Sample records for carbitols

  1. Short report on an accident during sodium cleanup with ethyl carbitol in a storage tank of a research facility

    A brief description is given of an accident which happened on 8 March 1996 during cleanup of a small amount of sodium (about 3 kg) within a 500 l storage tank of an FZK research facility, using ethyl carbitol (EC) as a reactant. An unexpected rapid decomposition of the compounds into ignitable gases which were then released through a safety valve into the building caused a deflagration event and, as a consequence, some damage to the building walls and to the research facility. The personnel were evacuated from the building before the event happened, and so nobody was injured. Sodium cleanup with ethyl carbitol was a well-established method, and cleaning procedures of the research facility were carried out since 1991 for more than twenty times without any problem. The advantage of heavy alcohol is low vapour pressure, high ignition point and mild reaction with sodium. In the paper, a short description is given of the main features of the research facility, of the usual cleanup procedure, and of the accident including its conditions. An analysis of the event (which is incomplete of course) is presented with regard to pressure, temperature and chemical composition. Finally, the consequences are addressed. The most important one is that sodium decommissioning with EC as reactant should be avoided until possible runaway reactions are sufficiently understood. (author)

  2. Uranium extraction selectivities of dibutyl carbitol and tributyl phosphate in the system UO2(NO3)2-HNO3-H2O-Al(NO3)3-solvent

    Historically, both the BUTEX (dibutyl carbitol-based) and PUREX (tributyl phosphate-based) processes have been used for uranium recovery and purification. Currently, BUTEX- and PUREX-type extraction processes are being used in series for recovery of isotopically enriched uranium at the Oak Ridge Y-12 Plant. The use of two solvents is predicated on the differing selectivities of each with regard to the contaminant elements present in the uranium source stream. As part of efforts to streamline plant operations in response to decreasing throughput requirements, the Y-12 Development Division is evaluating options for converting the existing two-solvent operation to a single-solvent process. At the request of the Y-12 Development Division, the Robotics and Process Division at the Oak Ridge National Laboratory has undertaken evaluation of solvents for use in a single-solvent recovery process. Initial efforts have been directed toward development of a single-solvent, dibutyl carbitol- or tributyl phosphate-based process that produces a product with purity equal to or exceeding what is currently obtained in the two-cycle, two-solvent operation. The test effort has involved both laboratory equilibrium determinations and engineering-scale process demonstrations in multistage flowsheets using centrifugal solvent extraction contactors. Excellent uranium recovery results have been obtained from both dibutyl carbitol- and tributyl phosphate-based solvent extraction flowsheets. Contaminant rejection performance by the two solvents is similar for many of the elements considered. Extraction of some contaminant elements by tributyl phosphate is significant enough to conclude that the solvent is not as selective for uranium as is dibutyl carbitol. This determination does not necessarily eliminate tributyl phosphate from consideration for use in a single-solvent process but does indicate a need for effective scrubbing of contaminants from uranium-loaded tributyl phosphate, possibly by

  3. Development and Characterization of Cinnamon Leaf Oil Nanocream for Topical Application

    Zainol, N. A.; T S Ming; Darwis, Y.


    Cinnamon leaf oil contains a high percentage of eugenol and has antimicrobial, antioxidant and antiinflammatory properties. However, the undiluted oil can cause irritation to the skin. Therefore, the aims of this study were to develop and evaluate cinnamon leaf oil nanocream using palm oil. Nanocream base was prepared using different ratios of oil, surfactants and water. The surfactant used were mixture of Tween 80:Carbitol or Tween 80:Span 65 at different hydrophile-lipophile balance values....

  4. Synthesis of ethanol 14C-1

    The direct reduction by LiAlH4, of a suspension of anhydrous sodium acetate in tetra-hydro-furfuryl-oxy-tetra-hydro-pyran is described. This study has shown that the ethanol thus obtained is impure and that the yields are erratic. On the contrary the reduction of acetyl chloride 1-14C by LiAlH4, in 'diethyl carbitol' leads to ethanol 1-14C of satisfactory purity with a yield of about 71 percent. (author)

  5. Preparation and Evaluation of Solid-Self-Emulsifying Drug Delivery System Containing Paclitaxel for Lymphatic Delivery

    Hea-Young Cho; Jun-Hyuk Kang; Lien Ngo; Phuong Tran; Yong-Bok Lee


    Solid-self-emulsifying drug delivery system (S-SEDDS) of paclitaxel (Ptx) was developed by the spray drying method with the purpose of improving the low bioavailability (BA) of Ptx. 10% oil (ethyl oleate), 80% surfactant mixture (Tween 80 : Carbitol, 90 : 10, w/w), and 10% cosolvent (PEG 400) were chosen according to their solubilizing capacity. The mean droplet size, zeta potential, and encapsulation efficiency of the prepared S-SEDDS were 16.9 ± 1.53 nm, 12.5 ± 1.66 mV, and 56.2 ± 8.1%, res...

  6. Peroxide formation and kinetics of sodium dissolution in alcohols

    Suitable techniques for sodium removal and decontamination of sodium wetted components of Liquid Metal Fast Reactors (LMFRs) are necessary both for repair, reuse and decommissioning of such components. Among the methods followed for sodium removal, alcohol dissolution is usually employed for small components like bellow sealed valves, gripping tools to handle core components and sodium sampling devices (primary and secondary). One of the concerns in the alcohol dissolution method is the possible role of peroxide formation in the ethoxy group during storage and handling leading to explosion. This paper describes the study of peroxide formation in ethyl carbitol and butyl cellosolve as well as some of the results of dissolution kinetic studies carried out in our laboratory using different alcohols. The peroxide formation of ethyl carbitol and butyl cellosolve were studied by iodometric technique. It has been found that the peroxide formation is less in sodium containing alcohol than in pure one. Ethyl carbitol, butyl cellosolve and Jaysol-SS (mixture of ethyl alcohol, methyl alcohol, isopropyl alcohol and methyl isobutyl ketone) were used in dissolution kinetics studies. The effects due to area and orientation of the fresh sodium surface have also been investigated. The reaction rates were studied in the temperature range of 303-343 K. The rate of dissolution was estimated by measuring the sodium content of alcohol at periodic intervals. It is found that the reaction rate varies in the order of ethyl alcohol-water mixture > Jaysol-SS > butyl cellosolve > ethyl carbitol. While cleaning sodium using alcohol, the concentration of alcohol is held essentially constant throughout the process. The rate of reaction depends only on the amount of sodium and follows pseudo-first order kinetics. Increase in surface area has a marked impact on the dissolution rate at lower temperatures while at higher temperatures, the temperature factor overrides the effect due to surface area


    Fleming Martínez


    Full Text Available In this communication some reported solubility values of vanillin (component 3 in 2-(2-ethoxyethoxyethanol (Carbitol®, component 1 + water (component 2 mixtures at five temperatures from 298.15 to 318.15 K were correlated with the Jouyban-Acree model combined with van’t Hoff or Apelblat equations, obtaining models in second degree regarding the mixtures compositions. Mean percentage deviations were near to 6.0%. On the other hand, by means of the inverse Kirkwood-Buff integrals it was demonstrated that vanillin is preferentially solvated by water in water-rich mixtures (with a minimum δx1,3 value in the mixture x1 = 0.05, i.e. –4.29 x 10–2 but preferentially solvated by the cosolvent in mixtures with compositions 0.12 < x1 < 1.00 (with a maximum δx1,3 value equal to 3.61 x 10–2 in the mixture x1 = 0.25. It is conjectural that hydrophobic hydration plays a relevant role in the first case, whereas, in the second case, vanillin would be acting as Lewis acid with Carbitol®.

  8. Formulation and development of a self-nanoemulsifying drug delivery system of irbesartan

    Jaydeep Patel


    Full Text Available Irbesartan (IRB is an angiotensin II receptor blocker antihypertensive agent. The aim of the present investigation was to develop a self-nanoemulsifying drug delivery system (SNEDDS to enhance the oral bioavailability of poorly water-soluble IRB. The solubility of IRB in various oils was determined to identify the oil phase of SNEDDS. Various surfactants and co-surfactants were screened for their ability to emulsify the selected oil. Pseudoternary phase diagrams were constructed to identify the efficient self-emulsifying region. The optimized SNEDDS formulation contained IRB (75 mg, Cremophor® EL (43.33%, Carbitol® (21.67% and Capryol® 90 (32%. SNEDDS was further evaluated for its percentage transmittance, emulsification time, drug content, phase separation, dilution, droplet size and zeta potential. The optimized formulation of IRB-loaded SNEDDS exhibited complete in vitro drug release in 15 min as compared with the plain drug, which had a limited dissolution rate. It was also compared with the pure drug solution by oral administration in male Wister rats. The in vivo study exhibited a 7.5-fold increase in the oral bioavailability of IRB from SNEDDS compared with the pure drug solution. These results suggest the potential use of SNEDDS to improve dissolution and oral bioavailability of poorly water-soluble IRB.

  9. Preparation and Evaluation of Solid-Self-Emulsifying Drug Delivery System Containing Paclitaxel for Lymphatic Delivery

    Hea-Young Cho


    Full Text Available Solid-self-emulsifying drug delivery system (S-SEDDS of paclitaxel (Ptx was developed by the spray drying method with the purpose of improving the low bioavailability (BA of Ptx. 10% oil (ethyl oleate, 80% surfactant mixture (Tween 80 : Carbitol, 90 : 10, w/w, and 10% cosolvent (PEG 400 were chosen according to their solubilizing capacity. The mean droplet size, zeta potential, and encapsulation efficiency of the prepared S-SEDDS were 16.9 ± 1.53 nm, 12.5 ± 1.66 mV, and 56.2 ± 8.1%, respectively. In the S-SEDDS, Ptx presents in the form of molecular dispersion in the emulsions or is distributed in an amorphous state or crystalline with very small size. The prepared S-SEDDS formulation showed 70 and 75% dissolution in 60 and 30 min in dissolution medium pH 1.2 and 6.8, respectively. Significant increase (P≤0.05 in the peak concentration (Cmax, the area under the curve (AUC0–∞, and the lymphatic targeting efficiency of Ptx was observed after the oral administration of the Ptx-loaded S-SEDDS to rats (20 mg/kg as Ptx. Our research suggests the prepared Ptx-loaded S-SEDDS can be a good candidate for the enhancement of BA and targeting drug delivery to the lymphatic system of Ptx.

  10. Development and Characterization of A Nanoemulsion Gel formulation for Transdermal delivery of Carvedilol

    Singh Bhuwanesh Pratap


    Full Text Available The aim of the present study was to develop nanoemulsion formulation for transdermal delivery of carvedilol to enhance the water solubility as well as bioavailability of drug. O/W nanoemulsions were prepared by the spontaneous emulsification method. Pseudoternary phase diagrams were constructed to obtain the nanoemulsion region. Oleic acid and IPM (3:1 was chosen as the oil phase, Tween 20 and carbitol were used as surfactant and cosurfactant respectively, on the basis of solubility studies, in formulation of nanoemulsion. Parameters evaluated included: thermodynamic stability testing, droplet size and in vitro mice skin permeation ware performed. Significant difference in the steady state flux (Jss, permeability coefficient (Kp and enhancement ratio (Er was observed in nanoemulsion formulations and control (P*** < 0.001. The composition of optimized formulation NEB1 which shows highest value of flux 211.8123 μg cm-2h-1 at the 24 h. Post application plasma carvedilol was increased 6.41 fold to marketed dosage form. The study suggested that nanoemulsion significantly enhanced bioavailability of transdermally applied carvedilol and eliminated the first pass metabolism.

  11. Fabrication of a nano-structured PbO{sub 2} electrode by using printing technology: surface characterization and application

    Kannan, K.; Muthuraman, G.; Cho, G.; Moon, I. S. [Sunchon National University, Suncheon (Korea, Republic of)


    This investigation aimed to introduce printing technology for the first time to prepare a nanostrucutured PbO{sub 2} electrode and its application to a cerium redox transfer process. The new method of nano-size PbO{sub 2} preparation demonstrated that nano-PbO{sub 2} could be obtained in less time and at less cost at room temperature. The prepared nano-PbO{sub 2} screen printed on a Ti electrode by three different compositions under similar conditions showed through surface and electrochemical analyses no adherence on Ti and no contact with other nano-PbO{sub 2} particles. Gravure printing of nano-PbO{sub 2} on a PET (poly ethylene thin) film at high pressure was done with two different compositions for the first time. The selective composition of 57.14 % nano-PbO{sub 2} powder with 4.28 % carbon black and 38.58 % ECA (ethyl carbitol acetate) produced a film with a nanoporous structure with an electron transfer ability. Finally, the optimized gravure-printed nano-PbO{sub 2} electrode was applied to the oxidation of Ce(III) to Ce(IV) by using cyclic voltammetry. The gravure-printed nano-PbO{sub 2} should pave the way to promising applications in electrochemical and sensor fields.

  12. Solubility and thermodynamic function of a new anticancer drug ibrutinib in 2-(2-ethoxyethoxy)ethanol + water mixtures at different temperatures

    Ibrutinib is a recently approved anticancer drug recommended for the treatment of mantle cell lymphoma and chronic lymphocytic leukemia. It has been reported as practically insoluble in water and hence it is available in the market at higher doses. Poor solubility of ibrutinib limits its development to oral solid dosage forms only. In this work, the solubilities of ibrutinib were measured in various 2-(2-ethoxyethoxy)ethanol (Carbitol) + water mixtures at T = (298.15 to 323.15) and p = 0.1 MPa. The solubility of ibrutinib was measured using an isothermal method. The thermodynamics function of ibrutinib was also studied. The measured solubilities of ibrutinib were correlated and fitted with Van’t Hoff, the modified Apelblat and Yalkowsky models. The results of curve fitting of all three models showed good correlation of experimental solubilities of ibrutinib with calculated ones. The mole fraction solubility of ibrutinib was observed highest in pure 2-(2-ethoxyethoxy)ethanol (2.67 · 10−2 at T = 298.15 K) and lowest in pure water (1.43 · 10−7 at T = 298.15 K) at T = (298.15 to 323.15) K. Thermodynamics data of ibrutinib showed an endothermic, spontaneous and an entropy-driven dissolution behavior of ibrutinib in all 2-(2-ethoxyethoxy)ethanol + water mixtures. Based on these results, ibrutinib has been considered as practically insoluble in water and freely soluble in 2-(2-ethoxyethoxy)ethanol. Therefore, 2-(2-ethoxyethoxy)ethanol could be used as a physiologically compatible cosolvent for solubilization and stabilization of ibrutinib in an aqueous media. The solubility data of this work could be extremely useful in preformulation studies and formulation development of ibrutinib

  13. Influence of the process parameters on the spray pyrolysis technique, on the synthesis of gadolinium doped-ceria thin film

    Graphical abstract: Gas-tight CGO made by spray pyrolysis suitable to be used as SOFC electrolyte. Display Omitted Highlights: ► Dense and crystalline CGO films deposited by spray pyrolysis on various substrates. ► Solvent did not have a strong influence on the film microstructure, defect concentration or thickness. ► The substrate did not have a strong influence on the film microstructure, defect concentration or thickness. ► Films with at least 2.5 μm of thickness presented high impermeability. ► The films obtained are suitable to use as a SOFC electrolyte. -- Abstract: This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce0.8Gd0.2O1.9−x, or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction (XRD

  14. 高载药量萘普生微乳凝胶的制备及离体经皮渗透性能研究%Preparation of Naproxen Microemulsion-Gel with High Drug Content and Investigation of Its in Vitro Transdermal Delivery Ability

    钟华; 徐珍; 段海龙; 张星星; 韩建勇; 田青平


    OBJECTIVE To prepare naproxen microemulsion-gel with high drug content and adhesiveness,and investigate its in vitro transdermal delivery ability. METHODS The ranges of microemulaion with the mixture of Tween 80 and Tween 20 as surfactant ,carbitol as cosurfactant,peponida as oil,were defined through construction of the pseudo-ternary phase diagrams. Drug-loaded microemulsions were prepared by phase transfer temperature method. Naproxen microemulsion-gel was prepared by directly adding car-bomer 980 into its microemulsion. The diffusion studies of all formulations were performed using a drag diffusion apparatus. The mean droplet sizes of naproxen microemulsion were measured via dynamic light scattering (DLS) on a Zetasizer,their microstructures were observed by transmission electron microscope (TEM). RESULTS Microemulsion range was largest when the mass ratio of Tween 80 and Tween 20 was 3:1,surfactant and cosurfactant was 2-1. While the microemulsion composed of 5% peponida,35% emulsifier and 60% water,drug loaded in microemulsion can attain 4% ,which was accorded with the characterization of microemulsion. Adding 2. 5% carbomer 980 into optimization microemulsion,even and transparence microemulsion-gel was obtained,which has the combination of o/w microstructure of microemulsion and the three-dimensional gel network of hydrogeL The viscosity of microemulsion-gel was increased from 104. 5 mPa · s to 18. 9 Pa · s,the steady-state permeation rates through excised cavia skin increased from (531.912 ± 1. 3) to (640. 327 ±0. 7)μg · cm-2 · h-1. CONCLUSION Naproxen microemulsion-gels prepared by selected carbitol as cosurfac-lant can obtain high drug content and percutaneous absorbtion,exhibit favourable adhesiveness,which may be a promising new dosage form for transdermal delivery of naproxen.%目的 制备载药量高、黏附性好的萘普生微乳凝胶,并考察其经皮渗透性能.方法 通过伪三元相图确定以Tween80和Tween20的混合物为乳化