are fitted to the quadratic equation K = K[sub 0](1[minus][alpha]X + [beta]X[sup 2]), which correlates the solubilization equilibrium constant (K) with the mole fraction of TCE (X) in the micelles or complexes at each temperature. Activity coefficients are also obtained for TCE in the PSS/CPC complexes as a function of X. The general solubilization of TCE in PSS/CPC complexes resembles that of TCE in CPC micelles, as well as that of benzene or toluene in CPC micelles, suggesting that TCE solubilizes in ionic micelles both within the hydrocarbon micellar interior and near the micellar surface. The presence of the polyelectrolyte causes a small decrease in the ability of the cationic surfactant to solubilize TCE, while greatly reducing the concentration of the surfactant present in monomeric form. PSS/CPC complexes may be useful in colloid-enhanced ultrafiltration processes to purify organic-contaminated water.

  8. Synthesis and Surface Activity of Novel Triazole-based Cationic Gemini Surfactants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The synthesis and surfactant activities of two new cationic gemini surfactants containingtriazole compound as spacer were described. Their critical micelle concentrations (CMC), whichare 1.8 × l0-4 mol/L and 3.9× 10-4 mol/L respectively, are much lower than that of conventionalsurfactant cetyltrimethyl ammonium chloride (CTAC). In addition, compared with some geminisurfactants containing phenylene, xylylene and stilbenyl as spacer, this new kind of surfactants hasgood solubility in water at room temperature because of containing more hydrophilic groups oratoms in molecules.

  9. Studies of the behaviour of alcohols as co-surfactants in stabilizing microemulsions

    Energy Technology Data Exchange (ETDEWEB)

    Bahadur, P. (Chemistry Dept., D.A.V. (P.G.) Coll., Muzaffarnagar- (India)); Chand, M. (Chemistry Dept., D.A.V. (P.G.) Coll., Muzaffarnagar- (India))

    Micoremulsion formation was investigated in the following quaternary systems. Water/oil/surfactant/co-surfactant alcohol systems i.e. (i) water/xylene, benzene, toluene/tween-20/propanol-1, propanol-2, methanol, (ii) water/xylene, benzene, toluene/sodium dodecyl benzene sulphonate/propanol-1, propanol-2, methanol, (iii) water/xylene, benzene, toluene/dodecyl ammonium chloride/propanol-1, propanol-2, methanol. The formation of microemulsions is explained in terms of ternary phase diagrams for all three nonionic, anionic and cationic surfactants used. The viscosities and densities of the microemulsions were determined in all the systems. (orig.)

  10. Micellization Behavior of Long-Chain Substituted Alkylguanidinium Surfactants

    Directory of Open Access Journals (Sweden)

    Roza Bouchal

    2016-02-01

    Full Text Available Surface activity and micelle formation of alkylguanidinium chlorides containing 10, 12, 14 and 16 carbon atoms in the hydrophobic tail were studied by combining conductivity and surface tension measurements with isothermal titration calorimetry. The purity of the resulting surfactants, their temperatures of Cr→LC and LC→I transitions, as well as their propensity of forming birefringent phases, were assessed based on the results of 1H and 13C NMR, differential scanning calorimetry (DSC, and polarizing microscopy studies. Whenever possible, the resulting values of Krafft temperature (TK, critical micelle concentration (CMC, minimum surface tension above the CMC, chloride counter-ion binding to the micelle, and the standard enthalpy of micelle formation per mole of surfactant (ΔmicH° were compared to those characterizing alkyltrimethylammonium chlorides or bromides with the same tail lengths. The value of TK ranged between 292 and 314 K and increased strongly with the increase in the chain length of the hydrophobic tail. Micellization was described as both entropy and enthalpy-driven. Based on the direct calorimetry measurements, the general trends in the CMC with the temperature, hydrophobic tail length, and NaCl addition were found to be similar to those of other types of cationic surfactants. The particularly exothermic character of micellization was ascribed to the hydrogen-binding capacity of the guanidinium head-group.

  11. Micellization Behavior of Long-Chain Substituted Alkylguanidinium Surfactants.

    Science.gov (United States)

    Bouchal, Roza; Hamel, Abdellah; Hesemann, Peter; In, Martin; Prelot, Bénédicte; Zajac, Jerzy

    2016-02-06

    Surface activity and micelle formation of alkylguanidinium chlorides containing 10, 12, 14 and 16 carbon atoms in the hydrophobic tail were studied by combining conductivity and surface tension measurements with isothermal titration calorimetry. The purity of the resulting surfactants, their temperatures of Cr→LC and LC→I transitions, as well as their propensity of forming birefringent phases, were assessed based on the results of ¹H and (13)C NMR, differential scanning calorimetry (DSC), and polarizing microscopy studies. Whenever possible, the resulting values of Krafft temperature (TK), critical micelle concentration (CMC), minimum surface tension above the CMC, chloride counter-ion binding to the micelle, and the standard enthalpy of micelle formation per mole of surfactant (ΔmicH°) were compared to those characterizing alkyltrimethylammonium chlorides or bromides with the same tail lengths. The value of TK ranged between 292 and 314 K and increased strongly with the increase in the chain length of the hydrophobic tail. Micellization was described as both entropy and enthalpy-driven. Based on the direct calorimetry measurements, the general trends in the CMC with the temperature, hydrophobic tail length, and NaCl addition were found to be similar to those of other types of cationic surfactants. The particularly exothermic character of micellization was ascribed to the hydrogen-binding capacity of the guanidinium head-group.

  12. Therapeutic Effects of Sodium Hyaluronate on Ocular Surface Damage Induced by Benzalkonium Chloride Preserved Anti-glaucoma Medications

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2015-01-01

    Conclusions: SH significantly improved both symptoms and signs of ocular surface damage in patients with BAC-preserved anti-glaucoma medications treatment. SH could be proposed as a new attempt to reduce ocular surface toxicity, and alleviate symptoms of ocular surface damage in BAC-preserved anti-glaucoma medications treatment.

  13. Alkylrhodamines enhance the toxicity of clotrimazole and benzalkonium chloride by interfering with yeast pleiotropic ABC-transporters.

    Science.gov (United States)

    Knorre, Dmitry A; Besedina, Elizaveta; Karavaeva, Iuliia E; Smirnova, Ekaterina A; Markova, Olga V; Severin, Fedor F

    2016-06-01

    ABC-transporters with broad substrate specificity are responsible for pathogenic yeast resistance to antifungal compounds. Here we asked whether highly hydrophobic chemicals with delocalized positive charge can be used to overcome the resistance. Such molecules efficiently penetrate the plasma membrane and accumulate inside the cells. We reasoned that these properties can convert an active efflux of the compounds into a futile cycle thus interfering with the extrusion of the antibiotics. To test this, we studied the effects of several alkylated rhodamines on the drug resistance of yeast Saccharomyces cerevisiae We found that octylrhodamine synergetically increases toxicity of Pdr5p substrate-clotrimazole, while the others were less effective. Next, we compared the contributions of three major pleiotropic ABC-transporters (Pdr5p, Yor1p, Snq2p) on the accumulation of the alkylated rhodamines. While all of the tested compounds were extruded by Pdr5p, Yor1p and Snq2p showed narrower substrate specificity. Interestingly, among the tested alkylated rhodamines, inactivation of Pdr5p had the strongest effect on the accumulation of octylrhodamine inside the cells, which is consistent with the fact that clotrimazole is a substrate of Pdr5p. As alkylated rhodamines were shown to be non-toxic on mice, our study makes them potential components of pharmacological antifungal compositions.

  14. Variations in biofilm formation, desiccation resistance and Benzalkonium chloride susceptibility among Listeria monocytogenes strains isolated in Canada

    DEFF Research Database (Denmark)

    Piercey, Marta J.; C. Ells, Timothy; Macintosh, Andrew J.

    2017-01-01

    of the SSI-1 (Stress Survival Islet) and LGI1/CC8 (Listeria Genomic Island 1 in a clonal complex 8 background) genetic markers. Genetic sequences from four strains representing different phenotypes were also probed for predicted amino acid differences in biofilm, desiccation, and membrane related genes....... The water isolates were among the most desiccation susceptible strains, while strains exhibiting desiccation resistance harboured SSI-1 or both the SSI-1 and LGI1/CC8 markers. BAC resistance was greatest in planktonic LGI1/CC8 cells (relative to non-LGI1/CC8 cells), and higher BAC concentrations were also...

  15. Influence of Suspended Emulsion Polymerization Conditions on Particle Characteristics of Polyvinyl Chloride Resin

    Institute of Scientific and Technical Information of China (English)

    包永忠; 魏真理; 翁志学; 黄志明

    2003-01-01

    Suspended emulsion polymerization of vinyl chloride was carried out in a 5 L autoclave. The influence of agitation, polymerization conversion, dispersant and surfactant on the average particle size (PS) and particle size distribution (PSD), particle morphology and porosity of polyvinyl chloride (PVC) resin was investigated. It showed that the agitator had great influence on the smooth operation of polymerization, PS and PSD. The PS increased and PSD became narrow as polymerization conversion became high. The porosity decreased with the increase of conversion. A convenient choice of additives, both dispersants and non-ionic surfactants, allows one to adjust PS and PSD. The PS decreased with the addition of polyvinyl alcohol or hydroxypropyl methylcellulose dispersants,and increased with the addition of Span surfactants. The addition of dispersants or surfactants also affected the morphology and porosity of resin, and PVC resin with looser agglomeration and homogeneous distribution of primary particles was prepared.

  16. Wettability of a quartz surface in the presence of four cationic surfactants.

    Science.gov (United States)

    Zhang, Lei; Wang, Zeng-Lin; Li, Zhen-Quan; Zhang, Lu; Xu, Zhi-Cheng; Zhao, Sui; Yu, Jia-Yong

    2010-12-21

    Advancing contact angle (θ) measurements were carried out for aqueous solutions of four cationic surfactants, hexadecanol glycidyl ether ammonium chloride (C(16)PC), guerbet alcohol hexadecyl glycidyl ether ammonium chloride (C(16)GPC), hexadecanol polyoxyethylene(3) glycidyl ether ammonium chloride (C(16)(EO)(3)PC), and guerbet alcohol hexadecyl polyoxyethylene(3) glycidyl ether ammonium chloride (C(16)G(EO)(3)PC), on the quartz surface using the sessile drop analysis. The influences of surfactant type and bulk concentration on contact angle were expounded, and the changes in adhesional tension and adhesion work were discussed. The contact angle increases up to a maximum with the increasing concentration for all cationic surfactants. Surfactants with branched chain have more hydrophobic group density on the quartz surface, which results in higher values of maxima in contact angle curves. When ethylene oxide groups CH(2)CH(2)O were incorporated in the hydrophobic group, the decrease in contact angle maximum was observed for C(16)(EO)(3)PC and C(16)G(EO)(3)PC. Moreover, an increase in quartz-water interfacial free energy (γ(SL)) has been observed due to the adsorption of four cationic surfactants. The four cationic surfactants can form a monolayer with alignment structure on the quartz surface through electrostatic interaction and then form the bilayer with increasing bulk concentration. In contrast with literature, the maximal contact angles may not necessarily correspond to the beginning of the formation of bilayer for cationic surfactants at the quartz-water interface. Moreover, the concentrations corresponding to maximal contact angles for C(16)PC and C(16)(EO)(3)PC were much lower than their CMC. The contact angle passes through a maximum at a concentration obviously higher than CMC for C(16)G(EO)(3)PC.

  17. Evaluation of surfactant flushing for remediating EDC-tar contamination

    Science.gov (United States)

    Liang, Chenju; Hsieh, Cheng-Lin

    2015-06-01

    Ethylene dichloride tar (EDC-tar) is a dense non-aqueous phase liquid (DNAPL) waste originated from the process of vinyl chloride production, with major constituents including chlorinated aliphatic and aromatic hydrocarbons. This study investigated the feasibility of Surfactant Enhanced Aquifer Remediation (SEAR) for treating EDC-tar contaminated aquifers. Initial experiments explored the potential to enhance the apparent solubility of EDC-tar using single or mixed surfactants. The results showed that an aqueous solution mixed anionic and non-ionic surfactants (i.e., SDS/Tween 80) exhibited higher EDC-tar apparent solubility and lower surface tension than other surfactant systems tested. Additionally, alkaline pH aids in increasing the EDC-tar apparent solubility. In column flushing experiments, it was seen that the alkaline mixed SDS/Tween 80 solution showed better removal of pure EDC-tar from silica sand porous media. Furthermore, separation of EDC-tar in the surfactant solution was conducted employing a salting-out effect. Significant separation of DNAPL was observed when 13 wt.% or more NaCl was added to the solution. Overall, this study evaluates the feasibility of using SEAR for remediating EDC-tar contaminated subsurface soil and groundwater.

  18. Sizing up surfactant synthesis.

    Science.gov (United States)

    Han, SeungHye; Mallampalli, Rama K

    2014-08-01

    Phosphatidylcholine is generated through de novo synthesis and remodeling involving a lysophospholipid. In this issue of Cell Metabolism, research from the Shimizu lab (Harayama et al., 2014) demonstrates the highly selective enzymatic behavior of lysophospholipid acyltransferases. The authors present an enzymatic model for phosphatidylcholine molecular species diversification that impacts surfactant formation.

  19. Mineralization of Surfactants by the Microbiota of Submerged Plant Detritus

    Science.gov (United States)

    Federle, Thomas W.; Ventullo, Roy M.

    1990-01-01

    In wetlands and canopied bodies of water, plant detritus is an important source of carbon and energy. Detrital materials possess a large surface area for sorption of dissolved organics and are colonized by a large and diverse microbiota. To examine the biodegradation of surfactants by these microorganisms, submerged oak leaves were obtained from a laundromat wastewater pond, its overflow, and a pristine control pond. Leaves were cut into disks and incubated in sterile water amended with 50 μg of 14C-labeled linear alkylbenzene sulfonate (LAS), linear alcohol ethoxylate, stearyltrimethyl ammonium chloride, distearyldimethyl ammonium chloride, benzoic acid, or mixed amino acids per liter. Sorption of the test compounds to the detritus and evolution of 14CO2 were followed with time. All of the compounds sorbed to the detritus to various degrees, with LAS and stearyltrimethyl ammonium chloride the most sorptive and benzoic acid the least. All compounds were mineralized without a lag. With leaves from the laundromat wastewater pond, half-lives were 12.6 days for LAS, 8.4 days for linear alcohol ethoxylate, 14.2 days for stearyltrimethyl ammonium chloride, 1.0 days for benzoic acid, and 2.7 days for mixed amino acids. Mineralization of LAS and linear alcohol ethoxylate by control pond leaves was slower and exhibited an S-shaped rather than a typical first-order pattern. This study shows that detritus represents a significant site of surfactant removal in detritus-rich systems. Images PMID:16348111

  20. CO2 philic surfactant as possible mobility control agent in EOR applications

    Science.gov (United States)

    Sagir, Muhammad; Tan, Isa M.; Mushtaq, Muhammad

    2014-10-01

    The effect of an in house developed CO2 philic surfactant in foam assisted WAG (FAWAG) on CO2 mobility is reported. We reacted methallyl chloride with nonylphenol ethoxylated alcohol and then sulfonated the produced product. The effect of surfactant on IFT between CO2 and brine was investigated in order to measure the affinity of surfactant with CO2. The detailed effects of pressure and temperature on IFT between CO2 / brine / surfactant at the specified pressure and temperature conditions is studied and reported. In-house developed surfactant effectively lowered down the IFT between CO2/brine from 32 mN/m to less than 6.10 mN / m. In addition, the newly developed surfactant was evaluated for its foam stability. The synthesized novel surfactant was further investigated for its effect on CO2 mobility in porous media and the findings are presented here. The in house developed surfactant has a great potential for CO2- EOR applications.

  1. Study on aqueous two-phase systems of the mixture SDS/CTAB surfactants

    Institute of Scientific and Technical Information of China (English)

    LI Ying; CHEN Yah-ming; ZHAO Kong-shuang; Takumi HIKIDA

    2004-01-01

    The phenomenon of two dilute aqueous phases composed of sodium dodecylsulfate (SDS) and cetyltrimethyl ammonium bromide(CTAB) was investigated under various conditions such as concentrations and molarratios of the two surfactants, the addition of sodium chloride and temperature. Vesicles formation was found in theboth phases by TEM image.

  2. Pulmonary surfactant in the airway physiology: a direct relaxing effect on the smooth muscle.

    Science.gov (United States)

    Calkovska, A; Uhliarova, B; Joskova, M; Franova, S; Kolomaznik, M; Calkovsky, V; Smolarova, S

    2015-04-01

    Beside alveoli, surface active material plays an important role in the airway physiology. In the upper airways it primarily serves in local defense. Lower airway surfactant stabilizes peripheral airways, provides the transport and defense, has barrier and anti-edematous functions, and possesses direct relaxant effect on the smooth muscle. We tested in vitro the effect of two surfactant preparations Curosurf® and Alveofact® on the precontracted smooth muscle of intra- and extra-pulmonary airways. Relaxation was more pronounced for lung tissue strip containing bronchial smooth muscle as the primary site of surfactant effect. The study does not confirm the participation of ATP-dependent potassium channels and cAMP-regulated epithelial chloride channels known as CFTR chloride channels, or nitric oxide involvement in contractile response of smooth muscle to surfactant.By controlling wall thickness and airway diameter, pulmonary surfactant is an important component of airway physiology. Thus, surfactant dysfunction may be included in pathophysiology of asthma, COPD, or other diseases with bronchial obstruction.

  3. MICROBIAL SURFACTANTS. I. GLYCOLIPIDS

    Directory of Open Access Journals (Sweden)

    Pirog T. Р.

    2014-02-01

    Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.

  4. MICROBIAL SURFACTANTS. II. LIPOPEPTIDES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2014-04-01

    Full Text Available The classification and the chemical structure of the lipopeptides and their producers (bacteria of the genera Bacillus and Pseudomonas are given. The role of the lipopeptides in cells motility, biofilm formation, metal binding and xenobiotics degradation and their action on the cells of pro- and eukaryotes is summarized. The stages of the nonribosomal lipopeptides synthesis and the role of two-component (GacA/GacS, ComA/ComP and the quorum system regulation of this process are shown. The potential of lactic acid bacteria and marine microorganisms as alternative surfactants producers (glycolipids, lipopeptides, phospholipids and fatty acids, glycolipopeptides are discussed. Their productivity and advantages over traditional producers are given as well. The properties of surfactants synthesized by lactic acid bacteria (the reduction of the surface tension, the critical micelle concentration, the stability in a wide range of pH, the temperature, the biological activity are summarized. Surfactants of nonpathogenic probiotic bacteria could be used as effective antimicrobial agents and antiadhesive and marine producers which able to synthesize unique metabolites that are not produced by other microorganisms.

  5. Surfactants at the Design Limit.

    Science.gov (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian

    2015-08-04

    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  6. BINDING ISOTHERMS SURFACTANT-PROTEINS

    Directory of Open Access Journals (Sweden)

    Elena Irina Moater

    2011-12-01

    Full Text Available The interactions between surfactants and proteins shows some similarities with interactions between surfactants and polymers, but the hydrophobic amphoteric nature of proteins and their secondary and tertiary structure components make them different from conventional polymer systems. Many studies from the past about surfactant - proteins bonding used the dialysis techniques. Other techniques used to determine the binding isotherm, included ultrafiltration, ultracentrifugation, potentiometry, ion-selective electrode method and surface tension. High affinity isotherms which are typical of an anionic surfactant - protein bonding, exhibit an initial increase steep followed by a slow growth region and then a vertical growth above a certain concentration. This isotherm is typical of ionic surfactant to protein binding. Often the high affinity initial bond appears at very low concentrations of surfactant and therefore in some protein-surfactant systems, the exact shape of the isotherm in this region may be missing. The surfactant - protein binding is influenced by a number of variables such as the nature and chain length of surfactant, pH, ionic strength, temperature, nature of this protein and additives.

  7. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash...... in marine atmospheric and submersed South Scandinavian environment. The design parameters are based on sequential measurements of 86 chloride profiles taken over ten years from 13 different types of concrete. The design parameters provide the input for an analytical model for chloride profiles as function...

  8. Preparation and evaluation of sulphonamide nonionic surfactants

    Directory of Open Access Journals (Sweden)

    Ahmed, M. H. M.

    2010-03-01

    Full Text Available Alkyl (octyl, decyl and dodecyl; C8,C10 and C12 benzene sulphonyl chloride was used in the preparation of a novel series of nonionic surfactants (IV-VIa-c, (VII-IX a-c and (X-XIIa-c. The preparations were completed by reacting each alkyl (C8,C10 and C12 benzene sulphonyl chloride with ethanolamine to give (I-III respectively. The resulting products were reacted separately with ethylene oxide in the presence of different (base KOH, Lewis acid SnCl4 and k10 clay catalysts to produce different moles of nonionic surfactants (5, 7 and 9 in sequence corresponding to (IV-VIa-c, (VII-IX a-c and (X-XIIa-c respectively. The chemical structures of prepared nonionic surfactants were elucidated by IR and 1HNMR spectra. The surface activity, biodegradability and biological activities of the prepared compounds were investigated. The obtained data show that these compounds have good surface and biological activities as well as reasonable biodegradability properties.Cloruros de sulfonilbenceno alquilados (octil, decil, dodecil; C8, C10 y C12 fueron usados en la preparación de una nueva serie de surfactantes no iónicos (IV-VIa-c, (VII-IX a-c and (X-XIIa-c. Las preparaciones fueron completadas por reacción de cada cloruro de sulfonilbenceno alquilado (C8, C10 y C12 con etanolamina para dar los compuestos (IIII, respectivamente. Los anteriores productos reaccionaron separadamente con óxido de etileno en presencia de diferentes catalizadores (la base KOH, el ácido de Lewis SnCl4 y la arcilla k10 para producir secuencialmente diferentes surfactantes no iónicos con distintos moles de óxido de etileno (5, 7 y 9: (IV-VIa-c, (VII-IXa-c and (X-XIIa-c, respectivamente. La estructura química de los surfactantes no iónicos preparados fueron elucidadas mediante sus espectros de IR y 1H RMN. Las propiedades tensoactivas, biodegradabilidad y actividad biológica de los compuestos preparados fueron investigados. Los datos obtenidos muestran que estos compuestos tienen

  9. Characterization of surfactant effects on the visible spectroscopy of lanthanide metal ion-triphenylmethane dye complexes

    Energy Technology Data Exchange (ETDEWEB)

    Klopf, G.J.

    1985-01-01

    To better define the mechanism responsible for sensitization, the interactions of representative cationic, anionic, and nonionic surfactants with several lanthanide metal ion-triphenylmethane dye complexes, particularly the gadolinium (Gd/sup +3/)-Chromeazurol S (CAS) complex, were characterized. Only cationic surfactants induced sensitization when added to the Gd/sup +3/-CAS complex. Sensitization induced by cetylpyridinium chloride (CPC) occurred at submicellar concentrations and was attributed to the formation of a 1:2:4 Gd/sup +3/-CAS-CPC ternary complex. Additional ternary complexes evidently form if excess CAS is present. Mechanisms are proposed for the sensitization of the reaction by quaternary compounds and by anionic surfactants. Although both micellar and submicellar concentrations were considered, adding the nonionic surfactant Triton X-100 to the Gd/sup +3/-CAS complex had little effect.

  10. Effect of surfactants and temperature on the hyperfiltration performance of poly(ether/urea) membranes

    Science.gov (United States)

    Leban, M. I.; Wydeven, T. J.

    1984-01-01

    The individual and combined effects of pasteurization temperature (347 K) and surfactants (anionic, cationic, and neutral) on a poly(ether/urea) thin-film hyperfiltration membrane were studied. Performance of this positively charged membrane was measured in terms of sodium chloride rejection and water flux. The observed effect was mostly on water flux and minimal on salt rejection. Pasteurization temperature caused an irreversible flux decline (flux decline slope of 0.09). The gradual flux reduction caused by neutral and cationic surfactants was reversible, whereas the flux reduction caused by anionic surfactant was irreversible and of similar magnitude to flux reduction caused by pasteurization temperature. The effects of anionic surfactant and pasteurization temperature were additive. Because of flux decline at elevated temperatures the poly(ether/urea) membrane is not very attractive for long-term spaceflight use.

  11. Synthesis and bio-physicochemical properties of amide-functionalized N-methylpiperazinium surfactants.

    Science.gov (United States)

    Chauhan, Vinay; Singh, Sukhprit; Mishra, Rachana; Kaur, Gurcharan

    2014-12-15

    Four new amide functionalized N-methylpiperazinium amphiphiles having tetradecyl, hexadecyl alkyl chain lengths and counterions; chloride or bromide have been synthesized and characterized by various spectroscopic techniques. These new surfactants have been investigated in detail for their self-assembling behavior by surface tension, conductivity and fluorescence measurements. The thermodynamic parameters of these surfactants indicate that micellization is exothermic and entropy-driven. The dynamic light scattering (DLS) and transmission electron microscopy (TEM) experiments have been performed to insight the aggregate size of these cationics. Thermal degradation of these new surfactants has also been evaluated by thermal gravimetric analysis (TGA). These new surfactants form stable complexes with DNA as acknowledged by agarose gel electrophoresis, ethidium bromide exclusion and zeta potential measurements. They have also been found to have low cytotoxicity by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on the C6 glioma cell line.

  12. A novel sodium N-fatty acyl amino acid surfactant using silkworm pupae as stock material

    Science.gov (United States)

    Wu, Min-Hui; Wan, Liang-Ze; Zhang, Yu-Qing

    2014-03-01

    A novel sodium N-fatty acyl amino acid (SFAAA) surfactant was synthesized using pupa oil and pupa protein hydrolysates (PPH) from a waste product of the silk industry. The aliphatic acids from pupa oil were modified into N-fatty acyl chlorides by thionyl chloride (SOCl2). SFAAA was synthesized using acyl chlorides and PPH. GC-MS analysis showed fatty acids from pupa oil consist mainly of unsaturated linolenic and linoleic acids and saturated palmitic and stearic acids. SFAAA had a low critical micelle concentration, great efficiency in lowering surface tension and strong adsorption at an air/water interface. SFAAA had a high emulsifying power, as well as a high foaming power. The emulsifying power of PPH and SFAAA in an oil/water emulsion was better with ethyl acetate as the oil phase compared to n-hexane. The environment-friendly surfactant made entirely from silkworm pupae could promote sustainable development of the silk industry.

  13. Compatibilization of HDPE/agar biocomposites with eutectic-based ionic liquid containing surfactant

    CERN Document Server

    Shamsuri, AA; Zainudin, ES; Tahir, PM

    2014-01-01

    In this research, eutectic-based ionic liquid specifically choline chloride/glycerol was prepared at a 1:2 mole ratio. The choline chloride/glycerol was added with the different content of surfactant (hexadecyltrimethylammonium bromide). The choline chloride/glycerol-hexadecyltrimethylammonium bromide was introduced into high-density polyethylene/agar biocomposites through melt mixing. The mechanical testing results indicated that the impact strength and tensile extension of the biocomposites increased with the introduction of the choline chloride/glycerol-hexadecyltrimethylammonium bromide. The scanning electron microscope, differential scanning calorimetry and thermal gravimetric analysis results exhibited that significant decrease in the number of agar fillers pull-out, melting point and thermal decomposition temperatures of the biocomposites are also due to the choline chloride/glycerol-hexadecyltrimethylammonium bromide. The Fourier transform infrared spectra and X-ray diffractometer patterns of the bioc...

  14. Interaction of nonionic surfactant AEO9 with ionic surfactants

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-guo; YIN Hong

    2005-01-01

    The interaction in two mixtures of a nonionic surfactant AEO9 (C12H25O(CH2CH2O)9H) and different ionic surfactants was investigated. The two mixtures were AEO9/sodium dodecyl sulfate (SDS) and AEO9/cetyltrimethylammonium bromide (CTAB) at molar fraction of AEO9, αAEO9 =0.5. The surface properties of the surfactants, critical micelle concentration (CMC),effectiveness of surface tension reduction (γCMC), maximum surface excess concentration (Гmax) and minimum area per molecule at the air/solution interface (Amin) were determined for both individual surfactants and their mixtures. The significant deviations from ideal behavior (attractive interactions) of the nonionic/ionic surfactant mixtures were determined. Mixtures of both AEO9/SDS and AEO9/CTAB exhibited synergism in surface tension reduction efficiency and mixed micelle formation, but neither exhibited synergism in surface tension reduction effectiveness.

  15. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  16. Surfactant monitoring by foam generation

    Science.gov (United States)

    Mullen, Ken I.

    1997-01-01

    A device for monitoring the presence or absence of active surfactant or other surface active agents in a solution or flowing stream based on the formation of foam or bubbles is presented. The device detects the formation of foam with a light beam or conductivity measurement. The height or density of the foam can be correlated to the concentration of the active surfactant present.

  17. Surfactant adsorption kinetics in microfluidics

    Science.gov (United States)

    Riechers, Birte; Maes, Florine; Akoury, Elias; Semin, Benoît; Gruner, Philipp; Baret, Jean-Christophe

    2016-10-01

    Emulsions are metastable dispersions. Their lifetimes are directly related to the dynamics of surfactants. We design a microfluidic method to measure the kinetics of adsorption of surfactants to the droplet interface, a key process involved in foaming, emulsification, and droplet coarsening. The method is based on the pH decay in the droplet as a direct measurement of the adsorption of a carboxylic acid surfactant to the interface. From the kinetic measurement of the bulk equilibration of the pH, we fully determine the adsorption process of the surfactant. The small droplet size and the convection during the droplet flow ensure that the transport of surfactant through the bulk is not limiting the kinetics of adsorption. To validate our measurements, we show that the adsorption process determines the timescale required to stabilize droplets against coalescence, and we show that the interface should be covered at more than 90% to prevent coalescence. We therefore quantitatively link the process of adsorption/desorption, the stabilization of emulsions, and the kinetics of solute partitioning—here through ion exchange—unraveling the timescales governing these processes. Our method can be further generalized to other surfactants, including nonionic surfactants, by making use of fluorophore-surfactant interactions.

  18. Impact of cationic surfactant on the self-assembly of sodium caseinate.

    Science.gov (United States)

    Vinceković, Marko; Curlin, Marija; Jurašin, Darija

    2014-08-27

    The impact of a cationic surfactant, dodecylammonium chloride (DDACl), on the self-assembly of sodium caseinate (SC) has been investigated by light scattering, zeta potential, and rheological measurements as well as by microscopy (transmission electron and confocal laser scanning microscopy). In SC dilute solutions concentration-dependent self-assembly proceeds through the formation of spherical associates and their aggregation into elongated structures composed of connected spheres. DDACl interacts with SC via its hydrophilic and hydrophobic groups, inducing changes in SC self-assembled structures. These changes strongly depend on the surfactant aggregation states (monomeric or micellar) as well as concentration ratio of both components, leading to the formation of soluble and insoluble complexes of nano- to microdimensions. DDACl monomers interact with SC self-assembled entities in a different way compared to their micelles. Surfactant monomers form soluble complexes (similar to surfactant mixed micelles) at lower SC concentration but insoluble gelatinous complexes at higher SC concentration. At surfactant micellar concentration soluble complexes with casein chains wrapped around surfactant micelles are formed. This study suggests that the use of proper cationic surfactant concentration will allow modification and control of structural changes of SC self-assembled entities.

  19. 苯扎溴铵生产的风险分析及安全措施%Hazard Analysis and Safety Measures for the Production of Benzalkonium Bromide

    Institute of Scientific and Technical Information of China (English)

    何伟平

    2015-01-01

    介绍了苯扎溴铵的反应原理及生产工艺。分析了其生产过程中的物质、工艺、设备等危险有害因素;结果表明其生产过程中涉及二甲胺、氯化苄、二甲基苄胺等危险化学品;若生产工艺和设备缺陷导致泄漏等,则存在火灾、爆炸、中毒等危险有害因素。并提出了安全管理、主要工艺技术和装置、设备检维修、事故应急救援等安全对策措施,建议安全设计和生产活动中应充分考虑这些危险有害因素,加强安全预防。%The production process and chemical reaction principle of benzalkonium bromide were introduced briefly. The material hazardous factors, process hazardous factors and equipment hazardous factors in the production were analyzed. The results showed that the production process involved hazardous chemicals such as dimethylamine, benzyl chloride and dimethyl benzylamine. If there were serious defects in the production process and equipments, the chemical leak could cause fire, explosion and poisoning in the production. Safety measures were put forward for the security management, major production process and installation, equipment maintenance and emergency rescue to prevent hazardous factors. The security precautions were strengthened, which was necessary to take these hazardous factors into fully consideration in the safety design and the production activities.

  20. Innovation in surfactant therapy II: surfactant administration by aerosolization.

    Science.gov (United States)

    Pillow, J Jane; Minocchieri, S

    2012-01-01

    Instilled bolus surfactant is the only approved surfactant treatment for neonatal respiratory distress syndrome. However, recent trends towards increased utilization of noninvasive respiratory support for preterm infants with surfactant deficiency have created a demand for a similarly noninvasive means of administering exogenous surfactant. Past approaches to surfactant nebulization met with varying success due to inefficient aerosol devices resulting in low intrapulmonary delivery doses of surfactant with variable clinical effectiveness. The recent development of vibrating membrane nebulizers, coupled with appropriate positioning of the interface device, indicates that efficient delivery of aerosolized surfactant is now a realistic goal in infants. Evidence of clinical effect despite low total administered dose in pilot studies, together with suggestions of enhanced homogeneity of pulmonary distribution indicate that this therapy may be applied in a cost-effective manner, with minimal patient handling and disruption. These studies need to be subjected to appropriately designed randomized controlled trials. Further work is also required to determine the optimum delivery route (mask, intranasal prong, nasopharyngeal or laryngeal), dosing amount and redosing interval.

  1. Effect of surfactant species and electrophoretic medium composition on the electrophoretic behavior of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis.

    Science.gov (United States)

    Fukai, Nao; Kitagawa, Shinya; Ohtani, Hajime

    2017-07-01

    We have recently demonstrated the separation of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis (NACZE) using a cationic surfactant of cetyltrimethylammonium chloride (CTAC). In this study, eight ionic surfactants were investigated for the separation of four synthetic polymers (polystyrene, polymethylmethacrylates, polybutadiene, and polycarbonate); only three surfactants (CTAC, dimethyldioctadecylammonium bromide, and sodium dodecylsulfate) caused their separation. The order of the interaction between the polymers and the surfactants depended on both the surfactant species and the composition of the electrophoretic medium. Their investigation revealed that the separation is majorly affected by the hydrophobic interactions between the polymers and the ionic surfactants. In addition, the electrophoretic behavior of polycarbonate suggested that electrostatic interaction also affects the selectivity of the polymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Interaction of nonionic surfactant AEO9 with ionic surfactants*

    OpenAIRE

    2005-01-01

    The interaction in two mixtures of a nonionic surfactant AEO9 (C12H25O(CH2CH2O)9H) and different ionic surfactants was investigated. The two mixtures were AEO9/sodium dodecyl sulfate (SDS) and AEO9/cetyltrimethylammonium bromide (CTAB) at molar fraction of AEO9, α AEO9=0.5. The surface properties of the surfactants, critical micelle concentration (CMC), effectiveness of surface tension reduction (γ CMC), maximum surface excess concentration (Γ max) and minimum area per...

  3. Temperature dependence of transport and equilibrium properties of alkylpyridinium surfactants in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Mohsin Ahmad; Dar, Aijaz Ahmed; Amin, Adil; Rashid, Peer Irfan [Department of Chemistry, University of Kashmir, Hazratbal Srinagar - 190006, J and K (India); Rather, Ghulam Mohammad [Department of Chemistry, University of Kashmir, Hazratbal Srinagar - 190006, J and K (India)], E-mail: gmrather2002@yahoo.com

    2007-11-15

    Conductivity measurements at varying concentrations and temperatures for two alkyl pyridinium surfactants-dodecylpyridinium chloride (DPC) and cetylpyridinium chloride (CPC) in aqueous medium have been performed. The resulting data in the lower concentration range were used for the determination of limiting transport parameters of the surfactant ions. Temperature dependence of limiting ion conductance {lambda}{sub +(surf.cation)}{sup 0} and limiting ion mobility u{sub +(surf.cation)}{sup 0} of surfactant ions were used for determination of standard partial molar enthalpy of activation for ion migration ({delta}H{sub {lambda}{sub +0}}) and the change in activation energy for translational mobility ({delta}E{sub trans}{sup 0}) of water molecules from surfactant ion hydration shell. The conductivity data at higher concentrations were used for determination of equilibrium micellar parameters, viz. critical micelle concentration (cmc), degree of counter ion dissociation ({alpha}), and aggregation number (n). Comparison of such parameters of the two surfactants at different temperatures was made in the light of molecular structure, ion-solvent, ion-ion, and solvent-solvent interactions.

  4. Surfactant enhanced volumetric sweep efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Harwell, J.H.; Scamehorn, J.F.

    1989-10-01

    Surfactant-enhanced waterflooding is a novel EOR method aimed to improve the volumetric sweep efficiencies in reservoirs. The technique depends upon the ability to induce phase changes in surfactant solutions by mixing with surfactants of opposite charge or with salts of appropriate type. One surfactant or salt solution is injected into the reservoir. It is followed later by injection of another surfactant or salt solution. The sequence of injections is arranged so that the two solutions do not mix until they are into the permeable regions well away from the well bore. When they mix at this point, by design they form a precipitate or gel-like coacervate phase, plugging this permeable region, forcing flow through less permeable regions of the reservoir, improving sweep efficiency. The selectivity of the plugging process is demonstrated by achieving permeability reductions in the high permeable regions of Berea sandstone cores. Strategies were set to obtain a better control over the plug placement and the stability of plugs. A numerical simulator has been developed to investigate the potential increases in oil production of model systems. Furthermore, the hardness tolerance of anionic surfactant solutions is shown to be enhanced by addition of monovalent electrolyte or nonionic surfactants. 34 refs., 32 figs., 8 tabs.

  5. MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-08-01

    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  6. Electrokinetic investigation of surfactant adsorption.

    Science.gov (United States)

    Bellmann, C; Synytska, A; Caspari, A; Drechsler, A; Grundke, K

    2007-05-15

    Fuerstenau [D.W. Fuerstenau, in: M.L. Hair (Ed.), Dekker, New York, 1971, p. 143] has already discussed the role of hydrocarbon chain of surfactants, the effect of alkyl chain length, chain structure and the pH of the solution on the adsorption process of surfactants. Later Kosmulski [M. Kosmulski, Chemical Properties of Material Surfaces, Surfactant Science Series, vol. 102, Dekker, New York, Basel, 2001] included the effect of surfactant concentration, equilibration time, temperature and electrolyte in his approaches. Certainly, the character of the head groups of the surfactant and the properties of the adsorbent surface are the basis for the adsorption process. Different surfactants and adsorbents cause different adsorption mechanisms described firstly by Rosen [M.J. Rosen, Surfactants and Interfacial Phenomena, second ed., Wiley, New York, 1989]. These adsorption mechanisms and their influencing factors were studied by electrokinetic investigations. Here only changes of the charges at the surfaces could be detected. To control the results of electrokinetic investigations they were compared with results from ellipsometric measurements. In the case of surfactant adsorption the chain length was vitally important. It could be shown by the adsorption of alkyl trimethyl ammonium bromides onto polymer films spin coated at wafer surfaces. The influence of the chain length depending on surface properties of the polymer film was studied. Streaming potential measurements were applied for these investigations. The obtained results enabled us to calculate the molar cohesive free energy per mol of CH2-group in the alkaline chain of the surfactant if all other specific adsorption effects were neglected.

  7. Anaerobic Biodegradation of Detergent Surfactants

    Directory of Open Access Journals (Sweden)

    Erich Jelen

    2009-03-01

    Full Text Available Detergent surfactantscan be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have strictly anaerobic conditions. This review gives an overview on anaerobic biodegradation processes, the methods for testing anaerobic biodegradability, and the anaerobic biodegradability of different detergent surfactant types (anionic, nonionic, cationic, amphoteric surfactants.

  8. Lithium Sulfuryl Chloride Battery.

    Science.gov (United States)

    Primary batteries , Electrochemistry, Ionic current, Electrolytes, Cathodes(Electrolytic cell), Anodes(Electrolytic cell), Thionyl chloride ...Phosphorus compounds, Electrical conductivity, Calibration, Solutions(Mixtures), Electrical resistance, Performance tests, Solvents, Lithium compounds

  9. Treatment with exogenous surfactant stimulates endogenous surfactant synthesis in premature infants with respiratory distress syndrome

    NARCIS (Netherlands)

    Bunt, JEH; Carnielli, VP; Janssen, DJ; Wattimena, JLD; Hop, WC; Sauer, PJ; Zimmermann, LJI

    2000-01-01

    Objective: Treatment of preterm infants with respiratory distress syndrome (RDS) with exogenous surfactant has greatly improved clinical outcome. Some infants require multiple doses, and it has not been studied whether these large amounts of exogenous surfactant disturb endogenous surfactant metabol

  10. Electrochemical Oscillations Induced by Surfactants

    Institute of Scientific and Technical Information of China (English)

    翟俊红; 贺占博

    2003-01-01

    A new type of electrochemical oscillation induced by surfactant was observed in experiments. The electrochemical system is a Daniell cell with a copper rod in CuSO4 aqueous and an aluminum rod in Al(NO3)3 aqueous as electrodes. The surfactants are CTAB, TX-100, SLS. The addition of trace surfactant solution by a micro-syringe made the original monotonously changing electrochemical system produce obvious periodic phenomena. At the mean time, the copper ion selective electrode and Hg2SO4 reference electrode were used to monitor the copper electrode reaction and determine its rate constant k of first order reaction. According to the experimental results of electrode reaction kinetics, the possible mechanism was found to be the polarization induced from the directional adsorption of trace surfactant on the electrode surface. That is the electrochemical oscillations.

  11. Persurf, a New Method to Improve Surfactant Delivery: A Study in Surfactant Depleted Rats

    OpenAIRE

    2012-01-01

    PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC) can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf) and to test in surfactant depleted Wistar rats whether Persurf achieves I.) a more homogenous pulmonary di...

  12. Emulsion electrospinning of polycaprolactone: influence of surfactant type towards the scaffold properties.

    Science.gov (United States)

    Hu, Jue; Prabhakaran, Molamma P; Ding, Xin; Ramakrishna, Seeram

    2015-01-01

    Producing uniform nanofibers in high quality by electrospinning remains a huge challenge, especially using low concentrated polymer solutions. However, emulsion electrospinning assists to produce nanofibers from less concentrated polymer solutions compared to the traditional electrospinning process. The influence of individual surfactants towards the morphology of the emulsion electrospun poly (ɛ-caprolactone)/bovine serum albumin (PCL/BSA) nanofibers were investigated by using (i) non-ionic surfactant sorbitane monooleate (Span80); (ii) anionic sodium dodecyl sulfate (SDS); and (iii) cationic benzyltriethylammonium chloride, and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer Pluronic F108 of different concentrations. The morphology, along with the chemical and mechanical properties of the fibers, was evaluated by field emission scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimetry, water contact angle, and tensile tester. With the addition of surfactants, the electrospinnability of dilute PCL solution was enhanced, with either branched or uniform fibers were obtained. Electrospinning of an emulsion containing 0.4% (w/v) SDS produced the smallest and the most uniform nanofibers (167 ± 39 nm), which was attributed to the high conductivity of the solution. Analysis revealed that the emulsion electrospun nanofibers containing different surfactants and surfactant concentrations differ in fiber morphology and mechanical properties. Results suggest that surfactants have the ability to modulate the fiber morphology via electrostatic and hydrogen bonding, depending on their chemical structure.

  13. Anomalous thickness variation of the foam films stabilized by weak non-ionic surfactants.

    Science.gov (United States)

    Qu, Xuan; Wang, Liguang; Karakashev, Stoyan I; Nguyen, Anh V

    2009-09-15

    The constant thickness (H) of metastable free films of various non-ionic surfactant solutions was measured at surfactant concentrations less than the critical micelle concentrations or solubility limits with fixed 5x10(-5) M sodium chloride (NaCl) serving as the background electrolyte. The surfactants include n-pentanol, n-octanol, methyl isobutyl carbinol (MIBC), polypropylene glycol (PPG-400), tetraethylene glycol monooctyl ether (C(8)E(4)), and tetraethylene glycol monodecyl ether (C(10)E(4)). H was interferometrically measured. For each surfactant in this study, the H-versus-surfactant-concentration curve finds a peak at a concentration around 5x10(-6)-1x10(-5) M and a valley at a higher concentration. The measured H values were compared to those predicted from the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, which considers solely the contribution from electrostatic double-layer repulsion with van der Waals attraction being neglected in the present work. In determining the double-layer repulsion, the ionic strength was determined from the electrolytic conductivity measurement of the film-forming solutions and the surface potential was estimated from the zeta-potential measurement of air bubbles. It was found that the DLVO theory failed to explain the thickness variance with surfactant concentration, implying that additional non-DLVO attractive forces might be required to explain the experimental results. Finally, the possible origins of these attractive forces were discussed.

  14. Sono-electroanalysis of copper: enhanced detection and determination in the presence of surfactants.

    Science.gov (United States)

    Hardcastle, Joanna Lorraine; Hignett, Geraldine; Melville, James L; Compton, Richard G

    2002-04-01

    Surfactant adsorption has been shown to have a passivating effect on the electrode surface during anodic stripping voltammetric measurements. In the present work the feasibility of sono-anodic stripping analysis for the determination of copper in aqueous media contaminated with surfactant has been studied at an unmodified bare glassy carbon electrode. We illustrate the deleterious effect of three common surfactants, sodium dodecyl sulfate (SDS), dodecyl pyridinium chloride (DPC) and Triton-X 100 (TX-100) on conventional electroanalysis. The analogous sono-electroanalytical response was investigated for each surfactant at ultrasound intensities above and below the cavitation threshold. The enhancement in the stripping signal observed is attributed to the increased mass transport due to acoustic streaming and above the cavitation threshold the intensity of cavitational events is significantly increased leading to shearing of adsorbed surfactant molecules from the surface. As a result accurate analyses for SDS concentrations up to 100 ppm are possible, with analytical signals visible in solutions of SDS and TX-100 of 1000 ppm. Analysis is reported in high concentration of surfactant with use of sono-solvent double extraction. The power of this technique is clearly illustrated by the ability to obtain accurate measurements of copper concentration from starting solutions containing 1000 ppm SDS or TX-100. This was also exemplified by analysis of the low concentration 0.3 microM Cu(II) solution giving a percentage recovery of 94% in the presence of 1000 ppm SDS or TX-100.

  15. Biomimicry of surfactant protein C.

    Science.gov (United States)

    Brown, Nathan J; Johansson, Jan; Barron, Annelise E

    2008-10-01

    Since the widespread use of exogenous lung surfactant to treat neonatal respiratory distress syndrome, premature infant survival and respiratory morbidity have dramatically improved. Despite the effectiveness of the animal-derived surfactant preparations, there still remain some concerns and difficulties associated with their use. This has prompted investigation into the creation of synthetic surfactant preparations. However, to date, no clinically used synthetic formulation is as effective as the natural material. This is largely because the previous synthetic formulations lacked analogues of the hydrophobic proteins of the lung surfactant system, SP-B and SP-C, which are critical functional constituents. As a result, recent investigation has turned toward the development of a new generation of synthetic, biomimetic surfactants that contain synthetic phospholipids along with a mimic of the hydrophobic protein portion of lung surfactant. In this Account, we detail our efforts in creating accurate mimics of SP-C for use in a synthetic surfactant replacement therapy. Despite SP-C's seemingly simple structure, the predominantly helical protein is extraordinarily challenging to work with given its extreme hydrophobicity and structural instability, which greatly complicates the creation of an effective SP-C analogue. Drawing inspiration from Nature, two promising biomimetic approaches have led to the creation of rationally designed biopolymers that recapitulate many of SP-C's molecular features. The first approach utilizes detailed SP-C structure-activity relationships and amino acid folding propensities to create a peptide-based analogue, SP-C33. In SP-C33, the problematic and metastable polyvaline helix is replaced with a structurally stable polyleucine helix and includes a well-placed positive charge to prevent aggregation. SP-C33 is structurally stable and eliminates the association propensity of the native protein. The second approach follows the same design

  16. MINERAL-SURFACTANT INTERACTIONS FOR MINIMUM REAGENTS PRECIPITATION AND ADSORPTION FOR IMPROVED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    P. Somasundaran

    2005-04-30

    The aim of this project is to delineate the role of mineralogy of reservoir rocks in determining interactions between reservoir minerals and externally added reagents (surfactants/polymers) and its effect on critical solid-liquid and liquid-liquid interfacial properties such as adsorption, wettability and interfacial tension in systems relevant to reservoir conditions. Previous studies have suggested that significant surfactant loss by precipitation or adsorption on reservoir minerals can cause chemical schemes to be less than satisfactory for enhanced oil recovery. Both macroscopic adsorption, wettability and microscopic orientation and conformation studies for various surfactant/polymer mixtures/reservoir rocks systems were conducted to explore the cause of chemical loss by means of precipitation or adsorption, and the effect of rock mineralogy on the chemical loss. During this period, the adsorption of mixed system of n-dodecyl-{beta}-D-maltoside (DM) and dodecyl sulfonate (C{sub 12}SO{sub 3}Na) has been studied. The effects of solution pH, surfactant mixing ratio and different salts on surfactant adsorption on alumina have been investigated in detail. Along with these adsorption studies, changes in mineral wettability due to the adsorption of the mixtures were determined under relevant conditions to identify the nano-structure of the adsorbed layers. Solution properties of C{sub 12}SO{sub 3}Na/DM mixtures were also studied to identify surfactant interactions that affect the mixed aggregate formation in solution. Adsorption of SDS on gypsum and limestone suggested stronger surfactant/mineral interaction than on alumina, due to the precipitation of surfactant by dissolved calcium ions. The effects of different salts such as sodium nitrate, sodium sulfite and sodium chloride on DM adsorption on alumina have also been determined. As surfactant hemimicelles at interface and micelles in solution have drastic effects on oil recovery processes, their microstructures in

  17. Surfactant for pediatric acute lung injury.

    Science.gov (United States)

    Willson, Douglas F; Chess, Patricia R; Notter, Robert H

    2008-06-01

    This article reviews exogenous surfactant therapy and its use in mitigating acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) in infants, children, and adults. Biophysical and animal research documenting surfactant dysfunction in ALI/ARDS is described, and the scientific rationale for treatment with exogenous surfactant is discussed. Major emphasis is placed on reviewing clinical studies of surfactant therapy in pediatric and adult patients who have ALI/ARDS. Particular advantages from surfactant therapy in direct pulmonary forms of these syndromes are described. Also discussed are additional factors affecting the efficacy of exogenous surfactants in ALI/ARDS.

  18. Dynamic interfacial behavior of decyl methylnaphthalene sulfonate surfactants for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Zhongkui; Ba Yan; Li Zongshi; Qiao Weihong; Cheng Luebai [State Key Lab. of Fine Chemicals, Dalian Univ. of Technology, Dalian (China)

    2004-10-01

    The high purity decyl methylnaphthalene sulfonate (DMNS) was synthesized, the purity was determined by HPLC and the structure was confirmed by IR, UV and ESI-MS. Dynamic interfacial tensions (DIT) between DMNS flooding systems and crude oil were measured and the effects of sodium carbonate concentration, surfactant concentration and sodium chloride concentration on the DIT behaviors were investigated. It's found that the surfactant concentration, alkali concentration and the salinity have obvious influences on DIT behaviors. DMNS possessed outstanding capacity and efficiency of lowering the DIT between oil and water. The minimum dynamic interfacial tension could reach 6.35 x 10{sup -6} mNm{sup -1} at a low concentration for added surfactant. DMNS might be used in Enhanced Oil Recovery with low costs and high efficiency. (orig.)

  19. Photoluminescence of CdSe/ZnS core-shell quantum dots stabilized in water with a pseudopeptidic gemini surfactant

    Science.gov (United States)

    Rubio, Jenifer; Izquierdo, M. Angeles; Burguete, M. Isabel; Galindo, Francisco; Luis, Santiago V.

    2011-09-01

    The use of pseudopeptidic gemini surfactants as stabilizers of hydrophobic quantum dots in water is discussed. Compound 1a acts as an intercalator with hydrophobic ligands of QDs transferring them from toluene to pure water yielding a fluorescent nanoparticle resistant to quenching by chloride anion (up to 0.1 M).The use of pseudopeptidic gemini surfactants as stabilizers of hydrophobic quantum dots in water is discussed. Compound 1a acts as an intercalator with hydrophobic ligands of QDs transferring them from toluene to pure water yielding a fluorescent nanoparticle resistant to quenching by chloride anion (up to 0.1 M). Electronic supplementary information (ESI) available: General experimental and synthetic procedures; NMR, ESI-MS spectra; FTIR, TEM and stability studies of water soluble QDs, fluorescent decay curves, effect of chloride, effect of concentration of 1a, and calculation of cmc. See DOI: 10.1039/c1nr10680e

  20. HPLC法测定吡嘧司特钾滴眼液中苯扎溴铵和苯扎氯铵量%Determination of Benzalkonium Bromide and Benzalkonium Chloride in Pemirolast Potassium Eye Drops by HPLC

    Institute of Scientific and Technical Information of China (English)

    刘春亮

    2013-01-01

    目的 建立HPLC法测定吡嘧司特钾滴眼液中苯扎溴铵和苯扎氯铵的含量.方法 色谱柱:C18(4.6 mm×150mm,5μm);流动相:0.02 mol·L-1庚烷磺酸钠溶液(含0.1%三乙胺,用磷酸调节pH为3.45±0.1)-乙腈(35∶65);检测波长:210 nm;柱温:40℃.结果 苯扎溴铵在49.86~997.2 ng范围内线性关系良好(r=0.9999),最小检出量为0.15 ng,平均回收率为97.4%,RSD为1.0%;苯扎氯铵在9.912~24.78 ng范围内呈良好的线性关系(r=0.9999),最小检出量为0.85 ng,平均回收率为99.9%,RSD为1.0%.结论 本方法简便、快速、准确、灵敏度高、重复性好,可用于吡嘧司特钾滴眼液中苯扎溴铵和苯扎氯铵的含量测定.

  1. Synthesis of carbohydrate-based surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.

    2016-11-22

    The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

  2. Improvements in permeation and fouling resistance of PVC ultrafiltration membranes via addition of Tetronic-1107 and Triton X-100 as two non-ionic and hydrophilic surfactants.

    Science.gov (United States)

    Rabiee, Hesamoddin; Seyedi, S Mojtaba; Rabiei, Hossein; Alvandifar, Negar

    2016-09-01

    Two non-ionic and hydrophilic surfactant additives, Tetronic-1107 and Triton X-100, were added to poly(vinyl chloride)/NMP polymeric solution to prepare ultrafiltration membranes via immersion precipitation. Surfactants at three different weight percentages up to 6 wt% were added, and the fabricated membranes were characterized and their performance for water treatment in the presence of bovine serum albumin (BSA) as a foulant was assessed. The scanning electron microscopy images indicated remarkable changes in morphology due to higher thermodynamic instability after surfactant addition. The membranes are more porous with more macro-voids in the sub-layer. Plus, the membranes become more hydrophilic. Water flux increases for the modified membranes by nearly two times and the ability of membranes for flux recovery increases from 66% to over 83%. BSA rejection reduces slightly with the addition of surfactants, however this parameter is still almost over 90% for the membranes with the highest amount of surfactants.

  3. Cyclic voltammetric technique for the determination of the critical micelle concentration of surfactants, self-diffusion coefficient of micelles, and partition coefficient of an electrochemical probe

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, A.B.; Nair, B.U. (Central Leather Research Inst., Madras (India))

    1991-10-31

    Critical micelle concentrations (cmc) of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC) surfactants in aqueous solution have been determined by using the cyclic voltammetric technique. (Co(en){sub 3})(ClO{sub 4}){sub 3} has been used as the redox-active electrochemical probe. The cmc values so obtained for the surfactants were found to be in good agreement with the literature values. The partition coefficient, K, of the electrochemical probe between water and surfactants in nonmicellar and micellar states was estimated using the peak current, i{sub p} and half-wave potential, E{sub 1/2} values. The self-diffusion coefficient, D{sub m}, interaction parameter, k{sub f}, and hydrodynamic radius of the micelles were also estimated. The results suggest that the probe is sensitive to the nature of surfactant as well as surfactant concentration.

  4. chloride mass balance

    African Journals Online (AJOL)

    Agadaga

    1Geology Department, Faculty of Sciences and Techniques, University ... characterization of groundwater, rainfall and the unsaturated zone were also carried out using a .... 2008 in collaboration with the Senegal National Meteorological .... [Cl]sm is estimated as average chloride concentration in ..... sands of Australia.

  5. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    and time, and where both the surface chloride concentration and the diffusion coefficient are allowed to vary in time; the Mejlbro-Poulsen model is the general solution to Fick’s 2nd law. The paper also presents conversion formulas for the four decisive but rather abstract parameters to parameters, which...

  6. Effects of Concentration and Conformation of Surfactants on Phase Separation of Surfactant-Water-Oil Systems

    Institute of Scientific and Technical Information of China (English)

    袁银权; 邹宪武; 刘昊阳

    2004-01-01

    The effects of surfactants on the phase separation of surfactant-water-oil systems have been investigated by using discontinuous molecular dynamic simulations. The phase separation speed and equilibrium configuration are dependent on the surfactant concentration and conformation. The equilibrium concentration of surfactants at the interface remains constant. With the increasing surfactant concentration, the equilibrium configuration crosses over from the disperse phase to the bicontinuous one. The crossover concentration is estimated. The conformation of the surfactant has little effect on the equilibrium concentration of surfactants at the interface,while it affects the equilibrium configuration after phase separation.

  7. Investigation on interaction of DNA and several cationic surfactants with different head groups by spectroscopy, gel electrophoresis and viscosity technologies.

    Science.gov (United States)

    Guo, Qing; Zhang, Zhaohong; Song, Youtao; Liu, Shuo; Gao, Wei; Qiao, Heng; Guo, Lili; Wang, Jun

    2017-02-01

    In this study, the interaction between DNA and several cationic surfactants with different head groups such as ethyl hexadecyl dimethyl ammonium bromide (EHDAB), hexadecyl dimethyl benzyl ammonium chloride (HDBAC), and cetyl pyridinium bromide (CPB) were investigated by UV-vis absorption, fluorescence and circular dichroism (CD) spectroscopy, gel electrophoresis, and viscosity technologies. The results show that these cationic surfactants can interact with DNA and major binding modes are electrostatic and hydrophobic. Also, CPB and HDBAC molecules interact with DNA by partial intercalation, and CPB has slightly stronger intercalation than HDBAC, while EHDAB interacts with DNA by non-intercalation. The different head groups of the surfactant molecules can influence the interaction strength. CPB has the stronger interaction with DNA than the others. Moreover, surfactant concentration, the ratio of DNA and fluorescence probe, ionic strength can influence the interaction. The surfactants may interact with DNA by the competition reactions with BR for DNA-BR. The increase of ionic strength may favor the surface binding between DNA and surfactants to some extent. This work provides deep mechanistic insight on the toxicity of cationic surfactants with different head groups to DNA molecules.

  8. Effects of pH and cationic and nonionic surfactants on the adsorption of pharmaceuticals to a natural aquifer material.

    Science.gov (United States)

    Hari, Ajai C; Paruchuri, Rajiv A; Sabatini, David A; Kibbey, Tohren C G

    2005-04-15

    A wide range of pharmaceutical compounds have been identified in the environment, and their presence is a topic of growing concern, both for human and ecological health. Adsorption to aquifer materials and sediments is an important factor influencing the fate and transport of pharmaceutical compounds in the environment. Surfactants and other amphiphiles are known to influence the adsorption of many compounds and may be present in the environment from wastewaters or other sources. The work described here examines the adsorption of four pharmaceutical compounds, acetaminophen, carbamazepine, nalidixic acid, and norfloxacin, in the presence of a natural aquifer material. Adsorption was studied as a function of pH and in the presence and absence of two surfactants, cetylpyridinium chloride (CPC), a cationic surfactant, and Tergitol NP9, an ethoxylated nonionic surfactant. In the absence of surfactants, results indicate a 1-2 orders of magnitude variation in adsorption affinity with changing pH for each of the two quinolone pharmaceuticals (nalidixic acid and norfloxacin) but no measurable adsorption for carbamazepine or acetaminophen. In the presence of surfactants, adsorption of acetaminophen and carbamazepine was enhanced to extents consistent with compound hydrophobicity, while adsorption of nalidixic acid and norfloxacin was not. At high pH values, the anionic species of nalidixic acid exhibited enhanced adsorption in the presence of the cationic surfactant, CPC.

  9. Complex Formation Between Polyelectrolytes and Ionic Surfactants

    OpenAIRE

    1998-01-01

    The interaction between polyelectrolyte and ionic surfactant is of great importance in different areas of chemistry and biology. In this paper we present a theory of polyelectrolyte ionic-surfactant solutions. The new theory successfully explains the cooperative transition observed experimentally, in which the condensed counterions are replaced by ionic-surfactants. The transition is found to occur at surfactant densities much lower than those for a similar transition in non-ionic polymer-sur...

  10. Binding of cationic surfactants to humic substances

    NARCIS (Netherlands)

    Ishiguro, M.; Tan, W.; Koopal, L.K.

    2007-01-01

    Commercial surfactants are introduced into the environment either through waste products or site-specific contamination. The amphiphilic nature of both surfactants and humic substances (HS) leads to their mutual attraction especially when surfactant and HS are oppositely charged. Binding of the cati

  11. Surfactant analysis in oil-containing fluids

    Energy Technology Data Exchange (ETDEWEB)

    Gronsveld, J.; Faber, M.J. (Koninklijke Shell Exploratie en Produktie Laboratorium, Rijswijk (Netherlands))

    The total surfactant concentration in aqueous phase samples can be analysed with a potentiometric titration. In enhanced oil recovery research, however, the surfactant is produced not only in aqueous phase samples but also in oleic phase samples. The oleic constituents in the oliec phase samples interfere in the surfactant analysis and, therefore, the titration method has been adapted. (orig.).

  12. Surfactant adsorption to soil components and soils

    NARCIS (Netherlands)

    Ishiguro, Munehide; Koopal, Luuk K.

    2016-01-01

    Soils are complex and widely varying mixtures of organic matter and inorganic materials; adsorption of surfactants to soils is therefore related to the soil composition. We first discuss the properties of surfactants, including the critical micelle concentration (CMC) and surfactant adsorption on

  13. Susceptibility of different bacterial species isolated from food animals to copper sulphate, zinc chloride and antimicrobial substances used for disinfection

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Hasman, Henrik

    2004-01-01

    that Danish bacterial isolates from livestock so far have not or have only to a limited degree developed resistance to antimicrobial compounds commonly used for disinfection. Acquired copper resistance was only found in enterococci. There were large differences in the intrinsic susceptibility of the different......A total of 569 different bacterial isolates (156 Salmonella, 202 E. coli, 43 S. aureus, 38 S. hyicus, 52 E. faecalis, 78 E faecium) were tested for susceptibility to copper sulphate, benzalkonium chloride, hydrogen peroxide and chlorhexidine using MIC determinations. A total of 442 isolates were...... of susceptibilities to the different antimicrobial agents. Large variations were observed in the susceptibility of the different bacterial species to the different compounds. Staphylococci were in general very susceptible to all antimicrobial compounds tested. The Salmonella isolates were in general less susceptible...

  14. Removal of petroleum aromatic hydrocarbons by surfactant-modified natural zeolite: the effect of surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Torabian, Ali; Seifi, Laleh; Bidhendi, Gholamreza Nabi; Azimi, Ali Akbar [Faculty of the Environment, University of Tehran (Iran); Kazemian, Hossein [SPAG Zeolite R and D Group, Technology Incubation Centre, Science and Technology Park of Tehran University, Tehran (Iran); Department of Chemical and Biochemical Engineering, University of Western Ontario, London, Ontario (Canada); Ghadiri, Seid Kamal [Department of Environmental Health Engineering, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran (Iran)

    2010-01-15

    Monoaromatic hydrocarbons including benzene, toluene, ethylbenzene and xylene isomers (BTEX) are a very important category of water pollutants. These volatile compounds are very hazardous because of their fast migration in soil and water bodies and their acute and chronic toxicities when inhaled or ingested, especially benzene which is a known carcinogenic molecule. In this study, a natural zeolite (i. e., clinoptilolite-rich tuffs) was modified by two cationic surfactants (i. e., hexadecyltrimethyl ammonium chloride (HDTMA-Cl), and N-cetylpyridinium bromide (CPB)). The prepared adsorbents were then characterized, and their adsorptive capabilities for BTEX examined at different experimental conditions. The results of adsorption tests at 24 h revealed that the adsorption capacity of the modified zeolites improved by increasing the surfactant loading (i. e., less than the critical micelle concentration (CMC), to higher than the CMC), which caused an increase in sorption capacity from 60 to 70% for HDTMA-modified samples, and from 47 to 99% for CPB-modified zeolite. Adsorption kinetic tests showed the optimum contact time was 48 h with an average BTEX removal of 90 and 93% for HDTMA-modified and CPB-modified zeolite, respectively. Results showed that by increasing of pH from 3 to 11, the sorption capacity of the adsorbent decreased markedly from 97 to 75%. Analyzing the influence of temperature showed that the adsorption efficiency of adsorbents for benzene reduced from 93% at 20 C to 10% at 4 C. However, the influence of temperature on other compounds was not remarkable. Overall, CPB-modified zeolite exhibited higher selectivity toward BTEX compounds at optimum experimental conditions. Although commercial powder activated carbon (PAC) showed a higher capacity for all BTEX compounds and faster adsorption kinetics, the adsorption capacity of the CPB-modified zeolite at optimized conditions was competitive with PAC results. (Abstract Copyright [2010], Wiley Periodicals

  15. Persurf, a new method to improve surfactant delivery: a study in surfactant depleted rats.

    Directory of Open Access Journals (Sweden)

    Wolfram Burkhardt

    Full Text Available PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf and to test in surfactant depleted Wistar rats whether Persurf achieves I. a more homogenous pulmonary distribution and II. a more homogenous recruitment of alveoli when compared with surfactant or PFC alone. METHODS: Three different PFC were mixed with surfactant and phospholipid concentration in the emulsion was measured. After surfactant depletion, animals either received 30 ml/kg of PF5080, 100 mg/kg of stained (green dye Curosurf™ or 30 ml/kg of Persurf. Lungs were fixated after 1 hour of ventilation and alveolar aeration and surfactant distribution was estimated by a stereological approach. RESULTS: Persurf contained 3 mg/ml phospholipids and was stable for more than 48 hours. Persurf-administration improved oxygenation. Histological evaluation revealed a more homogenous surfactant distribution and alveolar inflation when compared with surfactant treated animals. CONCLUSIONS: In surfactant depleted rats administration of PFC-in-surfactant emulsion leads to a more homogenous distribution and aeration of the lung than surfactant alone.

  16. [Strengthening Effects of Sodium Salts on Washing Kerosene Contaminated Soil with Surfactants].

    Science.gov (United States)

    Huang, Zhao-lu; Chen, Quan-yuan; Zhou, Juan; Xie, Mo-han

    2015-05-01

    The impact of sodium salt on kerosene contaminated soil washing with surfactants was investigated. The results indicated that sodium silicate greatly enhanced the washing efficiency of SDS. Sodium tartrate can largely enhance the washing efficiency of SDBS and Brij35. Sodium salts can enhance the washing efficiency on kerosene contaminated with TX-100. No significant differences were observed between different sodium salts. Sodium salt of humic acid and sodium silicate had similar enhancement on kerosene contaminated soil washing with saponin. Sodium humate can be a better choice since its application can also improve soil quality. The enhancement of sodium silicate on kerosene contaminated soil washing with Tw-80 increased with the increase of Tw-80 dosage. However, the impact of sodium chloride and sodium tartrate was opposite to sodium silicate. Sodium salts can reduce surface tension and critical micelle concentration of ionic surfactants to enhance the washing. Sodium salts can also reduce re-adsorption of oil to soil with nonionic surfactants to enhance the washing. Kerosene contamination can increase the contact angle of soil, which indicated the increase of hydrophilicity of soil. Washing with surfactants can reduce the hydrophilicitiy of soil according to contact angle measurement, which indicated that kerosene contaminated soil remediation with surfactant can also benefit nutrient and water transportation in the contaminated soil.

  17. Physical properties of botanical surfactants.

    Science.gov (United States)

    Müller, Lillian Espíndola; Schiedeck, Gustavo

    2017-08-24

    Some vegetal species have saponins in their composition with great potential to be used as natural surfactants in organic crops. This work aims to evaluate some surfactants physical properties of Quillaja brasiliensis and Agave angustifolia, based on different methods of preparation and concentration. The vegetal samples were prepared by drying and grinding, frozen and after chopped or used fresh and chopped. The neutral bar soap was used as a positive control. The drying and grinding of samples were the preparation method that resulted in higher foam column height in both species but Q. brasiliensis was superior to A. angustifolia in all comparisons and foam index was 2756 and 1017 respectively. Critical micelle concentration of Q. brasiliensis was 0.39% with the superficial tension of 54.40mNm(-1) while neutral bar soap was 0.15% with 34.96mNm(-1). Aspects such as genetic characteristics of the species, environmental conditions, and analytical methods make it difficult to compare the results with other studies, but Q. brasiliensis powder has potential to be explored as a natural surfactant in organic farming. Not only the surfactants physical properties of botanical saponins should be taken into account but also its effect on insects and diseases control when decided using them. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Interactions of Ovalbumin with Ionic Surfactants

    Institute of Scientific and Technical Information of China (English)

    GUO Xia; YAN Hui; GUO Rong

    2008-01-01

    The interactions of ovalbumin (OVA) with one anionic surfactant,sodium dodecyl sulfate (SDS),and two cationic surfactants,dodecyl trimethylammonium bromide (DTAB) and cetyl trimethylammonium bromide (CTAB),in water have been studied through fluorescence and UV-Vis spectroscopies and transmission electronic microscopy,combined with the measurement of conductivity.OVA can increase the critical micelle concentrations (cmc) of SDS and CTAB but has little effect on that of DTAB.The interaction between surfactant monomer and OVA is greater than that between surfactant micelles and OVA.Moreover,SDS can make OVA unfolded while cationic surfactants cannot.

  19. Surfactant gene polymorphisms and interstitial lung diseases

    Directory of Open Access Journals (Sweden)

    Pantelidis Panagiotis

    2001-11-01

    Full Text Available Abstract Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs. Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

  20. BINDING OF IONIC SURFACTANTS ON OPPOSITELY CHARGED POLYELECTROLYTES OBSERVED BY FLUORESCENCE METHODS

    Institute of Scientific and Technical Information of China (English)

    Zhen Tong; Chao-yang Wang; Bi-ye Ren; Xin-xing Liu; Fang Zeng

    2003-01-01

    Our recent studies concerning the binding of ionic surfactants on oppositely charged polyelectrolytes observed with fluorescence techniques are reviewed. The cationic surfactants cetyltrimethylammonium bromide (CTAB),dodecyltrimethylammonium chloride (DTAC), and nonionic surfactant octaethylene glycol monododecyl ether (C12E8) were allowed to bind on anionic poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and its pyrene and/or naphthalene labeled copolymers. The relative excimer emission intensity IE/IM of a cationic probe 1-pyrenemethylamine hydrochloride were chosen to monitor the binding process and the conformation change of surfactant-bound polyelectrolytes. The 1:1aggregation of polyelectrolyte-CTAB with respect to the charge was found as long as the CTAB concentration was slightly higher than its critical aggregation concentration (CAC). The intermolecular NRET indicated that the CTAB-bound polyelectrolytes aggregated together through the hydrophobic interaction between the CTAB tails. However, neither 1:1polyelectrolyte-DTAC aggregation nor intermolecular aggregation of DTAC-bound polyelectrolyte was observed owing to its weaker hydrophobicity of 12 carbon atoms in the tail, which is shorter than that of CTAB. As known from the fluorescence results, nonionic surfactant C12E8 did not bind on the anionic polyelectrolytes, but the presence of PAMPS promoted the micelle formation for C12E8 at the CAC slightly below its critical micelle concentration (CMC). The solid complex of dansyl labeled AMPS copolymer-surfactant exhibited a decrease in local polarity with increasing charge density of the polyelectrolyte or with alkane tail length of the surfactant. SAXS suggested a lamella structure for the AMPS copolymersurfactant solid complexes with a long period of 3.87 nm for CTAB and 3.04 nm for DTAC, respectively.

  1. Application of cetylpyridinium chloride in dispersion of antibacterial ceramic glaze

    Institute of Scientific and Technical Information of China (English)

    CHAI Li-yuan; CHENG Ming-ming; PENG Bing; HUANG Yi; ZHANG Xiao-fei

    2006-01-01

    The adsorption of cetylpyridinium chloride(CPC) onto a ceramic glaze mixture composed of limestone, feldspar, quartz,kaolin, and antibacterial agent was studied. Both adsorption isothermals and the average particle zeta potential were investigated in order to understand the suspension stability as a function of pH, ionic strength, and surfactant concentration. The results show that under the optimal conditions such as pH value of 7 or 9, 0.01 mol/L of ionic strength and around critical micelle concentration(CMC)of surfactant, antibacterial ceramic glaze acquires fine dispersion stability. The adsorption of CPC on ceramic glaze particles is in accordance with Langmuir model in 0.01mol/L at pH=7 and pH=9. The adsorption of small amounts of cationic CPC onto the primarily negatively charged surfaces of the particles in the pH range of 7-9 produces strong attraction and flocculation due to hydrophobic interactions. High concentration of surfactant under 0.01 mol/L of salt provides high zeta potential, which produces a high stability.

  2. Studies on interfacial behavior and wettability change phenomena by ionic and nonionic surfactants in presence of alkalis and salt for enhanced oil recovery

    Science.gov (United States)

    Kumar, Sunil; Mandal, Ajay

    2016-05-01

    Surfactant flooding is one of the most promising method of enhanced oil recovery (EOR) used after the conventional water flooding. The addition of alkali improves the performance of surfactant flooding due to synergistic effect between alkali and surfactant on reduction of interfacial tension (IFT), wettability alteration and emulsification. In the present study the interfacial tension, contact angle, emulsification and emulsion properties of cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polysorbate 80 (Tween 80) surfactants against crude oil have been investigated in presence of sodium chloride (NaCl) and alkalis viz. sodium hydroxide (NaOH), sodium carbonate (Na2CO3), ammonium hydroxide (NH4OH), sodium metaborate (SMB) and diethanolamine (DEA). All three surfactants significantly reduce the IFT values, which are further reduced to ultra-low value (∼10-4 mN/m) by addition of alkalis and salt. It has been found experimentally that alkali-surfactant systems change the wettability of an intermediate-wet quartz rock to water-wet. Emulsification of crude oil by surfactant and alkali has also been investigated in terms of the phase volume and stability of emulsion. A comparative FTIR analysis of crude oil and different emulsions were performed to investigate the interactions between crude oil and displacing water in presence of surfactant and alkali.

  3. Effect of different surfactants on removal efficiency of heavy metals in sewage sludge treated by a novel method combining bio-acidification with Fenton oxidation

    Institute of Scientific and Technical Information of China (English)

    任苗苗; 林宁波; 袁兴中; 朱艺; 黄华军; 曾光明; 李辉; 陈明; 王侯; 陈畅亚

    2014-01-01

    The aim of this work was to investigate the effect of different surfactants on the removal efficiency of heavy metals in sewage sludge treated by a method combining bio-acidification with Fenton oxidation. Four surfactants were adopted such as anionic surfactant (sodium dodecyl benzene sulfonate, SDBS), nonionic surfactants (tween-20 and tween-60) and cationic surfactant (hexadecyl trimethyl ammonium chloride, HTAC), respectively. The indigenous sulfur-oxidizing bacteria in bio-acidification phase were enriched and cultured from fresh activated sludge obtained from a wastewater treatment plant. It is shown that different surfactants exhibited distinct effect on the removal efficiency of heavy metals from sewage sludge. The nonionic surfactants, especially tween-60, promotes the solubilization of heavy metals, while the anionic and cationic surfactants hinder the removal of heavy metals. Copper is efficiently leached. The removal efficiency of cadium is relatively lower than that of Cu due to the demand for rigorous pH value. Lead is leached with a low efficiency as the formation of low soluble PbSO4 precipitates.

  4. Adsorption of dimeric surfactants in lamellar silicates

    Energy Technology Data Exchange (ETDEWEB)

    Balcerzak, Mateusz; Pietralik, Zuzanna [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Domka, Ludwik [Department of Metalorganic Chemistry, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań (Poland); Skrzypczak, Andrzej [Institute of Chemical Technology, Poznań University of Technology, Berdychowo 4, 60-965 Poznań (Poland); Kozak, Maciej, E-mail: mkozak@amu.edu.pl [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2015-12-01

    Highlights: • The intercalation of dimeric surfactants changed the morphology of MMT samples. • XRD indicated structures formed by surfactant molecules in interlayer space. • The four-step thermal decomposition of dimeric surfactant, confirms intercalation. - Abstract: The adsorption of different types of cationic surfactants in lamellar silicates changes their surface character from hydrophilic to hydrophobic. This study was undertaken to obtain lamellar silicates modified by a series of novel dimeric (gemini) surfactants of different length alkyl chains and to characterise these organophilised materials. Synthetic sodium montmorillonite SOMASIF® ME 100 (M) and enriched bentonite of natural origin (Nanoclay – hydrophilic bentonite®) were organophilised with dimeric (gemini) surfactants (1,1′-(1,4-butanediyl)bis(alkoxymethyl)imidazolium dichlorides). As a result of surfactant molecule adsorption in interlamellar space, the d-spacing (d{sub 001}) increased from 0.97 nm (for the anhydrous structure) to 2.04 nm. A Fourier transform infrared spectroscopy (FTIR) analysis of the modified systems reveals bands assigned to the stretching vibrations of the CH{sub 2} and CH{sub 3} groups and the scissoring vibrations of the NH group from the structure of the dimeric surfactants. Thermogravimetric (TG) and derivative thermogravimetric (DTG) studies imply a four-stage process of surfactant decomposition. Scanning electron microscopy (SEM) images provide information on the influence of dimeric surfactant intercalation into the silicate structures. Particles of the modified systems show a tendency toward the formation of irregularly shaped agglomerates.

  5. Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

    Institute of Scientific and Technical Information of China (English)

    DENG Qi-gang; YU Hong-wei; LIN Hong; JIA Li-hua; GUO Xiang-feng; ZHOU De-rui

    2005-01-01

    Four gemini cationic surfactants {N,N'-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, 1H NMR, 13C NMR and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.

  6. Use of highly saline ethoxylated surfactant system for oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Reisberg, J.

    1970-03-17

    An aqueous solution of a sulfated polyoxylated primary alcohol and a soluble inorganic electrolyte was used for enhanced oil recovery. The electrolyte should be present in a concentration exceeding the critical concentration for forming a two-phase coacervate system, by an amount sufficient to convert the two-phase system to a turbid dispersion. The dispersion permits an interfacial tension with petroleum of 10/sup -4/ dynes/cm. A berea core (400 md) was flooded to residual oil saturation before flooding with a 4 M sodium chloride brine which contained Tergitol 15-S4 (4 ethylene oxide units, sodium salt). A 1 PV slug of the surfactant solution left only about 7 percent PV of oil.

  7. Protolytic properties and complexation of DL-alpha-alanine and DL-alpha-valine and their dipeptides in aqueous and micellar solutions of surfactants

    NARCIS (Netherlands)

    Chernyshova, O. S.; Boychenko, Oleksandr; Abdulrahman, H.; Loginova, L. P.

    2013-01-01

    In this work we investigated the effect of the micellar media of anionic (sodium dodecylsulfate, SDS), cationic (cetylpiridinium chloride, CPC) and non-ionic (Brij-35) surfactants on the protolytic properties of amino acids DL-alpha-alanine, DL-alpha-valine and dipeptides L-alpha-alanyl-L-alpha-alan

  8. Oxomemazine hydro-chloride.

    Science.gov (United States)

    Siddegowda, M S; Butcher, Ray J; Akkurt, Mehmet; Yathirajan, H S; Ramesh, A R

    2011-08-01

    IN THE TITLE COMPOUND [SYSTEMATIC NAME: 3-(5,5-dioxo-phen-othia-zin-10-yl)-N,N,2-trimethyl-propanaminium chloride], C(18)H(23)N(2)O(2)S(+)·Cl(-), the dihedral angle between the two outer aromatic rings of the phenothia-zine unit is 30.5 (2)°. In the crystal, the components are linked by N-H⋯Cl and C-H⋯Cl hydrogen bonds and C-H⋯π inter-actions.

  9. Enhanced hydrolysis of bamboo biomass by chitosan based solid acid catalyst with surfactant addition in ionic liquid.

    Science.gov (United States)

    Si, Wenqing; Li, Yichen; Zheng, Jie; Wei, Shun'an; Wang, Dan

    2017-10-15

    Surfactants were used for the hydrolysis of bamboo biomass to enhance lignocellulose hydrolysis. Tween 80, polyethylene glycol 4000 (PEG 4000), and sodium dodecyl sulfate (SDS) were tested as surfactants for improving the bamboo hydrolysis with a novel sulfonated cross-linked chitosan solid acid catalyst (SCCAC) in ionic liquid (IL). Compared to the use of only SCCAC in 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl), the surfactants facilitated hydrolysis and improved the yield of total reducing sugar (TRS) under the same conditions. Tween 80 was the most effective surfactant, with a TRS yield of 68.01% achieved at 120°C after 24h. Surfactants broke the lignocellulose structure, promoted lignin removal, and increased positive interactions between cellulose and the catalyst, which were favorable for hydrolysis. This novel surfactant-assisted hydrolysis strategy with SCCAC and IL as the solvent demonstrated a promise for the large-scale transformation of biomass into biofuels and bioproducts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Surfactants in tribology, v.3

    CERN Document Server

    Biresaw, Girma

    2013-01-01

    The manufacture and use of almost every consumer and industrial product rely on application of advanced knowledge in surface science and tribology. These two disciplines are of critical importance in major economic sectors, such as mining, agriculture, manufacturing (including metals, plastics, wood, computers, MEMS, NEMS, appliances), construction, transportation, and medical instruments, transplants, and diagnostic devices. An up-to-date reference with contributions by experts in surface science and tribology, Surfactants in Tribology, Volume 3 discusses some of the underlying tribological a

  11. Anaerobic Biodegradation of Detergent Surfactants

    OpenAIRE

    Erich Jelen; Ute Merrettig-Bruns

    2009-01-01

    Detergent surfactantscan be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have str...

  12. Des surfactants « verts » préparés à partir de fractions protéiques industrielles de colza

    Directory of Open Access Journals (Sweden)

    Larré Colette

    2003-09-01

    Full Text Available Edible surfactants were prepared from rapeseed meal by functionalization of two types of products: proteins or peptide fractions obtained by enzymatical hydrolysis. Functionalization aimed to enhance the amphophilic characteristics of the products by grafting hydrophobic chains\\; it was based on acylation or sulfamidation of proteins and acylation of peptides. The interfacial properties of these “green” surfactants measured by lowering the surface tension, and increasing the stability of foams and emulsions, were improved, depending on the chemical reagent used. For example, peptides modified by C1 4 acyl chlorides exhibited the better emulsifying properties, whereas the better foaming properties were obtained with peptides modified by C 10 and C 12 acyl chlorides. These surfactants could diversify the uses of rapeseed derivatives, particularly in non food industries.

  13. The role of surfactants in Köhler theory reconsidered

    Directory of Open Access Journals (Sweden)

    R. Sorjamaa

    2004-05-01

    Full Text Available Atmospheric aerosol particles typically consist of inorganic salts and organic material. The inorganic compounds as well as their hygroscopic properties are well defined, but the effect of organic compounds on cloud droplet activation is still poorly characterized. The focus of the present study is in the organic compounds that are surface active i.e. they concentrate on droplet surface and decrease droplet surface tension. Gibbsian surface thermodynamics were used to find out how partitioning in binary and ternary aqueous solutions affects the droplet surface tension and the droplet bulk concentration in droplets large enough to act as cloud condensation nuclei. Sodium dodecyl sulfate was used as a model compound together with sodium chloride to find out the effect the correct evaluation of surfactant partitioning has on the solute effect (Raoult effect. While the partitioning is known to lead to higher surface tension compared to a case in which partitioning is neglected, the present results show that the partitioning also alters the solute effect, and that the change is large enough to further increase the critical supersaturation and hence decrease the droplet activation. The fraction of surfactant partitioned to droplet surface increases with decreasing droplet size, which suggests that surfactants might enhance the activation of larger particles relatively more thus leading to less dense clouds. Cis-pinonic acid-ammonium sulfate aqueous solution was studied in order to relate the partitioning to more realistic atmospheric situation and to find out the combined effects of dissolution and partitioning behaviour. The results show that correct partitioning consideration alters the shape of the Köhler curve when compared to a situation in which the partitioning is neglected either completely or in the Raoult effect.

  14. TURBULENCE TRANSPORT OF SURFACTANT SOLUTION FLOW DURING DRAG REDUCTION DEGENERATION

    Institute of Scientific and Technical Information of China (English)

    GU Wei-guo; WANG De-zhong

    2012-01-01

    Turbulence transport of surfactant solution flow during drag reduction degeneration is investigated experimentally in a two-dimensional channel.Particle Image Velocimetry (P1V) system is used to take two-dimensional velocity frames in the streamwise and wall-normal plane.The additive of surfactant is cetyltrimethyl ammonium chloride (CTAC) with the mass concentration of 25 ppm.Drag reduction degeneration happens in the CTAC solution flow,exhibiting the maximal drag reduction at Re =25000and losing drag reduction completely at Re =40 000.The velocity frames are statistically analyzed in four quadrants which are divided by the u -axis and v-axis.It is found that the phenomenon of“Zero Reynolds shear stress” is caused by the decrease of wallnormal fluctuations and its symmetrical distribution in quadrants.The increase of Reynolds number leads to the enhancement of turbulence burst phenomenon.During thc drag reduction degeneration,the CTAC solution flow contains both high turbulence intensity and drag reduction states.

  15. Surfactant inhibition in acute respiratory failure : consequences for exogenous surfactant therapy

    NARCIS (Netherlands)

    E.P. Eijking (Eric)

    1993-01-01

    textabstractThe neonatal respiratory distress syndrome (RDS) is characterized by immaturity of the lung, resulting in relative or absolute absence of pulmonary surfactant. Worldwide, neonates suffering from RDS have been treated successfully with exogenous surfactant preparations. Currently, exogeno

  16. Cationic versus anionic surfactant in tuning the structure and interaction of nanoparticle, protein, and surfactant complexes.

    Science.gov (United States)

    Mehan, Sumit; Aswal, Vinod K; Kohlbrecher, Joachim

    2014-08-26

    The structure and interaction in complexes of anionic Ludox HS40 silica nanoparticle, anionic bovine serum albumin (BSA) protein, and cationic dodecyl trimethylammonium bromide (DTAB) surfactant have been studied using small-angle neutron scattering (SANS). The results are compared with similar complexes having anionic sodium dodecyl sulfate (SDS) surfactant (Mehan, S; Chinchalikar, A. J.; Kumar, S.; Aswal, V. K.; Schweins, R. Langmuir 2013, 29, 11290). In both cases (DTAB and SDS), the structure in nanoparticle-protein-surfactant complexes is predominantly determined by the interactions of the individual two-component systems. The nanoparticle-surfactant (mediated through protein-surfactant complex) and protein-surfactant interactions for DTAB, but nanoparticle-protein (mediated through protein-surfactant complex) and protein-surfactant interactions for SDS, are found to be responsible for the resultant structure of nanoparticle-protein-surfactant complexes. Irrespective of the charge on the surfactant, the cooperative binding of surfactant with protein leads to micellelike clusters of surfactant formed along the unfolded protein chain. The adsorption of these protein-surfactant complexes for DTAB on oppositely charged nanoparticles gives rise to the protein-surfactant complex-mediated aggregation of nanoparticles (similar to that of DTAB surfactant). It is unlike that of depletion-induced aggregation of nanoparticles with nonadsorption of protein-surfactant complexes for SDS in similarly charged nanoparticle systems (similar to that of protein alone). The modifications in nanoparticle aggregation as well as unfolding of protein in these systems as compared to the corresponding two-component systems have also been examined by selectively contrast matching the constituents.

  17. Surfactant-enhanced cellulose nanocrystal Pickering emulsions.

    Science.gov (United States)

    Hu, Zhen; Ballinger, Sarah; Pelton, Robert; Cranston, Emily D

    2015-02-01

    The effect of surfactants on the properties of Pickering emulsions stabilized by cellulose nanocrystals (CNCs) was investigated. Electrophoretic mobility, interfacial tension, confocal microscopy and three-phase contact angle measurements were used to elucidate the interactions between anionic CNCs and cationic alkyl ammonium surfactants didecyldimethylammonium bromide (DMAB) and cetyltrimethylammonium bromide (CTAB). Both surfactants were found to adsorb onto CNCs with concentration-dependent morphology. At low concentrations, individual surfactant molecules adsorbed with alkyl tails pointing outward leading to hydrophobic CNCs. At higher concentrations, above the surfactant's apparent critical micelle concentration, surfactant aggregate morphologies on CNCs were inferred and the hydrophobicity of CNCs decreased. DMAB, which has two alkyl tails, rendered the CNCs more hydrophobic than CTAB which has only a single alkyl tail, at all surfactant concentrations. The change in CNC wettability from surfactant adsorption was directly linked to emulsion properties; adding surfactant increased the emulsion stability, decreased the droplet size, and controlled the internal phase of CNC Pickering emulsions. More specifically, a double transitional phase inversion, from oil-in-water to water-in-oil and back to oil-in-water, was observed for emulsions with CNCs and increasing amounts of DMAB (the more hydrophobic surfactant). With CNCs and CTAB, no phase inversion was induced. This work represents the first report of CNC Pickering emulsions with surfactants as well as the first CNC Pickering emulsions that can be phase inverted. The ability to surface modify CNCs in situ and tailor emulsions by adding surfactants may extend the potential of CNCs to new liquid formulations and extruded/spray-dried materials.

  18. Electrostatic Screening and Charge Correlation Effects in Micellization of Ionic Surfactants

    KAUST Repository

    Jusufi, Arben

    2009-05-07

    We have used atomistic simulations to study the role of electrostatic screening and charge correlation effects in self-assembly processes of ionic surfactants into micelles. Specifically, we employed grand canonical Monte Carlo simulations to investigate the critical micelle concentration (cmc), aggregation number, and micellar shape in the presence of explicit sodium chloride (NaCl). The two systems investigated are cationic dodecyltrimethylammonium chloride (DTAC) and anionic sodium dodecyl sulfate (SDS) surfactants. Our explicit-salt results, obtained from a previously developed potential model with no further adjustment of its parameters, are in good agreement with experimental data for structural and thermodynamic micellar properties. We illustrate the importance of ion correlation effects by comparing these results with a Yukawa-type surfactant model that incorporates electrostatic screening implicitly. While the effect of salt on the cmc is well-reproduced even with the implicit Yukawa model, the aggregate size predictions deviate significantly from experimental observations at low salt concentrations. We attribute this discrepancy to the neglect of ion correlations in the implicit-salt model. At higher salt concentrations, we find reasonable agreement of the Yukawa model with experimental data. The crossover from low to high salt concentrations is reached when the electrostatic screening length becomes comparable to the headgroup size. © 2009 American Chemical Society.

  19. Solubilization of Hydrophobic Dyes in Surfactant Solutions

    Directory of Open Access Journals (Sweden)

    Ali Reza Tehrani-Bagha

    2013-02-01

    Full Text Available In this paper, the use of surfactants for solubilization of hydrophobic organic dyes (mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration (CMC—there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution.

  20. Using biologically soft surfactants for dust suppression

    Energy Technology Data Exchange (ETDEWEB)

    Tkachenko, N.G.; Kolodiichak, V.K.; Motrii, A.E.; Severin, V.D.

    1982-07-01

    This article discusses environmental aspects of using surfactants in coal mines for dust suppression. Surfactants for underground black coal mines in the USSR are divided into three classes: so-called soft surfactants with a decomposition period from 1 to 3 days, hard surfactants with decomposition exceeding a month and an intermediary group. The decomposition process is analyzed; the role played by fermentation is stressed. Environmental effects of surfactant decomposition are evaluated. Selected surfactants tested in Soviet laboratories are described. The results of experimental use of diethanolamide as a surfactant for water injection in coal seams are evaluated. Wetting time amounts to 1 s when a 0.2% concentration is used. When surfactant concentration in water is reduced to 0.05% wetting time does not change; when concentration decreases to 0.025% wetting time increases to 3 s. Surfactant efficiency is investigated under operational conditions in a Donbass mine. Specifications of the working face, mining system and air pollution caused by a shearer loader are discussed. When diethanolamide is used dust suppression efficiency ranges from 86.4 to 90.4%. During the tests diethanolamide concentration in water was 0.05%.

  1. Remediation using trace element humate surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  2. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform distri

  3. Biophysical inhibition of pulmonary surfactant function by polymeric nanoparticles: role of surfactant protein B and C.

    Science.gov (United States)

    Beck-Broichsitter, Moritz; Ruppert, Clemens; Schmehl, Thomas; Günther, Andreas; Seeger, Werner

    2014-11-01

    The current study investigated the mechanisms involved in the process of biophysical inhibition of pulmonary surfactant by polymeric nanoparticles (NP). The minimal surface tension of diverse synthetic surfactants was monitored in the presence of bare and surface-decorated (i.e. poloxamer 407) sub-100 nm poly(lactide) NP. Moreover, the influence of NP on surfactant composition (i.e. surfactant protein (SP) content) was studied. Dose-elevations of SP advanced the biophysical activity of the tested surfactant preparation. Surfactant-associated protein C supplemented phospholipid mixtures (PLM-C) were shown to be more susceptible to biophysical inactivation by bare NP than phospholipid mixture supplemented with surfactant protein B (PLM-B) and PLM-B/C. Surfactant function was hindered owing to a drastic depletion of the SP content upon contact with bare NP. By contrast, surface-modified NP were capable of circumventing unwanted surfactant inhibition. Surfactant constitution influences the extent of biophysical inhibition by polymeric NP. Steric shielding of the NP surface minimizes unwanted NP-surfactant interactions, which represents an option for the development of surfactant-compatible nanomedicines.

  4. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform distri

  5. Interfacial behavior of pure surfactants for enhanced oil recovery. Part 1. A study on the adsorption and distribution of cetylbenzene sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Weihong Qiao; Liangjun Dong; Zhongkui Zhao; Jie Yang; Huamin Li; Zongshi Li [Dalian Univ. of Technology (China)

    2003-04-01

    The contents of pure alkyl benzene sulfonate surfactants in both the aqueous and oil phases were determined. The diffusion, adsorption and distribution of the surfactants in the oil and aqueous phases were studied at dynamic equilibrium and the effects of different structures on diffusion were investigated. N-nonane was used as the oil phase. The results indicate that the contents of the surfactants on both sides of the interface tend to increase with increasing sodium hydroxide and sodium chloride concentrations. The corresponding interfacial tensions, however, decrease gradually, and the quantities adsorbed at the oil-water interface reach a maximum value. The content of surfactant at the interface tends to be higher when the benzene ring is located near the middle of the carbon chain, so resulting in ultralow interfacial tension. (orig.)

  6. Efficacy and safety of benzalkonium chloride-free fixed-dose combination of latanoprost and timolol in patients with open-angle glaucoma or ocular hypertension

    OpenAIRE

    2014-01-01

    Purvi Bhagat,1 Kalyani Sodimalla,2 Chandrima Paul,3 Surinder S Pandav,4 Ganesh V Raman,5 Rengappa Ramakrishnan,6 Abhijeet Joshi,7 Atul Raut7 1Glaucoma Clinic, M & J Western Regional Institute of Ophthalmology, Civil Hospital, Ahmedabad, Gujarat, India; 2Glaucoma Department, PBMA’s H.V. Desai Eye Hospital, Maharashtra, India; 3Glaucoma Service, B B Eye Foundation, Kolkata, India; 4Advanced Eye Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, Indi...

  7. 一种苯扎氯铵复方消毒剂的性能观察%OBSERVATION ON PROPERTIES OF A COMPOUND BENZALKONIUM CHLORIDE DISINFECTANT

    Institute of Scientific and Technical Information of China (English)

    孙克勤; 姜霞; 郭金铭; 李月平; 宋立江; 韩艳淑; 崔玉杰

    2010-01-01

    目的:观察一种苯扎氯铵复方消毒剂的杀菌效果及其相关性能.方法:采用悬液定量杀菌试验和动物试验方法进行了实验室观察.结果:该复方消毒液含苯扎氯铵1 840 mg/L,性能稳定.用含苯扎氯铵1 460 mg/L的该消毒剂溶液,作用1.5 min,对悬液内金黄色葡萄球菌、铜绿假单胞菌和白色念珠菌的杀灭对数值均>5.00.该消毒液对小鼠急性经口毒性LD50均大于5 000 mg/kg(体重),小鼠骨髓嗜多染红细胞微核试验结果均为阴性.一次完整皮肤刺激试验、急性眼刺激试验、阴道黏膜刺激试验均无刺激作用.结论:该消毒剂有良好的杀菌作用,毒性低.

  8. 苯扎氯铵抑制微生物污垢的实验研究%Experimental Research on Biofouling Inhibition of Benzalkonium Chloride

    Institute of Scientific and Technical Information of China (English)

    常思远; 杨倩鹏; 史琳

    2015-01-01

    再生水源热泵系统换热表面上的微生物污垢是影响系统效率和安全的重要问题.苯扎氯铵能抑制微生物污垢的生长.本文进行挂片实验模拟微生物污垢形成的过程.成垢过程中每天将挂片在苯扎氯铵溶液中浸泡10 min,考察了溶液浓度和温度对抑垢效果的影响.对比了苯扎氯铵和次氯酸钠的抑垢效果,并考察了细菌对苯扎氯铵的抗药性.实验结果表明,苯扎氯铵对微生物污垢有抑制作用,该作用随浓度和温度的上升而增强,但会随时间逐渐减弱.

  9. 氧氟沙星滴眼液中苯扎氯铵的HPLC测定%Determination of Benzalkonium Chloride in Ofloxacin Eye Drops by HPLC

    Institute of Scientific and Technical Information of China (English)

    陈秋芬; 王小琳

    2005-01-01

    建立了离子对高效液相色谱法,测定氧氟沙星滴眼液中苯扎氯铵的含量.采用C18色谱柱,以0.02mol/L庚烷磺酸钠溶液(含0.1%三乙胺,pH 3.45±0.1)-乙腈(35:65)为流动相,检测波长210nm,柱温40℃.苯扎氯铵在10~70μg/ml浓度范围内线性关系良好(r=0.9997),方法平均回收率100.1%.

  10. 一种苯扎氯铵消毒液杀菌效果观察%OBSERVATION ON GERMICIDAL EFFICACY OF A BENZALKONIUM CHLORIDE DISINFECTANT SOLUTION

    Institute of Scientific and Technical Information of China (English)

    李春梅; 钟晓祝

    2010-01-01

    目的 观察一种含苯扎氯铵的皮肤黏膜消毒液的杀菌效果.方法 采用悬液定量杀菌试验方法,在实验室对其杀灭细菌繁殖体和真菌的效果进行了观察.结果 以1 000 mg/L苯扎氯铵消毒液作用1 min,对悬液中的大肠埃希菌、金黄色葡萄球菌和白色念珠菌的平均杀灭对数值均达5.0以上.结论 该苯扎氯铵消毒液对细菌繁殖体和真菌具有良好的杀灭效果.

  11. Chloride on the Move

    KAUST Repository

    Li, Bo

    2017-01-09

    Chloride (Cl−) is an essential plant nutrient but under saline conditions it can accumulate to toxic levels in leaves; limiting this accumulation improves the salt tolerance of some crops. The rate-limiting step for this process – the transfer of Cl− from root symplast to xylem apoplast, which can antagonize delivery of the macronutrient nitrate (NO3−) to shoots – is regulated by abscisic acid (ABA) and is multigenic. Until recently the molecular mechanisms underpinning this salt-tolerance trait were poorly defined. We discuss here how recent advances highlight the role of newly identified transport proteins, some that directly transfer Cl− into the xylem, and others that act on endomembranes in ‘gatekeeper’ cell types in the root stele to control root-to-shoot delivery of Cl−.

  12. The effect of surface topography on the micellisation of hexadecyltrimethylammonium chloride at the silicon-aqueous interface

    Energy Technology Data Exchange (ETDEWEB)

    Darkins, Robert; Sushko, Maria L.; Liu, Jun; Duffy, Dorothy M.

    2015-02-11

    Amphiphilic aggregation at solid-liquid interfaces can generate mesostructured micelles that can serve as soft templates. In this study we have simulated the self-assembly of hexadecyltrimethylammonium chloride (C16TAC) surfactants at the Si(100)- and Si(111)-aqueous interfaces. The surfactants are found to form semicylindrical micelles on Si(100) but hemispherical micelles on Si(111). This difference in micelle structure is shown to be a consequence of the starkly different surface topographies that result from the reconstruction of the two silicon surfaces. This reveals that micelle structure can be governed by epitaxial matching even with non-polar substrates.

  13. Hemolysis by surfactants--A review.

    Science.gov (United States)

    Manaargadoo-Catin, Magalie; Ali-Cherif, Anaïs; Pougnas, Jean-Luc; Perrin, Catherine

    2016-02-01

    An overview of the use of surfactants for erythrocyte lysis and their cell membrane action mechanisms is given. Erythrocyte membrane characteristics and its association with the cell cytoskeleton are presented in order to complete understanding of the erythrocyte membrane distortion. Cell homeostasis disturbances caused by surfactants might induce changes starting from shape modification to cell lysis. Two main mechanisms are hypothesized in literature which are osmotic lysis and lysis by solubilization even if the boundary between them is not clearly defined. Another specific mechanism based on the formation of membrane pores is suggested in the particular case of saponins. The lytic potency of a surfactant is related to its affinity for the membrane and the modification of the lipid membrane curvature. This is to be related to the surfactant shape defined by its hydrophobic and hydrophilic moieties but also by experimental conditions. As a consequence, prediction of the hemolytic potency of a given surfactant is challenging. Several studies are focused on the relation between surfactant erythrolytic potency and their physico-chemical parameters such as the critical micellar concentration (CMC), the hydrophile-lipophile balance (HLB), the surfactant membrane/water partition coefficient (K) or the packing parameter (P). The CMC is one of the most important factors considered even if a lytic activity cut-off effect points out that the only consideration of CMC not enough predictive. The relation K.CMC must be considered in addition to the CMC to predict the surfactant lytic capacity within the same family of non ionic surfactant. Those surfactant structure/lytic activity studies demonstrate the requirement to take into account a combination of physico-chemical parameters to understand and foresee surfactant lytic potency.

  14. Comprehensive review of several surfactants in marine environments: Fate and ecotoxicity.

    Science.gov (United States)

    Jackson, Mathew; Eadsforth, Charles; Schowanek, Diederik; Delfosse, Thomas; Riddle, Andrew; Budgen, Nigel

    2016-05-01

    Surfactants are a commercially important group of chemicals widely used on a global scale. Despite high removal efficiencies during wastewater treatment, their high consumption volumes mean that a certain fraction will always enter aquatic ecosystems, with marine environments being the ultimate sites of deposition. Consequently, surfactants have been detected within marine waters and sediments. However, aquatic environmental studies have mostly focused on the freshwater environment, and marine studies are considerably underrepresented by comparison. The present review aims to provide a summary of current marine environmental fate (monitoring, biodegradation, and bioconcentration) and effects data of 5 key surfactant groups: linear alkylbenzene sulfonates, alcohol ethoxysulfates, alkyl sulfates, alcohol ethoxylates, and ditallow dimethyl ammonium chloride. Monitoring data are currently limited, especially for alcohol ethoxysulfates and alkyl sulfates. Biodegradation was shown to be considerably slower under marine conditions, whereas ecotoxicity studies suggest that marine species are approximately equally as sensitive to these surfactants as freshwater species. Marine bioconcentration studies are almost nonexistent. Current gaps within the literature are presented, thereby highlighting research areas where additional marine studies should focus.

  15. Manipulating perfume delivery to the interface using polymer-surfactant interactions.

    Science.gov (United States)

    Bradbury, Robert; Penfold, Jeffrey; Thomas, Robert K; Tucker, Ian M; Petkov, Jordan T; Jones, Craig

    2016-03-15

    Enhanced delivery of perfumes to interfaces is an important element of their effectiveness in a range of home and personal care products. The role of polyelectrolyte-surfactant mixtures to promote perfume adsorption at interfaces is explored here. Neutron reflectivity, NR, was used to quantify the adsorption of the model perfumes phenylethanol, PE, and linalool, LL, at the air-water interface in the presence of the anionic surfactant sodium dodecylsulfate, SDS, and the cationic polyelectrolytes, poly(dimethyldiallyl ammonium chloride), polydmdaac, and poly(ethyleneimine), PEI. The strong SDS-polydmdaac interaction dominates the surface adsorption in SDS-polymer-perfume (PE, LL) mixtures, such that the PE and LL adsorption is greatly suppressed. For PEI-SDS-perfume mixtures the PEI-LL interaction competes with the SDS-PEI interaction at all pH at the surface and significant LL adsorption occurs, whereas for PE the PEI-SDS interaction dominates and the PE adsorption is greatly reduced. The use of the strong surface polyelectrolyte-ionic surfactant interaction to manipulate perfume adsorption at the air-water interface has been demonstrated. In particular the results show how the competition between polyelectrolyte, surfactant and perfume interactions at the surface and in solution affect the partitioning of perfumes to the surface.

  16. Structured fluids polymers, colloids, surfactants

    CERN Document Server

    Witten, Thomas A

    2010-01-01

    Over the last thirty years, the study of liquids containing polymers, surfactants, or colloidal particles has developed from a loose assembly of facts into a coherent discipline with substantial predictive power. These liquids expand our conception of what condensed matter can do. Such structured-fluid phenomena dominate the physical environment within living cells. This book teaches how to think of these fluids from a unified point of view showing the far-reaching effects ofthermal fluctuations in producing forces and motions. Keeping mathematics to a minimum, the book seeks the simplest expl

  17. Innovation in surfactant therapy I: surfactant lavage and surfactant administration by fluid bolus using minimally invasive techniques.

    Science.gov (United States)

    Dargaville, Peter A

    2012-01-01

    Innovation in the field of exogenous surfactant therapy continues more than two decades after the drug became commercially available. One such innovation, lung lavage using dilute surfactant, has been investigated in both laboratory and clinical settings as a treatment for meconium aspiration syndrome (MAS). Studies in animal models of MAS have affirmed that dilute surfactant lavage can remove meconium from the lung, with resultant improvement in lung function. In human infants both non-randomised studies and two randomised controlled trials have demonstrated a potential benefit of dilute surfactant lavage over standard care. The largest clinical trial, performed by our research group in infants with severe MAS, found that lung lavage using two 15-ml/kg aliquots of dilute surfactant did not reduce the duration of respiratory support, but did appear to reduce the composite outcome of death or need for extracorporeal membrane oxygenation. A further trial of lavage therapy is planned to more precisely define the effect on survival. Innovative approaches to surfactant therapy have also extended to the preterm infant, for whom the more widespread use of continuous positive airway pressure (CPAP) has meant delaying or avoiding administration of surfactant. In an effort to circumvent this problem, less invasive techniques of bolus surfactant therapy have been trialled, including instillation directly into the pharynx, via laryngeal mask and via brief tracheal catheterisation. In a recent clinical trial, instillation of surfactant into the trachea using a flexible feeding tube was found to reduce the need for subsequent intubation. We have developed an alternative method of brief tracheal catheterisation in which surfactant is delivered via a semi-rigid vascular catheter inserted through the vocal cords under direct vision. In studies to date, this technique has been relatively easy to perform, and resulted in rapid improvement in lung function and reduced need for

  18. 悬浮态乳液聚合条件对聚氯乙烯树脂颗粒特性的影响%Influence of Suspended Emulsion Polymerization Conditions on Particle Characteristics of Polyvinyl Chloride Resin

    Institute of Scientific and Technical Information of China (English)

    包永忠; 魏真理; 翁志学; 黄志明

    2003-01-01

    Suspended emulsion polymerization of vinyl chloride was carried out in a 5 L autoclave. The influenceof agitation, polymerization conversion, dispersant and surfactant on the average particle size (PS) and particle sizedistribution (PSD), particle morphology and porosity of polyvinyl chloride (PVC) resin was investigated. It showedthat the agitator had great influence on the smooth operation of polymerization, PS and PSD. The PS increasedand PSD became narrow as polymerization conversion became high. The porosity decreased with the increase ofconversion. A convenient choice of additives, both dispersants and non-ionic surfactants, allows one to adjust PSand PSD. The PS decreased with the addition of polyvinyl alcohol or hydroxypropyl methylcellulose dispersants,and increased with the addition of Span surfactants. The addition of dispersants or surfactants also affected themorphology and porosity of resin, and PVC resin with looser agglomeration and homogeneous distribution of primaryparticles was prepared.

  19. Effect of polyester blends in hydroentangled raw and bleached cotton nonwoven fabrics on the adsorption of alkyl-dimethyl-benzyl-ammonium chloride

    Science.gov (United States)

    The adsorption kinetics and isotherms of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on hydroentangled nonwoven fabrics (applicable for wipes) including raw cotton, bleached cotton, and their blends with polyester (PES) were stu...

  20. Surfactant Adsorption: A Revised Physical Chemistry Lab

    Science.gov (United States)

    Bresler, Marc R.; Hagen, John P.

    2008-01-01

    Many physical chemistry lab courses include an experiment in which students measure surface tension as a function of surfactant concentration. In the traditional experiment, the data are fit to the Gibbs isotherm to determine the molar area for the surfactant, and the critical micelle concentration is used to calculate the Gibbs energy of micelle…

  1. Surfactant effects on soil aggregate tensile strength

    Science.gov (United States)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  2. Anaerobic degradation and toxicity of commercial cationic surfactants in anaerobic screening tests.

    Science.gov (United States)

    García, M T; Campos, E; Sánchez-Leal, J; Ribosa, I

    2000-09-01

    Anaerobic biodegradability and toxicity on anaerobic bacteria of di(hydrogenated tallow) dimethyl ammonium chloride (DHTDMAC) and two esterquats have been investigated. A batch test system containing municipal digester solids as a source of anaerobic bacteria, based on the method proposed by the ECETOC, has been applied. To evaluate the potential toxicity of such surfactants on anaerobic sludge, a co-substrate, an easily biodegradable compound in anaerobic conditions, has been added to the samples to test and the effects on biogas production have been determined. For the esterquats studied high biodegradation levels were obtained and no toxic effects on anaerobic bacteria were observed even at the highest concentrations tested, 100 and 200 mg C/l, respectively. On the contrary, DHTDMAC was not degradated at the same test conditions. However, no inhibitory effects on the biogas production were detected for this surfactant at concentrations <100 mg C/l.

  3. Effect of silk protein surfactant on silk degumming and its properties.

    Science.gov (United States)

    Wang, Fei; Cao, Ting-Ting; Zhang, Yu-Qing

    2015-10-01

    The silk protein surfactant (SPS) first used as a silk degumming agent in this study is an amino acid-type anionic surfactant that was synthesized using silk fibroin amino acids and lauroyl chloride. We studied it systematically in comparison with the traditional degumming methods such as sodium carbonate (Na2CO3) and neutral soap (NS). The experimental results showed that the sericin can be completely removed from the silk fibroin fiber after boiling the fibers three times for 30 min and using a bath ratio of 1:80 (g/mL) and a concentration of 0.2% SPS in an aqueous solution. The results of the tensile properties, thermal analysis, and SEM all show that SPS is similar to the NS, far superior to Na2CO3. In short, SPS may be used as an environmentally friendly silk degumming/refining agent in the silk textile industry and in the manufacture of silk floss quilts.

  4. In situ X-ray polymerization: from swollen lamellae to polymer-surfactant complexes.

    Science.gov (United States)

    Agzenai, Yahya; Lindman, Björn; Alfredsson, Viveka; Topgaard, Daniel; Renamayor, Carmen S; Pacios, Isabel E

    2014-01-30

    The influence of the monomer diallyldimethylammonium chloride (D) on the lamellar liquid crystal formed by the anionic surfactant aerosol OT (AOT) and water is investigated, determining the lamellar spacings by SAXS and the quadrupolar splittings by deuterium NMR, as a function of the D or AOT concentrations. The cationic monomer D induces a destabilization of the AOT lamellar structure such that, at a critical concentration higher than 5 wt %, macroscopic phase separation takes place. When the monomer, which is dissolved in the AOT lamellae, is polymerized in situ by X-ray initiation, a new collapsed lamellar phase appears, corresponding to the complexation of the surfactant with the resulting polymer. A theoretical model is employed to analyze the variation of the interactions between the AOT bilayers and the stability of the lamellar structure.

  5. Metathesis depolymerization for removable surfactant templates.

    Energy Technology Data Exchange (ETDEWEB)

    Zifer, Thomas (Sandia National Laboratories, Livermore, CA); Wheeler, David Roger; Rahimian, Kamayar; McElhanon, James Ross (Sandia National Laboratories, Livermore, CA); Long, Timothy Michael; Jamison, Gregory Marks; Loy, Douglas Anson (Los Alamos National Laboratories, Los Alamos, NM); Kline, Steven R. (National Institute of Standards and Technology, Gaithersburg, MD); Simmons, Blake Alexander (Sandia National Laboratories, Livermore, CA)

    2005-03-01

    Current methodologies for the production of meso- and nanoporous materials include the use of a surfactant to produce a self-assembled template around which the material is formed. However, post-production surfactant removal often requires centrifugation, calcination, and/or solvent washing which can damage the initially formed material architecture(s). Surfactants that can be disassembled into easily removable fragments following material preparation would minimize processing damage to the material structure, facilitating formation of templated hybrid architectures. Herein, we describe the design and synthesis of novel cationic and anionic surfactants with regularly spaced unsaturation in their hydrophobic hydrocarbon tails and the first application of ring closing metathesis depolymerization to surfactant degradation resulting in the mild, facile decomposition of these new compounds to produce relatively volatile nonsurface active remnants.

  6. Enhanced Oil Recovery with Surfactant Flooding

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow

    Enhanced oil recovery (EOR) is being increasingly applied in the oil industry and several different technologies have emerged during, the last decades in order to optimize oil recovery after conventional recovery methods have been applied. Surfactant flooding is an EOR technique in which the phase...... both for complex surfactant systems as well as for oil and brine systems. It is widely accepted that an increase in oil recovery can be obtained through flooding, whether it is simple waterflooding, waterflooding where the salinity has been modified by the addition or removal of specific ions (socalled...... “smart” waterflooding) or surfactant flooding. High pressure experiments have been carried out in this work on a surfactant system (surfactant/ oil/ brine) and on oil/ seawater systems (oil/ brine). The high pressure experiments were carried out on a DBR JEFRI PVT cell, where a glass window allows...

  7. Fibrinogen stability under surfactant interaction.

    Science.gov (United States)

    Hassan, Natalia; Barbosa, Leandro R S; Itri, Rosangela; Ruso, Juan M

    2011-10-01

    Differential scanning calorimetry (DSC), circular dichroism (CD), difference spectroscopy (UV-vis), Raman spectroscopy, and small-angle X-ray scattering (SAXS) measurements have been performed in the present work to provide a quantitatively comprehensive physicochemical description of the complexation between bovine fibrinogen and the sodium perfluorooctanoate, sodium octanoate, and sodium dodecanoate in glycine buffer (pH 8.5). It has been found that sodium octanoate and dodecanoate act as fibrinogen destabilizer. Meanwhile, sodium perfluorooctanoate acts as a structure stabilizer at low molar concentration and as a destabilizer at high molar concentration. Fibrinogen's secondary structure is affected by all three studied surfactants (decrease in α-helix and an increase in β-sheet content) to a different extent. DSC and UV-vis revealed the existence of intermediate states in the thermal unfolding process of fibrinogen. In addition, SAXS data analysis showed that pure fibrinogen adopts a paired-dimer structure in solution. Such a structure is unaltered by sodium octanoate and perfluoroctanoate. However, interaction of sodium dodecanoate with the fibrinogen affects the protein conformation leading to a complex formation. Taken together, all results evidence that both surfactant hydrophobicity and tail length mediate the fibrinogen stability upon interaction. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Surfactant replacement therapy--economic impact.

    Science.gov (United States)

    Pejaver, R K; al Hifzi, I; Aldussari, S

    2001-06-01

    Surfactant replacement is an effective treatment for neonatal respiratory distress syndrome. (RDS). As widespread use of surfactant is becoming a reality, it is important to assess the economic implications of this new form of therapy. A comparison study was carried out at the Neonatal Intensive Care Unit (NICU) of Northwest Armed Forces Hospital, Saudi Arabia. Among 75 infants who received surfactant for RDS and similar number who were managed during time period just before the surfactant was available, but by set criteria would have made them eligible for surfactant. All other management modalities except surfactant were the same for all these babies. Based on the intensity of monitoring and nursing care required by the baby, the level of care was divided as: Level IIIA, IIIB, Level II, Level I. The cost per day per bed for each level was calculated, taking into account the use of hospital immovable equipment, personal salaries of nursing, medical, ancillary staff, overheads and maintenance, depreciation and replacement costs. Medications used, procedures done, TPN, oxygen, were all added to individual patient's total expenditure. 75 infants in the Surfactant group had 62 survivors. They spent a total of 4300 days in hospital. (av 69.35) Out of which 970 d (av 15.65 per patient) were ventilated days. There were 56 survivors in the non-surfactant group of 75. They had spent a total of 5023 days in the hospital (av 89.69/patient) out of which 1490 were ventilated days (av 26.60 d). Including the cost of surfactant (two doses), cost of hospital stay for each infant taking the average figures of stay would be SR 118, 009.75 per surfactant treated baby and SR 164, 070.70 per non-surfactant treated baby. The difference of 46,061 SR is 39.03% more in non-surfactant group. One Saudi rial = 8 Rs (approx at the time study was carried out.) Medical care cost varies from place to place. However, it is definitely cost-effective where surfactant is concerned. Quality adjusted

  9. Interaction of bovine serum albumin (BSA) with novel gemini surfactants studied by synchrotron radiation scattering (SR-SAXS), circular dichroism (CD), and nuclear magnetic resonance (NMR).

    Science.gov (United States)

    Gospodarczyk, W; Szutkowski, K; Kozak, M

    2014-07-24

    The interaction of three dicationic (gemini) surfactants-3,3'-[1,6-(2,5-dioxahexane)]bis(1-dodecylimidazolium) chloride (oxyC2), 3,3'-[1,16-(2,15-dioxahexadecane)]bis(1-dodecylimidazolium) chloride (oxyC12), and 1,4-bis(butane)imidazole-1-yl-3-dodecylimidazolium chloride (C4)--with bovine serum albumin (BSA) has been studied by the use of small-angle X-ray scattering (SAXS), circular dichroism (CD), and (1)H nuclear magnetic resonance diffusometry. The results of CD studies show that the conformation of BSA was changed dramatically in the presence of all studied surfactants. The greater decrease (from 56 to 24%) in the α-helical structure of BSA was observed for oxyC2 surfactant. The radii of gyration estimated from SAXS data varied between 3 and 26 nm for the BSA/oxyC2 and BSA/oxyC12 systems. The hydrodynamic radius of the BSA/surfactant system estimated from NMR diffusometry varies between 5 and 11 nm for BSA/oxyC2 and 5 and 8 nm for BSA/oxyC12.

  10. Surfactant-soil interactions during surfactant-amended remediation of contaminated soils by hydrophobic organic compounds: a review.

    Science.gov (United States)

    Laha, Shonali; Tansel, Berrin; Ussawarujikulchai, Achara

    2009-01-01

    Surfactants are amphiphilic molecules that reduce aqueous surface tension and increase the solubility of hydrophobic organic compounds (HOCs). Surfactant-amended remediation of HOC-contaminated soils and aquifers has received significant attention as an effective treatment strategy - similar in concept to using soaps and detergents as washing agents to remove grease from soiled fabrics. The proposed mechanisms involved in surfactant-amended remediation include: lowering of interfacial tension, surfactant solubilization of HOCs, and the phase transfer of HOC from soil-sorbed to pseudo-aqueous phase. However, as with any proposed chemical countermeasures, there is a concern regarding the fate of the added surfactant. This review summarizes the current state of knowledge regarding nonionic micelle-forming surfactant sorption onto soil, and serves as an introduction to research on that topic. Surfactant sorption onto soil appears to increase with increasing surfactant concentration until the onset of micellization. Sorbed-phase surfactant may account for the majority of added surfactant in surfactant-amended remediation applications, and this may result in increased HOC partitioning onto soil until HOC solubilization by micellar phase surfactant successfully competes with increased HOC sorption on surfactant-modified soil. This review provides discussion of equilibrium partitioning theory to account for the distribution of HOCs between soil, aqueous phase, sorbed surfactant, and micellar surfactant phases, as well as recently developed models for surfactant sorption onto soil. HOC partitioning is characterized by apparent soil-water distribution coefficients in the presence of surfactant.

  11. Different effects of surfactant proteins B and C - implications for development of synthetic surfactants.

    Science.gov (United States)

    Curstedt, Tore; Johansson, Jan

    2010-06-01

    Treatment of premature newborn rabbits with synthetic surfactants containing a surfactant protein C analogue in a simple phospholipid mixture gives similar tidal volumes as treatment with poractant alfa (Curosurf(R)) but ventilation with a positive end-expiratory pressure (PEEP) is needed for this synthetic surfactant to stabilize the alveoli at end-expiration. The effect on lung gas volumes seems to depend on the structure of the peptide since treatment with a synthetic surfactant containing the 21-residue peptide (LysLeu(4))(4)Lys (KL(4)) gives low lung gas volumes in experiments also performed with PEEP. Surfactant preparations containing both surfactant proteins B and C or their analogues prevent alveolar collapse at end-expiration even if ventilated without PEEP. Treatment of premature newborn rabbits with different natural surfactants indicates that both the lipid composition and the proteins are important in order to stabilize the alveoli at end-expiration. Synthetic surfactants containing two peptides may be able to replace natural surfactants within the near future but more trials need to be performed before any conclusion can be drawn about the ideal composition of this new generation of synthetic surfactants.

  12. Exogenous Pulmonary Surfactant as a Vehicle for Antimicrobials: Assessment of Surfactant-Antibacterial Interactions In Vitro

    Directory of Open Access Journals (Sweden)

    Alexei Birkun

    2014-01-01

    Full Text Available Owing to its unique surface-active properties, an exogenous pulmonary surfactant may become a promising drug delivery agent, in particular, acting as a vehicle for antibiotics in topical treatment of pneumonia. The purpose of this study was to assess a mutual influence of natural surfactant preparation and three antibiotics (amikacin, cefepime, and colistimethate sodium in vitro and to identify appropriate combination(s for subsequent in vivo investigations of experimental surfactant/antibiotic mixtures. Influence of antibiotics on surface-active properties of exogenous surfactant was assessed using the modified Pattle method. Effects of exogenous surfactant on antibacterial activity of antimicrobials against Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were evaluated using conventional microbiologic procedures. Addition of amikacin or cefepime to surfactant had no significant influence on surface-active properties of the latter. Obvious reduction of surface-active properties was confirmed for surfactant/colistimethate composition. When suspended with antibiotics, surfactant either had no impact on their antimicrobial activity (amikacin or exerted mild to moderate influence (reduction of cefepime bactericidal activity and increase of colistimethate bacteriostatic activity against S. aureus and P. aeruginosa. Considering favorable compatibility profile, the surfactant/amikacin combination is advisable for subsequent investigation of joint surfactant/antibacterial therapy in animals with bacterial pneumonia.

  13. Determination of antimony in rain water at the nanogram level with surfactant and brilliant green

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, A.N.; Patel, K.S. [School of Studies in Chemistry, Pt. Ravishankar University, Raipur (India)

    1998-01-01

    A new, simple, selective and sensitive method for the spectrophotometric determination of antimony in rain water is described. It includes preconcentrating Sb with surfactants (i.e. cetylpyridinium chloride (CPC) and Triton X-100 (TX-100)) into toluene and allowing the extract to react with a dye, i.e. brilliant green (BG). The value of apparent molar absorptivity is 5.55 x 10{sup 5} L-mol{sup -1} . cm{sup -1} at {lambda}{sub max} = 620 nm; the detection limit is 3 ng/mL Sb in rain water at 3-fold preconcentration. (orig.) With 1 fig., 2 tabs., 7 refs.

  14. Ultrasmall semiconductor particles sandwiched between surfactant headgroups in Langmuir-Blodgett films

    Energy Technology Data Exchange (ETDEWEB)

    Shuqian Xu; Xiao Kang Zhao, Fendler, J.H. (Syracuse Univ., NY (United States))

    1990-04-01

    Successful sandwiching of size-quantized hexametaphosphate-stabilized CdS particles between monomolecular layers of dioctadecyldimethylammonium chloride (DODAC) surfactants, deposited on solid substrates, was accomplished. Electrostatic forces are responsible for attracting the negatively charged CdS particles onto the cationic headgroups of the substrate-supported DODAC monolayer, immersed in the aqueous subphase. These forces also ensure that, during withdrawal of the DODAC-monolayer-coated substrate, the CdS particles remain in place, attract a second monolayer of DODAC, and thereby form a DODAC-CdS particle-DODAC sandwich.

  15. Dynamic properties of cationic diacyl-glycerol-arginine-based surfactant/phospholipid mixtures at the air/water interface.

    Science.gov (United States)

    Lozano, Neus; Pinazo, Aurora; Pérez, Lourdes; Pons, Ramon

    2010-02-16

    In this Article, we study the binary surface interactions of 1,2-dimyristoyl-rac-glycero-3-O-(N(alpha)-acetyl-L-arginine) hydrochloride (1414RAc) with 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) on 0.1 M sodium chloride solutions. 1414RAc is a novel monocationic surfactant that has potential applications as an antimicrobial agent, is biodegradable, and shows a toxicity activity smaller than that of other commercial cationic surfactants. DPPC phospholipid was used as a model membrane component. The dynamic surface tension of 1414RAc/DPPC aqueous dispersions injected into the saline subphase was followed by tensiometry. The layer formation for the mixtures is always accelerated with respect to DPPC, and surprisingly, the surface tension reduction is faster and reaches lower surface tension values at surfactant concentration below its critical micellar concentration (cmc). Interfacial dilational rheology properties of mixed films spread on the air/water interface were determined by the dynamic oscillation method using a Langmuir trough. The effect of surfactant mole fraction on the rheological parameters of 1414RAc/DPPC mixed monolayers was studied at a relative amplitude of area deformation of 5% and a frequency of 50 mHz. The monolayer viscoelasticity shows a nonideal mixing behavior with predominance of the surfactant properties. This nonideal behavior has been attributed to the prevalence of electrostatic interactions.

  16. A novel triazole-based cationic gemini surfactant: synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Lingguang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)]. E-mail: lgahu@163.com; Xie Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Shen Yuhua [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)

    2005-06-15

    A triazole-based cationic gemini surfactant, 3,5-bis(methylene octadecyl dimethylammonium chloride)-1,2,4-triazole (18-triazole-18) has been synthesized, and its effect on corrosion inhibition of A{sub 3} steel in 1 M HCl has been studied using the weight-loss method. The result showed that 18-triazole-18 acted as an excellent inhibitor in 1 M HCl. It was found that the adsorption mechanism of 18-triazole-18 on the steel surface in acid medium was quite different from that of cationic gemini surfactants containing dimethylene as a spacer, as well as that of conventional cationic single-chained surfactants, which is due to unique molecular structure of 18-triazole-18. 18-Triazole-18 may be adsorbed on the steel surface in acid medium through a maximum of four atoms or groups, i.e., the two nitrogen atoms of triazole ring and two quaternary ammonium head groups. Four regions of surfactant concentration could be divided to illustrate the adsorption of 18-triazole-18 on the steel surface, and four different adsorption mechanisms may take place in different regions of surfactant concentration.

  17. Studies Update Vinyl Chloride Hazards.

    Science.gov (United States)

    Rawls, Rebecca

    1980-01-01

    Extensive study affirms that vinyl chloride is a potent animal carcinogen. Epidemiological studies show elevated rates of human cancers in association with extended contact with the compound. (Author/RE)

  18. Investigation of the Structural Variation after the Intercalation of Cetylpyridinium Chloride into V2O5 Xerogel

    Directory of Open Access Journals (Sweden)

    Elidia Maria Guerra

    2014-08-01

    Full Text Available A new hybrid material using vanadium pentoxide xerogel in different concentration of the cationic surfactant cetylpyridinium chloride (V2O5CPC is investigated. The insertion was accompanied by XRD, FTIR and SEM characterization. These studies revealed the presence of a lamellar structure for the V2O5CPC hybrid material in all concentrations of cetylpyridinium chloride. The intercalation reaction was evidenced on basis of the increase in the d-spacing as well as the displacement of the infrared bands toward lower energy levels. The CPC intercalation occurred by reorganize intermittently forming two domains within the matrix.

  19. Evaluation of waste activated sludge as a coagulant aid for the treatment of industrial wastewater containing mixed surfactants.

    Science.gov (United States)

    Sriwiriyarat, Tongchai; Jangkorn, Siriprapha

    2009-04-01

    Wastewater generated by the industry manufacturing detergents and various kinds of consumer products normally contains very high contents of mixed surfactants, organic matters expressed as chemical oxygen demand (COD), and phosphates that must be treated prior to discharge to the aquatic environment. In this study, jar-test experiments were conducted to evaluate the waste activated sludge (WAS) as a coagulation aid in the coagulation-flocculation process with ferric chloride or aluminum sulfate as a coagulant for the treatment of wastewater collected from the aforementioned industry. The WAS was selected because of its adsorption capability of anionic surfactants and its availability from the wastage stream of biological wastewater treatment process. The effective dosages of both coagulants with and without the WAS additions were determined in this study. Without the WAS addition, the concentrations of 800 mg/L aluminum sulfate at the optimum pH value of 8 and 2208 mg/L ferric chloride at the optimum pH value of 12 were the optimum chemical dosages. It appears that aluminum sulfate was more effective than ferric chloride based on the chemical dosage and removal efficiency. The turbidity, suspended particles, anionic surfactants, COD, and phosphates removal efficiencies of aluminum sulfate and ferric chloride under the optimum dosage were 95.6, 88.2, 78.4, 73.5, 47.3% and 98.8, 92.0, 72.7, 67.5, 53.1%, respectively. The addition of 200 mg/L WAS was sufficient to reduce the optimum dosages of both chemicals by 200 mg/L. The cationic surfactant existing in the wastewater worked as a flocculating agent leading to the flocculation of waste activated sludge resulting in the enmeshment of the suspended particles and colloids on which the COD, anionic surfactants, and phosphates were adsorbed. However, the substances removal efficiencies of ferric chloride and aluminum sulfate were slightly enhanced and reduced, respectively. It is possibly explained that the settling time

  20. Fluorescence emission of pyrene in surfactant solutions.

    Science.gov (United States)

    Piñeiro, Lucas; Novo, Mercedes; Al-Soufi, Wajih

    2015-01-01

    The systematic description of the complex photophysical behaviour of pyrene in surfactant solutions in combination with a quantitative model for the surfactant concentrations reproduces with high accuracy the steady-state and the time resolved fluorescence intensity of pyrene in surfactant solutions near the cmc, both in the monomer and in the excimer emission bands. We present concise model equations that can be used for the analysis of the pyrene fluorescence intensity in order to estimate fundamental parameters of the pyrene-surfactant system, such as the binding equilibrium constant K of pyrene to a given surfactant micelle, the rate constant of excimer formation in micelles, and the equilibrium constant of pyrene-surfactant quenching. The values of the binding equilibrium constant K(TX100)=3300·10³ M⁻¹ and K(SDS)=190·10³ M⁻¹ for Triton X-100 (TX100) and SDS micelles, respectively, show that the partition of pyrene between bulk water and micelles cannot be ignored, even at relatively high surfactant concentrations above the cmc. We apply the model to the determination of the cmc from the pyrene fluorescence intensity, especially from the intensity ratio at two vibronic bands in the monomer emission or from the ratio of excimer to monomer emission intensity. We relate the finite width of the transition region below and above the cmc with the observed changes in the pyrene fluorescence in this region.

  1. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity.

  2. Surfactants tailored by the class Actinobacteria

    Directory of Open Access Journals (Sweden)

    Johannes H Kügler

    2015-03-01

    Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.

  3. Parameters Affecting Hydrogen Chloride Measurements

    Science.gov (United States)

    1993-06-01

    contain sea salt, which is hygroscopic because of the magnesium chloride present, or ammonium bisulfate , which mostly comes from sulfur pollution and is...boosters release hydrogen chloride as a combustion product, and hydrazines or nitric acid can be spilled from liquid fuel motors. Monitoring the...solubility constant, and the second is the acid ionization constant. From experimental work, the product of the two constants is well established (Reference

  4. Influence of surfactants in forced dynamic dewetting.

    Science.gov (United States)

    Henrich, Franziska; Fell, Daniela; Truszkowska, Dorota; Weirich, Marcel; Anyfantakis, Manos; Nguyen, Thi-Huong; Wagner, Manfred; Auernhammer, Günter K; Butt, Hans-Jürgen

    2016-09-20

    In this work we show that the forced dynamic dewetting of surfactant solutions depends sensitively on the surfactant concentration. To measure this effect, a hydrophobic rotating cylinder was horizontally half immersed in aqueous surfactant solutions. Dynamic contact angles were measured optically by extrapolating the contour of the meniscus to the contact line. Anionic (sodium 1-decanesulfonate, S-1DeS), cationic (cetyl trimethylammonium bromide, CTAB) and nonionic surfactants (C4E1, C8E3 and C12E5) with critical micelle concentrations (CMCs) spanning four orders of magnitude were used. The receding contact angle in water decreased with increasing velocity. This decrease was strongly enhanced when adding surfactant, even at surfactant concentrations of 10% of the critical micelle concentration. Plots of the receding contact angle-versus-velocity almost superimpose when being plotted at the same relative concentration (concentration/CMC). Thus the rescaled concentration is the dominating property for dynamic dewetting. The charge of the surfactants did not play a role, thus excluding electrostatic effects. The change in contact angle can be interpreted by local surface tension gradients, i.e. Marangoni stresses, close to the three-phase contact line. The decrease of dynamic contact angles with velocity follows two regimes. Despite the existence of Marangoni stresses close to the contact line, for a dewetting velocity above 1-10 mm s(-1) the hydrodynamic theory is able to describe the experimental results for all surfactant concentrations. At slower velocities an additional steep decrease of the contact angle with velocity was observed. Particle tracking velocimetry showed that the flow profiles do not differ with and without surfactant on a scales >100 μm.

  5. Chloride channels in stroke

    Institute of Scientific and Technical Information of China (English)

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN

    2013-01-01

    Vascular remodeling of cerebral arterioles,including proliferation,migration,and apoptosis of vascular smooth muscle cells (VSMCs),is the major cause of changes in the cross-sectional area and diameter of the arteries and sudden interruption of blood flow or hemorrhage in the brain,ie,stroke.Accumulating evidence strongly supports an important role for chloride (Clˉ) channels in vascular remodeling and stroke.At least three Clˉ channel genes are expressed in VSMCs:1) the TMEM16A (or Ano1),which may encode the calcium-activated Clˉ channels (CACCs); 2) the CLC-3 Clˉ channel and Clˉ/H+ antiporter,which is closely related to the volume-regulated Clˉ channels (VRCCs); and 3) the cystic fibrosis transmembrane conductance regulator (CFTR),which encodes the PKA-and PKC-activated Clˉ channels.Activation of the CACCs by agonist-induced increase in intracellular Ca2+ causes membrane depolarization,vasoconstriction,and inhibition of VSMC proliferation.Activation of VRCCs by cell volume increase or membrane stretch promotes the production of reactive oxygen species,induces proliferation and inhibits apoptosis of VSMCs.Activation of CFTR inhibits oxidative stress and may prevent the development of hypertension.In addition,Clˉ current mediated by gammaaminobutyric acid (GABA) receptor has also been implicated a role in ischemic neuron death.This review focuses on the functional roles of Clˉ channels in the development of stroke and provides a perspective on the future directions for research and the potential to develop Clˉ channels as new targets for the prevention and treatment of stroke.

  6. 21 CFR 184.1138 - Ammonium chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution....

  7. Surfactant-Assisted Coal Liquefaction

    Science.gov (United States)

    Hickey, Gregory S.; Sharma, Pramod K.

    1993-01-01

    Obtaining liquid fuels from coal which are economically competitive with those obtained from petroleum based sources is a significant challenge for the researcher as well as the chemical industry. Presently, the economics of coal liquefaction are not favorable because of relatively intense processing conditions (temperatures of 430 degrees C and pressures of 2200 psig), use of a costly catalyst, and a low quality product slate of relatively high boiling fractions. The economics could be made more favorable by achieving adequate coal conversions at less intense processing conditions and improving the product slate. A study has been carried out to examine the effect of a surfactant in reducing particle agglomeration and improving hydrodynamics in the coal liquefaction reactor to increase coal conversions...

  8. Gemini surfactants from natural amino acids.

    Science.gov (United States)

    Pérez, Lourdes; Pinazo, Aurora; Pons, Ramon; Infante, Mrosa

    2014-03-01

    In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural amino acid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing amino acids (Cys) as polar head groups, and Geminis with amino acids/peptides in the spacer chain are reviewed.

  9. Liquid-liquid extraction for surfactant-contaminant separation and surfactant reuse

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, M.A. [Surbec Environmental, Norman, OK (United States); Sabatini, D.A.; Harwell, J.H. [Univ. of Oklahoma, Norman, OK (United States)

    1997-07-01

    Liquid-liquid extraction was investigated for use with surfactant enhanced subsurface remediation. A surfactant liquid-liquid extraction model (SLLEM) was developed for batch equilibrium conditions based on contaminant partitioning between micellar, water, and solvent phases. The accuracy of this fundamental model was corroborated with experimental results (using naphthalene and phenanthrene as contaminants and squalane as the extracting solvent). The SLLEM model was then expanded to nonequilibrium conditions. The effectiveness of this nonequilibrium model was corroborated with experimental results from continuous flow hollow fiber membrane systems. The validated models were used to conduct a sensitivity analysis evaluating the effects of surfactants on the removal of the contaminants in liquid-liquid extraction systems. In addition, liquid-liquid extraction is compared to air stripping for surfactant-contaminant separation. Finally, conclusions are drawn as to the impact of surfactants on liquid-liquid extraction processes, and the significance of these impacts on the optimization of surfactant-enhanced subsurface remediation.

  10. Synthesis and Characterization of Zirconia Nanocrystallites by Cationic Surfactant and Anionic Surfactant

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Study on nanomaterials has attracted great interests in recent years. In this article,zirconia nanocrystallites of different structures have been successfully synthesized via hydrothermal methods with cationic surfactant (CTAB) and anionic surfactant (SDS), respectively. Differential Scanning Calorimeter (DSC-TG), X-ray Diffractometer (XRD), Transmission Electron Microscope (TEM), Ultraviolet-Visible (UV-vis) and N2 adsorption-desorption analyses are used for their structure characteristics. The results show that the cationic surfactant has a distinctive direction effect on the formation of zirconia nanocrystallites, while the anionic surfactant has a self-assembly synergistic effect on them. The sample synthesized with the cationic surfactant presents good dispersion with the main phase of tetragonal zirconia, and the average nanocryst al size is around 15nm after calcination at 500 ℃. While the sample synthesized with the anionic surfactant exhibits a worm-like mesoporous structure with pure tetragonal phase after calcination at 500 ℃ and with good thermal stability.

  11. Studies on the electrocapillary curves of anionic surfactants in presence of non-ionic surfactants.

    Science.gov (United States)

    Bembi, R; Goyal, R N; Malik, W U

    1976-09-01

    Polyoxyethylated non-ionic surfactants such as Tween 20, Tween 40, Nonidet P40 and Nonex 501 have been supposed to be associated with cationic characteristics. Studies on the effect of these surfactants on the electrocapillary curves of the anionic surfactants Aerosol IB, Manaxol OT and sodium lauryl sulphate (SLS), show that the electrocapillary maxima shift towards positive potentials. The order of adsorption of the anionic surfactants is SLS > Manaxol OT > Aerosol IB while the shift in maxima is in the order Aerosol IB ~ Manaxol OT > SLS which confirms association of cationic characteristics with the micelles of these non-ionic surfactants. The magnitude of the shift in electrocapillary maxima is Nonex 501 > Nonidet P40 > Tween 20 > Tween 40 which may be the order of magnitude of the positive charge carried by these non-ionic surfactants.

  12. Synthesis of novel quaternary ammonium surfactants containing adamantane

    Institute of Scientific and Technical Information of China (English)

    Jian Wei Guo; Xing Zhong; Hua Zhu; Li Juan Feng; Ying De Cui

    2012-01-01

    A series of novel quaternary ammonium surfactants containing adamantane were designed and synthesized from 1-adamantanecarboxylic acid.The structures of target surfactants were confirmed by 1H NMR,elements analysis and FTIR.Surface properties of these surfactants were investigated.Due to the lipophilicity of adamantane,the critical micelle concentration (CMC) and C20 values of the synthesized quaternary ammonium surfactants are lower than that of conventional quaternary ammonium surfactants.

  13. A high-resolution study of surfactant partitioning and kinetic limitations for two-component internally mixed aerosols

    Science.gov (United States)

    Suda, S. R.; Petters, M. D.

    2013-12-01

    Atmospheric aerosols serve as cloud condensation nuclei (CCN), altering cloud properties and ultimately affecting climate through their effect on the radiative balance. Aerosol CCN activity depends in part on aerosol composition and surfactant compounds are of particular interest because surfactants are enriched at the water/air interface, resulting in a radial concentration gradient within the aqueous droplet. Accurate treatment of the surfactant concentration gradient complicates the otherwise straightforward predictions of CCN activity for aerosols of known composition. To accurately evaluate predictions made by theory, laboratory studies investigating the relationship between critical supersaturation and dry diameter of particles that include surfactants require significant reduction in measurement uncertainty for both water-uptake and CCN measurements. Furthermore, uncertainties remain regarding kinetic limitations to surfactant partitioning that could result in deviation from predictions based on equilibrium thermodynamics. This study attempts to address some of these issues through high-resolution analysis of CCN activity of two-component mixed surfactant/non-surfactant aerosols at different internal mixing ratios performed with and without a water-uptake time delay to ascertain whether or not the observed effects are kinetically limited. We present new data for the aerosols consisting of 1) the ionic surfactant sodium dodecyl sulfate (SDS) with ammonium sulfate, 2) SDS with sodium chloride and 3) the strong non-ionic fluorosurfactant Zonyl with an organic proxy glucose. As a point of reference we also evaluated the mixture of ammonium sulfate with glucose. Aerosol activation diameters were determined using CCN analysis in conjunction with scanning mobility size classification and high sheath-to-aerosol flow ratios. This resulted in CCN-derived kappa values that could be determined within +/-5% relative error. To test whether dynamic surfactant partitioning

  14. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and...

  15. 40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

    Science.gov (United States)

    2010-07-01

    ... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene...

  16. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

    Directory of Open Access Journals (Sweden)

    Taku Fukuzawa

    Full Text Available Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+ and Ig-Hepta(-/- mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i balanced synthesis of surfactant lipids and proteins and (ii surfactant secretion, and (iii a stimulating effect on recycling (uptake in response to elevated levels of Sp-D in alveolar space.

  17. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

    Science.gov (United States)

    Fukuzawa, Taku; Ishida, Junji; Kato, Akira; Ichinose, Taro; Ariestanti, Donna Maretta; Takahashi, Tomoya; Ito, Kunitoshi; Abe, Jumpei; Suzuki, Tomohiro; Wakana, Shigeharu; Fukamizu, Akiyoshi; Nakamura, Nobuhiro; Hirose, Shigehisa

    2013-01-01

    Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+) and Ig-Hepta(-/-) mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i) balanced synthesis of surfactant lipids and proteins and (ii) surfactant secretion, and (iii) a stimulating effect on recycling (uptake) in response to elevated levels of Sp-D in alveolar space.

  18. Molecular-thermodynamic theory of micellization of multicomponent surfactant mixtures: 2. pH-sensitive surfactants.

    Science.gov (United States)

    Goldsipe, Arthur; Blankschtein, Daniel

    2007-05-22

    In article 1 of this series, we developed a molecular-thermodynamic (MT) theory to model the micellization of mixtures containing an arbitrary number of conventional (pH-insensitive) surfactants. In this article, we extend the MT theory to model mixtures containing a pH-sensitive surfactant. The MT theory was validated by examining mixtures containing both a pH-sensitive surfactant and a conventional surfactant, which effectively behave like ternary surfactant mixtures. We first compared the predicted micellar titration data to experimental micellar titration data that we obtained for varying compositions of mixed micelles containing the pH-sensitive surfactant dodecyldimethylamine oxide (C12DAO) mixed with either a cationic surfactant (dodecyltrimethylammonium bromide, C12TAB), a nonionic surfactant (dodecyl octa(ethylene oxide), C12E8), or an anionic surfactant (sodium dodecyl sulfate, SDS) surfactant. The MT theory accurately modeled the titration behavior of C12DAO mixed with C12E8. However, C12DAO was observed to interact more favorably with SDS and with C12TAB than was predicted by the MT theory. We also compared predictions to data from the literature for mixtures of C12DAO and SDS. Although the pH values of solutions with no added acid were modeled with only qualitative accuracy, the MT theory resulted in quantitatively accurate predictions of solution pH for mixtures containing added acid. In addition, the predicted degree of counterion binding yielded a lower bound to the experimentally measured value. Finally, we predicted the critical micelle concentration (cmc) of solutions of two pH-sensitive surfactants, tetradecyldimethylamine oxide (C14DAO) and hexadecyldimethyl betaine (C16Bet), at varying solution pH and surfactant composition. However, at the pH values considered, the pH sensitivity of C16Bet could be neglected, and it was equivalently modeled as a zwitterionic surfactant. The cmc's predicted using the MT theory agreed well with the experimental

  19. Effects of Interactions Among Surfactants,Water and Oil on Equilibrium Configuration of Surfactant-Water-Oil Systems

    Institute of Scientific and Technical Information of China (English)

    YUAN Yin-quan; SUN Zhi-bo; XIE Yun; ZOU Xian-wu

    2004-01-01

    The distribution and configuration of surfactants at interface in surfactant-water-oil systems have been investigated using discontinuous molecular dynamic simulations. There exists a certain equilibrium concentration of surfactants at interface for the systems with certain interactions among surfactant, water and oil. The interface length and equilibrium morphology of the systems are dependent on the equilibrium concentration of surfactants at interface and the total amount of surfactants. The interaction strengths among surfactant, water and oil determine the equilibrium concentration of surfactants at interface. Three typical configurations of surfactants at interface have been observed: ① surfactant molecules are perpendicular to the interface and arranged closely; ② perpendicular to the interface and arranged at interval of two particles; ③ lie down in the interface partly.

  20. Simple and rapid analytical method for the simultaneous determination of cetrimonium chloride and alkyl alcohols in hair conditioners.

    Science.gov (United States)

    Terol, A; Gómez-Mingot, M; Maestre, S E; Prats, S; Luis Todolí, J; Paredes, E

    2010-02-01

    A simple method for the simultaneous determination of a cationic surfactant (cetrimonium chloride) and four non-ionic surfactants (1-tetradecanol, 1-hexadecanol, 1-octadecanol and 1-eicosanol) has been developed. Direct extraction of the analytes from the sample with methanol and a subsequent separation using reversed-phase high-performance liquid chromatography with refractive index detection are the steps followed in the procedure. The column used was a Luna C18 and the mobile phase consisted of a 0.1 M KClO(4) solution prepared on a 95:5 mixture of methanol and water. This solution was adjusted to pH 2.8 with phosphoric acid. Recoveries close to 100% were obtained in spiked commercial hair conditioner samples for the surfactants assayed using this method. Limits of detection were 10.4, 16.7 and 22.9 mg kg(-1) of cetrimonium chloride, 1-hexadecanol, 1-hexadecanol and 1-1-octadecanol respectively. The methodology was successfully applied to nine commercial hair conditioners of several types and different brands. All hair conditioners but one contained at least two of the surfactants included in this study.

  1. CHLORIDE WASHER PERFORMACE TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, J; David Best, D; Robert Pierce, R

    2007-11-30

    Testing was performed to determine the chloride (Cl-) removal capabilities of the Savannah River National Laboratory (SRNL) designed and built Cl- washing equipment intended for HB-Line installation. The equipment to be deployed was tested using a cerium oxide (CeO2) based simulant in place of the 3013 plutonium oxide (PuO2) material. Two different simulant mixtures were included in this testing -- one having higher Cl- content than the other. The higher Cl- simulant was based on K-Area Interim Surveillance Inspection Program (KIS) material with Cl- content approximately equal to 70,000 ppm. The lower Cl- level simulant was comparable to KIS material containing approximately 8,000-ppm Cl- content. The performance testing results indicate that the washer is capable of reducing the Cl- content of both surrogates to below 200 ppm with three 1/2-liter washes of 0.1M sodium hydroxide (NaOH) solution. Larger wash volumes were used with similar results - all of the prescribed test parameters consistently reduced the Cl- content of the surrogate to a value below 200 ppm Cl- in the final washed surrogate material. The washer uses a 20-micron filter to retain the surrogate solids. Tests showed that 0.16-0.41% of the insoluble fraction of the starting mass passed through the 20-micron filter. The solids retention performance indicates that the fissile masses passing through the 20-micron filter should not exceed the waste acceptance criteria for discard in grout to TRU waste. It is recommended that additional testing be pursued for further verification and optimization purposes. It is likely that wash volumes smaller than those tested could still reduce the Cl- values to acceptable levels. Along with reduced wash volumes, reuse of the third wash volume (in the next run processed) should be tested as a wash solution minimization plan. A 67% reduction in the number of grouted paint pails could be realized if wash solution minimization testing returned acceptable results.

  2. Aggregation of sulfosuccinate surfactants in water

    Energy Technology Data Exchange (ETDEWEB)

    Magid, L.J.; Daus, K.A.; Butler, P.D.; Quincy, R.B.

    1983-12-22

    The aggregation of sodium di-n-alkyl sulfosuccinates in water (H/sub 2/O and D/sub 2/O at 45/sup 0/C) has been investigated. A self-consistent picture of the dependence of sodium ion binding on surfactant concentration is obtained from emf measurements, conductimetry, and small-angle neutron scattering (SANS) measurements. The concentration dependence of the micellar agregation number for the sulfosuccinates and related double-tailed surfactants depends markedly on surfactant solubility. A sphere-to-disk transition in micellar shape, which might have been expected as a precursor to formation of a lamellar mesophase, was not observed as the surfactant concentration was increased. 8 figures, 2 tables.

  3. Investigation of a polyether trisiloxane surfactant

    OpenAIRE

    Michel, Amandine

    2016-01-01

    Thanks to their adaptability and high efficiency compared to traditional carbon based surfactants, silicone surfactants are a success in many different applications, from pesticides to cosmetics, polyurethane foam, textile and car care products. In spite of those numerous applications, no analytical method existed for their trace determination in environmental samples and no data have been available regarding their environmental occurrence and fate. An analytical method for the trace ana...

  4. Surfactant apoprotein in nonmalignant pulmonary disorders.

    OpenAIRE

    Singh, G.; Katyal, S. L.

    1980-01-01

    Formalin-fixed, paraffin-embedded lungs exhibiting a variety of nonmalignant disorders were studied by immunoperoxidase staining using antibodies specific for surfactant apoprotein, IgG, IgM, IgA, albumin, fibrinogen, and lysozyme. Normal Type II pneumocytes showed staining for surfactant apoprotein in the perinuclear region only. The extent and intensity of staining for apoprotein was markedly increased in reactive Type II pneumocytes. This increase appeared to be a nonspecific reaction to l...

  5. Evaluation of Surfactant Effects on Newborns

    Directory of Open Access Journals (Sweden)

    N. Khalessi

    2006-10-01

    Full Text Available Introduction & Objective: One of the standard therapies in neonates with severe respiratory distress syndrome (RDS is surfactant administration in early course of therapy that cause reduction in mortality, pneumothorax and need to mechanical ventilation. In this study that was carried out in Aliasghar Hospital NICU in 1994-1995 & 2001-2002, the goal was to compare two groups of neonates with severe RDS that had been ventilated in the first 24 hours but one group had received surfactant and the other group (7 years ago was deprived of this substance. Materials & Methods: In our study, 36 neonates that received surfactant and 52 neonates with only mechanical ventilation therapy were compared. Data collected and analyzed using SPSS.Results: We found that mortality in patients with surfactant administration was significantly lower compared to the second group who did not receive surfactant. There were not any significant differences in incidences of HIV, pneumothorax, sepsis, and PDA and also course of hospitalization and need to ventilation between two groups. Conclusion: As a result, all of these findings reflect obligatory surfactant administration in sever RDS in NICU under observation of an educated expert.

  6. Nonlinear water waves with soluble surfactant

    Science.gov (United States)

    Lapham, Gary; Dowling, David; Schultz, William

    1998-11-01

    The hydrodynamic effects of surfactants have fascinated scientists for generations. This presentation describes an experimental investigation into the influence of a soluble surfactant on nonlinear capillary-gravity waves in the frequency range from 12 to 20 Hz. Waves were generated in a plexiglass wave tank (254 cm long, 30.5 cm wide, and 18 cm deep) with a triangular plunger wave maker. The tank was filled with carbon- and particulate-filtered water into which the soluble surfactant Triton-X-100® was added in known amounts. Wave slope was measured nonintrusively with a digital camera running at 225 fps by monitoring the position of light beams which passed up through the bottom of the tank, out through the wavy surface, and onto a white screen. Wave slope data were reduced to determine wave damping and the frequency content of the wave train. Both were influenced by the presence of the surfactant. Interestingly, a subharmonic wave occurring at one-sixth the paddle-driving frequency was found only when surfactant was present and the paddle was driven at amplitudes high enough to produce nonlinear waves in clean water. Although the origins of this subharmonic wave remain unclear, it appears to be a genuine manifestation of the combined effects of the surfactant and nonlinearity.

  7. Performance of some surfactants as wetting agents

    Energy Technology Data Exchange (ETDEWEB)

    Shalaby, M.N.; El-Shanny, O.A.A. [Egyptian Petroleum Research Institute (EPRI), Cairo (Egypt). Evaluation and Analysis Dept.

    2005-12-01

    The wetting power of anionic surfactant: sodium dodecyl sulfate (SDS), and nonionic surfactants: polyoxyethelene(14)monolaurate [La(EO){sub 14}] and polyoxyethelene(14)monoeleate [OI(EO){sub 14}] has been studied to determine their performance as wetting agents. The study reveals that the nonionic compound with a long hydrophobic chain exhibits higher wettability than the shorter one when used at very low cocentrations (below CMC) and the reverse is shown with high concentrations (above CMC). the wetting power of the investigated surfactants increases as the CMC values increases. In case of the nonionic compounds and at surfactant concentrations equal their CMC values, OI(EO){sub 14} shows a higher wetting power than La(EO){sub 14} while is possesses a lower HLB value. The anionic surfactant shows an optimum wetting in comparison with the tested nonionic one. The wettability of all the investigated samples increases as the surface tension of their solutions increases to the allowed limit that can be reached in the presence of surfactant. (orig.)

  8. Spinodal Decomposition in Mixtures Containing Surfactants

    Science.gov (United States)

    Melenekvitz, J.

    1998-03-01

    Spinodal decomposition in mixtures containing two immiscible liquids (A and B) plus surfactant was investigated using a recently developed (J. Melenkevitz and S. H. Javadpour, J. Chem. Phys., 107, 623 (1997).) 3-component Ginzburg-Landau model. The time dependent Ginzburg-Landau (TDGL) equations governing the evolution of structure were numerically integrated in 2-dimensions. We found the growth rate of the average domain size, R(t), decreased with increasing surfactant concentration over a wide range of relative amounts of A and B. This can be attributed to the surfactant accumulating at the growing interface between the immiscible liquids, which leads to a reduction in the surface tension. At late times, the growth rate was noticeably altered when thermal fluctuations were added to the numerical simulations. In this case, power law behavior was observed for R(t) at late times, R(t) ~ t^α, with the exponent α decreasing as the amount of surfactant increased. The dynamics at early times were determined by linearizing the TDGL equations about a uniformly mixed state. The growth rate at ealry times was found to be strongly dependent on the model parameters describing the surfactant miscibility in A and B and the surfactant strength. Comparison with recent measurements on SBR / PB mixtures with added PB-SBR diblock copolymer will also be presented.

  9. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2005-01-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Imbibition in an originally oil-wet 2D capillary is the fastest in the case of Alf-38 and slowest in the case of DTAB (among the surfactants studied). Force of adhesion studies and contact angle measurements show that greater wettability alteration is possible with these anionic surfactants than the cationic surfactant studied. The water imbibition rate does not increase monotonically with an increase in the surfactant concentration. A numerical model has been developed that fits the rate of imbibition. Plans for the next quarter include conducting simulation and imbibition studies.

  10. Electrochemical Chloride extraction using external electrodes?

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2006-01-01

    Electrochemical methods for the removal of chloride from concrete have been developed and the methods are primarily designed for situations where corrosion has started due to an increased chloride concentration in the vicinity of the reinforcement. In these methods the reinforcement is used...... as the cathode. However, some unwanted side effects can occur, including alkali-silica reaction and in some cases hydrogen embrittlement. It is also suggested also to use electrochemical chloride extraction in a preventive way in constructions where chloride induced corrosion is likely to be a problem after...... a period of time, i.e. remove the chlorides before the chloride front reaches the reinforcement. If the chlorides are removed from outer few centimetres from the surface, the chloride will not reach the reinforcement and cause damage. By using the electrochemical chloride removal in this preventive way...

  11. Silicone antifoam performance enhancement by nonionic surfactants in potato medium.

    Science.gov (United States)

    Christiano, Steven P; Fey, Kenneth C

    2003-01-01

    The ability of a silicone antifoam to retard foaming in a liquor prepared from potatoes is enhanced by the addition of ethoxylated nonionic surfactants. The enhancement is non-linear for surfactant concentration, with all 12 surfactants tested possessing a concentration at which foam heights strongly diminish, referred to as the surfactant critical antifoaming concentration (SCAFC). SCAFCs vary between surfactants, with lower values indicating better mass efficiency of antifoaming enhancement. SCAFCs decrease with degree of ethoxylation and decrease with the hydrophilic-lipophilic balance for ethoxylated nonionic surfactants. Surfactant addition produces a mixed water-surface layer containing surfactant and surface-active components in the potato medium. Surface tension reduction does not correlate well with antifoam performance enhancement. A model is proposed where surfactant adsorption promotes desorption of surface-active potato medium components from the water surface. At the SCAFC, desorption is not complete, yet the rate of bubble rupture is sufficiently enhanced to provide excellent foam control.

  12. Interactions of organic contaminants with mineral-adsorbed surfactants

    Science.gov (United States)

    Zhu, L.; Chen, B.; Tao, S.; Chiou, C.T.

    2003-01-01

    Sorption of organic contaminants (phenol, p-nitrophenol, and naphthalene) to natural solids (soils and bentonite) with and without myristylpyridinium bromide (MPB) cationic surfactant was studied to provide novel insight to interactions of contaminants with the mineral-adsorbed surfactant. Contaminant sorption coefficients with mineral-adsorbed surfactants, Kss, show a strong dependence on surfactant loading in the solid. At low surfactant levels, the Kss values increased with increasing sorbed surfactant mass, reached a maximum, and then decreased with increasing surfactant loading. The Kss values for contaminants were always higher than respective partition coefficients with surfactant micelles (Kmc) and natural organic matter (Koc). At examined MPB concentrations in water the three organic contaminants showed little solubility enhancement by MPB. At low sorbed-surfactant levels, the resulting mineral-adsorbed surfactant via the cation-exchange process appears to form a thin organic film, which effectively "adsorbs" the contaminants, resulting in very high Kss values. At high surfactant levels, the sorbed surfactant on minerals appears to form a bulklike medium that behaves essentially as a partition phase (rather than an adsorptive surface), with the resulting Kss being significantly decreased and less dependent on the MPB loading. The results provide a reference to the use of surfactants for remediation of contaminated soils/sediments or groundwater in engineered surfactant-enhanced washing.

  13. Bioaccumulation and toxicity of a cationic surfactant (DODMAC) in sediment dwelling freshwater invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Comber, S.D.W. [Atkins Ltd, Chilbrook, Oasis Business Park, Eynsham, Oxford, OX29 4AH (United Kingdom)], E-mail: sean.comber@atkinsglobal.com; Rule, K.L. [Centre for Environmental Sciences, University of Southampton, Southampton SO17 1BJ (United Kingdom); Conrad, A.U. [Scottish Environmental Protection Agency, SEPA Corporate Office, Erskine Court Castle Business Park, Stirling FK9 4TR (United Kingdom); Hoess, S. [ECOSSA, Thierschstrasser 43, 80538 Muenchen (Germany); Webb, S.F. [Procter and Gamble, Temselaan 100, Strombeek-Bever B1853 (Belgium); Marshall, S. [Unilever Colworth, Sharnbrook, Bedford MK44 1LQ (United Kingdom)

    2008-05-15

    Dimethyldioctadecylammonium chloride (DODMAC, CAS No. 107-64-2) is the principal active component of Di(hydrogenated tallow alkyl) dimethylammonium chloride (DHTDMAC, CAS No. 61789-80-8), a cationic surfactant formerly used principally in laundry fabric softeners. After discharge to water, DODMAC partitions strongly to sediment, therefore the assessment of the effects of DODMAC to benthic organisms is essential in any risk assessment. Chronic toxicity studies were conducted with Lumbriculus variegatus (Oligochaete), Tubifex tubifex (Oligochaete) and Caenorhabditis elegans (Nematode). NOECs were greater than 5738, 1515 and 1351 mg/kg dw, respectively, even for sub-lethal effects. Measurement of the route of uptake of DODMAC by L. variegatus demonstrated the relative importance of uptake via ingestion (86%) compared with direct contact with the sediment and via pore water (14%). The overall tendency of DODMAC to bioaccumulate, however, was low with measured accumulation factors of 0.22 and 0.78 for L. variegatus and T. tubifex, respectively. - The cationic surfactant, DODMAC, exhibits low bioavailability and toxicity to sediment dwelling organisms, with uptake dominated by ingestion.

  14. Critical interaction strength for surfactant-induced mesomorphic structures in polymer-surfactant systems

    NARCIS (Netherlands)

    Ruokolainen, J.; Torkkeli, M.; Serimaa, R.; Vahvaselka, S.; Saariaho, M.; ten Brinke, G.; Ikkala, O.; Vahvaselkä, Sakari

    1996-01-01

    The critical interaction strength to induce mesomorphic structures in flexible polymers by complexing with surfactants is determined by using surfactants with different hydrogen-bonding strengths;. Two essential requirements have to be satisfied: (i) the association has to be strong enough, otherwis

  15. Surfactant nebulization versus instillation during high frequency ventilation in surfactant-deficient rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1998-01-01

    Surfactant nebulization improves lung function at low alveolar doses of surfactant. However, efficiency of nebulization is low, and lung deposition seems to depend on lung aeration. High frequency ventilation (HFV) has been shown to improve lung aeration. We hypothesize that the combination of HFV a

  16. Lubiprostone: a chloride channel activator.

    Science.gov (United States)

    Lacy, Brian E; Levy, L Campbell

    2007-04-01

    In January 2006 the Food and Drug Administration approved lubiprostone for the treatment of chronic constipation in men and women aged 18 and over. Lubiprostone is categorized as a prostone, a bicyclic fatty acid metabolite of prostaglandin E1. Lubiprostone activates a specific chloride channel (ClC-2) in the gastrointestinal (GI) tract to enhance intestinal fluid secretion, which increases GI transit and improves symptoms of constipation. This article reviews the role of chloride channels in the GI tract, describes the structure, function, and pharmacokinetics of lubiprostone, and discusses clinically important data on this new medication.

  17. Surfactant Enhanced Electroremediation of Phenanthrene

    Institute of Scientific and Technical Information of China (English)

    佘鹏; 杨建刚; 等

    2003-01-01

    Removal of hydrophobic organic contaminants(HOCs) form soil of low permeability by electroremediation was investigated by using phenanthrene and kaolinite as a model system.Tween 80 was added into the purging solution in order to enhance the solubility of phenanthrene.The effects of pH on the adsorption of phenanthrene and Tween 80 on kaolinite and the magnitude of ζ-potential of kaolinite were examined,respectively.The effects of electric field strength indicated by electric current on the electroremediation behavior,including the pH of purging solution,the conductivity,phenanthrene concentration and flow rate of effluent,were experimentally investigated,repectively,In case of an electric field of 25mA applied for 72 hours,over 90% of phenanthrene was removed from 424g(dry mass)of kaolinite at an energy consumption of 0.148kW.h.The experimental results described in present study show that the addition of surfactant into purging solution greatly enhances the removel of HOCs by electroremediation.

  18. Interaction of cationic dye/surfactants with Klebsiella K18 capsular polysaccharides: Physico-chemical studies

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Ranendu Kumar, E-mail: rknath1959@gmail.com [Department of Chemistry, Tripura University, Suryamaninagar, Tripura-799130 (India); Singh, Th. Charanjit [Department of Chemistry, D.D.M. College, Khowai, Tripura-799 202 (India); Dasgupta, Satwati [Department of Chemistry, Tripura University, Suryamaninagar, Tripura-799130 (India); Mitra, Asish [Department of Chemistry, MBB College, Agartala, Tripura-799001 (India); Panda, Amiya Kumar [Department of Chemistry, University of North Bengal, P.O. North Bengal University, Dt: Darjeeling, West Bengal-734013 (India)

    2010-05-10

    Physico-chemical studies on the interaction of capsular polysaccharide (SPS) isolated from Klebsiella K18, with cationic dyes and surfactants have been reported. SPS is an integral component of gram-negative bacteria and having glucuronic acid as the potential anionic site, induced strong metachromasy (blue shift {approx} 110 nm) in the cationic dye pinacyanol chloride (PCYN). Reversal of metachromasy was observed upon addition of co-solvents which provides a qualitative measurement of stability and nature of metachromatic compound associated with PCYN-SPS interaction. Thermodynamic parameters such as association constant, changes in free energy, enthalpy and entropy of dye-polymer interaction, were evaluated which revealed the nature of interaction. Studies on fluorescence quenching of acridine orange (AO) was also performed. The interaction of SPS with cationic and cationic-non-ionic mixed surfactant systems have been studied by turbidimetry, spectrophotometry, spectrofluorometry and viscosity measurements. The studies could provide an understanding on the effects of the surfactants on binding with the polymer. The binding was found to be electrostatic in origin and also hydrophobic in nature to a certain extent.

  19. Automated electronic tongue based on potentiometric sensors for the determination of a trinary anionic surfactant mixture.

    Science.gov (United States)

    Cortina, Montserrat; Ecker, Christina; Calvo, Daniel; del Valle, Manuel

    2008-01-22

    An automated electronic tongue consisting of an array of potentiometric sensors and an artificial neural network (ANN) has been developed to resolve mixtures of anionic surfactants. The sensor array was formed by five different flow-through sensors for anionic surfactants, based on poly(vinyl chloride) membranes having cross-sensitivity features. Feedforward multilayer neural networks were used to predict surfactant concentrations. As a great amount of information is required for the correct modelling of the sensors response, a sequential injection analysis (SIA) system was used to automatically provide it. Dodecylsulfate (DS(-)), dodecylbenzenesulfonate (DBS(-)) and alpha-alkene sulfonate (ALF(-)) formed the three-analyte study case resolved in this work. Their concentrations varied from 0.2 to 4mM for ALF(-) and DBS(-) and from 0.2 to 5mM for DS(-). Good prediction ability was obtained with correlation coefficients better than 0.933 when the obtained values were compared with those expected for a set of 16 external test samples not used for training.

  20. Influence of Surfactant-polymer Complexes on Crystallization and Aggregation of CaCO3

    Institute of Scientific and Technical Information of China (English)

    PAN Yan; GUO Yu-peng; ZHAO Xu; WANG Zi-chen

    2012-01-01

    Hollow calcium carbonate(CaCO3) microspheres with different morphologies were synthesized via the precipitation reaction of calcium chloride with sodium carbonate in the presence of different surfactant-polymer complexes.The selected anionic surfactants were sodium dodecyl sulfonate(SDS) and sodium dodecyl benzenesulfonate(SDBS),respectively.The selected water-soluble polymers were polyacrylic acid(PAA) and polyvinyl pyrrolidone(PVP).In this work,SDS-PVP "pearl-necklace model" micellar complex was formed via hydrophobic effectiveness between SDS and PVP and it served as the spherical template to generate spherical CaCO3 aggregates with hollow microspheres composed of about 500 nm irregular shaped particles.SDS-PAA complexes and SDBS-PAA complexes formed "core-shell model" aggregates with calcium ions serving as the medium to link the anionic surfactant and the polymer.SDS-PAA "core-shell model" aggregates would act as templates for hollow CaCO3 microspheres consisting of 30-50 nm irregular shaped crystallites.SDBS-PAA "core-shell model" aggregates served as the spherical aggregate templates to generate spherical CaCO3 aggregates consisted of many small spherical particles which had grown together.All the obtained CaCO3 hollow microspheres are calcite particles.This research may provide new insight into the control of morphologies of hollow CaCO3 microspheres in the presence of surfactantpolymer complexes.

  1. Synthesis and interfacial properties of monoacyl glyceric acids as a new class of green surfactants.

    Science.gov (United States)

    Fukuoka, Tokuma; Ikeda, Shintaro; Habe, Hiroshi; Sato, Shun; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai; Sakaki, Keiji

    2012-01-01

    Glyceric acid (GA) is one of the most promising functional hydroxyl acids, and it is abundantly obtained from glycerol by a bioprocess using acetic acid bacteria. In this study, several monoacyl GAs were synthesized by esterification of GA and saturated fatty acyl chlorides (C12, C14, C16, and C18), forming a new class of bio-based surfactants. By the present method, a mixture of two isomers, namely 2-O-acyl and 3-O-acyl GAs, was produced, in which the 2-O-acyl derivatives were obtained as a major product. These isomers were isolated, and their surface-active properties were investigated for the first time. The surface tensions of 2-O-acyl GAs with different chain lengths were determined by the Wilhelmy method. At concentrations below 10(-4) M, the 2-O-acyl GAs exhibited higher surface-active properties compared to commercially available synthetic surfactants. For example, 2-O-lauroyl GA reduced the surface tension of water to around 25 mN/m above the critical micelle concentration (3.0×10(-4) M). In addition, 2-O-acyl derivatives showed higher surface-tension-lowering activity than 3-O-acyl GAs. The monoacyl GAs synthesized herein can potentially be used as "green surfactants."

  2. Dilute Surfactant Methods for Carbonate Formations

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2006-02-01

    There are many fractured carbonate reservoirs in US (and the world)