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Sample records for validated stability-indicating hplc-uv

  1. Development and validation of a stability-indicating HPLC-UV method for the determination of triamcinolone acetonide and its degradation products in an ointment formulation

    NARCIS (Netherlands)

    van Heugten, A J P; Boer, W.; de Vries, W S; Markesteijn, C M A; Vromans, H

    2018-01-01

    A stability indicating high performance liquid chromatography method has been developed for the determination of triamcinolone acetonide (TCA) and its main degradation products in ointment formulations. The method, based on extensive stress testing using metal salts, azobisisobutyronitrile, acid,

  2. Stability indicating HPLC-UV method for detection of curcumin in Curcuma longa extract and emulsion formulation.

    Science.gov (United States)

    Syed, Haroon Khalid; Liew, Kai Bin; Loh, Gabriel Onn Kit; Peh, Kok Khiang

    2015-03-01

    A stability-indicating HPLC-UV method for the determination of curcumin in Curcuma longa extract and emulsion was developed. The system suitability parameters, theoretical plates (N), tailing factor (T), capacity factor (K'), height equivalent of a theoretical plate (H) and resolution (Rs) were calculated. Stress degradation studies (acid, base, oxidation, heat and UV light) of curcumin were performed in emulsion. It was found that N>6500, Tcurcumin were ⩽0.87% and ⩽2.0%, while the inter-day precision and accuracy values were ⩽2.1% and ⩽-1.92. Curcumin degraded in emulsion under acid, alkali and UV light. In conclusion, the stability-indicating method could be employed to determine curcumin in bulk and emulsions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Simultaneous Chloramphenicol and Florfenicol Determination by A Validated DLLME-HPLC-UV Method in Pasteurized Milk

    OpenAIRE

    Karami-Osboo, Rouhollah; Miri, Ramin; Javidnia, Katayoun; Kobarfard, Farzad

    2016-01-01

    The antibiotic residues in milk are a well-known serious problem and pose several health hazards to consumers. We have described a simple, rapid, and inexpensive DLLME-HPLC/UV technique for the extraction of chloramphenicol and florfenicol residues in milk samples. Under the optimum conditions, linearity of the method was observed over the range 0.02-0.85 ?g/L with correlation coefficients > 0.999. The proposed method has been found to have a good limit of detection (signal to noise ratio = 3...

  4. Simultaneous Chloramphenicol and Florfenicol Determination by A Validated DLLME-HPLC-UV Method in Pasteurized Milk.

    Science.gov (United States)

    Karami-Osboo, Rouhollah; Miri, Ramin; Javidnia, Katayoun; Kobarfard, Farzad

    2016-01-01

    The antibiotic residues in milk are a well-known serious problem and pose several health hazards to consumers. We have described a simple, rapid, and inexpensive DLLME-HPLC/UV technique for the extraction of chloramphenicol and florfenicol residues in milk samples. Under the optimum conditions, linearity of the method was observed over the range 0.02-0.85 µg/L with correlation coefficients > 0.999. The proposed method has been found to have a good limit of detection (signal to noise ratio = 3) for chloramphenicol (12.5 µg/Kg) and florfenicol (12.2 µg/Kg), and precision with relative standard deviation values under 15% (RSD, n = 3). Good recoveries (69.1-79.4%) were obtained for the extraction of the target analytes in milk samples. This simple and economic method has been applied for analyses of 15 real milk samples. Among all samples only one of them was contaminated to florfenicol; 62.4 µg/Kg and contamination to chloramphenicol was not detected.

  5. Validation of an HPLC-UV method for the identification and quantification of bioactive amines in chicken meat

    Directory of Open Access Journals (Sweden)

    D.C.S. Assis

    2016-06-01

    Full Text Available ABSTRACT A high-performance liquid chromatography with ultraviolet detection (HPLC-UV method was validated for the study of bioactive amines in chicken meat. A gradient elution system with an ultraviolet detector was used after extraction with trichloroacetic acid and pre-column derivatization with dansyl chloride. Putrescine, cadaverine, histamine, tyramine, spermidine, and spermine standards were used for the evaluation of the following performance parameters: selectivity, linearity, precision, recovery, limits of detection, limits of quantification and ruggedness. The results indicated excellent selectivity, separation of all amines, a coefficient of determination greater than 0.99 and recovery from 92.25 to 102.25% at the concentration of 47.2mg.kg-1, with a limit of detection at 0.3mg.kg-1 and a limit of quantification at 0.9mg.kg-1 for all amines, with the exception of histamine, which exhibited the limit of quantification, of 1mg.kg-1. In conclusion, the performance parameters demonstrated adequacy of the method for the detection and quantification of bioactive amines in chicken meat.

  6. Development and validation of stability indicating studies of ...

    African Journals Online (AJOL)

    Development and validation of stability indicating studies of paliperidone ... A simple and sensitive stability indicating HPLC method is developed for the ... The developed method was proved adequate for quantitative determination of ... Browse By Country · List All Titles · Free To Read Titles This Journal is Open Access.

  7. Validation of an HPLC-UV method for the determination of ceftriaxone sodium residues on stainless steel surface of pharmaceutical manufacturing equipments.

    Science.gov (United States)

    Akl, Magda A; Ahmed, Mona A; Ramadan, Ahmed

    2011-05-15

    In pharmaceutical industry, an important step consists in the removal of possible drug residues from the involved equipments and areas. The cleaning procedures must be validated and methods to determine trace amounts of drugs have, therefore, to be considered with special attention. An HPLC-UV method for the determination of ceftriaxone sodium residues on stainless steel surface was developed and validated in order to control a cleaning procedure. Cotton swabs, moistened with extraction solution (50% water and 50% mobile phase), were used to remove any residues of drugs from stainless steel surfaces, and give recoveries of 91.12, 93.8 and 98.7% for three concentration levels. The precision of the results, reported as the relative standard deviation (RSD), were below 1.5%. The method was validated over a concentration range of 1.15-6.92 μg ml(-1). Low quantities of drug residues were determined by HPLC-UV using a Hypersil ODS 5 μm (250×4.6 mm) at 50 °C with an acetonitrile:water:pH 7:pH 5 (39-55-5.5-0.5) mobile phase at flow rate of 1.5 ml min(-1), an injection volume of 20 μl and were detected at 254 nm. A simple, selective and sensitive HPLC-UV assay for the determination of ceftriaxone sodium residues on stainless steel surfaces was developed, validated and applied. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. A validated HPLC-UV method for the analysis of galloylquinic acid derivatives and flavonoids in Copaifera langsdorffii leaves.

    Science.gov (United States)

    Motta, Erick Vicente da Silva; da Costa, Juliana de Carvalho; Bastos, Jairo Kenupp

    2017-09-01

    Copaifera langsdorffii Desf. (Fabaceae, Caesalpinioideae), popularly known as "copaiba" or "pau d'óleo", is a species of tree that is found throughout Brazil. The leaves of this tree are used in folk medicine to treat kidney stones. Galloylquinic acid derivatives and flavonoids are the main secondary metabolites found in C. langsdorffii leaves and are likely to be responsible for the effectiveness of this treatment. As an attempt to produce a phytotherapic, we have developed a reliable HPLC-UV method for the quality control of C. langsdorffii leaves. Phenolic compounds were extracted from C. langsdorffii leaves using 70% aqueous ethanol as the extraction solvent. HPLC-UV analyses were carried out on a Synergi Polar-RP column (100×3.0mm, 2.5μm), and the mobile phase was made up of formic acid-water (0.1:99.9, solvent A), and isopropanol-methanol-acetonitrile (5:40:60, solvent B). The elution gradient was A:B (90:10 to 85:15) in 8.0min, followed by A:B (85:15 to 64:36) up to 30.0min, using a flow rate of 0.7mL/min, and UV detection at 280nm. This method was used to quantify nine galloylquinic acid derivatives and two flavonoids, which gave a good detection response and linearity in the range of 1.88-110.0μg/mL. Furthermore, the detection and quantification limits ranged from 0.070 to 0.752μg/mL, and 0.211-2.278μg/mL respectively, with a maximum RSD of 4.18%. The method is reliable for the quality control of C. langsdorffii raw material, its hydroethanolic extract, and could potentially be used to quantify these compounds in other Copaifera species. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. A Simple, Fast, Low Cost, HPLC/UV Validated Method for Determination of Flutamide: Application to Protein Binding Studies.

    Science.gov (United States)

    Esmaeilzadeh, Sara; Valizadeh, Hadi; Zakeri-Milani, Parvin

    2016-06-01

    The main goal of this study was development of a reverse phase high performance liquid chromatography (RP-HPLC) method for flutamide quantitation which is applicable to protein binding studies. Ultrafilteration method was used for protein binding study of flutamide. For sample analysis, flutamide was extracted by a simple and low cost extraction method using diethyl ether and then was determined by HPLC/UV. Acetanilide was used as an internal standard. The chromatographic system consisted of a reversed-phase C8 column with C8 pre-column, and the mobile phase of a mixture of 29% (v/v) methanol, 38% (v/v) acetonitrile and 33% (v/v) potassium dihydrogen phosphate buffer (50 mM) with pH adjusted to 3.2. Acetanilide and flutamide were eluted at 1.8 and 2.9 min, respectively. The linearity of method was confirmed in the range of 62.5-16000 ng/ml (r(2) > 0.99). The limit of quantification was shown to be 62.5 ng/ml. Precision and accuracy ranges found to be (0.2-1.4%, 90-105%) and (0.2-5.3 %, 86.7-98.5 %) respectively. Acetanilide and flutamide capacity factor values of 1.35 and 2.87, tailing factor values of 1.24 and 1.07 and resolution values of 1.8 and 3.22 were obtained in accordance with ICH guidelines. Based on the obtained results a rapid, precise, accurate, sensitive and cost-effective analysis procedure was proposed for quantitative determination of flutamide.

  10. A Validated Stability-Indicating HPLC Method for Simultaneous Determination of Amoxicillin and Enrofloxacin Combination in an Injectable Suspension

    Directory of Open Access Journals (Sweden)

    Nidal Batrawi

    2017-02-01

    Full Text Available The combination of amoxicillin and enrofloxacin is a well-known mixture of veterinary drugs; it is used for the treatment of Gram-positive and Gram-negative bacteria. In the scientific literature, there is no high-performance liquid chromatography (HPLC-UV method for the simultaneous determination of this combination. The objective of this work is to develop and validate an HPLC method for the determination of this combination. In this regard, a new, simple and efficient reversed-phase HPLC method for simultaneous qualitative and quantitative determination of amoxicillin and enrofloxacin, in an injectable preparation with a mixture of inactive excipients, has been developed and validated. The HPLC separation method was performed using a reversed-phase (RP-C18e (250 mm × 4.0 mm, 5 μm column at room temperature, with a gradient mobile phase of acetonitrile and phosphate buffer containing methanol at pH 5.0, a flow rate of 0.8 mL/min and ultraviolet detection at 267 nm. This method was validated in accordance with the Food and Drug Administration (FDA and the International Conference on Harmonisation (ICH guidelines and showed excellent linearity, accuracy, precision, specificity, robustness, ruggedness, and system suitability results within the acceptance criteria. A stability-indicating study was also carried out and indicated that this method can also be used for purity and degradation evaluation of these formulations.

  11. Development and Validation of a Stability-Indicating LC-UV Method ...

    African Journals Online (AJOL)

    Keywords: Ketotifen, Cetirizine, Stability indicating method, Stressed conditions, Validation. Tropical ... in biological fluids [13] are also reported. Stability indicating HPLC method is reported for ketotifen where drug is ..... paracetamol, cetirizine.

  12. A VALIDATED STABILITY INDICATED RP-HPLC METHOD FOR DUTASTERIDE

    OpenAIRE

    D. Pavan Kumar a, b *, Naga Jhansi a, G. Srinivasa Rao b, Kirti Kumar Jain a

    2018-01-01

    ABSTRACT A Simple, Stability indicating, Isocratic, reverse phase High Performance Liquid Chromatographic (RPLC) related substance method was developed for Dutasteride in API. This method separates the impurities which are co-eluting in the pharmacopeia method. Successful separation of degradation impurities and synthetic impurities was achieved by YMC Triat phenyl column. Chromatographic was carried out on YMC Triat phenyl (150 X 4.6 mm, 3.0µm) column using 0.01M Potassium Dihydrogen Pho...

  13. Development and validation of RP-HPLC-UV/ Vis method for determination of phenolic compounds in several personal care products

    International Nuclear Information System (INIS)

    Mohammed Akkbik; Zaini Asim; Fasihuddin Ahmad

    2011-01-01

    A HPLC method with ultraviolet-visible spectrophotometry detection has been optimized and validated for the simultaneous determination of phenolic compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as antioxidants, and octyl methyl cinnamate (OMC) as UVB-filter in several personal care products. The dynamic range was between 1 to 250 mg/ L with relative standard deviation less than 0.25 %, (n=4). Limit of detection for BHA, BHT and OMC were 0.196, 0.170 and 0.478 mg/ L, respectively. While limit of quantification for BHA, BHT and OMC were 0.593, 0.515 and 1.448 mg/ L, respectively. The recovery for BHA, BHT and OMC ranged from 92.1-105.9 %, 83.2-108.9 % and 87.3-103.7 %, respectively. The concentration ranges of BHA, BHT and OMC in 12 commercial personal care samples were 0.13-4.85, 0.16-2.30 and 0.12-65.5 mg/ g, respectively. The concentrations of phenolic compounds in these personal care samples were below than maximum allowable concentration in personal care formulation for example 0.0004 - 10 mg/ g, 0.002 - 5 mg/ g and up to 100 mg/ g for BHA, BHT and OMC, respectively. (author)

  14. Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract.

    Science.gov (United States)

    Ganzera, Markus; Aberham, Anita; Stuppner, Hermann

    2006-05-31

    Grapefruit seed extracts are used in cosmetics, food supplements, and pesticides because of their antimicrobial properties, but suspicions about the true nature of the active compounds arose when synthetic disinfectants such as benzethonium or benzalkonium chloride were found in commercial products. The HPLC method presented herein allows the quality assessment (qualitative and quantitative) of these products for the first time. On the basis of a standard mixture of 18 preservatives most relevant for food and grapefruit products, a method was developed allowing the baseline separation of all compounds within 40 min. Optimum results were obtained with a C-8 stationary phase and a solvent system comprising aqueous trifluoroacetic acid, acetonitrile, and 2-propanol. The assay was fully validated and shown to be sensitive (LOD or = 96.1%), repeatable (sigma(rel) < or = 3.5%), precise (intra-day variation < or = 4.5%, interday variation < or = 4.1%), and rugged. Without any modifications the method could be adopted for LC-MS experiments, where the compounds of interest were directly assignable in positive ESI mode. The quantitative results of several products for ecofarming confirmed previous studies, as seven out of nine specimens were adulterated with preservatives in varying composition. The samples either contained benzethonium chloride (2.5-176.9 mg/mL) or benzalkonium chloride (138.2-236.3 mg/mL), together with smaller amounts of 4-hydroxybenzoic acid esters, benzoic acid, and salicylic acid.

  15. Development and Validation of a Stability-Indicating RP-HPLC ...

    African Journals Online (AJOL)

    Development and Validation of a Stability-Indicating RP-HPLC Method for ... of Paracetamol, Tramadol HCl and Domperidone in a Combined Dosage Form. ... testing, as well as for quality control of the combined drugs in pharmaceutical ...

  16. Development and Validation of a Stability-Indicating HPLC Method for the Simultaneous Determination of Florfenicol and Flunixin Meglumine Combination in an Injectable Solution

    Directory of Open Access Journals (Sweden)

    Nidal Batrawi

    2017-01-01

    Full Text Available The combination of the powerful antimicrobial agent florfenicol and the nonsteroidal anti-inflammatory flunixin meglumine is used for the treatment of bovine respiratory disease (BRD and control of BRD-associated pyrexia, in beef and nonlactating dairy cattle. This study describes the development and validation of an HPLC-UV method for the simultaneous determination of florfenicol and flunixin, in an injectable preparation with a mixture of excipients. The proposed RP-HPLC method was developed by a reversed phase- (RP- C18e (250 mm × 4.6 mm, 5 μm column at room temperature, with an isocratic mobile phase of acetonitrile and water mixture, and pH was adjusted to 2.8 using diluted phosphoric acid, a flow rate of 1.0 mL/min, and ultraviolet detection at 268 nm. The stability-indicating method was developed by exposing the drugs to stress conditions of acid and base hydrolysis, oxidation, photodegradation, and thermal degradation; the obtained degraded products were successfully separated from the APIs. This method was validated in accordance with FDA and ICH guidelines and showed excellent linearity, accuracy, precision, specificity, robustness, LOD, LOQ, and system suitability results within the acceptance criteria.

  17. Development and Validation of a HPLC-UV Method for the Evaluation of Ellagic Acid in Liquid Extracts of Eugenia uniflora L. (Myrtaceae Leaves and Its Ultrasound-Assisted Extraction Optimization

    Directory of Open Access Journals (Sweden)

    Paulo Isaac Dias Assunção

    2017-01-01

    Full Text Available A simple HPLC-UV method has been developed and validated for the quantification of ellagic acid (EA in ethanol extracts of Eugenia uniflora L. (Myrtaceae leaves. The ultrasound-assisted extraction (UAE optimization was performed using a Box Behnken design (33 combined with response surface methodology to study the effects of the ethanol concentration (%, w/w, extraction time (minutes, and temperature (°C on the EA concentration. The optimized results showed that the highest extraction yield of EA by UAE was 26.0 μg mL−1 when using 44% (w/w ethanol as the solvent, 22 minutes as the extraction time, and 59°C as the extraction temperature. The concentration of EA in relation to the predicted value was 93.7%  ±  0.4. UAE showed a strong potential for EA extraction.

  18. Development and Validation of a HPLC-UV Method for the Evaluation of Ellagic Acid in Liquid Extracts of Eugenia uniflora L. (Myrtaceae) Leaves and Its Ultrasound-Assisted Extraction Optimization.

    Science.gov (United States)

    Assunção, Paulo Isaac Dias; da Conceição, Edemilson Cardoso; Borges, Leonardo Luiz; de Paula, Joelma Abadia Marciano

    2017-01-01

    A simple HPLC-UV method has been developed and validated for the quantification of ellagic acid (EA) in ethanol extracts of Eugenia uniflora L. (Myrtaceae) leaves. The ultrasound-assisted extraction (UAE) optimization was performed using a Box Behnken design (3 3 ) combined with response surface methodology to study the effects of the ethanol concentration (%, w/w), extraction time (minutes), and temperature (°C) on the EA concentration. The optimized results showed that the highest extraction yield of EA by UAE was 26.0  μ g mL -1 when using 44% (w/w) ethanol as the solvent, 22 minutes as the extraction time, and 59°C as the extraction temperature. The concentration of EA in relation to the predicted value was 93.7%  ±  0.4. UAE showed a strong potential for EA extraction.

  19. Development and Validation of a Stability-Indicating LC-UV Method ...

    African Journals Online (AJOL)

    Development and Validation of a Stability-Indicating LC-UV Method for Simultaneous Determination of Ketotifen and Cetirizine in Pharmaceutical Dosage Forms. ... 5 μm) using an isocratic mobile phase that consisted of acetonitrile and 10 mM disodium hydrogen phosphate buffer (pH 6.5) in a ratio of 45:55 % v/v at a flow ...

  20. Development and Validation of a HPLC-UV Method for Extraction Optimization and Biological Evaluation of Hot-Water and Ethanolic Extracts of Dendropanax morbifera Leaves

    Directory of Open Access Journals (Sweden)

    Hyung-Jae Choi

    2018-03-01

    Full Text Available Dendropanax morbifera Leveille (Araliaceae has been used in traditional oriental remedies for cancer, inflammation, diabetes, and thrombosis. However, a validated analytical method, standardization, and optimization of extraction conditions with respect to biological activity have not been reported. In this study, a simple and validated HPLC method for identifying and quantifying active substances in D. morbifera was developed. Hot water and ethanolic D. morbifera leaf extracts from different production regions were prepared and evaluated with regard to their chemical compositions and biological activities. The contents of active compounds such as rutin and chlorogenic acid were determined in four samples collected from different regions. The 80% ethanolic extract showed the best antioxidant activity, phenolic content, reducing power, and xanthine oxidase (XO inhibitory activity. The validated HPLC method confirmed the presence of chlorogenic acid and rutin in D. morbifera leaf extracts. The antioxidant and XO inhibitory activity of D. morbifera extract could be attributed to the marker compounds. Collectively, these results suggest that D. morbifera leaves could be beneficial for the treatment or prevention of hyperuricemia-related disease, and the validated HPLC method could be a useful tool for the quality control of food or drug formulations containing D. morbifera.

  1. A validated stability-indicating UPLC method for desloratadine and its impurities in pharmaceutical dosage forms.

    Science.gov (United States)

    Rao, Dantu Durga; Satyanarayana, N V; Malleswara Reddy, A; Sait, Shakil S; Chakole, Dinesh; Mukkanti, K

    2010-02-05

    A novel stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the determination of purity of desloratadine in presence of its impurities and forced degradation products. The method was developed using Waters Aquity BEH C18 column with mobile phase containing a gradient mixture of solvents A and B. The eluted compounds were monitored at 280nm. The run time was 8min within which desloratadine and its five impurities were well separated. Desloratadine was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Desloratadine was found to degrade significantly in oxidative and thermal stress conditions and stable in acid, base, hydrolytic and photolytic degradation conditions. The degradation products were well resolved from main peak and its impurities, thus proved the stability-indicating power of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of desloratadine in pharmaceutical dosage forms.

  2. Development and validation of a stability indicating HPTLC-densitometric method for lafutidine

    Directory of Open Access Journals (Sweden)

    Dinesh Dhamecha

    2013-01-01

    Full Text Available Background: A simple, selective, precise, and stability indicating high-performance thin layer chromatographic method has been established and validated for analysis of lafutidine in bulk drug and formulations. Materials and Methods: The compounds were analyzed on aluminum backed silica gel 60 F 254 plates with chloroform:ethanol:acetic Acid (8:1:1 as mobile phase. Densitometric analysis of lafutidine was performed at 230 nm. Result : Regression analysis data for the calibration plots were indicative of good linear relationship between response and concentration over the range 100-500 ng per spot. The correlation coefficient (r 2 was 0.998±0.002. Conclusion: Lafutidine was subjected to acid, base, peroxide, and sunlight degradation. In stability tests, the drug was susceptible to acid and basic hydrolysis, oxidation, and photodegradation.

  3. Development and validation of a new HPLC-UV method for the simultaneous determination of triclabendazole and ivermectin B1a in a pharmaceutical formulation.

    Science.gov (United States)

    Shurbaji, Maher; Abu Al Rub, Mohamad H; Saket, Munib M; Qaisi, Ali M; Salim, Maher L; Abu-Nameh, Eyad S M

    2010-01-01

    A rapid, simple, and sensitive RP-HPLC analytical method was developed for the simultaneous determination of triclabendazole and ivermectin in combination using a C18 RP column. The mobile phase was acetonitrile-methanol-water-acetic acid (56 + 36 + 7.5 + 0.5, v/v/v/v) at a pH of 4.35 and flow rate of 1.0 mL/min. A 245 nm UV detection wavelength was used. Complete validation, including linearity, accuracy, recovery, LOD, LOQ, precision, robustness, stability, and peak purity, was performed. The calibration curve was linear over the range 50.09-150.26 microg/mL for triclabendazole with r = 0.9999 and 27.01-81.02 microg/mL for ivermectin with r = 0.9999. Calculated LOD and LOQ for triclabendazole were 0.03 and 0.08 microg/mL, respectively, and for ivermectin 0.07 and 0.20 microg/mL, respectively. The intraday precision obtained was 98.71% with RSD of 0.87% for triclabendazole and 100.79% with RSD 0.73% for ivermectin. The interday precision obtained was 99.51% with RSD of 0.35% for triclabendazole and 100.55% with RSD of 0.59% for ivermectin. Robustness was also studied, and there was no significant variation of the system suitability of the analytical method with small changes in experimental parameters.

  4. Development and validation of stability indicating UPLC assay method for ziprasidone active pharma ingredient

    Directory of Open Access Journals (Sweden)

    Sonam Mittal

    2012-01-01

    Full Text Available Background: Ziprasidone, a novel antipsychotic, exhibits a potent highly selective antagonistic activity on D2 and 5HT2A receptors. Literature survey for ziprasidone revealed several analytical methods based on different techniques but no UPLC method has been reported so far. Aim: Aim of this research paper is to present a simple and rapid stability indicating isocratic, ultra performance liquid chromatographic (UPLC method which was developed and validated for the determination of ziprasidone active pharmaceutical ingredient. Forced degradation studies of ziprasidone were studied under acid, base, oxidative hydrolysis, thermal stress and photo stress conditions. Materials and Methods: The quantitative determination of ziprasidone drug was performed on a Supelco analytical column (100×2.1 mm i.d., 2.7 ΅m with 10 mM ammonium acetate buffer (pH: 6.7 and acetonitrile (ACN as mobile phase with the ratio (55:45-Buffer:ACN at a flow rate of 0.35 ml/ min. For UPLC method, UV detection was made at 318 nm and the run time was 3 min. Developed UPLC method was validated as per ICH guidelines. Results and Conclusion: Mild degradation of the drug substance was observed during oxidative hydrolysis and considerable degradation observed during basic hydrolysis. During method validation, parameters such as precision, linearity, ruggedness, stability, robustness, and specificity were evaluated, which remained within acceptable limits. Developed UPLC method was successfully applied for evaluating assay of Ziprasidone active Pharma ingredient.

  5. Simultaneous determination of domperidone and Itopride in pharmaceuticals and human plasma using RP-HPLC/UV detection: Method development, validation and application of the method in in-vivo evaluation of fast dispersible tablets.

    Science.gov (United States)

    Khan, Amjad; Iqbal, Zafar; Khadra, Ibrahim; Ahmad, Lateef; Khan, Abad; Khan, Muhammad Imran; Ullah, Zia; Ismail

    2016-03-20

    Domperidone and Itopride are pro-kinetic agents, regulating the gastric motility and are commonly prescribed as anti emetic drugs. In the present study a simple, rapid and sensitive RP-HPLC/UV method was developed for simultaneous determination of Domperidone and Itopride in pharmaceutical samples and human plasma, using Tenofavir as internal standard. Experimental conditions were optimized and method was validated according to the standard guidelines. Combination of water (pH 3.0) and acetonitrile (65:35 v/v) was used as mobile phase, pumped at the flow rate of 1.5 ml/min. Detector wavelength was set at 210 nm and column oven temperature was 40oC. Unlike conventional liquid-liquid extraction, simple precipitation technique was applied for drug extraction from human plasma using acetonitrile for deprotienation. The method showed adequate separation of both the analytes and best resolution was achieved using Hypersil BDS C8 column (150 mm × 4.6 mm, 5 μm). The method was quite linear in the range of 20-600 ng/ml. Recovery of the method was 92.31% and 89.82% for Domperidone and Itopride, respectively. Retention time of both the analytes and internal standard was below 15 min. The lower limit of detection (LLOD) and lower limit of quantification (LLOQ) for Domperidone were 5 and 10 ng/ml while for Itopride was 12 and 15 ng/ml, respectively. The developed method was successfully applied for in-vivo analysis of fast dispersible tablets of Domperidone in healthy human volunteer. The proposed method was a part of formulation development study and was efficiently applied for determination of the two drugs in various pharmaceutical products and human plasma. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. A validated specific stability-indicating RP-HPLC assay method for Ambrisentan and its related substances.

    Science.gov (United States)

    Narayana, M B V; Chandrasekhar, K B; Rao, B M

    2014-09-01

    A validated specific stability-indicating reverse-phase liquid chromatographic method was developed for the quantitative determination of Ambrisentan as well as its related substances in bulk samples, pharmaceutical dosage forms in the presence of degradation products and its related impurities. Forced degradation studies were performed on bulk samples of Ambrisentan as per the ICH-prescribed stress conditions using acid, base, oxidative, thermal stress and photolytic degradation to show the stability-indicating power of the LC method. Significant degradation in acidic, basic stress conditions was observed and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from the forced degradation studies and the impurity-spiked solution. Good resolution between the peaks corresponds to Ambrisentan-related impurities and degradation products from the analyte were achieved on a SunFire C18 column using a mobile phase consisting of a mixture of potassium dihydrogen orthophosphate at a pH adjusted to 2.5 with ortho-phosphoric acid in water and a mixture of acetonitrile:methanol using a simple linear gradient. The detection was carried out at 225 nm. The limit of detection and the limit of quantification for the Ambrisentan and its related impurities were established. The stressed test solutions were assayed against the qualified working standard of Ambrisentan and the mass balance in each case was between 98.9 and 100.3%, indicating that the developed LC method was stability indicating. Validation of the developed LC method was carried out as per the ICH requirements. The developed method was found to be suitable to check the quality of bulk samples of Ambrisentan at the time of batch release and also during its storage (long-term and accelerated stability). © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Eid Manal

    2011-03-01

    Full Text Available Abstract Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm. Method (IIA describes quantitative fluorescence quenching of eosin upon addition of the studied drug where the decrease in the fluorescence intensity was directly proportional to the concentration of ebastine; the fluorescence quenching was measured at 553 nm after excitation at 457 nm. This method was extended to (Method IIB to apply first and second derivative synchronous spectrofluorimetric method (FDSFS & SDSFS for the simultaneous analysis of EBS in presence of its alkaline, acidic, and UV degradation products. The proposed methods were successfully applied for the determination of the studied compound in its dosage forms. The results obtained were in good agreement with those obtained by a comparison method. Both methods were utilized to investigate the kinetics of the degradation of the drug.

  8. Validation of a stability-indicating spectrometric method for the determination of sulfacetamide sodium in pure form and ophthalmic preparations

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    Sofia Ahmed

    2017-01-01

    Full Text Available Introduction: Sulfacetamide sodium is a widely used sulfonamide for ophthalmic infections. Objective: A number of analytical methods have been reported for the analysis of sulfacetamide but they lack the ability to determine both the active drug and its major degradation product, sulfanilamide, simultaneously in a sample. Materials and Methods: In the present study a simple, rapid and economical stability-indicating UV spectrometric method has been validated for the simultaneous assay of sulfacetamide sodium and sulfanilamide in pure form and in ophthalmic preparations. Results: The method has been found to be accurate (recovery 100.03 ±0.589% and precise (RSD 0.587% with detectable and quantifiable limits of 1.67×10–6 M (0.04 mg% and 5.07×10–6 M (0.13 mg%, respectively for the assay of pure sulfacetamide sodium. The method is also found to be accurate and precise to small changes in wavelength, pH and buffer concentration as well as to forced degradation. The study further includes the validation of the method for the assay of pure sulfanilamide in solution, which has been found to be accurate, precise and robust. Conclusion: The results indicate that the proposed two-component spectrometric method is stability-indicating and can be used for the simultaneous assay of both sulfacetamide sodium and sulfanilamide in synthetic mixtures and degraded solutions.

  9. Stability-Indicating Validated HPLC Method for Analysis of Berberine Hydrochloride and Trimethoprim in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Jing-Chun Wang

    2013-01-01

    Full Text Available A stability-indicating HPLC method was developed and validated for the determination of berberine hydrochloride and trimethoprim in pharmaceutical dosage form in the presence of degradation products. The proposed RP-HPLC method utilizes an Agilent TC-C18, 4.6 mm × 250 mm, 5 μm, column using a mobile phase consisting of acetonitrile-50 mM potassium dihydrogen phosphate (30 : 70, v/v, pH adjusted to 3 with orthophosphoric acid at a flow rate of 1.0 mL/min and UV detection at 271 nm. The linearity of berberine hydrochloride and trimethoprim was in the range of 2 to 60 μg/mL (r=0.9996 and 1 to 30 μg/mL (r=0.9995, respectively. Repeatability and intermediate precisions were also determined with percentage relative standard deviation (% RSD less than 2.0%. The limits of detection were found to be 9.8 ng/mL for berberine hydrochloride and 2.5 ng/mL for trimethoprim. The mean recoveries for berberine hydrochloride and trimethoprim were 99.8 and 98.8%, respectively. The stability of the two drugs was determined under different conditions and the proposed method has shown effective separation for their degradation products. And the proposed assays method can thus be considered stability-indicating.

  10. A validated stability-indicating HPLC method for the simultaneous determination of pheniramine maleate and naphazoline hydrochloride in pharmaceutical formulations.

    Science.gov (United States)

    Huang, Taomin; Chen, Nianzu; Wang, Donglei; Lai, Yonghua; Cao, Zhijuan

    2014-02-01

    A simple, rapid, and accurate stability-indicating reverse phase liquid chromatographic method was developed and validated for the simultaneous determination of pheniramine maleate and naphazoline hydrochloride in bulk drugs and pharmaceutical formulations. Optimum chromatographic separations among pheniramine maleate, naphazoline hydrochloride and stress-induced degradation products have been achieved within 10 minutes by using an Agilent zorbax eclipse XDB C18 column (150 mm × 4.6 mm, 5 μm) as the stationary phase with a mobile phase consisted of 10 mM phosphate buffer pH 2.8 containing 0.5% triethlamine and methanol (68:32, v/v) at a flow rate of 1 mL min-1. Detection was performed at 280 nm using a diode array detector. Theoretical plates for pheniramine maleate and naphazoline hydrochloride were calculated to be 6762 and 6475, respectively. The method was validated in accordance with ICH guidelines with respect to linearity, accuracy, precision, robustness, specificity, limit of detection and quantitation. Regression analysis showed good correlations (R2 > 0.999) for pheniramine maleate in the concentration range of 150-1200 μg mL-1 and naphazoline hydrochloride in 12.5-100 μg mL-1. The method results in excellent separation of both the analytes and degradation products. The peak purity factor is ≥980 for both analytes after all types of stress, indicating complete separation of both analyte peaks from the stress induced degradation products. Overall, the proposed stability-indicating method was suitable for routine quality control and drug analysis of pheniramine maleate and naphazoline hydrochloride in pharmaceutical formulations.

  11. Validated stability-indicating methods for the determination of zafirlukast in the presence of its alkaline hydrolysis degradation product

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    Amal M. Abou Al Alamein

    2012-12-01

    Full Text Available Three simple stability-indicating methods for the analysis of Zafirlukast (ZAF in the presence of its alkaline degradation products were developed and validated as per the International Conference on Harmonization (ICH guidelines to evaluate the stability-indicating power of the proposed methods. The developed high-performance liquid chromatographic technique was achieved on ZORBAX–ODS (5 μm, 150 × 4.6 mm, i.d. by isocratic elution with a mixture of acetonitrile/0.05 M phosphate buffer, pH 5.0, (50:50; v/v as a mobile phase at flow rate of 1.0 mL min−1, followed by UV detection at 240 nm. The method could determine ZAF in the range of 2–40 μg mL−1 with a mean percentage recovery of 99.73 ± 0.903. The proposed HPLC method was utilized to investigate the kinetics of alkaline degradation of ZAF. First derivative of the ratio spectra (1DD method was applied to analyze the drug under investigation without any interference from its degradation product with a linearity range of 4–32 μg mL−1 and with a mean percentage recovery of 99.85 ± 0.608. A chemometric method was also developed using the partial least squares (PLS model for selective determination of ZAF in the range of 4–40 μg mL−1, the mean percentage recovery was found to be 100.00 ± 0.336.

  12. Development and validation of a stability-indicating RP–HPLC method for estimation of atazanavir sulfate in bulk

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    S. Dey

    2017-04-01

    Full Text Available A stability-indicating reverse phase–high performance liquid chromatography (RP–HPLC method was developed and validated for the determination of atazanavir sulfate in tablet dosage forms using C18 column Phenomenix (250 mm×4.6 mm, 5 μm with a mobile phase consisting of 900 mL of HPLC grade methanol and 100 mL of water of HPLC grade. The pH was adjusted to 3.55 with acetic acid. The mobile phase was sonicated for 10 min and filtered through a 0.45 μm membrane filter at a flow rate of 0.5 mL/min. The detection was carried out at 249 nm and retention time of atazanavir sulfate was found to be 8.323 min. Linearity was observed from 10 to 90 μg/mL (coefficient of determination R2 was 0.999 with equation, y=23.427x+37.732. Atazanavir sulfate was subjected to stress conditions including acidic, alkaline, oxidation, photolysis and thermal degradation, and the results showed that it was more sensitive towards acidic degradation. The method was validated as per ICH guidelines.

  13. Kinetic Study of the Alkaline Degradation of Oseltamivir Phosphate and Valacyclovir Hydrochloride using Validated Stability Indicating HPLC

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    Ramzia I. Al-Bagary

    2014-01-01

    Full Text Available Aqueous alkaline degradation was performed for oseltamivir phosphate (OP and valacyclovir hydrochloride (VA. Isocratic stability indicating the use of high-performance liquid chromatography (HPLC was presented for each drug in the presence of its degradation product. The separations were performed using the Nucleosil ODS column and a mobile phase consisting of phosphate buffer (pH = 7, acetonitrile, and methanol 50:25:25 (v/v/v for OP. For VA separation, a Nucleosil CN column using phosphate buffer (pH = 7 and methanol 85:15 (v/v was used as a mobile phase. Ultraviolet detection at 210 nm and 254 nm was used for OP and VA, respectively. The method showed high sensitivity concerning linearity, accuracy, and precision over the range 1-250 μg mL −1 for both drugs. The proposed method was used to determine the drug in its pharmaceutical formulation and to investigate the degradation kinetics of each drug's alkaline-stressed samples. The reactions were found to follow a first-order reaction. The activation energy could also be estimated. International Conference on Harmonisation guidelines were adopted for method validation.

  14. Analytical Method Validation of High-Performance Liquid Chromatography and Stability-Indicating Study of Medroxyprogesterone Acetate Intravaginal Sponges

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    Nidal Batrawi

    2017-02-01

    Full Text Available Medroxyprogesterone acetate is widely used in veterinary medicine as intravaginal dosage for the synchronization of breeding cycle in ewes and goats. The main goal of this study was to develop reverse-phase high-performance liquid chromatography method for the quantification of medroxyprogesterone acetate in veterinary vaginal sponges. A single high-performance liquid chromatography/UV isocratic run was used for the analytical assay of the active ingredient medroxyprogesterone. The chromatographic system consisted of a reverse-phase C18 column as the stationary phase and a mixture of 60% acetonitrile and 40% potassium dihydrogen phosphate buffer as the mobile phase; the pH was adjusted to 5.6. The method was validated according to the International Council for Harmonisation (ICH guidelines. Forced degradation studies were also performed to evaluate the stability-indicating properties and specificity of the method. Medroxyprogesterone was eluted at 5.9 minutes. The linearity of the method was confirmed in the range of 0.0576 to 0.1134 mg/mL ( R 2 > 0.999. The limit of quantification was shown to be 3.9 µg/mL. Precision and accuracy ranges were found to be %RSD <0.2 and 98% to 102%, respectively. Medroxyprogesterone capacity factor value of 2.1, tailing factor value of 1.03, and resolution value of 3.9 were obtained in accordance with ICH guidelines. Based on the obtained results, a rapid, precise, accurate, sensitive, and cost-effective analysis procedure was proposed for quantitative determination of medroxyprogesterone in vaginal sponges. This analytical method is the only available method to analyse medroxyprogesterone in veterinary intravaginal dosage form.

  15. Development and Validation of Stability Indicating HPTLC and HPLC Methods for Simultaneous Determination of Telmisartan and Atorvastatin in Their Formulations

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    Kaliappan Ilango

    2013-01-01

    Full Text Available The present study describes development and subsequent validation of stability indicating HPLC and HPTLC methods for simultaneous estimation of Telmisartan (TLM and Atorvastatin (ATV in their combined formulation. The proposed RP-HPLC method utilizes a Phenomenex Luna C18 column using acetonitrile: 0.025 M ammonium acetate (38 : 52%, v/v as mobile phase (pH 3.8, flow rate of 1.0 mL/min. Quantification was achieved with UV detection at 281 nm over concentration range of 12 to 72 μg/mL for TLM and 3 to 18 μg/mL for ATV respectively. In HPTLC, separations were performed on silica gel 60 F254 using toluene-methanol-ethyl acetate-acetic acid (5 : 1 : 1 : 0.3, v/v as mobile phase. The compact bands of TLM and ATV at 0.37 ± 0.02 and 0.63 ± 0.01 respectively were scanned at 279 nm. Linear regression analysis revealed linearity in the range of 40 to 240 ng/band for TLM and 10 to 60 ng/band for ATV respectively. For both the methods, dosage form was exposed to thermal, photolytic, acid, alkali and oxidative stress. The methods distinctly separated the drugs and degradation products even in actual samples. In conclusion, the proposed HPLC and HPTLC methods were appropriate for routine quantification of TLM and ATV in tablet formulation.

  16. Development and validation of a stability-indicating LC method for the assay of lodenafil carbonate in tablets.

    Science.gov (United States)

    Codevilla, Cristiane Franco; Lemos, Alice Machado; Delgado, Leila Schreiner; Rolim, Clarice Madalena Bueno; Adams, Andréa Inês Horn; Bergold, Ana Maria

    2011-08-01

    A stability-indicating liquid chromatographic method has been developed for the quantitative determination of lodenafil carbonate in tablets. The method employs a Synergi Fusion C18 column (250 × 4.6 mm, i.d., 4 μm particle size), with mobile phase consisting of a mixture of methanol-acetic acid 0.1% pH 4.0 (65:35, v/v) and UV detection at 290 nm, using a photodiode array detector. A linear response (r = 0.9999) was observed in the range of 10-80 μg/mL. The method showed good recoveries (average 100.3%) and also intra and inter-day precision (RSD lodenafil carbonate peak. The method was found to be stability-indicating and due to its simplicity and accuracy can be applied for routine quality control analysis of lodenafil carbonate in tablets.

  17. Development and Validation of a Stability-Indicating RP-HPLC Method for Rapid Determination of Doxycycline in Pharmaceutical Bulk and Dosage Forms

    OpenAIRE

    Shabnam Pourmoslemi, Soroush Mirfakhraee, Saeid Yaripour, Ali Mohammadi

    2016-01-01

    Background: A rapid stability-indicating RP-HPLC method for analysis of doxycycline in the presence of its degradation products was developed and validated. Methods: Forced degradation studies were carried out on bulk samples and capsule dosage forms of doxycycline using acid, base, H2O2, heat, and UV light as described by ICH for stress conditions to demonstrate the stability-indicating power of the method. Separations were performed on a Perfectsil® Target ODS column (3-5µm, 125 mm×4 mm), u...

  18. Development and validation of a stability-indicating RP-HPLC method for determination of atomoxetine hydrochloride in tablets.

    Science.gov (United States)

    Patel, Sejal K; Patel, Natvarlal J

    2010-01-01

    This paper describes the development of a stability-indicating RP-HPLC method for the determination of atomoxetine hydrochloride (ATX) in the presence of its degradation products generated from forced decomposition studies. The drug substance was subjected to stress conditions of acid, base, oxidation, wet heat, dry heat, and photodegradation. In stability tests, the drug was susceptible to acid, base, oxidation, and dry and wet heat degradation. It was found to be stable under the photolytic conditions tested. The drug was successfully separated from the degradation products formed under stress conditions on a Phenomenex C18 column (250 x 4.6 mm id, 5 microm particle size) by using acetonitrile-methanol-0.032 M ammonium acetate (55 + 05 + 40, v/v/v) as the mobile phase at 1.0 mL/min and 40 degrees C. Photodiode array detection at 275 nm was used for quantitation after RP-HPLC over the concentration range of 0.5-5 microg/mL with a mean recovery of 100.8 +/- 0.4% for ATX. Statistical analysis demonstrated that the method is repeatable, specific, and accurate for the estimation of ATX. Because the method effectively separates the drug from its degradation products, it can be used as a stability-indicating method.

  19. Analysis of brominated and phosphate-based flame retardants in polymer samples by HPLC-UV/MS and online-GPC-HPLC-UV

    Energy Technology Data Exchange (ETDEWEB)

    Schlummer, M.; Brandl, F. [Fraunhofer-Institut fuer Verfahrenstechnik und Verpackung (IVV), Freising (Germany); Maeurer, A.

    2004-09-15

    Here we present two analytical approaches for the identification and quantification of brominated and phosphate-based flame retardants. The first is an HPLC-UV/MS approach, which allows the separation and unequivocal identification and quantification of at least 15 different technical flame retardants. The second approach was set-up as a screening tool, consisting of a GPC separation coupled to an HPLC-UV device.

  20. A validated stability-indicating RP-HPLC method for paracetamol and lornoxicam: Application to pharmaceutical dosage forms

    Directory of Open Access Journals (Sweden)

    Karunakaran Kulandaivelu

    2014-01-01

    Full Text Available A new method for the simultaneous determination of paracetamol (PR and lornoxicam (LR has been developed by reversed phase HPLC from the combination drug product. The separation achieved on C18 column using acetonitrile and 0.02 M potassium dihydrogen phosphate was in the ratio of 35:65 (v/v as mobile phase at a flow rate of 1.0 mL/min. Both the components were monitored at a single wavelength at 260 nm and the column temperature was maintained at 30°C throughout the analysis. A linear response was found in the concentration range of 125-375 μg/mL for PR and 2-6 μg/mL for LR, with the correlation coefficient of more than 0.999. Although the tablet contained a high dose of PR (500 mg and a low dose of LR (8 mg, the single HPLC method was developed and the intra as well as inter day precision was obtained at less than 2% of RSD. The accuracy results obtained were between 98% and 102%. The drug was intentionally degraded under acidic, basic, peroxide, thermal, and photolytic conditions. The major degradation observed for both PR and LR under peroxide condition indicated that the drug product is susceptible to oxidation. The degraded peaks were properly resolved from PR and LR. Hence, the method is stability indicating.

  1. Development and Validation of a Stability-Indicating RP-HPLC Method for Rapid Determination of Doxycycline in Pharmaceutical Bulk and Dosage Forms

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    Shabnam Pourmoslemi, Soroush Mirfakhraee, Saeid Yaripour, Ali Mohammadi

    2016-06-01

    Full Text Available Background: A rapid stability-indicating RP-HPLC method for analysis of doxycycline in the presence of its degradation products was developed and validated. Methods: Forced degradation studies were carried out on bulk samples and capsule dosage forms of doxycycline using acid, base, H2O2, heat, and UV light as described by ICH for stress conditions to demonstrate the stability-indicating power of the method. Separations were performed on a Perfectsil® Target ODS column (3-5µm, 125 mm×4 mm, using a mobile phase consisting of methanol-50 mM ammonium acetate buffer (containing 0.1% v/v trifluoroacetic acid and 0.1% v/v triethylamine, pH 2.5 (50:50 v/v at room temperature. The flow rate was 0.8 mL/min. Results: The method linearity was investigated in the range of 25–500 µg/mL (r > 0.9999. The LOD and LOQ were 5 and 25 µg/mL, respectively. The method selectivity was evaluated by peak purity test using a diode array detector. There was no interference among detection of doxycycline and its stressed degradation products. Total peak purity numbers were in the range of 0.94-0.99, indicating the homogeneity of DOX peaks. Conclusion: These data show the stability-indicating nature of the method for quality control of doxycycline in bulk samples and capsule dosage forms.

  2. Stability indicating method development and validation of assay method for the estimation of rizatriptan benzoate in tablet

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    Chandrashekhar K. Gadewar

    2017-05-01

    Full Text Available A simple, sensitive, precise and specific high performance liquid chromatography method was developed and validated for the determination of rizatriptan in rizatriptan benzoate tablet. The separation was carried out by using a mobile phase consisting of acetonitrile: pH 3.4 phosphate buffer in ratio of 20:80. The column used was Zorbax SB CN 250 mm × 4.6 mm, 5 μ with a flow rate of 1 ml/min using UV detection at 225 nm. The retention time of rizatriptan and benzoic acid was found to be 4.751 and 8.348 min respectively. A forced degradation study of rizatriptan benzoate in its tablet form was conducted under the condition of hydrolysis, oxidation, thermal and photolysis. Rizatriptan was found to be stable in basic buffer while in acidic buffer was found to be degraded (water bath at 60 °C for 15 min. The detector response of rizatriptan is directly proportional to concentration ranging from 30% to 160% of test concentration i.e. 15.032 to 80.172 mcg/ml. Results of analysis were validated statistically and by recovery studies (mean recovery = 99.44. The result of the study showed that the proposed method is simple, rapid, precise and accurate, which is useful for the routine determination of rizatriptan in pharmaceutical dosage forms.

  3. A validated stability-indicating LC method for the separation of enantiomer and potential impurities of Linezolid using polar organic mode

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    T. Satyanarayana Raju

    2012-08-01

    Full Text Available Although a number of methods are available for evaluating Linezolid and its possible impurities, a common method for separation if its potential impurities, degradants and enantiomer in a single method with good efficiency remain unavailable. With the objective of developing an advanced method with shorter runtimes, a simple, precise, accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. This method is capable of separating all the related substances of Linezolid along with the chiral impurity. This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product. The method was developed using Chiralpak IA (250 mm×4.6 mm, 5 μm column. A mixture of acetonitrile, ethanol, n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v ratio was used as a mobile phase. The eluted compounds were monitored at 254 nm. Linezolid was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH guidelines with respect to specificity, limit of detection, limit of quantification, precision, linearity, accuracy, robustness and system suitability. Keywords: HPLC, Linezolid, Validation, Polar organic mode, Stability-indicating

  4. A validated stability-indicating RP-HPLC method for levofloxacin in the presence of degradation products, its process related impurities and identification of oxidative degradant.

    Science.gov (United States)

    Lalitha Devi, M; Chandrasekhar, K B

    2009-12-05

    The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of levofloxacin as well as its related substances determination in bulk samples, pharmaceutical dosage forms in the presence of degradation products and its process related impurities. Forced degradation studies were performed on bulk sample of levofloxacin as per ICH prescribed stress conditions using acid, base, oxidative, water hydrolysis, thermal stress and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed during oxidative stress and the degradation product formed was identified by LCMS/MS, slight degradation in acidic stress and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies and the impurity spiked solution. Good resolution between the peaks corresponds to process related impurities and degradation products from the analyte were achieved on ACE C18 column using the mobile phase consists a mixture of 0.5% (v/v) triethyl amine in sodium dihydrogen orthophosphate dihydrate (25 mM; pH 6.0) and methanol using a simple linear gradient. The detection was carried out at 294 nm. The limit of detection and the limit of quantitation for the levofloxacin and its process related impurities were established. The stressed test solutions were assayed against the qualified working standard of levofloxacin and the mass balance in each case was in between 99.4 and 99.8% indicating that the developed LC method was stability indicating. Validation of the developed LC method was carried out as per ICH requirements. The developed LC method was found to be suitable to check the quality of bulk samples of levofloxacin at the time of batch release and also during its stability studies (long term and accelerated stability).

  5. Establishment of inherent stability on piracetam by UPLC/HPLC and development of a validated stability-indicating method

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    Kapendra Sahu

    2017-02-01

    Full Text Available A novel comparative force degradation UPLC assay method was developed and validated for Piracetam and its degradation products. Piracetam was subjected to acid (5 M HCl, neutral (water and alkaline (0.5 M NaOH hydrolytic conditions at 80 °C, as well as to oxidative decomposition (H2O2 at room temperature. Photolytic studies were carried out by exposing this drug into sunlight (60,000–70,000 lux for 2 d. Additionally, the solid drug was subjected to 50 °C for 60 days in a hot air oven for thermal degradation. The UPLC chromatographic separation was performed on Acquity UPLC BEH C18 column (1.7 μm, 2.1 mm × 150 mm using isocratic mode (ACN:water, 25:75 v/v at a flow rate of 0.15 mL min−1 and HPLC chromatographic separation was achieved on phenomenex C18 using isocratic mode (ACN:10 mM ammonium acetate, pH 5.0, 20:80 v/v at a flow rate of 0.9 mL/min. Piracetam was found to degrade only in the base and shows stable behavior under all stress conditions. The UPLC and HPLC linearity of the proposed method was investigated in the range of 10–50 μg mL−1. The r2 value of UPLC and HPLC was found to be 0.999 and 0.999, respectively. Method detection limit (MDL and Method quantification limit (MQL were found to be 0.180 μg mL−1and 1.10 μg mL−1 for UPLC and 0.500 μg mL−1and 1.700 μg mL−1 for HPLC respectively. The %RSD values for intra-day and inter-day precision were <1.2%, confirming that the method was sufficiently precise. The validation studies were carried out fulfilling ICH requirements. The developed method was simple, fast, accurate and precise and hence could be applied for routine quality control analysis of Piracetam in solid dosage forms.

  6. Validation of a stability-indicating hydrophilic interaction liquid chromatographic method for the quantitative determination of vitamin k3 (menadione sodium bisulfite) in injectable solution formulation.

    Science.gov (United States)

    Ghanem, Mashhour M; Abu-Lafi, Saleh A; Hallak, Hussein O

    2013-01-01

    A simple, specific, accurate, and stability-indicating method was developed and validated for the quantitative determination of menadione sodium bisulfite in the injectable solution formulation. The method is based on zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) coupled with a photodiode array detector. The desired separation was achieved on the ZIC-HILIC column (250 mm × 4.6 mm, 5 μm) at 25°C temperature. The optimized mobile phase consisted of an isocratic solvent mixture of 200mM ammonium acetate (NH4AC) solution and acetonitrile (ACN) (20:80; v/v) pH-adjusted to 5.7 by glacial acetic acid. The mobile phase was fixed at 0.5 ml/min and the analytes were monitored at 261 nm using a photodiode array detector. The effects of the chromatographic conditions on the peak retention, peak USP tailing factor, and column efficiency were systematically optimized. Forced degradation experiments were carried out by exposing menadione sodium bisulfite standard and the injectable solution formulation to thermal, photolytic, oxidative, and acid-base hydrolytic stress conditions. The degradation products were well-resolved from the main peak and the excipients, thus proving that the method is a reliable, stability-indicating tool. The method was validated as per ICH and USP guidelines (USP34/NF29) and found to be adequate for the routine quantitative estimation of menadione sodium bisulfite in commercially available menadione sodium bisulfite injectable solution dosage forms.

  7. Development and validation of a stability-indicating capillary zone electrophoretic method for the assessment of entecavir and its correlation with liquid chromatographic methods.

    Science.gov (United States)

    Dalmora, Sergio Luiz; Nogueira, Daniele Rubert; D'Avila, Felipe Bianchini; Souto, Ricardo Bizogne; Leal, Diogo Paim

    2011-01-01

    A stability-indicating capillary zone electrophoresis (CZE) method was validated for the analysis of entecavir in pharmaceutical formulations, using nimesulide as an internal standard. A fused-silica capillary (50 µm i.d.; effective length, 40 cm) was used while being maintained at 25°C; the applied voltage was 25 kV. A background electrolyte solution consisted of a 20 mM sodium tetraborate solution at pH 10. Injections were performed using a pressure mode at 50 mbar for 5 s, with detection at 216 nm. The specificity and stability-indicating capability were proven through forced degradation studies, evaluating also the in vitro cytotoxicity test of the degraded products. The method was linear over the concentration range of 1-200 µg mL(-1) (r(2) = 0.9999), and was applied for the analysis of entecavir in tablet dosage forms. The results were correlated to those of validated conventional and fast LC methods, showing non-significant differences (p > 0.05).

  8. Establishment of inherent stability of pramipexole and development of validated stability indicating LC–UV and LC–MS method

    Directory of Open Access Journals (Sweden)

    Shubhangi M. Pawar

    2013-04-01

    Full Text Available Pramipexole belongs to a class of nonergot dopamine agonist recently approved for the treatment of early and advanced Parkinson's disease. A validated specific stability indicating reversed-phase liquid chromatographic method has been developed for the quantitative determination of pramipexole in bulk as well as in pharmaceutical dosage forms in the presence of degradation products. Forced degradation studies were performed by exposition of drug to hydrolytic (acidic and basic, oxidative and photolytic stress conditions, as defined under ICH guideline Q1A (R2. Significant degradation was observed under hydrolytic, oxidative and photolytic conditions and the degradation products formed were identified by LC–MS. Keywords: Degradation products, Forced degradation/stress studies, Liquid chromatography mass spectrometry, Pramipexole, Reversed-phase liquid chromatography

  9. Development, validation and comparison of two stability-indicating RP-LC methods using charged aerosol and UV detectors for analysis of lisdexamfetamine dimesylate in capsules

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    Graciela Carlos

    2016-11-01

    Full Text Available Two new stability-indicating liquid chromatographic methods using two detectors, an ultraviolet (UV and a charged aerosol detector (CAD simultaneously connected in series were validated for the assessment of lisdexamfetamine dimesylate (LDX in capsule. The method was optimized and the influence of individual parameters on UV and CAD response and sensitivity was studied. Chromatography was performed on a Zorbax CN column (250 mm × 4.6 mm, 5 μm in an isocratic elution mode, using acetonitrile and 20 mM ammonium formate at pH 4.0 (50:50, v/v as mobile phase and UV detection at 207 nm. The developed method was validated according to ICH guidelines and the parameters’ specificity, limit of detection, limit of quantitation, linearity, accuracy, precision and robustness were evaluated. CAD is designated to be a non-linear detector in a wide dynamic range, however, the method was linear over the concentration range of 70–130 μg mL−1 in both detectors. The method was precise and accurate. Robustness study was performed by a Plackett–Burman design, delivering results within the acceptable range. Neither the excipients nor the degradation products showed interference in the method after studies of specificity as well as under stress conditions. The results of the LC-UV and LC-CAD methods were statistically compared through ANOVA and showed no significant difference (p > 0.05. Both proposed methods could be considered interchangeable and stability-indicating, and can be applied as an appropriate quality control tool for routine analysis of LDX in capsule.

  10. 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.

  11. [Application of HPLC-UV method for aripiprazole determination in serum].

    Science.gov (United States)

    Synowiec, Anna; Gomółka, Ewa; Zyss, Tomasz; Zieba, Andrzej; Florek, Ewa; Piekoszewski, Wojciech

    2012-01-01

    Aripiprazole is a new drug applied in schizophrenia treatment. There are not strict indications for aripiprazole therapeutic drug monitoring. Despite, serum aripiprazole measuring would help control the drug doses effectiveness. The drug monitoring can eliminate overdosing, adverse effects and let control proper drug ingestion. The aim of the paper was to develop a simple method for aripiprazole determination in serum for therapeutic drug monitoring. High performance liquid chromatography with spectrophotometric detection (HPLC-UV) was used. Resolution was performed on LC-8 column; moving phase was solution 0,025M trimethylammonium buffer: acetonitrile (62:38). Isocratic flow was 1,2 ml/min; internal standard (IS) was promazine; monitored wavelength was lambda=214 nm. The validation parameters were: limits of linearity (LOL) 100-800 ng/ml, limit of detection (LOD) 10 ng/ml, limit of quantity (LOQ) 100 ng/ml. Coefficient of variation (CV) describing accuracy and precision didn't cross 10%. The method was useful for therapeutic drug monitoring in serum of patients treated with aripiprazole.

  12. Stability indicating RP-HPLC method development and validation for the simultaneous determination of aminexil and minoxidil in pharmaceutical dosage form.

    Science.gov (United States)

    Siddiraju, S; Sahithi, M

    2015-03-01

    The objective of the present work is to develop stability indicating high-performance liquid chromatographic method for the simultaneous determination of aminexil and minoxidil in pharmaceutical dosage form. The chromatographic separation was achieved with BDS Hypersil C18 column (250 mm×4.6 mm×5 μ) as stationary phase and phosphate buffer and acetonitrile (78:22) as mobile phase. The method was employed by using a flow rate of 1.1 mL/min kept at 30°C. The detection wavelength was kept at 238 nm by using photo-diode array detector. The retention times of the aminexil and minoxidil were found to be 2.3 min and 3.9 min, respectively. The method developed was validated in accordance with ICH guidelines with respect to the stability indicating capacity of the method including system suitability, accuracy, precision, linearity, range, limit of detection, limit of quantification and robustness. The linearity responses of aminexil and minoxidil were found to be in the concentration ranges of 18.75-112.5 μg/mL and 25-150 μg/mL, respectively. The LOD and LOQ values for aminexil were found to be 0.31 and 0.92 μg/mL and minoxidil were found to be 0.03 and 0.10 μg/mL respectively. The percentage recoveries for both the drugs were found in the range of 98-101%. This method is accurate, precise and sensitive; hence, it can be employed for routine quality control of aminexil and minoxidil in pharmaceutical industries and drug testing laboratories. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. A novel validated stability indicating high performance liquid chromatographic method for estimation of degradation behavior of ciprofloxacin and tinidazole in solid oral dosage

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    Bhupendrasinh K Vaghela

    2013-01-01

    Full Text Available Objective: The objective of current investigation was to study the degradation behavior of Ciprofloxacin and Tinidazole. The study was performed as per International Conference on Harmonization recommended stress condition. A novel stability-indicating reverse phase HPLC method was developed for the determination of Ciprofloxacin and Tinidazole purity in the presence of its impurities and forced degradation products. This method is also capable to separate placebo peaks as well in pharmaceutical dosage forms. The solid oral dosage form was subjected to the stress conditions such as oxidative, acid, base hydrolysis, heat and photolytic degradation. Materials and Methods: The method was developed using Waters symmetry shield, Reverse Phase (RP C18, 250mm x 4.6mm, 5΅ as a stationary phase. The mobile phase containing a gradient mixture of solvent A and B. 10mM phosphate buffer, adjusted pH 3.0 with phosphoric acid was used as a buffer. Buffer pH 3.0 was used as solvent A and buffer pH 3.0: Acetonitrile in the ratio of 20: 80 v/v were used as solvent B. The eluted compounds were monitored 278 nm (Ciprofloxacin, 317 nm (Tinidazole. The run time was 50 minute. Results: In the precision study the % RSD for the result of Ciprofloxacin, Tinidazole and its impurities was below 10%. The method was linear with the correlation coefficient greater than 0.997. The percentage recoveries were calculated and observed from 93.0% to 106.7%.The peak purity of Ciprofloxacin, Tinidazole peak had not shown any flag, thus proved the stability-indicating power of the method. Conclusion: The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.

  14. A validated stability-indicating LC method for the separation of enantiomer and potential impurities of Linezolid using polar organic mode.

    Science.gov (United States)

    Satyanarayana Raju, T; Vishweshwari Kutty, O; Ganesh, V; Yadagiri Swamy, P

    2012-08-01

    Although a number of methods are available for evaluating Linezolid and its possible impurities, a common method for separation if its potential impurities, degradants and enantiomer in a single method with good efficiency remain unavailable. With the objective of developing an advanced method with shorter runtimes, a simple, precise, accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. This method is capable of separating all the related substances of Linezolid along with the chiral impurity. This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product. The method was developed using Chiralpak IA (250 mm×4.6 mm, 5 μm) column. A mixture of acetonitrile, ethanol, n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v) ratio was used as a mobile phase. The eluted compounds were monitored at 254 nm. Linezolid was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, limit of detection, limit of quantification, precision, linearity, accuracy, robustness and system suitability.

  15. Development and validation of a stability-indicating RP-HPLC method for assay of betamethasone and estimation of its related compounds.

    Science.gov (United States)

    Fu, Qiang; Shou, Minshan; Chien, Dwight; Markovich, Robert; Rustum, Abu M

    2010-02-05

    Betamethasone (9alpha-fluoro-16beta-methylprednisolone) is one of the members of the corticosteriod family of active pharmaceutical ingredient (API), which is widely used as an anti-inflammatory agent and also as a starting material to manufacture various esters of betamethasone. A stability-indicating reverse-phase high performance liquid chromatography (RP-HPLC) method has been developed and validated which can separate and accurately quantitate low levels of 26 betamethasone related compounds. The stability-indicating capability of the method was demonstrated through adequate separation of all potential betamethasone related compounds from betamethasone and also from each other that are present in aged and stress degraded betamethasone stability samples. Chromatographic separation of betamethasone and its related compounds was achieved by using a gradient elution at a flow rate of 1.0mL/min on a ACE 3 C18 column (150mmx4.6mm, 3microm particle size, 100A pore size) at 40 degrees C. Mobile phase A of the gradient was 0.1% methanesulfonic acid in aqueous solution and mobile phase B was a mixture of tert-butanol and 1,4-dioxane (7:93, v/v). UV detection at 254nm was employed to monitor the analytes. For betamethasone 21-aldehyde, the QL and DL were 0.02% and 0.01% respectively. For betamethasone and the rest of the betamethasone related compounds, the QL and DL were 0.05% and 0.02%. The precision of betamethasone assay is 0.6% and the accuracy of betamethasone assay ranged from 98.1% to 99.9%.

  16. Development and validation of stability indicating method for the quantitative determination of venlafaxine hydrochloride in extended release formulation using high performance liquid chromatography

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    Jaspreet Kaur

    2010-01-01

    Full Text Available Objective : Venlafaxine,hydrochloride is a structurally novel phenethyl bicyclic antidepressant, and is usually categorized as a serotonin-norepinephrine reuptake inhibitor (SNRI but it has been referred to as a serotonin-norepinephrine-dopamine reuptake inhibitor. It inhibits the reuptake of dopamine. Venlafaxine HCL is widely prescribed in the form of sustained release formulations. In the current article we are reporting the development and validation of a fast and simple stability indicating, isocratic high performance liquid chromatographic (HPLC method for the determination of venlafaxine hydrochloride in sustained release formulations. Materials and Methods : The quantitative determination of venlafaxine hydrochloride was performed on a Kromasil C18 analytical column (250 x 4.6 mm i.d., 5 μm particle size with 0.01 M phosphate buffer (pH 4.5: methanol (40: 60 as a mobile phase, at a flow rate of 1.0 ml/min. For HPLC methods, UV detection was made at 225 nm. Results : During method validation, parameters such as precision, linearity, accuracy, stability, limit of quantification and detection and specificity were evaluated, which remained within acceptable limits. Conclusions : The method has been successfully applied for the quantification and dissolution profiling of Venlafaxine HCL in sustained release formulation. The method presents a simple and reliable solution for the routine quantitative analysis of Venlafaxine HCL.

  17. A Validated Stability-indicating Reverse Phase HPLC Assay Method for the Determination of Memantine Hydrochloride Drug Substance with UV-Detection Using Precolumn Derivatization Technique

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    Bhavil Narola

    2010-01-01

    Full Text Available This present paper deals with the development and validation of a stability indicating high performance liquid chromatographic method for the quantitative determination of Memantine hydrochloride. Memantine hydrochloride was derivatized with 0.015 M 9-fluorenylmethyl chloroformate (FMOC and 0.5 M borate buffer solution by keeping it at room temperature for about 20 minutes and the chromatographic separation achieved by injecting 10 μL of the derivatized mixture into a Waters HPLC system with photodiode array detector using a kromasil C18 column (150 × 4.6 mm, 5 μ, The mobile phase consisting of 80% acetonitrile and 20% phosphate buffer solution and a flow rate of 2 milliliter/minute. The Memantine was eluted at approximately 7.5 minutes. The volume of FMOC used in derivatization, concentration of FMOC and derivatization time was optimized and used. Forced degradation studies were performed on bulk sample of Memantine hydrochloride using acid (5.0 Normal (N hydrochloric acid, base (1.0 N sodium hydroxide, oxidation (30% hydrogen peroxide, thermal (105 ° C, photolytic and humidity conditions. The developed LC method was validated with respect to specificity, precision (% RSD about 0.70%, linearity (linearity of range about 70-130 μg/mL, ruggedness (Overall % RSD about 0.35%, stability in analytical solution (Cumulative % RSD about 0.11% after 1450 min. and robustness.

  18. A Stability-Indicating HPLC-DAD Method for Determination of Ferulic Acid into Microparticles: Development, Validation, Forced Degradation, and Encapsulation Efficiency

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    Jessica Mendes Nadal

    2015-01-01

    Full Text Available A simple stability-indicating HPLC-DAD method was validated for the determination of ferulic acid (FA in polymeric microparticles. Chromatographic conditions consisted of a RP C18 column (250 mm × 4.60 mm, 5 μm, 110 Å using a mixture of methanol and water pH 3.0 (48 : 52 v/v as mobile phase at a flow rate of 1.0 mL/min with UV detection at 320 nm. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of quantification, limit of detection, accuracy, precision, and robustness provided suitable results regarding all parameters investigated. The calibration curve was linear in the concentration range of 10.0–70.0 μg/mL with a correlation coefficient >0.999. Precision (intraday and interday was demonstrated by a relative standard deviation lower than 2.0%. Accuracy was assessed by the recovery test of FA from polymeric microparticles (99.02% to 100.73%. Specificity showed no interference from the components of polymeric microparticles or from the degradation products derived from acidic, basic, and photolytic conditions. In conclusion, the method is suitable to be applied to assay FA as bulk drug and into polymeric microparticles and can be used for studying its stability and degradation kinetics.

  19. Nifedipine-loaded polymeric nanocapsules: validation of a stability-indicating HPLC method to evaluate the drug entrapment efficiency and in vitro release profiles.

    Science.gov (United States)

    Granada, Andréa; Tagliari, Monika Piazzon; Soldi, Valdir; Silva, Marcos António Segatto; Zanetti-Ramos, Betina Ghiel; Fernandes, Daniel; Stulzer, Hellen Karine

    2013-01-01

    A simple stability-indicating analytical method was developed and validated to quantify nifedipine in polymeric nanocapsule suspensions; an in vitro drug release study was then carried out. The analysis was performed using an RP C18 column, UV-Vis detection at 262 nm, and methanol-water (70 + 30, v/v) mobile phase at a flow rate of 1.2 mL/min. The method was validated in terms of specificity, linearity and range, LOQ, accuracy, precision, and robustness. The results obtained were within the acceptable ranges. The nanocapsules, made of poly(epsilon-caprolactone), were prepared by the solvent displacement technique and showed high entrapment efficiency. The entrapment efficiency was 97.6 and 98.2% for the nifedipine-loaded polymeric nanocapsules prepared from polyvinyl alcohol (PVA) and Pluronic F68 (PF68), respectively. The particle size and zeta potential of nanocapsules were found to be influenced by the nature of the stabilizer used. The mean diameter and zeta potential for nanocapsules with PVA and PF68 were 290.9 and 179.9 nm, and -17.7 mV and -32.7 mV, respectively. The two formulations prepared showed a drug release of up to 70% over 4 days. This behavior indicates the viability of this drug delivery system for use as a controlled-release system.

  20. A Validated Stability-indicating Reverse Phase HPLC Assay Method for the Determination of Memantine Hydrochloride Drug Substance with UV-Detection Using Precolumn Derivatization Technique

    Directory of Open Access Journals (Sweden)

    Bhavil Narola

    2010-07-01

    Full Text Available This present paper deals with the development and validation of a stability indicating high performance liquid chromatographic method for the quantitative determination of Memantine hydrochloride. Memantine hydrochloride was derivatized with 0.015 M 9-fluorenylmethyl chloroformate (FMOC and 0.5 M borate buffer solution by keeping it at room temperature for about 20 minutes and the chromatographic separation achieved by injecting 10 µL of the derivatized mixture into a Waters HPLC system with photodiode array detector using a kromasil C18 column (150 × 4.6 mm, 5 µ. The mobile phase consisting of 80% acetonitrile and 20% phosphate buffer solution and a flow rate of 2 milliliter/minute. The Memantine was eluted at approximately 7.5 minutes. The volume of FMOC used in derivatization, concentration of FMOC and derivatization time was optimized and used. Forced degradation studies were performed on bulk sample of Memantine hydrochloride using acid (5.0 Normal (N hydrochloric acid, base (1.0 N sodium hydroxide, oxidation (30% hydrogen peroxide, thermal (105°C, photolytic and humidity conditions. The developed LC method was validated with respect to specificity, precision (% RSD about 0.70%, linearity (linearity of range about 70–130 µg/mL, ruggedness (Overall % RSD about 0.35%, stability in analytical solution (Cumulative % RSD about 0.11% after 1450 min. and robustness.

  1. A Stability-Indicating HPLC-DAD Method for Determination of Stiripentol: Development, Validation, Kinetics, Structure Elucidation and Application to Commercial Dosage Form

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    Hany W. Darwish

    2014-01-01

    Full Text Available A rapid, simple, sensitive, and accurate isocratic reversed-phase stability-indicating high performance liquid chromatography method has been developed and validated for the determination of stiripentol and its degradation product in its bulk form and pharmaceutical dosage form. Chromatographic separation was achieved on a Symmetry C18 column and quantification was achieved using photodiode array detector (DAD. The method was validated in accordance with the ICH requirements showing specificity, linearity (r2=0.9996, range of 1–25 μg/mL, precision (relative standard deviation lower than 2%, accuracy (mean recovery 100.08±1.73, limits of detection and quantitation (LOD = 0.024 and LOQ = 0.081 μg/mL, and robustness. Stiripentol was subjected to various stress conditions and it has shown marked stability under alkaline hydrolytic stress conditions, thermal, oxidative, and photolytic conditions. Stiripentol degraded only under acidic conditions, forming a single degradation product which was well resolved from the pure drug with significantly different retention time values. This degradation product was characterized by 1H-NMR and 13C-NMR spectroscopy as well as ion trap mass spectrometry. The results demonstrated that the method would have a great value when applied in quality control and stability studies for stiripentol.

  2. A Validated Stability Indicating RP-HPLC Method for the Determination of Emtricitabine, Tenofovir Disoproxil Fumarate, Elvitegravir and Cobicistat in Pharmaceutical Dosage Form

    Science.gov (United States)

    Runja, Chinnalalaiah; Ravi Kumar, Pigili; Avanapu, Srinivasa Rao

    2016-01-01

    A new simple, rapid stability indicating assay method has been developed and validated for the determination of emtricitabine, tenofovir disoproxil fumarate, elvitegravir and cobicistat using reverse-phase high-performance liquid chromatography in their pharmaceutical dosage form. The chromatographic separation was performed on an ODS column (250 × 4.6 mm, 5 µm) using mobile phase A (potassium dihydrogen orthophosphate, pH adjusted to 2.5) and mobile phase B (acetonitrile) in the ratio of 55:45% v/v at a flow rate of 1 mL/min. The analytes were detected at 250 nm. The method was found to be linear in the concentration range of 2–12 µg/mL for EMT, 3–18 µg/mL for TNDF, 1.5–9 µg/mL for ELV and COB, with the coefficient value (R2) of >0.9990. The accuracy was measured via recovery studies and found to be acceptable, and the percentage recoveries were found in the range of 99.93–100.08 ± 0.5%. Forced degradation studies were also conducted, and the drugs were subjected to various stress conditions such as acid hydrolysis, base hydrolysis, oxidative, photolytic and thermal degradation. The proposed method was successfully validated and applied for the quantitative estimation of these drugs in both bulk and tablet dosage forms. PMID:26865655

  3. QbD-Based Development and Validation of a Stability-Indicating HPLC Method for Estimating Ketoprofen in Bulk Drug and Proniosomal Vesicular System.

    Science.gov (United States)

    Yadav, Nand K; Raghuvanshi, Ashish; Sharma, Gajanand; Beg, Sarwar; Katare, Om P; Nanda, Sanju

    2016-03-01

    The current studies entail systematic quality by design (QbD)-based development of simple, precise, cost-effective and stability-indicating high-performance liquid chromatography method for estimation of ketoprofen. Analytical target profile was defined and critical analytical attributes (CAAs) were selected. Chromatographic separation was accomplished with an isocratic, reversed-phase chromatography using C-18 column, pH 6.8, phosphate buffer-methanol (50 : 50v/v) as a mobile phase at a flow rate of 1.0 mL/min and UV detection at 258 nm. Systematic optimization of chromatographic method was performed using central composite design by evaluating theoretical plates and peak tailing as the CAAs. The method was validated as per International Conference on Harmonization guidelines with parameters such as high sensitivity, specificity of the method with linearity ranging between 0.05 and 250 µg/mL, detection limit of 0.025 µg/mL and quantification limit of 0.05 µg/mL. Precision was demonstrated using relative standard deviation of 1.21%. Stress degradation studies performed using acid, base, peroxide, thermal and photolytic methods helped in identifying the degradation products in the proniosome delivery systems. The results successfully demonstrated the utility of QbD for optimizing the chromatographic conditions for developing highly sensitive liquid chromatographic method for ketoprofen. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. ESI-MSn and LC-ESI-MS studies to characterize forced degradation products of bosentan and a validated stability-indicating LC-UV method.

    Science.gov (United States)

    Bansal, Gulshan; Singh, Ranjit; Saini, Balraj; Bansal, Yogita

    2013-01-01

    The present study reports the characterization of forced degradation products of bosentan and a validated stability-indicating HPLC method for the stability testing of bosentan tablets. The forced degradation was carried out under the conditions of hydrolysis, oxidation, dry heat and photolysis. The drug was found unstable in acid, alkali and oxidative media whereas stable to the hydrolysis in water, to dry heat and to photolysis. In total, six degradation products were formed in all conditions which were resolved in a single run on a C-18 column with gradient elution using ammonium acetate buffer (pH 4.5, 5.0mM), methanol and acetonitrile. Structures of all the degradation products were characterized through +ESI-MS(n) and LC-ESI-MS spectral data of bosentan as well as LC-ESI-MS spectral data of the products. The products II-VI were characterized as 6-amino-[2,2']bipyrimidinyl-4,5-diol, 6-amino-5-(2-methoxyphenoxy)-[2,2']-bipyrimidinyl-4-ol, 2-[6-amino-5-(2-methoxyphenoxy)-[2,2']-bipyrimidinyl-4-yloxy]-ethanol, 4-tert-butyl-N-[6-(1-methoxyethoxy)-5-(2-methoxyphenoxy)-[2,2']-bipyrimidinyl-4-yl]-benzenesulfonamide and 4-tert-butyl-N-[6-hydroxy-5-(2-methoxyphenoxy)-[2,2']bipyrimidinyl-4-yl]-benzenesulfonamide, respectively. The peak of the product I was found to be due to two secondary degradation products which co-eluted and were characterized as β-hydroxyethyl p-tert-butylphenylsulfonate (Ia) and 2-[2-(2-hydroxyethoxy)-phenoxy]-ethanol (Ib). These products were formed due to hydrolysis of sulfonamide and alkylaryl ether and the diaryl ether linkages as well as dehydration of the primary alcohol group. The most probable degradation mechanisms were proposed. The HPLC method was found to be stability-indicating, linear (2-100 μg ml(-1)), accurate, precise, sensitive, specific, rugged and robust for quantitation of the drug. The method was applied to the stability testing of the commercially available bosentan tablets successfully. Copyright © 2012 Elsevier B.V. All

  5. Simultaneous Determination of Florfenicol and Diclazuril in Compound Powder by RP-HPLC-UV Method

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    Leilei Guo

    2014-01-01

    Full Text Available A RP-HPLC-UV method was developed and validated for simultaneous determination of florfenicol and diclazuril in compound powder. The separation involved using a SinoChoom ODS-BP C18 (5 μm, 4.6 mm × 250 mm analytical column. The mobile phase was a mixture of acetonitrile-0.2% phosphoric acid (pH was adjusted to 3.0 with triethylamine. The ratio of acetonitrile and 0.2% phosphoric acid in the mobile phase was 60 : 40 (v/v from 0 minutes to 6 minutes and 70 : 30 (v/v from 6.1 minutes to 15 minutes. The flow rate was 1 mL/min. The temperature of the analytical column was maintained at 30°C. The detection was monitored at 225 nm and 277 nm for florfenicol and diclazuril, respectively. The excipients in the compound powder did not interfere with the drug peaks. The calibration curves of florfenicol and diclazuril were fairly linear over the concentration ranges between 50.0–500.0 μg/mL (r=0.9995 and 10.0–100.0 μg/mL (r=0.9992, respectively. The RSD of both the intraday and interday variations was below 2.1% for florfenicol and diclazuril. The method was successfully validated according to International Conference on Harmonisation and proved to be suitable for the simultaneous determination of florfenicol and diclazuril in compound powder.

  6. Simultaneous determination of some water-soluble vitamins and preservatives in multivitamin syrup by validated stability-indicating high-performance liquid chromatography method.

    Science.gov (United States)

    Vidović, Stojanka; Stojanović, Biljana; Veljković, Jelena; Prazić-Arsić, Ljiljana; Roglić, Goran; Manojlović, Dragan

    2008-08-22

    HPLC stability-indicating method has been developed for the simultaneous determination of some water-soluble vitamins (ascorbic acid, thiamine hydrochloride, riboflavin-5'-phosphate sodium, pyridoxine hydrochloride, nicotinamide, D(+)-panthenol) and two preservatives (methylparaben and sodium benzoate) in multivitamin syrup preparation. Water-soluble vitamins, preservatives and their degradants were separated on Zorbax SB-Aq (C(18)) (250 mm x 4.6 mm, 5 microm) column at an ambient temperature. Combined isocratic and gradient elution was performed with a mobile phase consisting of 0.0125 M hexane-1-sulfonic acid sodium salt in 0.1% (m/v) o-phosphoric acid, pH 2.4-2.5 (solvent A) and acetonitrile (solvent B) at the flow-rate 1 ml min(-1). Starting with solvent A an isocratic elution was performed for 15 min, then the composition was changed to 85% of A and 15% of B during the next 20 min and it was constant for 5 min, then the composition was changed to 70% of A and 30% of B during next 15 min and it was constant for 5 min and finally was changed to 100% of A as at the beginning of the elution. Detection was performed with diode array detector at 210, 230 and 254 nm. Multivitamin syrup preparation was subjected to stress testing (forced degradation) in order to demonstrate that degradants from the vitamins, preservatives and/or product excipients do not interfere with the quantification of vitamins and preservatives. Typical validation characteristics: selectivity, accuracy, precision, linearity, range, limit of quantification and limit of detection were evaluated for vitamins and preservatives.

  7. Stability indicators in network reconstruction.

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    Michele Filosi

    Full Text Available The number of available algorithms to infer a biological network from a dataset of high-throughput measurements is overwhelming and keeps growing. However, evaluating their performance is unfeasible unless a 'gold standard' is available to measure how close the reconstructed network is to the ground truth. One measure of this is the stability of these predictions to data resampling approaches. We introduce NetSI, a family of Network Stability Indicators, to assess quantitatively the stability of a reconstructed network in terms of inference variability due to data subsampling. In order to evaluate network stability, the main NetSI methods use a global/local network metric in combination with a resampling (bootstrap or cross-validation procedure. In addition, we provide two normalized variability scores over data resampling to measure edge weight stability and node degree stability, and then introduce a stability ranking for edges and nodes. A complete implementation of the NetSI indicators, including the Hamming-Ipsen-Mikhailov (HIM network distance adopted in this paper is available with the R package nettools. We demonstrate the use of the NetSI family by measuring network stability on four datasets against alternative network reconstruction methods. First, the effect of sample size on stability of inferred networks is studied in a gold standard framework on yeast-like data from the Gene Net Weaver simulator. We also consider the impact of varying modularity on a set of structurally different networks (50 nodes, from 2 to 10 modules, and then of complex feature covariance structure, showing the different behaviours of standard reconstruction methods based on Pearson correlation, Maximum Information Coefficient (MIC and False Discovery Rate (FDR strategy. Finally, we demonstrate a strong combined effect of different reconstruction methods and phenotype subgroups on a hepatocellular carcinoma miRNA microarray dataset (240 subjects, and we

  8. An HPLC-UV method for the measurement of permeability of marker drugs in the Caco-2 cell assay

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    J.M. Kratz

    2011-06-01

    Full Text Available The Caco-2 cell line has been used as a model to predict the in vitro permeability of the human intestinal barrier. The predictive potential of the assay relies on an appropriate in-house validation of the method. The objective of the present study was to develop a single HPLC-UV method for the identification and quantitation of marker drugs and to determine the suitability of the Caco-2 cell permeability assay. A simple chromatographic method was developed for the simultaneous determination of both passively (propranolol, carbamazepine, acyclovir, and hydrochlorothiazide and actively transported drugs (vinblastine and verapamil. Separation was achieved on a C18 column with step-gradient elution (acetonitrile and aqueous solution of ammonium acetate, pH 3.0 at a flow rate of 1.0 mL/min and UV detection at 275 nm during the total run time of 35 min. The method was validated and found to be specific, linear, precise, and accurate. This chromatographic system can be readily used on a routine basis and its utilization can be extended to other permeability models. The results obtained in the Caco-2 bi-directional transport experiments confirmed the validity of the assay, given that high and low permeability profiles were identified, and P-glycoprotein functionality was established.

  9. Stress degradation studies of Telmisartan and Metoprolol extended release tablets by a validated stability indicating reverse phase-high performance liquid chromatography method

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    Kabeer Ahmed Shaikh

    2014-01-01

    Full Text Available Background and Aim: A sensitive reverse phase high-performance liquid chromatographic method has been developed for the simultaneous determination of Telimisartan and Metoprolol in tablet dosage form. Materials and Method: The chromatographic separation was achieved on Inertsil ODS 3V, 150 x 4.6 mm, 5μ analytical column. Mobile phase consisting of mobile phase A- 0.05M sodium dihydrogen phosphate buffer pH 3.0 and mobile phase B-Acetonitrile, with gradient program time in min /Mobile phase B% 0/22, 4/45, 6/45,18/22, 20/22. Detector was set at 222nm. Results and Conclusion: The described method shows excellent linearity over a range of 80-2 μg mL−1 for Telmisartan and 100-4 μg mL−1 for Metoprolol. The correlation coefficient for Telmisartan is 0.9998 and Metoprolol is 0.9999. The proposed method was found to be suitable for determination of Telmisartan and Metoprolol in tablet dosage form. Forced degradation of the drug product was conducted in accordance with the ICH guideline. Acidic, basic, hydrolytic, oxidative, thermal and photolytic degradation was used to assess the stability indicating power of the method. The drug product was found to be stable in acid, oxidation, thermal and photolytic stress condition and found degradation in base hydrolysis stress condition.

  10. Validated stability indicating liquid chromatographic determination of ebastine in pharmaceuticals after pre column derivatization: Application to tablets and content uniformity testing

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    Eid Manal

    2011-05-01

    Full Text Available Abstract An accurate, simple, sensitive and selective reversed phase liquid chromatographic method has been developed for the determination of ebastine in its pharmaceutical preparations. The proposed method depends on the complexation ability of the studied drug with Zn2+ ions. Reversed phase chromatography was conducted using an ODS C18 (150 × 4.6 mm id stainless steel column at ambient temperature with UV-detection at 260 nm. A mobile phase containing 0.025%w/v Zn2+ in a mixture of (acetonitril/methanol; 1/4 and Britton Robinson buffer (65:35, v/v adjusted to pH 4.2, has been used for the determination of ebastine at a flow rate of 1 ml/min. The calibration curve was rectilinear over the concentration range of 0.3 - 6.0 μg/ml with a detection limit (LOD of 0.13 μg/ml, and quantification limit (LOQ of 0.26 μg/ml. The proposed method was successfully applied for the analysis of ebastine in its dosage forms, the obtained results were favorably compared with those obtained by a comparison method. Furthermore, content uniformity testing of the studied pharmaceutical formulations was also conducted. The composition of the complex as well as its stability constant was also investigated. Moreover, the proposed method was found to be a stability indicating one and was utilized to investigate the kinetics of alkaline and ultraviolet induced degradation of the drug. The first-order rate constant and half life of the degradation products were calculated.

  11. Chromatographic analyses of fatty acid methyl esters by HPLC-UV and GC-FID

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Myller S.; Pinho, David M.M.; Suarez, Paulo A.Z., E-mail: psuarez@unb.br [Laboratorio de Materiais e Combustiveis, Instituto de Quimica, Universidade de Brasilia, DF (Brazil); Mendonca, Marcio A. [Faculdade de Agronomia e Medicina Veterinaria, Universidade de Brasilia, DF (Brazil); Resck, Ines S. [Laboratorio de Ressonancia Magnetica Nuclear, Universidade de Brasilia, DF (Brazil)

    2012-04-15

    An analytical method using high performance liquid chromatography with UV detection (HPLC-UV) (method A) was used for simultaneous determination of total amounts of triacylglycerides, diacylglycerides, monoacylglycerides and fatty acid methyl esters in alcoholysis of different oil (cotton, canola, sunflower, corn and soybean) samples. Analyses were carried out at 40 deg C for 20 min using a gradient of methanol (MeOH) and 2-propanol-hexane 5:4 (v/v) (PrHex): 100% of MeOH in 0 min, 50% of MeOH and 50% of PrHex in 10 min maintained with isocratic elution for 10 min. Another HPLC-UV method (method B) with acetonitrile isocratic elution for 34 min was used to determine the fatty acid composition of oils analyzing their methyl ester derivatives. Contents were determined with satisfactory repeatability (relative standard deviation, RSD < 3%), linearity (r{sup 2} > 0.99) and sensitivity (limit of quantification). Method B was compared with an official gas chromatographic method with flame ionization detection (GC-FID) from American Oil Chemists' Society (AOCS) in the determination of fatty acid methyl esters (FAME) in biodiesel real samples. (author)

  12. Development and application of a validated stability-indicating HPLC method for simultaneous determination of granisetron hydrochloride, benzyl alcohol and their main degradation products in parenteral dosage forms.

    Science.gov (United States)

    Hewala, Ismail; El-Fatatre, Hamed; Emam, Ehab; Mubrouk, Mokhtar

    2010-06-30

    A simple, rapid and sensitive reversed phase high performance liquid chromatographic method using photodiode array detection was developed and validated for the simultaneous determination of granisetron hydrochloride, benzyl alcohol, 1-methyl-1H-indazole-3-carboxylic acid (the main degradation product of granisetron) and benzaldehyde (the main degradation product of benzyl alcohol) in granisetron injections. The separation was achieved on Hypersil BDS C8 (250 mm x 4.6 mm i.d., 5 microm particle diameter) column using a mobile phase consisted of acetonitrile:0.05 M KH(2)PO(4):triethylamine (22:100:0.15) adjusted to pH 4.8. The column was maintained at 25 degrees C and 20 microL of solutions was injected. Photodiode array detector was used to test the peak purity and the chromatograms were extracted at 210 nm. Naphazoline hydrochloride was used as internal standard. The method was validated with respect to specificity, linearity, accuracy, precision, limit of quantitation and limit of detection. The validation acceptance criteria were met in all cases. Identification of the pure peaks was carried out using library match programmer and wavelengths of derivative optima of the spectrograms of the peaks. The method was successfully applied to the determination of the investigated drugs and their degradation products in different batches of granisetron injections. The method was proved to be sensitive for the determination down to 0.03 and 0.01% of granisetron degradation product and benzaldehyde, respectively, which are far below the compendia limits for testing these degradation products in their corresponding intact drugs. Copyright 2010 Elsevier B.V. All rights reserved.

  13. On-site comprehensive analysis of explosives using HPLC-UV-PAED

    Science.gov (United States)

    Marple, Ronita L.; LaCourse, William R.

    2004-03-01

    High-performance liquid chromatography with ultra violet and photo-assisted electrochemical detection (HPLC-UV-PAED) has been developed for the sensitive and selective detection of explosives in ground water and soil extracts. Fractionation and preconcentration of explosives is accomplished with on-line solid phase extraction (SPE), which minimizes sample pretreatment and enables faster and more accurate on-site assessment of a contaminated site. Detection limits are equivalent or superior (i.e., applicable, as it is capable of determining a wider range of organic nitro compounds. Soil samples are extracted using pressurized fluid extraction (PFE), and this technique is automatable, field-compatible, and environmentally friendly, adding to the overall efficiency of the methodology.

  14. A validated stability indicating high-performance liquid chromatographic method for simultaneous estimation of cefuroxime sodium and sulbactam sodium in injection dosage form

    Directory of Open Access Journals (Sweden)

    Falguni M Patel

    2012-01-01

    Full Text Available Background: A fixed dose combination of cefuroxime sodium (β lactam antibiotic and sulbactam sodium (β Lactamase inhibitor is used in ratio of 2:1 as powder for injection for the treatment of resistant lower respiratory tract and other infections. Aims: A simple, precise, and accurate ion-pair reverse-phase high-performance liquid chromatography (RP-HPLC method was developed and validated for determination of cefuroxime Na(CEF and sulbactam Na(SUL in injection. Materials and Methods: Isocratic RP-HPLC separation was achieved on an ACE C 18 column (150×4.6 mm id, 5 μm particle size using the mobile phase 0.002 M tetrabutylammonium hydroxide sulfate (TBAH in 10 mm potassium di-hydrogen phosphate buffer-acetonitrile (86:14 v/v, pH 3.7 at a flow rate of 1.0 ml/min. Results and Conclusion: The retention time of sulbactam Na and cefuroxime Na were 3.2 min and 10.2 min, respectively. The ion-pairing reagent improved the retention of highly polar sulbactam Na on reverse-phase column. The detection was performed at 210 nm. The method was validated for linearity, precision, accuracy, robustness, solution stability, and specificity. The method was validated for linearity, precision, accuracy, robustness, solution stability, and specificity. The method was linear in the concentration range of 10-100 μg/ml for cefuroxime Na and 5-50 μg/ml for sulbactam Na, with a correlation coefficient of 0.9999 and 0.9998 for the respective drugs. The intraday precision was 0.13-0.21% and 0.48-0.65%, and the interday precision was 0.32-0.81% and 0.60-0.83% for cefuroxime Na and sulbactam Na, respectively. The accuracy (recovery was found to be in the range of 98.76-100.61% and 98.99-100.30% for cefuroxime Na and sulbactam Na, respectively. The drugs were found to degrade under hydrolytic and oxidative conditions. The drugs could be effectively separated from different degradation products, and hence the method can be used for stability analysis.

  15. A validated stability-indicating high performance liquid chromatographic method for moxifloxacin hydrochloride and ketorolac tromethamine eye drops and its application in pH dependent degradation kinetics

    Directory of Open Access Journals (Sweden)

    Jayant B Dave

    2013-01-01

    Full Text Available Background and Aim: A fixed dose combination of moxifloxacin hydrochloride and ketorolac tromethamine is used in ratio of 1:1 as eye drops for the treatment of the reduction of post operative inflammatory conditions of the eye. A simple, precise, and accurate High Performance Liquid Chromatographic (HPLC method was developed and validated for determination of moxifloxacin hydrochloride and ketorolac tromethamine in eye drops. Materials and Methods: Isocratic HPLC separation was achieved on a ACE C 18 column (C 18 (5 μm, 150 mm×4.6 mm, i.d. using the mobile phase 10 mM potassium di-hydrogen phosphate buffer pH 4.6-Acetonitrile (75:25 v/v at a flow rate of 1.0 mL/min. The detection was performed at 307 nm. Drugs were subjected to acid, alkali and neutral hydrolysis, oxidation and photo degradation. Moreover, the proposed HPLC method was utilized to investigate the pH dependent degradation kinetics of moxifloxacin hydrochloride and ketorolac tromethamine in buffer solutions at different pH values like 2.0, 6.8 and 9.0. Results and Conclusion: The retention time (t R of moxifloxacin hydrochloride and ketorolac tromethamine were 3.81±0.01 and 8.82±0.02 min, respectively. The method was linear in the concentration range of 2-20 μ/mL each for moxifloxacin hydrochloride and ketorolac tromethamine with a correlation coefficient of 0.9996 and 0.9999, respectively. The method was validated for linearity, precision, accuracy, robustness, specificity, limit of detection and limit of quantitation. The drugs could be effectively separated from different degradation products and hence the method can be used for stability analysis. Different kinetics parameters like apparent first-order rate constant, half-life and t 90 (time for 90% potency left were calculated.

  16. Development and Validation of Stability-Indicating Method for Estimation of Chlorthalidone in Bulk and Tablets with the Use of Experimental Design in Forced Degradation Experiments

    Directory of Open Access Journals (Sweden)

    Sandeep Sonawane

    2016-01-01

    Full Text Available Chlorthalidone was subjected to various forced degradation conditions. Substantial degradation of chlorthalidone was obtained in acid, alkali, and oxidative conditions. Further full factorial experimental design was applied for acid and alkali forced degradation conditions, in which strength of acid/alkali, temperature, and time of heating were considered as independent variables (factors and % degradation was considered as dependent variable (response. Factors responsible for acid and alkali degradation were statistically evaluated using Yates analysis and Pareto chart. Furthermore, using surface response curve, optimized 10% degradation was obtained. All chromatographic separation was carried out on Phenomenex HyperClone C 18 column (250 × 4.6 mm, 5 μ, using mobile phase comprising methanol : acetonitrile : phosphate buffer (20 mM (pH 3.0 adjusted with o-phosphoric acid: 30 : 10 : 60% v/v. The flow rate was kept constant at 1 mL/min and eluent was detected at 241 nm. In calibration curve experiments, linearity was found to be in the range of 2–12 μg/mL. Validation experiments proved good accuracy and precision of the method. Also there was no interference of excipients and degradation products at the retention time of chlorthalidone, indicating specificity of the method.

  17. RP-HPLC Method Development and Validation for the Determination and Stability Indicative Studies of Montelukast in Bulk and its Pharmaceutical Formulations

    Directory of Open Access Journals (Sweden)

    A. Patnaik

    2012-01-01

    Full Text Available A simple, precise, accurate, economical and reproducible HPLC method for estimation of montelukast in tablet dosage form has been developed. Quantitative HPLC was performed with Shimadzu LC2010c HT with Winchrom Software with UV-Visible detector (SPD-IOA, PUMP (LC-IOAT and (LC-IOATvp. Phenomenex C8, 5 μm, 25 cm × 4.6 mm i.d. column was used in the study. The mobile phase of ACN: Acetate buffer= 6.5:3.5 of pH 3 were used in this study. The conditions optimized were: flow rate (1 mL/minute, wavelength (222 nm and run time was 20 min. Retention time was found to be 3.08 min. The linearity was found to be in the concentration range of 10-100 μg/mL. The developed method was evaluated in the assay of commercially available tablet moni containing 10 mg of montelukast. The amount of drug in tablet was found to be 10.34 mg/tab for the brand. Results of analysis were validated statistically and by recovery studies. The recovery studies 99.67% was indicative of the accuracy of proposed method. The precision was calculated as repeatability, inter and intraday variation (%RSD for the drug. By using the method, stability of the drug has been studied.

  18. Qualitative and quantitative determination of yohimbine in authentic yohimbe bark and in commercial aphrodisiacs by HPLC-UV-API/ MS methods.

    Science.gov (United States)

    Zanolari, Boris; Ndjoko, Karine; Ioset, Jean-Robert; Marston, Andrew; Hostettmann, Kurt

    2003-01-01

    The development and validation of a rapid qualitative and quantitative method based on an HPLC-UV-MS technique with atmospheric pressure chemical ionisation and electrospray ionisation for the analysis of yohimbine in a number of commercial aphrodisiac products is reported. HPLC with multiple-stage mass spectrometry experiments allowed the identification of the target compound and increased the selectivity of complex analyses such as those involved with multi-botanical preparations. The precision and the robustness of the method were improved by the use of two internal standards: codeine for UV detection and deuterium-labelled yohimbine for MS detection. Twenty commercial aphrodisiac preparations were analysed and the amount of yohimbine measured and expressed as the maximal dose per day suggested on product labels ranged from 1.32 to 23.16 mg.

  19. Mitoxantrone Loaded Superparamagnetic Nanoparticles for Drug Targeting: A Versatile and Sensitive Method for Quantification of Drug Enrichment in Rabbit Tissues Using HPLC-UV

    Directory of Open Access Journals (Sweden)

    Rainer Tietze

    2010-01-01

    Full Text Available In medicine, superparamagnetic nanoparticles bound to chemotherapeutics are currently investigated for their feasibility in local tumor therapy. After intraarterial application, these particles can be accumulated in the targeted area by an external magnetic field to increase the drug concentration in the region of interest (Magnetic-Drug-Targeting. We here present an analytical method (HPLC-UV, to detect pure or ferrofluid-bound mitoxantrone in a complex matrix even in trace amounts in order to perform biodistribution studies. Mitoxantrone could be extracted in high yields from different tissues. Recovery of mitoxantrone in liver tissue (5000 ng/g was 76±2%. The limit of quantification of mitoxantrone standard was 10 ng/mL ±12%. Validation criteria such as linearity, precision, and stability were evaluated in ranges achieving the FDA requirements. As shown for pilot samples, biodistribution studies can easily be performed after application of pure or ferrofluid-bound mitoxantrone.

  20. Removal of Mefenamic acid from aqueous solutions by oxidative process: Optimization through experimental design and HPLC/UV analysis.

    Science.gov (United States)

    Colombo, Renata; Ferreira, Tanare C R; Ferreira, Renato A; Lanza, Marcos R V

    2016-02-01

    Mefenamic acid (MEF) is a non-steroidal anti-inflammatory drug indicated for relief of mild to moderate pain, and for the treatment of primary dysmenorrhea. The presence of MEF in raw and sewage waters has been detected worldwide at concentrations exceeding the predicted no-effect concentration. In this study, using experimental designs, different oxidative processes (H2O2, H2O2/UV, fenton and Photo-fenton) were simultaneously evaluated for MEF degradation efficiency. The influence and interaction effects of the most important variables in the oxidative process (concentration and addition mode of hydrogen peroxide, concentration and type of catalyst, pH, reaction period and presence/absence of light) were investigated. The parameters were determined based on the maximum efficiency to save time and minimize the consumption of reagents. According to the results, the photo-Fenton process is the best procedure to remove the drug from water. A reaction mixture containing 1.005 mmol L(-1) of ferrioxalate and 17.5 mmol L(-1) of hydrogen peroxide, added at the initial reaction period, pH of 6.1 and 60 min of degradation indicated the most efficient degradation, promoting 95% of MEF removal. The development and validation of a rapid and efficient qualitative and quantitative HPLC/UV methodology for detecting this pollutant in aqueous solution is also reported. The method can be applied in water quality control that is generated and/or treated in municipal or industrial wastewater treatment plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Effect of fungal mycelia on the HPLC-UV and UV-vis spectrophotometric assessment of mycelium-bound epoxide hydrolase using glycidyl phenyl ether.

    Science.gov (United States)

    Dolcet, Marta M; Torres, Mercè; Canela, Ramon

    2016-06-25

    The use of mycelia as biocatalysts has technical and economic advantages. However, there are several difficulties in obtaining accurate results in mycelium-catalysed reactions. Firstly, sample extraction, indispensable because of the presence of mycelia, can bring into the extract components with a similar structure to that of the analyte of interest; secondly, mycelia can influence the recovery of the analyte. We prepared calibration standards of 3-phenoxy-1,2-propanediol (PPD) in the pure solvent and in the presence of mycelia (spiked before or after extraction) from five fungi (Aspergillus niger, Aspergillus tubingensis, Penicillium aurantiogriseum, Penicillium sp. and Aspergillus terreus). The quantification of PPD was carried out by HPLC-UV and UV-vis spectrophotometry. The manuscript shows that the last method is as accurate as the HPLC method. However, the colorimetric method led to a higher data throughput, which allowed the study of more samples in a shorter time. Matrix effects were evaluated visually from the plotted calibration data and statistically by simultaneously comparing the intercept and slope of calibration curves performed with solvent, post-extraction spiked standards and pre-extraction spiked standards. Significant differences were found between the post- and pre-extraction spiked matrix-matched functions. Pre-extraction spiked matrix-matched functions based on A. tubingensis mycelia, selected as the reference, were validated and used to compensate for low recoveries. These validated functions were successfully applied to the quantification of PPD achieved during the hydrolysis of glycidyl phenyl ether by mycelium-bound epoxide hydrolases and equivalent hydrolysis yields were determined by HPLC-UV and UV-vis spectrophotometry. This study may serve as starting point to implement matrix effects evaluation when mycelium-bound epoxide hydrolases are studied. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Validação de metodologia para a determinação simultânea dos antioxidantes sintéticos em óleos vegetais, margarinas e gorduras hidrogenadas por CLAE/UV Validation of methodology for the simultaneous determination of synthetic antioxidants in vegetables oils, margarine and vegetables hydrogenated fats by HPLC/UV

    Directory of Open Access Journals (Sweden)

    Emy Takemoto

    2009-01-01

    Full Text Available The use of antioxidants either to prevent or retard food's lipids oxidation was approved after inquires that verified their security within a daily intake limit. In this study, the methodology was developed and validated for the analysis of synthetic antioxidants: propylgallate (PG, tert-butylhydroquinone (TBHQ, butylhydroxyanisole (BHA, octylgallate (OG and butylhydroxytoluene (BHT in vegetables oils, margarine and hydrogenated fats by high performance liquid chromatographic. The methodology revealed itself efficient, with recovery rates above 90% for all antioxidant substances, besides good linearity in concentration range of 40-240 mg kg-1 (r = 0,999, repeatability with CV < 3,7% and limit of quantification 16.55, 10.32, 1.40, 3.76 and 9.30 mg/kg for BHT, BHA, PG, OG and TBHQ, respectively.

  3. DEVELOPMENT AND VALIDATION OF STABILITY-INDICATING ...

    African Journals Online (AJOL)

    complete separation of torsemide from its degradation product on C8 column ... and quantification of raw material and pharmaceutical products, no method .... themobile phase for 2D, 1DD, TLC and HPLC methods, respectively were prepared. .... the testing of those features which are susceptible to change during storage ...

  4. UPLC and LC-MS studies on degradation behavior of irinotecan hydrochloride and development of a validated stability-indicating ultra-performance liquid chromatographic method for determination of irinotecan hydrochloride and its impurities in pharmaceutical dosage forms.

    Science.gov (United States)

    Kumar, Navneet; Sangeetha, Dhanaraj; Reddy, Sunil P

    2012-10-01

    The objective of the current investigation was to study the degradation behavior of irinotecan hydrochloride under different International Conference on Harmonization (ICH) recommended stress conditions using ultra-performance liquid chromatography and liquid chromatography-mass spectrometry and to establish a validated stability-indicating reverse-phase ultra-performance liquid chromatographic method for the quantitative determination of irinotecan hydrochloride and its seven impurities and degradation products in pharmaceutical dosage forms. Irinotecan hydrochloride was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Irinotecan hydrochloride was found to degrade significantly in oxidative and base hydrolysis and photolytic degradation conditions. The degradation products were well resolved from the main peak and its impurities, thus proving the stability-indicating power of the method. Chromatographic separation was achieved on a Waters Acquity BEH C8 (100 × 2.1 mm) 1.7-µm column with a mobile phase containing a gradient mixture of solvent A (0.02M KH(2)PO(4) buffer, pH 3.4) and solvent B (a mixture of acetonitrile and methanol in the ratio of 62:38 v/v). The mobile phase was delivered at a flow rate of 0.3 mL/min with ultraviolet detection at 220 nm. The run time was 8 min, within which irinotecan and its seven impurities and degradation products were satisfactorily separated. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of irinotecan hydrochloride in pharmaceutical dosage forms.

  5. Quantification of nimesulide in human plasma by high-performance liquid chromatography with ultraviolet detector (HPLC-UV): application to pharmacokinetic studies in 28 healthy Korean subjects.

    Science.gov (United States)

    Kim, Mi-Sun; Park, Yoo-Sin; Kim, Shin-Hee; Kim, Sang-Yeon; Lee, Min-Ho; Kim, Youn-Hee; Kim, Do-Wan; Yang, Seok-Chul; Kang, Ju-Seop

    2012-05-01

    Nimesulide is a selective COX-2 inhibitor that is as effective as the classical non-acidic nonsteroidal anti-inflammatory drugs in the relief of various pain and inflammatory conditions, but is better tolerated with lower incidences of adverse effects than other drugs. After oral dose of 100 mg nimesulide to western subjects, a mean maximal concentration (C(max)) of 2.86 ∼ 6.5 µg/mL was reached at 1.22 ∼ 2.75 h and mean t(1/2β) of 1.8 ∼ 4.74 h. This study developed a robust method for quantification of nimesulide for the pharmacokinetics and suitability of its dosage in Korea and compared its suitability with other racial populations. Nimesulide and internal standard were extracted from acidified samples with methyl tert-butyl ether and analyzed by high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The 28 healthy volunteers took 2 tablets of 100 mg nimesulide and blood concentrations were analyzed during the 24 h post dose. Several pharmacokinetic parameters were represented: AUC(0-infinity) = 113.0 mg-h/mL, C(max) = 12.06 mg/mL, time for maximal concentrations (T(max)) = 3.19 h and t(1/2β) = 4.51 h. These were different from those of western populations as follows: AUC was 14.5% and C(max) was 28% that of of Korean subjects and T(max) and t(1/2β) were also different. The validated HPLC-UV method was successfully applied for the pharmacokinetic studies of nimesulide in Korean subjects. Because the pharmacokinetics of nimesulide were different from western populations, its dosage regimen needs to be adjusted for Koreans. © The Author [2012]. Published by Oxford University Press. All rights reserved.

  6. Authentication and Quantitation of Fraud in Extra Virgin Olive Oils Based on HPLC-UV Fingerprinting and Multivariate Calibration

    Science.gov (United States)

    Carranco, Núria; Farrés-Cebrián, Mireia; Saurina, Javier

    2018-01-01

    High performance liquid chromatography method with ultra-violet detection (HPLC-UV) fingerprinting was applied for the analysis and characterization of olive oils, and was performed using a Zorbax Eclipse XDB-C8 reversed-phase column under gradient elution, employing 0.1% formic acid aqueous solution and methanol as mobile phase. More than 130 edible oils, including monovarietal extra-virgin olive oils (EVOOs) and other vegetable oils, were analyzed. Principal component analysis results showed a noticeable discrimination between olive oils and other vegetable oils using raw HPLC-UV chromatographic profiles as data descriptors. However, selected HPLC-UV chromatographic time-window segments were necessary to achieve discrimination among monovarietal EVOOs. Partial least square (PLS) regression was employed to tackle olive oil authentication of Arbequina EVOO adulterated with Picual EVOO, a refined olive oil, and sunflower oil. Highly satisfactory results were obtained after PLS analysis, with overall errors in the quantitation of adulteration in the Arbequina EVOO (minimum 2.5% adulterant) below 2.9%. PMID:29561820

  7. Determination of benzodiazepines in beverages using green extraction methods and capillary HPLC-UV detection.

    Science.gov (United States)

    Piergiovanni, Maurizio; Cappiello, Achille; Famiglini, Giorgio; Termopoli, Veronica; Palma, Pierangela

    2018-05-30

    Dispersive liquid-liquid microextraction with and without ultrasound assistance (DLLME, UA-DLLME) and microextraction with packed sorbent (MEPS) methods for the extraction and determination of eight different benzodiazepines (BDZ) (chlordiazepoxide, flurazepam, bromazepam, oxazepam, lorazepam, clobazam, clonazepam, and flunitrazepam) in three commercial non-alcoholic and light alcoholic beverages were optimized and compared. Benzodiazepines are frequently used for their extensive diffusion and strong numbing effect in drug-facilitated crimes (DFC). The tiny small amount of sample required for DLLME and MEPS extraction makes them very suitable for specimens collected at the crime scene of DFCs. Microextraction techniques are of increasing interest thanks to their accordance to green analytical chemistry (GAC) guidelines providing good recovery values. Ultrasound assistance (UA-DLLME) was used to investigate whether this type of energy can improve the recoveries of the analytes. Analyses of the extracts were performed with reverse-phase capillary high-performance liquid chromatography with UV detection (HPLC - UV), thanks to low environmental impact, robustness, diffusion, and affordability. Recovery percentages at three different concentrations in the three beverages were between 14.30% and 103.28% with intraday and interday RSD lower than ±2.78%. The same samples were extracted using a MEPS protocol, and the results were compared with those obtained with DLLME. MEPS gave recoveries between 20.90% and 101.88% for all matrices showing a better performance than DLLME at higher concentrations, though lower recoveries were observed with diluted samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. A simple, rapid and stability indicating validated method for quantification of lamotrigine in human plasma and dry plasma spot using LC-ESI-MS/MS: Application in clinical study.

    Science.gov (United States)

    Namdev, Kuldeep Kumar; Dwivedi, Jaya; Chilkoti, Deepak Chandra; Sharma, Swapnil

    2018-01-01

    Lamotrigine (LTZ) is a phenyltriazine derivative which belongs to anti-epileptic drugs (AEDs) class and prescribed as mono- or adjunctive-therapy in treatment of epilepsy. Therapeutic drug monitoring (TDM) of AEDs provides a valid clinical tool in optimization of overall therapy. However, TDM is challenging due to the high biological samples (plasma/blood) storage/shipment costs and the limited availability of laboratories providing TDM services. Sampling in the form of dry plasma spot (DPS) or dry blood spot (DBS) are suitable alternative to overcome these issues. We developed and validated a new method for quantification of LTZ in human plasma and DPS. The extraction of LTZ from plasma and DPS was performed using liquid-liquid extraction with diethyl ether and an extraction solution composed of diethyl ether- methyl tert-butyl ether- acetone (50:30:20, v/v/v), respectively. Lamotrigine- 13C3, d3 was used as internal standard (ISTD) and the chromatographic separation was achieved on Hypurity Advance C18 column (150×4.6mm, 5μm). Quantitative estimation of LTZ and ISTD was performed on a liquid chromatography tandem mass spectrometer coupled with electrospray ionization interface operated under positive mode of ionization. Calibration curves were linear (r 2 >0.99) over the concentration range of 10-3020ng/mL for both plasma and DPS. Statistical analysis provides insignificant difference between LTZ concentration extracted from plasma and DPS samples. The method is found suitable for application in clinical study and in therapeutic monitoring of LTZ. To the best of our knowledge this is the first report which describing a validated stability indicating assay for quantification of LTZ in dry plasma spot. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. HPLC-UV Polyphenolic Profiles in the Classification of Olive Oils and Other Vegetable Oils via Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Mireia Farrés-Cebrián

    2016-12-01

    Full Text Available High performance liquid chromatography-ultraviolet (HPLC-UV was applied to the analysis and characterization of olive oils and other vegetable oils. A chromatographic separation on a Zorbax Eclipse XDB-C8 reversed-phase column was proposed under gradient elution, employing 0.1% formic acid aqueous solution and methanol as mobile phase, for the determination of 14 polyphenols and phenolic acids, allowing us to obtain compositional profiles in less than 20 min. Acceptable sensitivity (limit of detection (LOD values down to 80 µg/L in the best of cases, linearity (r2 higher than 0.986, good run-to-run and day-to-day precisions (relative standard deviation (RSD values lower than 11.5%, and method trueness (relative errors lower than 6.8% were obtained. The proposed HPLC-UV method was then applied to the analysis of 72 oil samples (47 olive oils and 27 vegetable oils including sunflower, soy, corn, and mixtures of them. Analytes were recovered using a liquid–liquid extraction method employing ethanol:water 70:30 (v/v solution and hexane as extracting and defatting solvents, respectively. HPLC-UV polyphenolic profiles using peak areas were then analysed by principal component analysis (PCA to extract information from the most significant data contributing to the characterization and classification of olive oils against other vegetable oils, as well as among Arbequina and Picual olive oil varieties. PCA results showed a noticeable difference between olive oils and the other classes. In addition, a reasonable discrimination of olive oils as a function of fruit varieties was also encountered.

  10. Isolation and identification of phytochemicals and biological activities of Hericium ernaceus and their contents in Hericium strains using HPLC/UV analysis.

    Science.gov (United States)

    Lee, Dong Gu; Kang, Hee-Wan; Park, Chun-Geon; Ahn, Young-Sup; Shin, Yusu

    2016-05-26

    Hericium ernaceus has been traditionally used for the treatment of dyspepsia, gastric ulcer and enervation in traditional Chinese medicine for a long time. To examine the effect of Hericium strains on their ability to inhibit LPS and interferon-γ induced NO production in cell culture and the bioassay correlation of hericenone C, D, F, isolated from H. ernaceus. Hericenone C, D, F were isolated from H. ernaceus by open column chromatography and identified on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenone C, D, and F in Hericium strains were determined by HPLC/UV analysis. In order to investigate the anti-inflammatory effect of Hericium strains extracts, RAW 264.7 cells were treated with 200μg/mL of Hericium strains extracts for 48h. Cell growth was assessed by MTT assay. Phytochemical constituents were isolated from H. ernaceus by open column chromatography. Their structures were elucidated as hericenones C, D, and F on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenones C, D, and F in Hericium strains were determined by HPLC/UV analysis. Hericenones C, D, and F contents were highest in Norugungdenglee-2 (8.289±0.593mg/g), KFRI-1453 (4.657±0.462mg/g), and KFRI-1093 (5.408±0.420mg/g) strains, respectively. All Hericium strains extracts tested inhibited the lipopolysaccharide- and interferon-γ-induced inflammatory activity of RAW264.7 cells. The strain KFRI-1093 about 39.6% reduced NO generation with compared to control. We believe that the anti-inflammatory effect of KFRI-1093 was due to hericenone F content. Our results contribute towards validation of the traditional use, natural drugs and health supplements. And also, the developed simple, accurate and rapid LC method can be used determinate the content of hericenones from other Hericium strains. Copyright © 2016. Published by Elsevier Ireland Ltd.

  11. Qualitative and Quantitative Analysis of Lignan Constituents in Caulis Trachelospermi by HPLC-QTOF-MS and HPLC-UV

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    Xiao-Ting Liu

    2015-05-01

    Full Text Available A high-performance liquid chromatography coupled with quadrupole tandem time-of-flight mass (HPLC-QTOF-MS and ultraviolet spectrometry (HPLC-UV was established for simultaneous qualitative and quantitative analysis of the major chemical constituents in Caulis Trachelospermi, respectively. The analysis was performed on an Agilent Zorbax Eclipse Plus C18 column (4.6 mm × 150 mm, 5 μm using a binary gradient system of water and methanol, with ultraviolet absorption at 230 nm. Based on high-resolution ESI-MS/MS fragmentation behaviors of the reference standards, the characteristic cleavage patterns of lignano-9, 9'-lactones and lignano-8'-hydroxy-9, 9'-lactones were obtained. The results demonstrated that the characteristic fragmentation patterns are valuable for identifying and differentiating lignano-9,9'-lactones and lignano-8'-hydroxy-9,9'-lactones. As such, a total of 25 compounds in Caulis Trachelospermi were unambiguously or tentatively identified via comparisons with reference standards or literature. In addition, 14 dibenzylbutyrolatone lignans were simultaneously quantified in Caulis Trachelospermi by HPLC-UV method. The method is suitable for the qualitative and quantitative analyses of dibenzylbutyrolatone lignans in Caulis Trachelospermi.

  12. Quantitative and qualitative analysis of the novel antitumor 1,3,4-oxadiazole derivative (GLB) and its metabolites using HPLC-UV and UPLC-QTOF-MS

    Science.gov (United States)

    Li, Pu; Wang, Xin; Li, Jian; Meng, Zhi-Yun; Li, Shu-Chun; Li, Zhong-Jun; Lu, Ying-Yuan; Ren, Hong; Lou, Ya-Qing; Lu, Chuang; Dou, Gui-Fang; Zhang, Guo-Liang

    2015-01-01

    Fructose-based 3-acetyl-2,3-dihydro-1,3,4-oxadiazole (GLB) is a novel antitumor agent and belongs to glycosylated spiro-heterocyclic oxadiazole scaffold derivative. This research first reported a simple, specific, sensitive and stable high performance liquid chromatography -ultraviolet detector (HPLC-UV) method for the quantitative determination of GLB in plasma. In this method, the chromatographic separation was achieved with a reversed phase C18 column. The calibration curve for GLB was linear at 300 nm. The lower limit of quantification was 10 ng/mL. The precision, accuracy and stability of the method were validated adequately. This method was successfully applied to the pharmacokinetic study in rats for detection of GLB after oral administration. Moreover, the structures of parent compound GLB and its two major metabolites M1 and M2 were identified in plasma using an ultra performance liquid chromatography- electrospray ionization-quadrupole-time of flight- mass spectrometry (UPLC-ESI-QTOF-MS) method. Our results indicated that the di-hydroxylation (M1) and hydroxylation (M2) of GLB are the major metabolites. In conclusion, the present study provided valuable information on an analytical method for the determination of GLB and its metabolites in rats, can be used to support further developing of this antitumor agent. PMID:26148672

  13. Determination of chlorpropham (CIPC) residues, in the concrete flooring of potato stores, using quantitative (HPLC UV/VIS) and qualitative (GCMS) methods.

    Science.gov (United States)

    Douglas, Leisa; MacKinnon, Gillian; Cook, Gordon; Duncan, Harry; Briddon, Adrian; Seamark, Steven

    2018-03-01

    Isopropyl-N-(3-chlorophenyl) carbamate (CIPC, common name Chlorpropham) is commonly used for post-harvest sprout inhibition in stored potatoes. It is applied as a thermal fog which results in loss to the fabric of the store and the atmosphere. Recently, there have been concerns in the United Kingdom because of cross contamination of other crop commodities that were stored in buildings with a history of CIPC usage. This cross contamination may have occurred because of retained residues in the fabric of the stores. The retention of CIPC in concrete is poorly understood; therefore the requirement for a robust analytical method for the detection and quantification of CIPC in concrete is a critical first step in tackling this problem. A method using High-Performance Liquid Chromatography with ultraviolet detection (HPLC UV/VIS) was validated. CIPC recoveries at three concentration levels (0.4, 4.0 and 40.0 μg g -1 ) were in the range of 90.7-97.0% with relative standard deviations between 2.14 and 3.01%. The limits of detection and quantification were 0.03 and 0.1 μg g -1 , respectively. This study confirmed that CIPC was persistent in concrete to a depth of 4 cm, with >90% within the top 1 cm of the flooring. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. An Exploration on the Suitability of Airborne Carbonyl Compounds Analysis in relation to Differences in Instrumentation (GC-MS versus HPLC-UV and Standard Phases (Gas versus Liquid

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    Ki-Hyun Kim

    2014-01-01

    Full Text Available The relative performance figure of merits was investigated for the two most common analytical methods employed for carbonyl compounds (CC, for example, between high performance liquid chromatography (HPLC-UV detector (with 2,4-dinitrophenylhydrazine (DNPH derivatization and thermal desorption (TD-gas chromatography (GC-mass spectrometry (MS (without derivatization. To this end, the suitability of each method is assessed by computing the relative recovery (RR between the gas- and liquid-phase standards containing a suite of CC such as formaldehyde (FA, acetaldehyde (AA, propionaldehyde (PA, butyraldehyde (BA, isovaleraldehyde (IA, and valeraldehyde (VA along with benzene (B as a recovery reference for the GC method. The results confirm that a TD-GC-MS is advantageous to attain the maximum recovery for the heavier CCs (i.e., with molecular weights (MW above BA−MW ≥ 74. On the other hand, the HPLC-UV is favorable for the lighter CCs (like FA and AA with the least bias. Such compound-specific responses for each platform are validated by relative ordering of CCs as a function of response factor (RF, method detection limit (MDL, and recovery pattern. It is thus desirable to understand the advantages and limitations of each method to attain the CC data with the least experimental bias.

  15. Chemical fingerprinting and quantitative analysis of a Panax notoginseng preparation using HPLC-UV and HPLC-MS

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    Shao Qing

    2011-02-01

    Full Text Available Abstract Background Xuesaitong (XST injection, consisting of total saponins from Panax notoginseng, was widely used for the treatment of cardio- and cerebro-vascular diseases in China. This study develops a simple and global quality evaluation method for the quality control of XST. Methods High performance liquid chromatography-ultraviolet detection (HPLC-UV was used to identify and quantify the chromatographic fingerprints of the XST injection. Characteristic common peaks were identified using HPLC with photo diode array detection/electrospray ionization tandem mass spectrometry (HPLC-PDA/ESI-MSn. Results Representative fingerprints from ten batches of samples showed 27 'common saponins' all of which were identified and quantified using ten reference saponins. Conclusion Chemical fingerprinting and quantitative analysis identified most of the common saponins for the quality control of P. notoginseng products such as the XST injection.

  16. Carrier mediated hollow fiber liquid phase microextraction combined with HPLC-UV for preconcentration and determination of some tetracycline antibiotics.

    Science.gov (United States)

    Shariati, Shahab; Yamini, Yadollah; Esrafili, Ali

    2009-02-01

    In the present study, a simple and efficient preconcentration method was developed using carrier mediated three phase liquid phase microextraction prior to HPLC-UV for simultaneous extraction and determination of trace amounts of highly hydrophilic tetracycline antibiotics including tetracycline (TCN), oxytetracycline (OTCN) and doxycycline (DCN) in bovine milk, human plasma and water samples. For extraction, 11.0 mL of the aqueous sample containing TCNs and 0.05 M Na(2)HPO(4) (9.10.995). Finally, applicability of the proposed method was successfully confirmed by extraction and determination of the drugs in water and plasma samples as well as in bovine milk samples with low and high fat contents. Comparing to the traditional methods, the proposed method exhibits high sensitivity and high preconcentration factors as well as good precision. The extraction setup is simple and due to active transport of analytes, high cleanup effect and good selectivity are obtained in extraction process.

  17. Comparison of HPLC, UV spectrophotometry and potentiometric titration methods for the determination of lumefantrine in pharmaceutical products.

    Science.gov (United States)

    da Costa César, Isabela; Nogueira, Fernando Henrique Andrade; Pianetti, Gérson Antônio

    2008-09-10

    This paper describes the development and evaluation of a HPLC, UV spectrophotometry and potentiometric titration methods to quantify lumefantrine in raw materials and tablets. HPLC analyses were carried out using a Symmetry C(18) column and a mobile phase composed of methanol and 0.05% trifluoroacetic acid (80:20), with a flow rate of 1.0ml/min and UV detection at 335nm. For the spectrophotometric analyses, methanol was used as solvent and the wavelength of 335nm was selected for the detection. Non-aqueous titration of lumefantrine was carried out using perchloric acid as titrant and glacial acetic acid/acetic anhydride as solvent. The end point was potentiometrically determined. The three evaluated methods showed to be adequate to quantify lumefantrine in raw materials, while HPLC and UV methods presented the most reliable results for the analyses of tablets.

  18. Simultaneous Determination and Pharmacokinetic Study of Quercetin, Luteolin, and Apigenin in Rat Plasma after Oral Administration of Matricaria chamomilla L. Extract by HPLC-UV

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    Xiaoxv Dong

    2017-01-01

    Full Text Available A simple and sensitive HPLC-UV method has been developed for the simultaneous determination of quercetin, luteolin, and apigenin in rat plasma after oral administration of Matricaria chamomilla L. extract. The flow rate was set at 1.0 ml/min and the detection wavelength was kept at 350 nm. The calibration curves were linear in the range of 0.11–11.36 μg/ml for quercetin, 0.11–11.20 μg/ml for luteolin, and 0.11–10.60 μg/ml for apigenin, respectively. The intraday and interday precisions (RSD were less than 8.32 and 8.81%, respectively. The lower limits of quantification (LLOQ of the three compounds were 0.11 μg/ml. The mean recoveries for quercetin, luteolin, and apigenin were 99.11, 95.62, and 95.21%, respectively. Stability studies demonstrated that the three compounds were stable in the preparation and analytical process. The maximum plasma concentration (Cmax was 0.29 ± 0.06, 3.04 ± 0.60, and 0.42 ± 0.10 μg/ml, respectively. The time to reach the maximum plasma concentration (Tmax was 0.79 ± 0.25, 0.42 ± 0.09, and 0.51 ± 0.13 h, respectively. The validated method was successfully applied to investigate the pharmacokinetics study of quercetin, luteolin, and apigenin in rat plasma after oral administration of M. chamomilla extract.

  19. Development of an HPLC-UV Method for the Analysis of Drugs Used for Combined Hypertension Therapy in Pharmaceutical Preparations and Human Plasma

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    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available A simple, rapid, and selective HPLC-UV method was developed for the determination of antihypertensive drug substances: amlodipine besilat (AML, olmesartan medoxomil (OLM, valsartan (VAL, and hydrochlorothiazide (HCT in pharmaceuticals and plasma. These substances are mostly used as combinations. The combinations are found in various forms, especially in current pharmaceuticals as threesome components: OLM, AML, and HCT (combination I and AML, VAL, and HCT (combination II. The separation was achieved by using an RP-CN column, and acetonitrile-methanol-10 mmol orthophosphoric acid pH 2.5 (7 : 13 : 80, v/v/v was used as a mobile phase; the detector wavelength was set at 235 nm. The linear ranges were found as 0.1–18.5 μg/mL, 0.4–25.6 μg/mL, 0.3–15.5 μg/mL, and 0.3–22 μg/mL for AML, OLM, VAL, and HCT, respectively. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. According to the validation studies, the developed method was found to be reproducible and accurate as shown by RSD ≤6.1%, 5.7%, 6.9%, and 4.6% and relative mean error (RME ≤10.6%, 5.8%, 6.5%, and 6.8% for AML, OLM, VAL, and HCT, respectively. Consequently, the method was applied to the analysis of tablets and plasma of the patients using drugs including those substances.

  20. Preparation of magnetic ODS-PAN thin-films for microextraction of quetiapine and clozapine in plasma and urine samples followed by HPLC-UV detection.

    Science.gov (United States)

    Li, Dan; Zou, Juan; Cai, Pei-Shan; Xiong, Chao-Mei; Ruan, Jin-Lan

    2016-06-05

    In this study, conventional thin-film microextraction (TFME) was endowed with magnetic by introducing superparamagnetic SiO2@Fe3O4 nanoparticles in thin-films. Novel magnetic octadecylsilane (ODS)-polyacrylonitrile (PAN) thin-films were prepared by spraying, and used for the microextraction of quetiapine and clozapine in plasma and urine samples, followed by the detection of HPLC-UV. The influencing factors on the extraction efficiency of magnetic ODS-PAN TFME, including pH, extraction time, desorption solvent, desorption time, and ion strength were investigated systematically. Under the optimal conditions, both analytes showed good linearity over ranges of 0.070-9.000μgmL(-1) and 0.012-9.000μgmL(-1) in plasma and urine samples, respectively, with correlation coefficients (R(2)) above 0.9990. Limits of detection (LODs) for quetiapine in plasma and urine samples were 0.013 and 0.003μgmL(-1), respectively. LODs for clozapine in plasma and urine samples were 0.015 and 0.003μgmL(-1), respectively. The relative standard deviations (RSDs) for quetiapine and clozapine were less than 9.23%. After the validation, the protocol was successfully applied for the determination of quetiapine and clozapine in patients' plasma and urine samples with satisfactory recoveries between 99-110%. The proposed magnetic ODS-PAN TFME was very simple, fast and easy to handle. It showed high potential as a powerful pretreatment technology for routine therapeutic drug monitoring (TDM) in plasma and urine samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Fast and sensitive HPLC/UV method for cefazolin quantification in plasma and subcutaneous tissue microdialysate of humans and rodents applied to pharmacokinetic studies in obese individuals.

    Science.gov (United States)

    Palma, Eduardo Celia; Laureano, João Victor; de Araújo, Bibiana Verlindo; Meinhardt, Nelson Guardiola; Stein, Airton Tetelbom; Dalla Costa, Teresa

    2018-04-14

    Antimicrobial prophylactic dosing of morbidly obese patients may differ from normal weighted individuals owing to alterations in drug tissue distribution. Drug subcutaneous tissue distribution can be investigated by microdialysis patients and animals. The need for cefazolin prophylactic dose adjustment in obese patients remains under discussion. The paper describes the validation of an HPLC-UV method for cefazolin quantification in plasma and microdialysate samples from clinical and pre-clinical studies. A C 18 column with an isocratic mobile phase was used for drug separation, with detection at 272 nm. Total and unbound cefazolin lower limit of quantitation was 5 μg/mL in human plasma, 2 μg/mL in rat plasma, and 0.5 and 0.025 μg/mL in human and rat microdialysate samples, respectively. The maximum intra- and inter-day imprecisions were 10.7 and 8.1%, respectively. The inaccuracy was <9.7%. The limit of quantitation imprecision and inaccuracy were < 15%. Cefazolin stability in the experimental conditions was confirmed. Cefazolin plasma concentrations and subcutaneous tissue penetration were determined by microdialysis in morbidly obese patients (2 g i.v. bolus) and diet-induced obese rats (30 mg/kg i.v. bolus) using the method. This method has the main advantages of easy plasma clean-up and practicability and has proven to be useful in cefazolin clinical and pre-clinical pharmacokinetic investigations. Copyright © 2018 John Wiley & Sons, Ltd.

  2. Enrichment of steroid hormones in water with porous and hydrophobic polymer-based SPE followed by HPLC-UV determination.

    Science.gov (United States)

    Hu, Yinfen; Zhang, Man; Tong, Changlun; Wu, Jianmin; Liu, Weiping

    2013-10-01

    There have been great concerns about the persistence of steroid hormones in surface water. Since the concentrations of these compounds in water samples are usually at a trace level, the efficient enrichment of steroid hormones is vital for further analysis. In this work, a porous and hydrophobic polymer was synthesized and characterized. The composition of solvent used as porogen in the synthetic process was shown to have an effect on the morphology of the polymer, which was successfully used as an SPE sorbent for simultaneously enriching steroid hormones in surface water samples. The recoveries of the steroid hormones on the custom-made polymer ranged from 93.4 to 106.2%, whereas those on commercialized ENVI-18, LC-18, and Oasis HLB ranged from 54.8 to 104.9, 66 to 93.6, and 77.2 to 106%, respectively. Five types of steroid hormones were simultaneously measured using HPLC-UV after they were enriched by the custom-made sorbent. Based on these findings, the SPE-HPLC method was developed. The LODs of this method for estriol, estradiol, estrone, androstenedione, progesterone were 0.07, 0.43, 0.61, 0.27, and 0.42 μg/L, respectively, while precision and reproducibility RSDs were <6.40 and 7.49%, respectively. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Determination of organophosphorus pesticides and their major degradation product residues in food samples by HPLC-UV.

    Science.gov (United States)

    Peng, Guilong; He, Qiang; Lu, Ying; Mmereki, Daniel; Zhong, Zhihui

    2016-10-01

    A simple method based on dispersive solid-phase extraction (DSPE) and dispersive liquid-liquid microextraction method based on solidification of floating organic droplets (DLLME-SFO) was developed for the extraction of chlorpyrifos (CP), chlorpyrifos-methyl (CPM), and their main degradation product 3,5,6-trichloro-2-pyridinol (TCP) in tomato and cucumber samples. The determination was carried out by high performance liquid chromatography with ultraviolet detection (HPLC-UV). In the DSPE-DLLME-SFO, the analytes were first extracted with acetone. The clean-up of the extract by DSPE was carried out by directly adding activated carbon sorbent into the extract solution, followed by shaking and filtration. Under the optimum conditions, the proposed method was sensitive and showed a good linearity within a range of 2-500 ng/g, with the correlation coefficients (r) varying from 0.9991 to 0.9996. The enrichment factors ranged from 127 to 138. The limit of detections (LODs) were in the range of 0.12-0.68 ng/g, and the relative standard deviations (RSDs) for 50 ng/g of each analytes in tomato samples were in the range of 3.25-6.26 % (n = 5). The proposed method was successfully applied for the extraction and determination of the mentioned analytes residues in tomato and cucumber samples, and satisfactory results were obtained.

  4. Simple and Selective HPLC-UV/Vis Bioanalytical Method to Determine Aluminum Phthalocyanine Chloride in Skin Permeation Studies

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    Thaiene Avila Reis

    2018-01-01

    Full Text Available Considering the feasibility of the aluminum phthalocyanine chloride (AlPcCl application in the topical photodynamic therapy of cutaneous tumors and the lack of HPLC methods capable of supporting skin permeation experiments using this compound, the aim of this study was to obtain a simple and selective chromatographic method for AlPcCl determination in skin matrices. A HPLC-UV/Vis method was developed using a normal-phase column operating at 30°C, an isocratic mobile phase of methanol : phosphoric acid (0.01 M at 1.5 mL/min, and detection at 670 nm. The method exhibited (i selectivity against various contaminants found in the different skin layers, (ii high drug extraction capacity from the hair follicle (>70% and remaining skin (>80%, and (iii low limits of detection and of quantification (0.03 and 0.09 μg/mL, resp.. The method was also linear in the range from 0.1 to 5.0 µg/mL (r = 0.9994 and demonstrated robustness with regard to experimental chromatographic parameters according to a factorial design. Lastly, the developed method was successfully tested in in vitro skin permeation studies of AlPcCl, proving its effectiveness in the development of pharmaceutical delivery systems containing this drug for topical photodynamic therapy of skin cancers.

  5. Determination of hydroxyurea in human plasma by HPLC-UV using derivatization with xanthydrol.

    Science.gov (United States)

    Legrand, Tiphaine; Rakotoson, Marie-Georgine; Galactéros, Frédéric; Bartolucci, Pablo; Hulin, Anne

    2017-10-01

    A simple and rapid high performance liquid chromatography (HPLC) method using ultraviolet (UV) detection was developed to determine hydroxyurea (HU) concentration in plasma sample after derivatization with xanthydrol. Two hundred microliters samples were spiked with methylurea (MeU) as internal standard and proteins were precipitated by adding methanol. Derivatization of HU and MeU was immediately performed by adding 0.02M xanthydrol and 1.5M HCl in order to obtain xanthyl-derivatives of HU and MeU that can be further separated using HPLC and quantified using UV detection at 240nm. Separation was achieved using a C18 column with a mobile phase composed of 20mM ammonium acetate and acetonitrile in gradient elution mode at a flow rate of 1mL/min. The total analysis time did not exceed 18min. The method was found linear from 5 to 400μM and all validation parameters fulfilled the international requirements. Between- and within-run accuracy error ranged from -4.7% to 3.2% and precision was lower than 12.8%. This simple method requires small volume samples and can be easily implemented in most clinical laboratories to develop pharmacokinetics studies of HU and to promote its therapeutic monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Easy-Assessment of Levofloxacin and Minocycline in Relevant Biomimetic Media by HPLC-UV Analysis.

    Science.gov (United States)

    Matos, Ana C; Pinto, Rosana V; Bettencourt, Ana F

    2017-08-01

    Simple, economic and environmental friendly high-performance liquid chromatography methods for levofloxacin and minocycline quantification in biomimetic media were developed and validate including their stability at body temperature, an often neglected evaluation parameter. Both methods are similar only differing in the wavelength setting, i.e., for levofloxacin and minocycline quantification the UV detection was set at 284 and at 273 nm, respectively. The separation of both antibiotics was achieved using a reversed-phase column and a mobile phase consisting of acetonitrile and water (15:85) with 0.6% triethylamine, adjusted to pH 3. As an internal standard for levofloxacin quantification, minocycline was used and vice versa. The calibration curves for both methods were linear (r = 0.99) over a concentration range of 0.3-16 μg/mL and 0.5-16 μg/mL for levofloxacin and minocycline, respectively, with precision, accuracy and recovery in agreement with international guidelines requirement. Levofloxacin revealed stability in all media and conditions, including at 37°C, with exception to freeze-thaw cycle conditions. Minocycline presented a more accentuated degradation profile over prolonged time courses, when compared to levofloxacin. Reported data is of utmost interest for pharma and biomaterials fields regarding the research and development of new local drug-delivery-systems containing either of these two antibiotics, namely when monitoring the in vitro release studies of those systems. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Comparison of microbiological assay and HPLC-UV for determination of fluconazole in capsules

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    Kelly Marques Queiroz

    2009-12-01

    Full Text Available The development of a specific agar diffusion bioassay for the quantitative determination of fluconazole formulated in capsules was carried out using a strain of Candida albicans ATCC 18804 as the test organism. A prospective validation of the method showed adequate linearity (r²=0.9995, precision (R.S.D. = 4.0% for intra-day and 4.5% for inter-day precision and accuracy (mean recovery = 102.9%. High performance liquid chromatography was chosen as a comparison method for the fluconazole determination. The contents of fluconazole determined by both methods, for four capsule samples, showed a strong correlation, confirmed by Pearson's correlation coefficient value (r = 0.9884. The bioassay is a suitable method for both research and pharmaceutical industry laboratories.Este trabalho visou ao desenvolvimento e validação de um método microbiológico por difusão em ágar para quantificação de fluconazol em cápsulas utilizando o isolado Candida albicans ATCC 18804 como reagente biológico. O método foi validado e foi verificada linearidade (r²=0,9995, precisão (D.P.R. = 4.0% para precisão intra-dia e 4,5% para precisão inter-dia e exatidão (recuperação média = 102,9%. Concomitantemente, foi realizado o doseamento de fluconazol nas cápsulas por meio de cromatografia líquida de alta eficiência. Os teores encontrados por ambos os métodos demonstraram alta correlação, confirmada pelo Coeficiente de Correlação de Pearson (r = 0,9884. O ensaio microbiológico desenvolvido pode ser considerado ferramenta valiosa tanto para a pesquisa científica quanto para a rotina da indústria farmacêutica.

  8. Development and validation of a new method for the quantification of norfloxacin by HPLC-UV and its application to a comparative pharmacokinetic study in human volunteers Desenvolvimento e validação de um método para quantificação de norfloxacino por cromatografia líquida de alta eficiência e aplicação a estudo de farmacocinética comparada em voluntários humanos

    Directory of Open Access Journals (Sweden)

    Danilo César Galindo Bedor

    2007-06-01

    Full Text Available The development and validation of a simple and accurate method based on HPLC with ultraviolet detection for the quantification of norfloxacin (NFX in human plasma and its application to a bioequivalence study between two norfloxacin formulations is described. NFX and the internal standard (cyprofloxacin were extracted from plasma using liquid-liquid extraction. Chromatographic separation of norfloxacin, cyprofloxacin and plasma interferents was achieved with a C-18 column and a mobile phase consisting of 20 mM sodium hydrogen phosphate buffer pH 3.0 and acetonitrile (88:12, v/v and quantitation was done at 280 nm. The method was linear from 25 to 3000 ng mL-1 (r² > 0.997578, and norfloxacin and cyprofloxacin had an average recovery from plasma of 93.9% and 91.2% respectively. The RSD of inter-day quality control samples at the lower limit of quantification was less than 15%. After a single oral dose (400 mg of norfloxacin administered to healthy human volunteers using a randomized 2x2 crossover design, pharmacokinetic parameters (AUC0-t, AUC0-¥, Cmax, t1/2 were derived from the plasma concentration curves for both formulations. Pharmacokinetic analysis of the data showed that the two formulations were bioequivalent, while no adverse reactions to the drug were observed.O desenvolvimento e validação de um método simples e preciso por CLAE-UV para quantificação de norfloxacino (NFX em plasma humano e a sua aplicação a um estudo de bioequivalência entre duas formulações são descritos. NFX e o padrão interno (ciprofloxacino, PI foram extraídos do plasma através de extração líquido-líquido. A separação cromatográfica do NFX, do PI e dos interferentes do plasma foi realizada com uma coluna C-18 e fase móvel composta de tampão fosfato de sódio 20 mM pH 3,0 e acetonitrila (88/12, v/v e quantificado em 280 nm. A resposta do detector aos analitos mostrou-se linear entre 25 a 3000 ng mL-1 (r² > 0,997578 e a recuperação média de

  9. Development and application of a validated stability-indicating high-performance liquid chromatographic method using photodiode array detection for simultaneous determination of granisetron, methylparaben, propylparaben, sodium benzoate, and their main degradation products in oral pharmaceutical preparations.

    Science.gov (United States)

    Hewala, Ismail; El-Fatatry, Hamed; Emam, Ehab; Mabrouk, Mokhtar

    2011-01-01

    A simple, rapid, and sensitive RP-HPLC method using photodiode array detection was developed and validated for the simultaneous determination of granisetron hydrochloride, 1-methyl-1H-indazole-3-carboxylic acid (the main degradation product of granisetron), sodium benzoate, methylparaben, propylparaben, and 4-hydroxybenzoic acid (the main degradation product of parabens) in granisetron oral drops and solutions. The separation of the compounds was achieved within 8 min on a SymmetryShield RP18 column (100 x 4.6 mm id, 3.5 microm particle size) using the mobile phase acetonitrile--0.05 M KH2PO4 buffered to pH 3 using H3PO4 (3+7, v/v). The photodiode array detector was used to test the purity of the peaks, and the chromatograms were extracted at 240 nm. The method was validated, and validation acceptance criteria were met in all cases. The robust method was successfully applied to the determination of granisetron and preservatives, as well as their degradation products in different batches of granisetron oral drops and solutions. The method proved to be sensitive for determination down to 0.04% (w/w) of granisetron degradation product relative to granisetron and 0.03% (w/w) 4-hydroxybenzoic acid relative to total parabens.

  10. Cluster analysis of commercial samples of Bauhinia spp. using HPLC-UV/PDA and MCR-ALS/PCA without peak alignment procedure.

    Science.gov (United States)

    Ardila, Jorge Armando; Funari, Cristiano Soleo; Andrade, André Marques; Cavalheiro, Alberto José; Carneiro, Renato Lajarim

    2015-01-01

    Bauhinia forficata Link. is recognised by the Brazilian Health Ministry as a treatment of hypoglycemia and diabetes. Analytical methods are useful to assess the plant identity due the similarities found in plants from Bauhinia spp. HPLC-UV/PDA in combination with chemometric tools is an alternative widely used and suitable for authentication of plant material, however, the shifts of retention times for similar compounds in different samples is a problem. To perform comparisons between the authentic medicinal plant (Bauhinia forficata Link.) and samples commercially available in drugstores claiming to be "Bauhinia spp. to treat diabetes" and to evaluate the performance of multivariate curve resolution - alternating least squares (MCR-ALS) associated to principal component analysis (PCA) when compared to pure PCA. HPLC-UV/PDA data obtained from extracts of leaves were evaluated employing a combination of MCR-ALS and PCA, which allowed the use of the full chromatographic and spectrometric information without the need of peak alignment procedures. The use of MCR-ALS/PCA showed better results than the conventional PCA using only one wavelength. Only two of nine commercial samples presented characteristics similar to the authentic Bauhinia forficata spp., considering the full HPLC-UV/PDA data. The combination of MCR-ALS and PCA is very useful when applied to a group of samples where a general alignment procedure could not be applied due to the different chromatographic profiles. This work also demonstrates the need of more strict control from the health authorities regarding herbal products available on the market. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Use of diffusion-ordered NMR spectroscopy and HPLC-UV-SPE-NMR to identify undeclared synthetic drugs in medicines illegally sold as phytotherapies.

    Science.gov (United States)

    Silva, Lorena M A; Filho, Elenilson G A; Thomasi, Sérgio S; Silva, Bianca F; Ferreira, Antonio G; Venâncio, Tiago

    2013-09-01

    The informal (and/or illegal) e-commerce of pharmaceutical formulations causes problems that governmental health agencies find hard to control, one of which concerns formulas sold as natural products. The purpose of this work was to explore the advantages and limitations of DOSY and HPLC-UV-SPE-NMR. These techniques were used to identify the components of a formula illegally marketed in Brazil as an herbal medicine possessing anti-inflammatory and analgesic properties. DOSY was able to detect the major components present at higher concentrations. Complete characterization was achieved using HPLC-UV-SPE-NMR, and 1D and 2D NMR analyses enabled the identification of known synthetic drugs. These were ranitidine and a mixture of orphenadrine citrate, piroxicam, and dexamethasone, which are co-formulated in a remedy called Rheumazim that is used to relieve severe pain, but it is prohibited in Brazil because of a lack of sufficient pharmacokinetic and pharmacodynamic information. Copyright © 2013 John Wiley & Sons, Ltd.

  12. A Modified Method for Determination of Lumefantrine in Human Plasma by HPLC-UV and Combination of Protein Precipitation and Solid-Phase Extraction: Application to a Pharmacokinetic Study

    Directory of Open Access Journals (Sweden)

    Liusheng Huang

    2010-03-01

    Full Text Available An HPLC-UV method was developed and validated for the determination of lumefantrine in human plasma. Lumefantrine and its internal standard halofantrine were extracted from plasma samples using protein precipitation with acetonitrile (0.2% perchloric acid followed by solid-phase extraction with Hypersep C8 cartridges. Chromatographic separation was performed on a Zorbax SB-CN HPLC column (3.0 × 150 mm, 3.5 μm with water/methanol (0.1% TFA as the mobile phases in a gradient elution mode. Detection was performed using UV/vis detector at λ = 335 nm. The method showed to be linear over a range of 50–10,000 ng/mL with acceptable intra- and inter-day precision and accuracy. The mean recoveries were 88.2% for lumefatrine and 84.5% for the I.S. The internal standard halofantrine is readily available from commercial sources. This method was successfully applied to a pharmacokinetic interaction study between a first-line antimalarial combination (artemether—lumefantrine and antiretroviral therapy.

  13. Determination of Diacetyl in Beer by a Precolumn Derivatization-HPLC-UV Method Using 4-(2,3-Dimethyl-6-quinoxalinyl)-1,2-benzenediamine as a Derivatizing Reagent.

    Science.gov (United States)

    Wang, Ji-Yu; Wang, Xin-Jie; Hui, Xian; Hua, Shui-Hong; Li, Heng; Gao, Wen-Yun

    2017-03-29

    Diacetyl is an important flavoring compound in many foods, especially in beer. In the present study, we developed and validated a new precolumn derivatization HPLC-UV method for the determination of diacetyl using 4-(2,3-dimethyl-6-quinoxalinyl)-1,2-benzenediamine as a novel derivatizing reagent. After derivatization with the reagent at a pH value 4.0 at ambient temperature for 10 min, diacetyl was analyzed on an ODS column and detected at 254 nm. The results show that the correlation coefficient of the method is 0.9991 in the range of 0.10 to 100.0 μM diacetyl, and the limit of detection is 0.02 μM. The method was further evaluated in the analysis of beer samples with the recoveries ranging from 94.4 to 102.6% and RSDs from 1.36 to 3.33%. The concentrations of diacetyl in 8 beer samples were determined in the range of 0.19 to 0.42 μM. The method established in this study may be well suitable for the determination of diacetyl in beer.

  14. Toxic actions of dinoseb in medaka (Oryzias latipes) embryos as determined by in vivo 31P NMR, HPLC-UV and 1H NMR metabolomics.

    Science.gov (United States)

    Viant, Mark R; Pincetich, Christopher A; Hinton, David E; Tjeerdema, Ronald S

    2006-03-10

    Changes in metabolism of Japanese medaka (Oryzias latipes) embryos exposed to dinoseb (2-sec-butyl-4,6-dinitrophenol), a substituted dinitrophenol herbicide, were determined by in vivo (31)P NMR, high-pressure liquid chromatography (HPLC)-UV, and (1)H NMR metabolomics. ATP and phosphocreatine (PCr) metabolism were characterized within intact embryos by in vivo (31)P NMR; concentrations of ATP, GTP, ADP, GDP, AMP and PCr were determined by HPLC-UV; and changes in numerous polar metabolites were characterized by (1)H NMR-based metabolomics. Rangefinding exposures determined two sublethal doses of dinoseb, 50 and 75 ppb, in which embryos survived from 1-day post fertilization (DPF) through the duration of embryogenesis. In vivo (31)P NMR data were acquired from 900 embryos in 0, 50, and 75 ppb dinoseb at 14, 62, and 110 h (n = 6 groups) after initiation of exposure. After 110 h, embryos were observed for normal development and hatching success, then either preserved in 10% formalin for growth analysis or flash frozen and extracted for HPLC-UV and (1)H NMR analysis. Dinoseb exposure at both concentrations resulted in significant declines in [ATP] and [PCr] at 110 h as measured by in vivo (31)P NMR (p fashion. Metabolic effects measured by in vivo (31)P NMR showed a significant increase in orthophosphate levels (P(i); p < 0.05), and significant decreases in [ATP], [PCr] and the PCr/P(i) ratio (p < 0.05). Metabolomics revealed a dose-response relationship between dinoseb and endogenous metabolite changes, with both dinoseb concentrations producing significantly different metabolic profiles from controls (p < 0.05). Metabolic changes included decreased concentrations of ATP, PCr, alanine and tyrosine, and increased concentrations of lactate with medaka embryotoxicity. This study demonstrated that medaka embryos respond to dinoseb with significant changes in metabolism, reduced growth and heart rates, and increased abnormal development and post-exposure mortality. All

  15. Stability-Indicating HPLC Determination of Gemcitabine in Pharmaceutical Formulations

    Science.gov (United States)

    Singh, Rahul; Shakya, Ashok K.; Naik, Rajashri; Shalan, Naeem

    2015-01-01

    A simple, sensitive, inexpensive, and rapid stability indicating high performance liquid chromatographic method has been developed for determination of gemcitabine in injectable dosage forms using theophylline as internal standard. Chromatographic separation was achieved on a Phenomenex Luna C-18 column (250 mm × 4.6 mm; 5μ) with a mobile phase consisting of 90% water and 10% acetonitrile (pH 7.00 ± 0.05). The signals of gemcitabine and theophylline were recorded at 275 nm. Calibration curves were linear in the concentration range of 0.5–50 μg/mL. The correlation coefficient was 0.999 or higher. The limit of detection and limit of quantitation were 0.1498 and 0.4541 μg/mL, respectively. The inter- and intraday precision were less than 2%. Accuracy of the method ranged from 100.2% to 100.4%. Stability studies indicate that the drug was stable to sunlight and UV light. The drug gives 6 different hydrolytic products under alkaline stress and 3 in acidic condition. Aqueous and oxidative stress conditions also degrade the drug. Degradation was higher in the alkaline condition compared to other stress conditions. The robustness of the methods was evaluated using design of experiments. Validation reveals that the proposed method is specific, accurate, precise, reliable, robust, reproducible, and suitable for the quantitative analysis. PMID:25838825

  16. An examination of endoparasites and fecal testosterone levels in flying squirrels (Glaucomys spp.) using high performance liquid chromatography-ultra-violet (HPLC-UV).

    Science.gov (United States)

    Waksmonski, Sarah N; Huffman, Justin M; Mahan, Carolyn G; Steele, Michael A

    2017-08-01

    The immuno-competence hypothesis proposes that higher levels of testosterone increases the susceptibility to parasitism. Here we examined the testosterone levels in two species of flying squirrels ( Glaucomys ): one known to regularly host a nematode species ( Strongyloides robustus ) without ill effects ( G. volans ) and a closely related species that is considered negatively affected by the parasite. We quantified fecal testosterone levels in northern and southern flying squirrels ( G. sabrinus, G. volans ) with high-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV), and compared levels to endoparasites detected in individual squirrels. Qualitatively, we found highest levels of testosterone in male northern flying squirrels infected with Strongyloides robustus . This analytical approach represents an alternative and equally reliable method to using enzyme-linked immunosorbent assay (ELISA), for detecting and quantifying fecal testosterone levels.

  17. An examination of endoparasites and fecal testosterone levels in flying squirrels (Glaucomys spp. using high performance liquid chromatography-ultra-violet (HPLC-UV

    Directory of Open Access Journals (Sweden)

    Sarah N. Waksmonski

    2017-08-01

    Full Text Available The immuno-competence hypothesis proposes that higher levels of testosterone increases the susceptibility to parasitism. Here we examined the testosterone levels in two species of flying squirrels (Glaucomys: one known to regularly host a nematode species (Strongyloides robustus without ill effects (G. volans and a closely related species that is considered negatively affected by the parasite. We quantified fecal testosterone levels in northern and southern flying squirrels (G. sabrinus, G. volans with high-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV, and compared levels to endoparasites detected in individual squirrels. Qualitatively, we found highest levels of testosterone in male northern flying squirrels infected with Strongyloides robustus. This analytical approach represents an alternative and equally reliable method to using enzyme-linked immunosorbent assay (ELISA, for detecting and quantifying fecal testosterone levels.

  18. HPLC-UV Analysis Coupled with Chemometry to Identify Phenolic Biomarkers from Medicinal Plants, used as Ingredients in Two Food Supplement Formulas

    Directory of Open Access Journals (Sweden)

    Raluca Maria Pop

    2013-11-01

    Full Text Available . High performance liquid chromatography (HPLC with UV detection is nowadays the reference method to identify and quantify the biomarkers of quality and authenticity of plants and food supplements. Seven medicinal plants were collected from wild flora: Taraxacum officinalis (1, Cynara scolimus (2, Silybum marianum (3, Hypericum perforatum (4,  Chelidonium majus (5, Lycopodium clavatum (6 and  Hippophae rhamnoides (7  leaves and fruits.  Two products (A and B were obtained by mixing individual plant powders. Therefore product A was obtained by mixing dandelion, artichoke and milk thistle, 1:1:1 while product B by mixing St John’s wort, Celandine and Wolf’s claw, 1:1:1. The methanolic extracts of individual plants as well as three different extracts of products A and B (using acidulated water, neutral water and acidulated methanol were analyzed using HPLC-UV for their phenolics’ fingerprint and composition. The qualitative (untargeted analysis and quantitative (targeted analysis results were further compared using Principal Component Analysis (PCA in order to identify their specific biomarkers. Thus, quantitative evaluation of individual phenolics in case of individual plants and products A and B extracts, showed specific and significant differences of composition. Both products A and B contained elagic acid as major compound. For product A, good biomarkers were trans-cinnamic, chlorogenic, caffeic and p-coumaric acids, as well silymarin and silibine originating from milk thistle. For product B, good biomarkers were quercetin and kaempherol, gallic and protocatecuic acids, this product being rich in flavonoids. In conclusion, HPLC-UV coupled with PCA analysis proved to be a rapid and useful way to identify the main biomarkers of plants’ authentication, as well of final products’ quality and safety.

  19. A Stability Indicating HPLC Method for the Determination of ...

    African Journals Online (AJOL)

    Erah

    stability indicating reverse phase HPLC method for estimating meloxicam (MLX) in bulk ... acetonitrile-water-glacial acetic acid [55:40:5 (% v/v)] at a flow rate of 1ml/min and detection wavelength .... pore and degassed before use. ... determined to assess the effect of small but ... deviation, the standard error of slope, and the.

  20. Preparation of Dry Extract of Mikania glomerata Sprengel (Guaco and Determination of Its Coumarin Levels by Spectrophotometry and HPLC-UV

    Directory of Open Access Journals (Sweden)

    Maria da Penha Henriques do Amaral

    2012-08-01

    Full Text Available Guaco (Mikania glomerata Sprengel syrup is one of the most popular herbal medicines used to treat the symptoms of asthmatic bronchitis, cough and hoarseness. The coumarin 2H-1-benzopyran-2-one, is one of the major constituents of Guaco and contributes to its pharmacological effects. The pharmaceutical capsule form of dry extract of Guaco is recommended by the Brazilian Program of Medicinal Plants and Herbal Medicines and used in primary health care. In order to identify a new protocol to obtain the raw material for Guaco capsule production we evaluated two methods, including a freeze-drying process (lyophilization and the spray-dryer technique, as well as the use of two adjuvants, Maltodextrins and Aerosil®, in different concentrations. The coumarin levels of the dried extracts were analyzed by UV-spectrophotometry and HPLC-UV/DAD. The adjuvant Aerosil® 8% showed better dry powder physical appearance. Lyophilization was observed to be the best process to obtain the dry extract of Guaco based on the measured coumarin levels.

  1. Assessment of repeatability of composition of perfumed waters by high-performance liquid chromatography combined with numerical data analysis based on cluster analysis (HPLC UV/VIS - CA).

    Science.gov (United States)

    Ruzik, L; Obarski, N; Papierz, A; Mojski, M

    2015-06-01

    High-performance liquid chromatography (HPLC) with UV/VIS spectrophotometric detection combined with the chemometric method of cluster analysis (CA) was used for the assessment of repeatability of composition of nine types of perfumed waters. In addition, the chromatographic method of separating components of the perfume waters under analysis was subjected to an optimization procedure. The chromatograms thus obtained were used as sources of data for the chemometric method of cluster analysis (CA). The result was a classification of a set comprising 39 perfumed water samples with a similar composition at a specified level of probability (level of agglomeration). A comparison of the classification with the manufacturer's declarations reveals a good degree of consistency and demonstrates similarity between samples in different classes. A combination of the chromatographic method with cluster analysis (HPLC UV/VIS - CA) makes it possible to quickly assess the repeatability of composition of perfumed waters at selected levels of probability. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  2. HPLC-UV Method for the Identification and Screening of Hydroquinone, Ethers of Hydroquinone and Corticosteroids Possibly Used as Skin-Whitening Agents in Illicit Cosmetic Products.

    Science.gov (United States)

    Gimeno, Pascal; Maggio, Annie-Françoise; Bancilhon, Marjorie; Lassu, Nelly; Gornes, Hervé; Brenier, Charlotte; Lempereur, Laurent

    2016-03-01

    Corticosteroids, hydroquinone and its ethers are regulated in cosmetics by the Regulation 1223/2009. As corticosteroids are forbidden to be used in cosmetics and cannot be present as contaminants or impurities, an identification of one of these illicit compounds deliberately introduced in these types of cosmetics is enough for market survey control. In order to quickly identify skin-whitening agents present in illegal cosmetics, this article proposes an HPLC-UV method for the identification and screening of hydroquinone, 3 ethers of hydroquinone and 39 corticosteroids that may be found in skin-whitening products. Two elution gradients were developed to separate all compounds. The main solvent gradient (A) allows the separation of 39 compounds among the 43 compounds considered in 50 min. Limits of detection on skin-whitening cosmetics are given. For compounds not separated, a complementary gradient elution (B) using the same solvents is proposed. Between 2004 and 2009, a market survey on "skin-whitening cosmetic" was performed on 150 samples and highlights that more than half of the products tested do not comply with the Cosmetic Regulation 1223/2009 (amending the Council Directive 76/768/EEC). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Determination of Carbonyl Compounds in Cork Agglomerates by GDME-HPLC-UV: Identification of the Extracted Compounds by HPLC-MS/MS.

    Science.gov (United States)

    Brandão, Pedro Francisco; Ramos, Rui Miguel; Almeida, Paulo Joaquim; Rodrigues, José António

    2017-02-08

    A new approach is proposed for the extraction and determination of carbonyl compounds in solid samples, such as wood or cork materials. Cork products are used as building materials due to their singular characteristics; however, little is known about its aldehyde emission potential and content. Sample preparation was done by using a gas-diffusion microextraction (GDME) device for the direct extraction of volatile aldehydes and derivatization with 2,4-dinitrophenylhydrazine. Analytical determination of the extracts was done by HPLC-UV, with detection at 360 nm. The developed methodology proved to be a reliable tool for aldehyde determination in cork agglomerate samples with suitable method features. Mass spectrometry studies were performed for each sample, which enabled the identification, in the extracts, of the derivatization products of a total of 13 aldehydes (formaldehyde, acetaldehyde, furfural, propanal, 5-methylfurfural, butanal, benzaldehyde, pentanal, hexanal, trans-2-heptenal, heptanal, octanal, and trans-2-nonenal) and 4 ketones (3-hydroxy-2-butanone, acetone, cyclohexanone, and acetophenone). This new analytical methodology simultaneously proved to be consistent for the identification and determination of aldehydes in cork agglomerates and a very simple and straightforward procedure.

  4. Quantification of active principles and pigments in leaf extracts of Isatis tinctoria by HPLC/UV/MS.

    Science.gov (United States)

    Mohn, Tobias; Potterat, Olivier; Hamburger, Matthias

    2007-02-01

    An HPLC method has been developed and validated for the quantification of the pharmacologically active principles tryptanthrin (1), 1,3-dihydro-3-[(4-hydroxy-3,5-dimethoxyphenyl)methylene]-2 H-indol-2-one (indolinone) (3), indirubin (4), alpha-linolenic acid (2), and indigo (5), an isomer of indirubin, in extracts from the traditional anti-inflammatory plant Isatis tinctoria (woad). The chromatographic separation was performed on a C-18 column with a linear gradient of acetonitrile in water containing 0.1% formic acid. The method combines UV and electrospray MS detection in the positive ion mode for the detection of the alkaloids, with a switch to the negative mode for the analysis of alpha-linolenic acid. The method was applied to the analysis of woad extracts obtained by supercritical fluid (SFE) CO2 extraction, and by pressurized liquid extraction (PLE) with dichloromethane and methanol, respectively. While the highest concentration of alpha-linolenic acid was found in the SFE extract (7.43%), the concentrations of tryptanthrin , indolinone, indirubin and indigo were the highest in the dichloromethane extract (0.30, 0.035, 2.48 and 0.84%, respectively). Compound 3 was not detected in the methanolic extract and only traces of compounds 1, 4 and 5 and low amount of alpha-linolenic acid (0.39%) were present in this extract.

  5. Determination of antazoline hydrochloride in Beagle dog plasma by HPLC-UV and its application to pharmacokinetics.

    Science.gov (United States)

    Li, Xiaotian; Chu, Yanle; Ke, Yu; Wang, Linxi; Yu, Tong; Hao, Lianqi

    2013-06-15

    In order to evaluate the pharmacokinetics characteristic of antazoline hydrochloride in Beagle dogs, a sensitive and specific HPLC method was developed and validated using phenacetin as the internal standard (IS). The analyte and the IS were extracted from dog plasma by ethyl acetate under the basic condition. The analyte was separated by a C18 column and detected with a variable wavelength UV-detector. The mobile phase consisted of methanol-5mmolL(-1) tetrabutyl ammonium bromide (45:55, v/v) containing 0.5% glacial acetic acid in a flow rate of 1.0mLmin(-1). Standard calibration graph for antazoline was linear over a curve range of 20-1600ngmL(-1) (R>0.99) and the lower limit of quantification was 20ngmL(-1) using a plasma sample of 500μL. The intra- and inter-day precision values were less than 14.3% relative standard deviation (RSD). The intra-day assay accuracy was in the range of 98.1-100.6% and the inter-day assay accuracy in the range of 99.2-101.1%. The extraction recoveries were on the average of 88.4% for antazoline and 76.8% for IS. Plasma samples were stable at least for 1 month at -20°C. This method was successfully applied to pharmacokinetics study of antazoline after intravenous administration to Beagle dogs. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Design of a controlled release system of OP-1 and TGF-β1 based in microparticles of sodium alginate and release characterization by HPLC-UV.

    Science.gov (United States)

    Oliva-Rodríguez, Ricardo; Pérez-Urizar, José; Dibildox-Alvarado, Estela; Martínez-Saldaña, María Consolación; Avelar-González, Francisco Javier; Flores-Reyes, Héctor; Pozos-Guillén, Amaury de Jesús; Guerrero-Barrera, Alma Lilián

    2011-12-01

    A new system for sustained release of growth factors, such as osteogenic protein 1 (OP-1) and transforming growth factor β1 (TGF-β1), intended to repair and promote dental tissue regeneration in rats was designed and characterized in this work. The release system was made with microparticles of sodium alginate, produced by ionic gelling dripping technique. The release profiles of OP-1 and TGF-β1 from biopolymer matrix were determined by high-performance liquid chromatography (HPLC), and with this purpose, an HPLC-UV method was developed. About 80% of each growth factor was released in the first 24 h, reaching almost 100% in 168 h. The system was tested during the tissue repair in rat molars in comparison with calcium hydroxide and both growth factors not encapsulated. The dentin sialoprotein (DSP) was used as a repair marker. It was detected by immunohistochemistry, after 14- and 28-d post-treatment. X (2) test (p ≤ 0.001) and Fisher exact test (p ≤ 0.05) were applied for assessment of the amount of immunostaining. The treatment with encapsulated OP-1 showed an increased DSP immunostaining after 14 d and did not find any significant difference with the immunostaining observed for calcium hydroxide treatment. Treatment with TGF-β1 did not show significant difference with calcium hydroxide. Treatment with both factors OP-1 and TGF-β1 showed higher DSP immunostaining in comparison with calcium hydroxide treatment. In conclusion, the combination of both growth factors encapsulated showed more DSP immunostaining in comparison with each one separated, either encapsulated or not.

  7. Investigation of anti-Hepatitis C virus, sofosbuvir and daclatasvir, in pure form, human plasma and human urine using micellar monolithic HPLC-UV method and application to pharmacokinetic study.

    Science.gov (United States)

    Zidan, Dalia W; Hassan, Wafaa S; Elmasry, Manal S; Shalaby, Abdalla A

    2018-06-01

    Simultaneous determination of sofosbuvir (SOF), and daclatasvir (DAC) in their dosage forms, human urine and human plasma using simple and rapid micellar high performance liquid chromatographic method coupled with UV detection (HPLC-UV) had been developed and validated. These drugs are described as co-administered for treatment of Hepatitis C virus (HCV). HCV is the cause of Hepatitis C and some cancers such as liver cancer (hepatocellular carcinoma) and lymphomas in humans. Separation and quantitation were carried out on anonyx™ C 8 monolithic (100 × 4.6 mm (i.d.) analytical column maintained at 25 °C. The mobile phase consisted of 0.1 M sodium dodecyl sulfate (SDS) solution containing 20% (V/V) n-propanolol and 0.3% (V/V) triethylamine and pH was adjusted to 6.5 using 0.02 M phosphoric acid, respectively. The retention times of SOF and DAC were 4.8 min, and 6.5 min, respectively. Measurements were made at flow rate of 0.5 mL/min with injection volume of 20 μL and ultraviolet (UV) detection at 226 nm. Linearity of SOF and DAC was obtained over concentration ranges of 50-400, and 40-400 ng/mL, respectively in pure form, 60-300 and 50-300 ng/mL, respectively for human plasma and over 50-400, and 40-400 ng/mL, respectively for human urine with correlation coefficient >0.999. The proposed method demonstrated excellent intra- and inter-day precision and accuracy. The suggested method was applied for determination of the drugs in pure, dosage form, and in real human plasma, real human urine and drug-dissolution test of their tablets. The obtained results have been statistically compared to reported method to give a conclusion that there is no significant differences. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Quantification and localization of hesperidin and rutin in Citrus sinensis grafted on C. limonia after Xylella fastidiosa infection by HPLC-UV and MALDI imaging mass spectrometry.

    Science.gov (United States)

    Soares, Márcio Santos; da Silva, Danielle Fernandes; Forim, Moacir Rossi; da Silva, Maria Fátima das Graças Fernandes; Fernandes, João Batista; Vieira, Paulo Cezar; Silva, Denise Brentan; Lopes, Norberto Peporine; de Carvalho, Sérgio Alves; de Souza, Alessandra Alves; Machado, Marcos Antônio

    2015-07-01

    A high performance liquid chromatography-ultraviolet (HPLC-UV) method was developed for quantifying hesperidin and rutin levels in leaves and stems of Citrus limonia, with a good linearity over a range of 1.0-80.0 and 1.0-50.0 μg mL(-1) respectively, with r(2)>0.999 for all curves. The limits of detection (LOD) for both flavonoids were 0.6 and 0.5 μg mL(-1), respectively, with quantification (LOQ) being 2.0 and 1.0 μg mL(-1), respectively. The quantification method was applied to Citrus sinensis grafted onto C. limonia with and without CVC (citrus variegated chlorosis) symptoms after Xylella fastidiosa infection. The total content of rutin was low and practically constant in all analyses in comparison with hesperidin, which showed a significant increase in its amount in symptomatic leaves. Scanning electron microscopy studies on leaves with CVC symptoms showed vessel occlusion by biofilm, and a crystallized material was noted. Considering the difficulty in isolating these crystals for analysis, tissue sections were analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) to confirm the presence of hesperidin at the site of infection. The images constructed from MS/MS data with a specific diagnostic fragment ion (m/z 483) also showed higher ion intensities for it in infected plants than in healthy ones, mainly in the vessel regions. These data suggest that hesperidin plays a role in the plant-pathogen interaction, probably as a phytoanticipin. This method was also applied to C. sinensis and C. limonia seedlings, and comparison with the graft results showed that the rootstock had an increased hesperidin content ∼3.6 fold greater in the graft stem than in the stem of C. sinensis seedlings. Increase in hesperidin content by rootstock can be related to induced internal defense mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. HPLC-UV, MALDI-TOF-MS and ESI-MS/MS analysis of the mechlorethamine DNA crosslink at a cytosine-cytosine mismatch pair.

    Directory of Open Access Journals (Sweden)

    Pornchai Rojsitthisak

    Full Text Available Mechlorethamine [ClCH(2CH(2N(CH(3CH(2CH(2Cl], a nitrogen mustard alkylating agent, has been proven to form a DNA interstrand crosslink at a cytosine-cytosine (C-C mismatch pair using gel electrophoresis. However, the atomic connectivity of this unusual crosslink is unknown.HPLC-UV, MALDI-TOF-MS, and ESI-MS/MS were used to determine the atomic connectivity of the DNA C-C crosslink formed by mechlorethamine, MALDI-TOF-MS of the HPLC-purified reaction product of mechlorethamine with the DNA duplex d[CTCACACCGTGGTTC]•d[GAACCACCGTGTGAG] (underlined bases are a C-C mismatch pair indicated formation of an interstrand crosslink at m/z 9222.088 [M-2H+Na](+. Following enzymatic digestion of the crosslinked duplex by snake venom phosphodiesterase and calf intestinal phosphatase, ESI-MS/MS indicated the presence of dC-mech-dC [mech = CH(2CH(2N(CH(3CH(2CH(2] at m/z 269.2 [M](2+ (expected m/z 269.6, exact mass 539.27 and its hydrolytic product dC-mech-OH at m/z 329.6 [M](+ (expected m/z 329.2. Fragmentation of dC-mech-dC gave product ions at m/z 294.3 and 236.9 [M](+, which are both due to loss of the 4-amino group of cytosine (as ammonia, in addition to dC and dC+HN(CH(3CH = CH(2, respectively. The presence of m/z 269.2 [M](2+ and loss of ammonia exclude crosslink formation at cytosine N(4 or O(2 and indicate crosslinking through cytosine N(3 with formation of two quaternary ammonium ions.Our results provide an important addition to the literature, as the first example of the use of HPLC and MS for analysis of a DNA adduct at the N(3 position of cytosine.

  10. Stability-indicating HPLC determination of pramipexole dihydrochloride in bulk drug and pharmaceutical dosage form

    OpenAIRE

    Panditrao, Vedavati M; Sarkate, Aniket P; Sangshetti, Jaiprakash N; Wakte, Pravin S; Shinde, Devanand B

    2011-01-01

    A novel stability-indicating high-performance liquid chromatographic assay method was developed and validated for quantitative determination of pramipexole dihydrochloride in bulk drugs and in pharmaceutical dosage form in the presence of degradation products. An isocratic, reversed phase HPLC method was developed to separate the drug from the degradation products, using an Ace5-C18 (250×4.6 mm, 5 µm) advance chromatography column, and 10 mmol L-1 ammonium acetate and acetonitrile (75:25 v/v)...

  11. Stability-indicating RP-HPLC method for the simultaneous determination of escitalopram oxalate and clonazepam.

    Science.gov (United States)

    Kakde, Rajendra B; Satone, Dinesh D; Gadapayale, Kamalesh K; Kakde, Megha G

    2013-07-01

    The objective of the current study was to develop a validated, specific stability-indicating reversed-phase liquid chromatographic (LC) method for the quantitative determination of escitalopram oxalate and clonazepam and their related substances in bulk drugs and pharmaceutical dosage forms in the presence of degradation products. Forced degradation studies were performed on the pure drugs of escitalopram oxalate and clonazepam, as per the stress conditions prescribed by the International Conference on Harmonization (ICH) using acid, base, oxidation, thermal stress and photolytic degradation to show the stability-indicating power of the method. Significant degradation was observed during acid and alkaline hydrolysis and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies. Good resolution between the peaks corresponded to the active pharmaceutical ingredients, escitalopram oxalate and clonazepam, and degradation products from the analyte were achieved on an ODS Hypersil C18 column (250 × 4.6 mm) using a mobile phase consisting of a mixture of acetonitrile-50 mM phosphate buffer + 10 mM triethylamine (70:30, v/v). The detection was conducted at 268 nm. The limit of detection and the limit of quantitation for escitalopram oxalate and clonazepam were established. The stress test solutions were assayed against the qualified working standards of escitalopram oxalate and clonazepam, which indicated that the developed LC method was stability-indicating. Validation of the developed LC method was conducted as per ICH requirements. The developed LC method was found to be suitable to check the quality of bulk samples of escitalopram oxalate and clonazepam.

  12. Stability-Indicating RP-HPLC Method for Assay of Silver Lactate

    Directory of Open Access Journals (Sweden)

    V. Srinivasan

    2011-01-01

    Full Text Available A simple, economic and time-efficient stability-indicating, reverse-phase high-performance liquid chromatographic (RP-HPLC method has been developed for analysis of silver lactate in the presence of degradation products generated by decomposition. When silver lactate was subjected to acid hydrolysis, base hydrolysis, oxidative, photolytic, humidity and thermal stress, degradation was observed during base hydrolysis, oxidation, humidity and thermal stress. The drug was found to be stable to other stress conditions. Successful chromatographic condition of the drug from the degradation products formed under stress conditions was achieved on a phenomenex Gemini column with potassium dihydrogen phosphate buffer, pH adjusted to 2.2 with orthophosphoric acid, as mobile phase. The method was validated for linearity, precision, specificity and robustness and can be used for quality-control during manufacture and assessment of the stability of samples of silver lactate. To the best of our knowledge, a validated stability-indicating LC assay method for silver lactate based on lactic acid is reported for the first time.

  13. Stability Indicating RP-HPLC Method for Determination of Valsartan in Pure and Pharmaceutical Formulation

    Directory of Open Access Journals (Sweden)

    S. K. Patro

    2010-01-01

    Full Text Available A simple, rapid and accurate and stability indicating RP-HPLC method was developed for the determination of valsartan in pure and tablet forms. The method showed a linear response for concentrations in the range of 50-175 µg/mL using 0.01 M NH4H2PO4 (pH 3.5 buffer: methanol [50:50] as the mobile phase with detection at 210 nm and a flow rate of 1 mL/min and retention time 11.041 min. The method was statistically validated for accuracy, precision, linearity, ruggedness, robustness, forced degradation, solution stability and selectivity. Quantitative and recovery studies of the dosage form were also carried out and analyzed; the % RSD from recovery studies was found to be less than 1. Due to simplicity, rapidity and accuracy of the method, we believe that the method will be useful for routine quality control analysis.

  14. Two Validated HPLC Methods for the Quantification of Alizarin and other Anthraquinones in Rubia tinctorum Cultivars

    NARCIS (Netherlands)

    Derksen, G.C.H.; Lelyveld, G.P.; Beek, van T.A.; Capelle, A.; Groot, de Æ.

    2004-01-01

    Direct and indirect HPLC-UV methods for the quantitative determination of anthraquinones in dried madder root have been developed, validated and compared. In the direct method, madder root was extracted twice with refluxing ethanol-water. This method allowed the determination of the two major native

  15. HPLC-DAD stability indicating determination of nizatidine in bulk and capsules dosage form

    Directory of Open Access Journals (Sweden)

    Tarek S. Belal

    2013-12-01

    Full Text Available This work describes the stability-indicating determination of the H2-receptor antagonist nizatidine in its bulk and capsules dosage form using high performance liquid chromatography coupled with diode array detector (HPLC-DAD. The developed method involved the use of Thermo Hypersil BDS-C8 (4.6 × 250 mm, 5 μm particle size column and a mobile phase composed of 0.05 M phosphoric acid and acetonitrile (50:50, v/v. The mobile phase was pumped at a flow rate of 1 mL/min. Quantification of nizatidine was based on measuring its peak area at 320 nm. The retention time for nizatidine was about 3.61 min. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to linearity, range, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curve of nizatidine was linear in the range of 5–50 μg/mL with correlation coefficient >0.9999. The drug was subjected to forced-degradation conditions of acidic and basic hydrolysis, oxidation, dry heat and UV photolysis where it showed considerable degradation in basic and oxidative conditions. The proposed method proved to be specific and stability-indicating by resolution of the drug from its forced-degradation products. The validated HPLC method was applied to the analysis of nizatidine in capsules dosage form where it was quantified with recoveries not less than 98.2%. Assay results were statistically compared to USP 2011 pharmacopeial method where no significant difference was observed between the proposed and reference methods.

  16. Stability-Indicating HPLC Assay for Determination of Idebenone in Pharmaceutical Forms

    Directory of Open Access Journals (Sweden)

    Sonoube Kombath

    2015-01-01

    Full Text Available A stability-indicating method was validated for the determination in pharmaceutical forms of idebenone a coenzyme Q10-like compound. The assay was achieved by liquid chromatography analysis using a reversed-phase C18 column and a detector set at 480 nm. The optimized mobile phase consisted of isocratic flow rate at 1.0 mL/min for 3 min with methanol. The linearity of the assay was demonstrated in the range of 3.0 to 8.0 mg/mL with a correlation coefficient r2>0.998. The limits of detection and quantification were 0.03 and 0.05 mg/mL, respectively. The intraday and interday precisions were less than 1.0%. Accuracy of the method ranged from 98.6 to 101.5% with RSD < 0.6%. Specificity of the assay showed no interference from tablets components and breakdown products formed by alkaline, acidic, oxidative, sunlight, and high temperature conditions. This method allows accurate and reliable determination of idebenone for drug stability assay in pharmaceutical studies.

  17. Simultaneous separation and analysis of water- and fat-soluble vitamins on multi-modal reversed-phase weak anion exchange material by HPLC-UV.

    Science.gov (United States)

    Dabre, Romain; Azad, Nazanin; Schwämmle, Achim; Lämmerhofer, Michael; Lindner, Wolfgang

    2011-04-01

    Several methods for the separation of vitamins on HPLC columns were already validated in the last 20 years. However, most of the techniques focus on separating either fat- or water-soluble vitamins and only few methods are intended to separate lipophilic and hydrophilic vitamins simultaneously. A mixed-mode reversed-phase weak anion exchange (RP-WAX) stationary phase was developed in our laboratory in order to address such mixture of analytes with different chemical characteristics, which are difficult to separate on standard columns. The high versatility in usage of the RP-WAX chromatographic material allowed a baseline separation of ten vitamins within a single run, seven water-soluble and three fat-soluble, using three different chromatographic modes: some positively charged vitamins are eluted in ion exclusion and ion repulsion modes whereas the negatively charged molecules are eluted in the ion exchange mechanism. The non-charged molecules are eluted in a classical reversed-phase mode, regarding their polarities. The method was validated for the vitamin analysis in tablets, evaluating selectivity, robustness, linearity, accuracy, and precision. The validated method was finally employed for the analysis of the vitamin content of some commercially available supplement tablets. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. New Stability Indicating RP-HPLC Method for the Estimation of Cefpirome Sulphate in Bulk and Pharmaceutical Dosage Forms

    OpenAIRE

    Rao, Kareti Srinivasa; Kumar, Keshar Nargesh; Joydeep, Datta

    2011-01-01

    A simple stability indicating reversed-phase HPLC method was developed and subsequently validated for estimation of Cefpirome sulphate (CPS) present in pharmaceutical dosage forms. The proposed RP-HPLC method utilizes a LiChroCART-Lichrosphere100, C18 RP column (250 mm ? 4mm ? 5 ?m) in an isocratic separation mode with mobile phase consisting of methanol and water in the proportion of 50:50 % (v/v), at a flow rate 1ml/min, and the effluent was monitored at 270 nm. The retention time of CPS wa...

  19. Development and Validation of a Stability-Indicating LC-UV Method ...

    African Journals Online (AJOL)

    Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved. Available online at http://www.tjpr.org ... dihydrochloride in solid dosage forms. Methods: Chromatographic separation was achieved on Grace Smart C18 column (250 × 4.6 mm, 5 μm) using an isocratic mobile ...

  20. Stability Indicating Reverse Phase HPLC Method for Estimation of Rifampicin and Piperine in Pharmaceutical Dosage Form.

    Science.gov (United States)

    Shah, Umang; Patel, Shraddha; Raval, Manan

    2018-01-01

    High performance liquid chromatography is an integral analytical tool in assessing drug product stability. HPLC methods should be able to separate, detect, and quantify the various drug-related degradants that can form on storage or manufacturing, plus detect any drug-related impurities that may be introduced during synthesis. A simple, economic, selective, precise, and stability-indicating HPLC method has been developed and validated for analysis of Rifampicin (RIFA) and Piperine (PIPE) in bulk drug and in the formulation. Reversed-phase chromatography was performed on a C18 column with Buffer (Potassium Dihydrogen Orthophosphate) pH 6.5 and Acetonitrile, 30:70), (%, v/v), as mobile phase at a flow rate of 1 mL min-1. The detection was performed at 341 nm and sharp peaks were obtained for RIFA and PIPE at retention time of 3.3 ± 0.01 min and 5.9 ± 0.01 min, respectively. The detection limits were found to be 2.385 ng/ml and 0.107 ng/ml and quantification limits were found to be 7.228ng/ml and 0.325ng/ml for RIFA and PIPE, respectively. The method was validated for accuracy, precision, reproducibility, specificity, robustness, and detection and quantification limits, in accordance with ICH guidelines. Stress study was performed on RIFA and PIPE and it was found that these degraded sufficiently in all applied chemical and physical conditions. Thus, the developed RP-HPLC method was found to be suitable for the determination of both the drugs in bulk as well as stability samples of capsule containing various excipients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. A comparative study of voltage stability indices in a power system

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, A.K. [I.I.T., Kharagpur (India). Dept. of Electrical Engineering; Hazarika, D. [Assam Engineering College (India)

    2000-11-01

    The paper compares the effectiveness of voltage stability indices in providing information about the proximity of voltage instability of a power system. Three simple voltage stability indices are proposed and their effectiveness is compared with some of the recently proposed indices. The comparison is carried out over a wide range of system operating conditions by changing the load power factor and feeder X/R ratios. Test results for the IEEE 57 bus and IEEE 118 bus system are presented. (author)

  2. Development of an Ion-Pairing Reagent and HPLC-UV Method for the Detection and Quantification of Six Water-Soluble Vitamins in Animal Feed

    Directory of Open Access Journals (Sweden)

    Ho Jin Kim

    2016-01-01

    Full Text Available A novel and simple method for detecting six water-soluble vitamins in animal feed using high performance liquid chromatography equipped with a photodiode array detector (HPLC/PDA and ion-pairing reagent was developed. The chromatographic peaks of the six water-soluble vitamins were successfully identified by comparing their retention times and UV spectra with reference standards. The mobile phase was composed of buffers A (5 mM PICB-6 in 0.1% CH3COOH and B (5 mM PICB-6 in 65% methanol. All peaks were detected using a wavelength of 270 nm. Method validation was performed in terms of linearity, sensitivity, selectivity, accuracy, and precision. The limits of detection (LODs for the instrument employed in these experiments ranged from 25 to 197 μg/kg, and the limits of quantification (LOQs ranged from 84 to 658 μg/kg. Average recoveries of the six water-soluble vitamins ranged from 82.3% to 98.9%. Method replication resulted in intraday and interday peak area variation of <5.6%. The developed method was specific and reliable and is therefore suitable for the routine analysis of water-soluble vitamins in animal feed.

  3. Microwave-assisted extraction of herbacetin diglucoside from flax (Linum usitatissimum L.) seed cakes and its quantification using an RP-HPLC-UV system.

    Science.gov (United States)

    Fliniaux, Ophélie; Corbin, Cyrielle; Ramsay, Aina; Renouard, Sullivan; Beejmohun, Vickram; Doussot, Joël; Falguières, Annie; Ferroud, Clotilde; Lamblin, Frédéric; Lainé, Eric; Roscher, Albrecht; Grand, Eric; Mesnard, François; Hano, Christophe

    2014-03-10

    Flax (Linum usitatissimum L.) seeds are widely used for oil extraction and the cold-pressed flaxseed (or linseed) cakes obtained during this process constitute a valuable by-product. The flavonol herbacetin diglucoside (HDG) has been previously reported as a constituent of the flaxseed lignan macromolecule linked through ester bonds to the linker molecule hydroxymethylglutaric acid. In this context, the development and validation of a new approach using microwave-assisted extraction (MAE) of HDG from flaxseed cakes followed by quantification with a reverse-phase HPLC system with UV detection was purposed. The experimental parameters affecting the HDG extraction yield, such as microwave power, extraction time and sodium hydroxide concentration, from the lignan macromolecule were optimized. A maximum HDG concentration of 5.76 mg/g DW in flaxseed cakes was measured following an irradiation time of 6 min, for a microwave power of 150 W using a direct extraction in 0.1 M NaOH in 70% (v/v) aqueous methanol. The optimized method was proven to be rapid and reliable in terms of precision, repeatability, stability and accuracy for the extraction of HDG. Comparison with a conventional extraction method demonstrated that MAE is more effective and less time-consuming.

  4. Development of an Ion-Pairing Reagent and HPLC-UV Method for the Detection and Quantification of Six Water-Soluble Vitamins in Animal Feed.

    Science.gov (United States)

    Kim, Ho Jin

    2016-01-01

    A novel and simple method for detecting six water-soluble vitamins in animal feed using high performance liquid chromatography equipped with a photodiode array detector (HPLC/PDA) and ion-pairing reagent was developed. The chromatographic peaks of the six water-soluble vitamins were successfully identified by comparing their retention times and UV spectra with reference standards. The mobile phase was composed of buffers A (5 mM PICB-6 in 0.1% CH3COOH) and B (5 mM PICB-6 in 65% methanol). All peaks were detected using a wavelength of 270 nm. Method validation was performed in terms of linearity, sensitivity, selectivity, accuracy, and precision. The limits of detection (LODs) for the instrument employed in these experiments ranged from 25 to 197 μg/kg, and the limits of quantification (LOQs) ranged from 84 to 658 μg/kg. Average recoveries of the six water-soluble vitamins ranged from 82.3% to 98.9%. Method replication resulted in intraday and interday peak area variation of water-soluble vitamins in animal feed.

  5. Analysis of Flavone C-Glycosides in the Leaves of Clinacanthus nutans (Burm. f.) Lindau by HPTLC and HPLC-UV/DAD

    Science.gov (United States)

    Chelyn, June Lee; Omar, Maizatul Hasyima; Mohd Yousof, Nor Syaidatul Akmal; Ranggasamy, Ramesh; Wasiman, Mohd Isa; Ismail, Zakiah

    2014-01-01

    Clinacanthus nutans (family Acanthaceae) has been used for the treatment of inflammation and herpes viral infection. Currently, there has not been any report on the qualitative and quantitative determination of the chemical markers in the leaves of C. nutans. The C-glycosidic flavones such as shaftoside, isoorientin, orientin, isovitexin, and vitexin have been found to be major flavonoids in the leaves of this plant. Therefore, we had developed a two-step method using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC) for the rapid identification and quantification of the flavones C-glycosides in C. nutans leaves. The TLC separation of the chemical markers was achieved on silica gel 60 plate using ethyl acetate : formic acid : acetic acid : water (100 : 11 : 11 : 27 v/v/v/v) as the mobile phase. HPLC method was optimized and validated for the quantification of shaftoside, orientin, isovitexin, and vitexin and was shown to be linear in concentration range tested (0.4–200 μg/mL, r 2 ≥ 0.996), precise (RSD ≤ 4.54%), and accurate (95–105%). The concentration of shaftoside, orientin, vitexin, and isovitexin in C. nutans leave samples was 2.55–17.43, 0.00–0.86, 0.00–2.01, and 0.00–0.91 mmol/g, respectively. PMID:25405231

  6. Analysis of Flavone C-Glycosides in the Leaves of Clinacanthus nutans (Burm. f. Lindau by HPTLC and HPLC-UV/DAD

    Directory of Open Access Journals (Sweden)

    June Lee Chelyn

    2014-01-01

    Full Text Available Clinacanthus nutans (family Acanthaceae has been used for the treatment of inflammation and herpes viral infection. Currently, there has not been any report on the qualitative and quantitative determination of the chemical markers in the leaves of C. nutans. The C-glycosidic flavones such as shaftoside, isoorientin, orientin, isovitexin, and vitexin have been found to be major flavonoids in the leaves of this plant. Therefore, we had developed a two-step method using thin-layer chromatography (TLC and high pressure liquid chromatography (HPLC for the rapid identification and quantification of the flavones C-glycosides in C. nutans leaves. The TLC separation of the chemical markers was achieved on silica gel 60 plate using ethyl acetate : formic acid : acetic acid : water (100 : 11 : 11 : 27 v/v/v/v as the mobile phase. HPLC method was optimized and validated for the quantification of shaftoside, orientin, isovitexin, and vitexin and was shown to be linear in concentration range tested (0.4–200 μg/mL, r2 ≥ 0.996, precise (RSD ≤ 4.54%, and accurate (95–105%. The concentration of shaftoside, orientin, vitexin, and isovitexin in C. nutans leave samples was 2.55–17.43, 0.00–0.86, 0.00–2.01, and 0.00–0.91 mmol/g, respectively.

  7. Stability-Indicating HPLC Method for Simultaneous Determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in Ophthalmic Solution.

    Science.gov (United States)

    AlAani, Hashem; Alnukkary, Yasmin

    2016-03-01

    A simple stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in ophthalmic solution in the presence of 2-amino-1-(4-nitrophenyl)propane-1,3-diol, a degradation product of Chloramphenicol, and Dexamethasone, a degradation product of Dexamethasone Sodium Phosphate. Effective chromatographic separation was achieved using C18 column (250 mm, 4.6 mm i.d., 5 μm) with isocratic mobile phase consisting of acetonitrile - phosphate buffer (pH 4.0; 0.05 M) (30:70, v/v) at a flow rate of 1 mL/minute. The column temperature was maintained at 40°C and the detection wavelength was 230 nm. The proposed HPLC procedure was statistically validated according to the ICH guideline, and was proved to be stability-indicating by resolution of the APIs from their forced degradation products. The developed method is suitable for the routine analysis as well as stability studies.

  8. Stability Indicating HPLC Method for Simultaneous Quantification of Trihexyphenidyl Hydrochloride, Trifluoperazine Hydrochloride and Chlorpromazine Hydrochloride from Tablet Formulation

    Directory of Open Access Journals (Sweden)

    P. Shetti

    2010-01-01

    Full Text Available A new, simple, precise, rapid, selective and stability indicating reversed-phase high performance liquid chromatographic (HPLC method has been developed and validated for simultaneous quantification of trihexyphenidyl hydrochloride, trifluoperazine hydrochloride and chlorpromazine hydrochloride from combined tablet formulation. The method is based on reverse-phase using C-18 (250×4.6 mm, 5 μm particle size column. The separation is achieved using isocratic elution by methanol and ammonium acetate buffer (1% w/v, pH 6.5 in the ratio of 85:15 v/v, pumped at flow rate 1.0 mL/min and UV detection at 215 nm. The column is maintained at 30 °C through out the analysis. This method gives baseline resolution. The total run time is 15 min. Stability indicating capability is established buy forced degradation experiment. The method is validated for specificity, accuracy, precision and linearity as per International conference of harmonisation (ICH. The method is accurate and linear for quantification of trihexyphenidyl hydrochloride, trifluoperazine hydrochloride and Chlorpromazine hydrochloride between 5 - 15 μg/mL, 12.5- 37.5 μg/mL and 62.5 - 187.5 μg/mL respectively.

  9. Stability-indicating UPLC method for determining related substances and degradants in dronedarone.

    Science.gov (United States)

    Pydimarry, Surya Prakash Rao; Cholleti, Vijay Kumar; Vangala, Ranga Reddy

    2014-08-01

    A simple, sensitive and reproducible method was developed on ultra-performance liquid chromatography coupled with photodiode array detection for the quantitative determination of dronedarone hydrochloride (DRO) in drug substance and pharmaceutical dosage forms. The method is applicable for the quantification of related substances and assays of drug substances. Chromatographic separation was achieved on Acquity UPLC BEH C8 100 mm, 2.1 mm and 1.7 µm columns, using gradient elution within a short run time of 10.0 min. The eluted compounds were monitored at 288 nm, the flow rate was 0.5 mL/min and the column oven temperature was maintained at 40°C. The resolution of DRO and 11 impurities (potentials and by-products) was greater than 2.0 for all pairs of components. The high correlation coefficient value (>0.9995) indicates the clear correlations between the concentrations of investigated compound and their peak areas within the test ranges. The repeatability and intermediate precision, expressed by the relative standard deviation, were less than 2.5%. The accuracy and validity of the method were further ascertained by performing recovery studies via a spike method. The accuracy of the method, expressed as relative error, was satisfactory. No interference was observed from concomitant substances normally added to the tablets. DRO was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. DRO was found to degrade significantly in acid and base stress conditions and to remain stable in thermal, photolytic degradation, oxidative and hydrolytic conditions. The degradation products were well resolved from primary peak and its impurities, proving that the method is stability indicating. The developed method was validated as per International Conference on Harmonization guidelines with respect to specificity, limit of detection, limit of quantification, linearity, accuracy, precision, solution stability and robustness

  10. Wide Area Prosumption Control and Sensitivities of Aperiodic Small Signal Stability Indicators

    DEFF Research Database (Denmark)

    Wittrock, Martin Lindholm; Jóhannsson, Hjörtur; Nielsen, Arne Hejde

    2014-01-01

    and patterns, stability indicators for aperiodic small signal angular stability (ASSA) are examined, while the concept of prosumption is described. The methodology presented is shown to be able to assess the margin to instability and to predict how this margin can be affected if a load is changed in the grid...

  11. Determination of Histamine in Fishery Products by HPLC-UV Method%高效液相色谱-紫外检测法测定水产品中组胺的含量

    Institute of Scientific and Technical Information of China (English)

    邢丽红; 冷凯良; 孙伟红; 李兆新; 苗钧魁; 翟毓秀

    2011-01-01

    [Objective] The aim was to construct a method for the determination of histamine in fishery products by HPLC-UV. [ Method] Histamine in the test sample was extracted with perchloric acid, and then derived by dansyl chloride, and nextly determined by high performanoe liquid chromatograph with UV detector, at last quantified by an external standard mode. [ Result] The histamine showed a good linear relationship within the range of 0. 5 -20 μg/ml with the correlation coefficient r >0.999. The average recoveries ranged from 81.0% to 94.8% and the relative standard deviation was all below 10% when the addition concentration of histamine in the blank sample was within 50 - 1000 mg/kg. The detection limit of histamine was 25 mg/kg and the limit of quantification was 50 mg/kg. [ Conclusion] The sample was easy to operate, which could satisfy the requirements of the determination of histamine in fishery products.%[目的]建立一种测定水产品中组胺含量的高效液相色谱-紫外检测法.[方法]用高氯酸提取水产品中的组胺,丹磺酰氯衍生后,用配有紫外检测器的高效液相色谱仪进行测定,外标法定量.[结果]组胺在0.5-20.0μg/ml范围内线性关系良好,相关系数r>0.999.空白样品中组胺添加浓度在50~1000mg/kg时,平均回收率在81.O%~94.8%,批次内和批次间相对标准偏差均<10%.组胺的检出限为25 mg/kg,定量限为50 mg/kg.[结论]该方法操作简便,能够满足水产品中组胺含量的测定要求.

  12. Stability-Indicating RP-HPLC Method for Determination of Guanfacine Hydrochloride in Bulk Drugs and in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Vinod K. Ahirrao

    2011-04-01

    Full Text Available A novel stability-indicating RP-HPLC method was developed and validated for quantitative determination of guanfacine hydrochloride in bulk drug and in pharmaceutical dosage form. An isocratic, reversed phase HPLC method was developed to separate the drug from the degradation products, using Apollo, C18 (250mm x 4.6mm, 5µm column with mobile phase of 50mM Ammonium acetate (volatile buffer and acetonitrile (65:35, v/v. UV detection has been done at wavelength 220 nm. The guanfacine hydrochloride was subjected to the stress conditions of hydrolysis (acid, base, oxidation, photolysis and thermal degradation. The stressed samples were analyzed by the proposed method. The analyte peak shape was excellent. The described method shows excellent linearity over a range of 30 – 450 µg/mL. The correlation coefficient for guanfacine hydrochloride was 0.999. The limit of detection for Guanfacine hydrochloride is 0.011 µg/mL and the limit of quantification is 0.038 µg/mL respectively.Degradation was observed for guanfacine hydrochloride in base, thermal and in 30% H2O2 conditions. The drug was found to be stable in the other stress conditions attempted. The degradation products were well resolved from main peak. The percentage recovery of guanfacine hydrochloride was ranged from (99.2% to 100.5% in pharmaceutical dosage form. The developed method was validated with respect to the linearity, accuracy (recovery, precision, specificity and robustness. The forced degradation studies prove the stability indicating power of the method.

  13. Stability Indicating RP-HPLC Method for Simultaneous Determination of Aspirin and Clopidrogel in Dosage Form

    International Nuclear Information System (INIS)

    Mohd Gousuddin; Sengupta, P.; Tripathi, V.D.; Das, A.

    2016-01-01

    Stability-indicating High Performance Liquid Chromatographic (HPLC) method was developed for simultaneous Aspirin and Clopidogrel, A Phenomenex Gemini C-18, 5 μm column having 250 mm x 4.6 mm i.d. in isocratic mode, with mobile phase containing buffer solution 0.3 % orthophosphoric acid : acetonitrile (65:35, v/v). The flow rate was 1 ml/ min and effluents were monitored at 266 nm. For linearity seven points calibration curve were obtained in a concentration range from 0.030-0.120 mg/ ml for aspirin and 0.015-0.060 mg/ ml for clopidogrel with correlation coefficient 0.9999. In the present study stability indicating HPLC method for the combination was tested by degrading the drugs together under various stress conditions like acid hydrolysis, base hydrolysis, oxidation, thermal and photolytic stress which is recommended by ICH guideline. (author)

  14. Stability Indicating LC-Method for Estimation of Paracetamol and Lornoxicam in Combined Dosage Form

    OpenAIRE

    Shah, Dimal A.; Patel, Neel J.; Baldania, Sunil L.; Chhalotiya, Usman K.; Bhatt, Kashyap K.

    2011-01-01

    A simple, specific and stability indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of paracetamol and lornoxicam in tablet dosage form. A Brownlee C-18, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.05 M potassium dihydrogen phosphate:methanol (40:60, v/v) was used. The flow rate was 1.0 ml/min and effluents were monitored at 266 nm. The retention times of paracetamol and lornoxicam ...

  15. Stability-indicating liquid chromatographic method for quantification of new anti-epileptic drug lacosamide in bulk and pharmaceutical formulation

    Directory of Open Access Journals (Sweden)

    Chhalotiya Usmangani K.

    2012-01-01

    Full Text Available An isocratic stability indicating reversed-phase liquid chromatographic determination was developed for the quantitative determination of lacosamide in the pharmaceutical dosage form. A Hypersil C-18, 4.5μm column with mobile phase containing acetonitrile-water (20:80, v/v was used. The flow rate was 1.0 mL min-1 and effluents were monitored at 258 nm. The retention time of lacosamide was 8.9 min. The method was found to be linear in the concentration range of 5-100 μg/ml and the recovery was found to be in the range of 99.15 - 100.09 %. The limit of detection and limit of quantification were found to be 2 μg/ml and 5 μg/ml, respectively. Lacosamide stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The drug was found to be stable to the dry heat and acidic condition attempted. The proposed method was validated and successfully applied to the estimation of lacosamide in tablet dosage forms.

  16. Stability indicating RP-HPLC method for simultaneous determination of pantoprazole sodium and itopride hydrochloride in bulk and capsule

    Directory of Open Access Journals (Sweden)

    Krishna R. Gupta

    2011-03-01

    Full Text Available A stability indicating reversed-phase HPLC method has been developed and subsequently validated for simultaneous estimation of pantoprazole present as pantoprazole sodium sesquihydrate (PSS, and itopride hydrochloride from their combination product. The proposed RP-HPLC method utilizes a Phenomenex® C18, 5 µm, 250 mm X 4.6 mm i.d. column, mobile phase consisting of phosphate buffer and acetonitrile in the proportion of 55:45 (v/v with apparent pH adjusted to 5.0, and UV detection at 289.0 nm using a UV detector. PAN, ITH and their combination drug product were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. The described method was linear over a range of 4-20 µg/mL for PAN and 15-75 µg/mL for ITH. The mean recoveries were 100.02 and 99.88 for PAN and ITH, respectively. Chromatographic peak purity data of PAN and ITH indicated no co-eluting peaks with the main peaks of drugs which demonstrated the specificity of assay method for their estimation in presence of degradation products. The proposed method can be useful in the quality control of combination drug products.

  17. New Stability Indicating RP-HPLC Method for the Estimation of Cefpirome Sulphate in Bulk and Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Rao, Kareti Srinivasa; Kumar, Keshar Nargesh; Joydeep, Datta

    2011-01-01

    A simple stability indicating reversed-phase HPLC method was developed and subsequently validated for estimation of Cefpirome sulphate (CPS) present in pharmaceutical dosage forms. The proposed RP-HPLC method utilizes a LiChroCART-Lichrosphere100, C18 RP column (250 mm × 4mm × 5 μm) in an isocratic separation mode with mobile phase consisting of methanol and water in the proportion of 50:50 % (v/v), at a flow rate 1ml/min, and the effluent was monitored at 270 nm. The retention time of CPS was 2.733 min and its formulation was exposed to acidic, alkaline, photolytic, thermal and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. The described method was linear over a range of 0.5-200μg/ml. The percentage recovery was 99.46. F-test and t-test at 95% confidence level were used to check the intermediate precision data obtained under different experimental setups; the calculated value was found to be less than the critical value.

  18. Stability indicating high performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in combined dosage form

    Directory of Open Access Journals (Sweden)

    Deepak Bageshwar

    2011-11-01

    Full Text Available A specific, precise and stability indicating high-performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in pharmaceutical formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F254 as the stationary phase. The solvent system consisted of methanol:water:ammonium acetate; 4.0:1.0:0.5 (v/v/v. This system was found to give compact and dense spots for both itopride hydrochloride (Rf value of 0.55±0.02 and pantoprazole sodium (Rf value of 0.85±0.04. Densitometric analysis of both drugs was carried out in the reflectance–absorbance mode at 289 nm. The linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9988±0.0012 in the concentration range of 100–400 ng for pantoprazole sodium. Also, the linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9990±0.0008 in the concentration range of 200–1200 ng for itopride hydrochloride. The method was validated for specificity, precision, robustness and recovery. Statistical analysis proves that the method is repeatable and selective for the estimation of both the said drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method. Keywords: Gastroesophageal reflux disease (GERD, Itopride hydrochloride, Pantoprazole sodium, High performance thin layer chromatography (HPTLC, Stability indicating, Forced degradation

  19. Stability-Indicating HPTLC Method for Simultaneous Estimation of Flurbiprofen and Chloramphenicol in Ophthalmic Solution.

    Science.gov (United States)

    Sadakwala, Vaishnavi M; Chauhan, Renu S; Shah, Shailesh A; Shah, Dinesh R

    2016-01-01

    A specific, accurate and reproducible stability-indicating high performance thin layer chromatography (HPTLC) method was developed for the estimation of flurbiprofen and chloramphenicol in the presence of their degradation products. Degradation studies of both the drugs were carried out in acidic, alkaline, neutral, oxidative, photolytic and thermal stress conditions. Separation was performed on thin layer chromatography plate precoated with silica gel 60 F254 using ethyl acetate : n-hexane : methanol : tri-ethyl amine (5 : 4 : 2 : 0.5, v/v/v/v). Spots at retention factor 0.29 and 0.62 were recognized as flurbiprofen and chloramphenicol, respectively, and were quantified through densitometric measurements at wavelength 267 nm. Method was found to be linear over the concentration range 12-60 ng/spot with correlation coefficient of 0.9997 for flurbiprofen and 200-1,000 ng/spot with correlation coefficient of 0.9977 for chloramphenicol. The proposed method was applied to the estimation of flurbiprofen and chloramphenicol in commercial ophthalmic formulation. The developed HPTLC method can be applied for routine analysis of flurbiprofen and chloramphenicol in the presence of their degradation products in their individual as well as combined pharmaceutical formulations. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Stability-Indicating Assay for the Determination of Pentobarbital Sodium in Liquid Formulations

    Directory of Open Access Journals (Sweden)

    Myriam Ajemni

    2015-01-01

    Full Text Available A stability-indicating assay by reversed-phase high performance liquid chromatography (RP-HPLC method was developed for the determination of pentobarbital sodium in oral formulations: a drug used for infant sedation in computed tomography (CT or magnetic resonance imaging (MRI scan. The chromatographic separation was achieved on a reversed-phase C18 column, using isocratic elution and a detector set at 214 nm. The optimized mobile phase consisted of a 0.01 M potassium buffer pH 3 and methanol (40 : 60, v/v. The flow rate was 1.0 mL/min and the run time of analysis was 5 min. The linearity of the method was demonstrated in the range of 5 to 250 μg/mL pentobarbital sodium solution (r2 = 0.999. The limit of detection and limit of quantification were 2.10 and 3.97 μg/mL, respectively. The intraday and interday precisions were less than 2.1%. Accuracy of the method ranged from 99.2 to 101.3%. Stability studies indicate that the drug is stable to sunlight and in aqueous solution. Accelerated pentobarbital sodium breakdown by strong alkaline, acidic, or oxidative stress produced noninterfering peaks. This method allows accurate and reliable determination of pentobarbital sodium for drug stability assay in pharmaceutical studies.

  1. Stability indicating high performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in combined dosage form.

    Science.gov (United States)

    Bageshwar, Deepak; Khanvilkar, Vineeta; Kadam, Vilasrao

    2011-11-01

    A specific, precise and stability indicating high-performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in pharmaceutical formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F 254 as the stationary phase. The solvent system consisted of methanol:water:ammonium acetate; 4.0:1.0:0.5 (v/v/v). This system was found to give compact and dense spots for both itopride hydrochloride ( R f value of 0.55±0.02) and pantoprazole sodium ( R f value of 0.85±0.04). Densitometric analysis of both drugs was carried out in the reflectance-absorbance mode at 289 nm. The linear regression analysis data for the calibration plots showed a good linear relationship with R 2 =0.9988±0.0012 in the concentration range of 100-400 ng for pantoprazole sodium. Also, the linear regression analysis data for the calibration plots showed a good linear relationship with R 2 =0.9990±0.0008 in the concentration range of 200-1200 ng for itopride hydrochloride. The method was validated for specificity, precision, robustness and recovery. Statistical analysis proves that the method is repeatable and selective for the estimation of both the said drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method.

  2. A rapid stability indicating LC-method for determination of praziquantel in presence of its pharmacopoeial impurities

    Directory of Open Access Journals (Sweden)

    Hisham Hashem

    2017-02-01

    Full Text Available This study reports for the first time about a stability indicating RP-HPLC method for quantitative determination of Praziquantel (PZQ in bulk powder and dosage form and in presence of its pharmacopoeial impurities. The chromatographic separation was carried out on (Caltrex AI® calixarene column, a relatively new packing material. Chromatography was done using an isocratic binary mobile phase consisting of ACN and 25 mM ammonium acetate (NH4Ac in the ratio of 40:60 at flow rate of 1 mL min−1, 30 °C and 210 nm wavelength for detection. The elution time of PZQ was found to be 6.15 ± 0.03 min. The method was validated for system suitability, linearity, precision, limits of detection and quantitation, specificity, stability and robustness. The robustness study was done for small changes in temperature, flow rate, wavelength of detection and % of ACN in mobile phase. Stability tests were done through exposure of the analyte solution to five different stress conditions: Reflux with 1 N HCl, reflux with 1 N NaOH, reflux with 30% H2O2, thermal degradation of powder and exposure to UV radiation. Limits of detection and quantification were found to be 0.56 and 1.70 μg mL−1, respectively. The recovery value of this method was 100.30% ± 1.10 and the reproducibility was within 1.31.

  3. Stability indicating spectrophotometric and spectrodensitometric methods for the determination of diatrizoate sodium in presence of its degradation product

    Science.gov (United States)

    Abd El-Rahman, Mohamed K.; Riad, Safaa M.; Abdel Gawad, Sherif A.; Fawaz, Esraa M.; Shehata, Mostafa A.

    2015-02-01

    Three sensitive, selective, and precise stability indicating methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA), in the presence of its acidic degradation product (highly cytotoxic 3,5 diamino metabolite) and in pharmaceutical formulation were developed and validated. The first method is a first derivative (D1) spectrophotometric one, which allows the determination of DTA in the presence of its degradate at 231.2 nm (corresponding to zero crossing of the degradate) over a concentration range of 2-24 μg/mL with mean percentage recovery 99.95 ± 0.97%. The second method is the first derivative of the ratio spectra (DD1) by measuring the peak amplitude at 227 nm over the same concentration range as D1 spectrophotometric method, with mean percentage recovery 99.99 ± 1.15%. The third method is a TLC-densitometric one, where DTA was separated from its degradate on silica gel plates using chloroform:methanol:ammonium hydroxide (20:10:2 by volume) as a developing system. This method depends on quantitative densitometric evaluation of thin layer chromatogram of DTA at 238 nm over a concentration range of 4-20 μg/spot, with mean percentage recovery 99.88 ± 0.89%. The selectivity of the proposed methods was tested using laboratory-prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed.

  4. Stability-indicating methods for the determination of racecadotril in the presence of its degradation products.

    Science.gov (United States)

    Mohamed, Afaf O; Fouad, Manal M; Hasan, Mona M; Abdel Razeq, Sawsan A; Elsherif, Zeinab A

    2009-12-01

    Three stability-indicating methods were developed for the determination of racecadotril (RCT) in the presence of its alkaline degradation products. The first was an HPLC method in which efficient chromatographic separation was achieved on a C18 analytical column and a mobile phase of acetonitrile-methanol-water-acetic acid (52:28:20:0.1, v/v/v/v). Linearity was obtained in the range of 4-40 microg/mL with mean accuracy of 99.5 +/- 0.88%. The second method was a densitometric evaluation of thin-layer chromatograms of the drug using a mobile phase of isopropanol-ammonia (33%)-n-hexane (9:0.5:20, v/v/v). The chromatograms were scanned at 232 nm, a wavelength at which RCT can be readily separated from its degradation products and determined in the range of 2-20 microg per spot with mean accuracy of 99.5 +/- 0.56%. The third method is based on the use of first-derivative spectrophotometry (D1) at 240 nm, and the drug was determined in the range of 5-40 microg/mL with mean accuracy of 99.2 +/- 1.02%. The three methods provided satisfactory recovery of the intact drug (100.8 +/- 0.82, 100.4 +/- 0.55, and 99.9 +/- 0.72%, respectively) in the presence of up to 90% of its degradation products. Determination was also successful when analyzing RCT in a formulation in the form of acetorphan packets. Results were statistically analyzed and found to be in accordance with those given by a reported method.

  5. Stability-indicating UPLC method for determination of Valsartan and their degradation products in active pharmaceutical ingredient and pharmaceutical dosage forms.

    Science.gov (United States)

    Krishnaiah, Ch; Reddy, A Raghupathi; Kumar, Ramesh; Mukkanti, K

    2010-11-02

    A simple, precise, accurate stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the quantitative determination of purity of Valsartan drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. The method was developed using Waters Aquity BEH C18 (100 mm x 2.1 mm, 1.7 microm) column with mobile phase containing a gradient mixture of solvents A and B. The eluted compounds were monitored at 225 nm, the run time was within 9.5 min, which Valsartan and its seven impurities were well separated. Valsartan was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Valsartan was found to degrade significantly in acid and oxidative stress conditions and stable in base, hydrolytic and photolytic degradation conditions. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per international conference on harmonization (ICH) guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of Valsartan in pharmaceutical dosage forms.

  6. Application of spectrophotometric, densitometric, and HPLC techniques as stability indicating methods for determination of Zaleplon in pharmaceutical preparations

    Science.gov (United States)

    Metwally, Fadia H.; Abdelkawy, M.; Abdelwahab, Nada S.

    2007-12-01

    Spectrophotometric, spectrodensitometric and HPLC are stability indicating methods described for determination of Zaleplon in pure and dosage forms. As Zaleplon is easily degradable, the proposed techniques in this manuscript are adopted for its determination in presence of its alkaline degradation product, namely N-[4-(3-cyano-pyrazolo[1,5a]pyridin-7-yl)-phenyl]- N-ethyl-acetamide. These approaches are successfully applied to quantify Zaleplon using the information included in the absorption spectra of appropriate solutions. The second derivative (D 2) spectrophotometric method, allows determination of Zaleplon without interference of its degradate at 235.2 nm using 0.01N HCl as a solvent with obedience to Beer's law over a concentration range of 1-10 μg ml -1 with mean percentage recovery 100.24 ± 0.86%. The first derivative of the ratio spectra ( 1DD) based on the simultaneous use of ( 1DD) and measurement at 241.8 nm using the same solvent and over the same concentration range as (D 2) spectrophotometric method, with mean percentage recovery 99.9 ± 1.07%. The spectrodensitometric analysis allows the separation and quantitation of Zaleplon from its degradate on silica gel plates using chloroform:acetone:ammonia solution (9:1:0.2 by volume) as a mobile phase. This method depends on quantitave densitometric evaluation of thin layer chromatogram of Zaleplon at 338 nm over a concentration range of 0.2-1 μg band -1, with mean percentage recovery 99.73 ± 1.35. Also a reversed-phase liquid chromatographic method using 5-C8 (22 cm × 4.6 mm i.d. 5 μm particle size) column was described and validated for quantitation of Zaleplon using acetonitrile:deionised water (35:65, v/v) as a mobile phase using Paracetamol as internal standard and a flow rate of 1.5 ml min -1 with UV detection of the effluent at 232 nm at ambient temperature over a concentration range of 2-20 μg ml -1 with mean percentage recovery 100.19 ± 1.15%. The insignificance difference of the proposed

  7. Stability indicating studies on NMITLI 118RT+ (standardized extract of withania somnifera dunal)

    OpenAIRE

    Ahmad, Hafsa; Khandelwal, Kiran; Pachauri, Shakti Deep; Sanghwan, Rajender Singh; Dwivedi, Anil Kumar

    2014-01-01

    Background: Withania somnifera Dunal (Ashwagandha) is an Indian medicinal plant of great medicinal value; used in many clinically proven conditions. NMITLI-118RT+ is a candidate drug under a Council of Scientific and Industrial Research (CSIR) networking project. It is a chemotype of W. somnifera's root extract, which has been used for the present study. Objectives: The present investigation aims to develop and validate a simple isocratic reverse phase-high performance liquid chromatography (...

  8. A comparative study between three stability indicating spectrophotometric methods for the determination of diatrizoate sodium in presence of its cytotoxic degradation product based on two-wavelength selection

    Science.gov (United States)

    Riad, Safaa M.; El-Rahman, Mohamed K. Abd; Fawaz, Esraa M.; Shehata, Mostafa A.

    2015-06-01

    Three sensitive, selective, and precise stability indicating spectrophotometric methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA) in the presence of its acidic degradation product (highly cytotoxic 3,5-diamino metabolite) and in pharmaceutical formulation, were developed and validated. The first method is ratio difference, the second one is the bivariate method, and the third one is the dual wavelength method. The calibration curves for the three proposed methods are linear over a concentration range of 2-24 μg/mL. The selectivity of the proposed methods was tested using laboratory prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed.

  9. Ratio manipulating spectrophotometry versus chemometry as stability indicating methods for cefquinome sulfate determination.

    Science.gov (United States)

    Yehia, Ali M; Arafa, Reham M; Abbas, Samah S; Amer, Sawsan M

    2016-01-15

    Spectral resolution of cefquinome sulfate (CFQ) in the presence of its degradation products was studied. Three selective, accurate and rapid spectrophotometric methods were performed for the determination of CFQ in the presence of either its hydrolytic, oxidative or photo-degradation products. The proposed ratio difference, derivative ratio and mean centering are ratio manipulating spectrophotometric methods that were satisfactorily applied for selective determination of CFQ within linear range of 5.0-40.0 μg mL(-1). Concentration Residuals Augmented Classical Least Squares was applied and evaluated for the determination of the cited drug in the presence of its all degradation products. Traditional Partial Least Squares regression was also applied and benchmarked against the proposed advanced multivariate calibration. Experimentally designed 25 synthetic mixtures of three factors at five levels were used to calibrate and validate the multivariate models. Advanced chemometrics succeeded in quantitative and qualitative analyses of CFQ along with its hydrolytic, oxidative and photo-degradation products. The proposed methods were applied successfully for different pharmaceutical formulations analyses. These developed methods were simple and cost-effective compared with the manufacturer's RP-HPLC method. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Chemical fingerprint and simultaneous determination of alkaloids and flavonoids in aerial parts of genus Peganum indigenous to China based on HPLC-UV: application of analysis on secondary metabolites accumulation.

    Science.gov (United States)

    Wen, Fangfang; Cheng, Xuemei; Liu, Wei; Xuan, Min; Zhang, Lei; Zhao, Xin; Shan, Meng; Li, Yan; Teng, Liang; Wang, Zhengtao; Wang, Changhong

    2014-12-01

    The aerial parts of genus Peganum are officially used in traditional Chinese medicine. The paper aims to establish a high-performance liquid chromatography (HPLC) method for fingerprint analysis and simultaneous determination of three alkaloids and two flavonoids in aerial parts of genus Peganum, and to analyze accumulative difference of secondary metabolites in inter-species, individuals of plants, inter-/intra-population and from different growing seasons. HPLC analysis was performed on a C18 column with gradient elution using 0.1% trifloroacetic acid and acetonitrile as mobile phase and detected at 265 nm, by conventional methodology validation. For fingerprint analysis, the RSDs of relative retention time and relative peak area of the characteristic peaks were within 0.07-0.78 and 0.94-9.09%, respectively. For simultaneous determination of vasicine, harmaline, harmine, deacetylpeganetin and peganetin, all calibration curves showed good linearity (r > 0.9990) within the test range. The relative standard deviations of precision, repeatability and stability test did not exceed 2.37, 2.68 and 2.67%, respectively. The average recoveries for the five analytes were between 96.47 and 101.20%. HPLC fingerprints play a minor role in authenticating and differentiating the herbs of different species of genus Peganum. However, the secondary metabolites levels of alkaloids and flavonoids in aerial parts of genus Peganum rely on species-, habitat-, and growth season-dependent accumulation. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Optimization of Forced Degradation Using Experimental Design and Development of a Stability-Indicating Liquid Chromatographic Assay Method for Rebamipide in Bulk and Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    Sandeep SONAWANE

    2016-09-01

    Full Text Available A novel stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of rebamipide in bulk and tablet dosage form. Rebamipide (drug and drug product solutions were exposed to acid and alkali hydrolysis, thermal stress, oxidation by hydrogen peroxide and photodegradation. Experimental design has been used during forced degradation to determine significant factors responsible for degradation and to obtain optimal degradation conditions. In addition, acid and alkali hydrolysis was performed using a microwave oven. The chromatographic method employed the HiQ sil C-18HS (250 × 4.6 mm; 5 μm column with mobile phase consisting of 0.02 M potassium phosphate (pH adjusted to 6.8 and methanol (40:60, v/v and the detection was performed at 230 nm. The procedure was validated for specificity, linearity, accuracy, precision and robustness. There was no interference observed of excipients and degradation products in the determination of the active pharmaceutical ingredient. The method showed good accuracy and precision (intra and inter day and the response was linear in a range from 0.5 to 5 μg mL−1. The method was found to be simple and fast with less trial and error experimentation by making use of experimental design. Also, it proved that microwave energy can be used to expedite hydrolysis of rebamipide.

  12. A Simple and Specific Stability- Indicating RP-HPLC Method for Routine Assay of Adefovir Dipivoxil in Bulk and Tablet Dosage Form.

    Science.gov (United States)

    Darsazan, Bahar; Shafaati, Alireza; Mortazavi, Seyed Alireza; Zarghi, Afshin

    2017-01-01

    A simple and reliable stability-indicating RP-HPLC method was developed and validated for analysis of adefovir dipivoxil (ADV).The chromatographic separation was performed on a C 18 column using a mixture of acetonitrile-citrate buffer (10 mM at pH 5.2) 36:64 (%v/v) as mobile phase, at a flow rate of 1.5 mL/min. Detection was carried out at 260 nm and a sharp peak was obtained for ADV at a retention time of 5.8 ± 0.01 min. No interferences were observed from its stress degradation products. The method was validated according to the international guidelines. Linear regression analysis of data for the calibration plot showed a linear relationship between peak area and concentration over the range of 0.5-16 μg/mL; the regression coefficient was 0.9999and the linear regression equation was y = 24844x-2941.3. The detection (LOD) and quantification (LOQ) limits were 0.12 and 0.35 μg/mL, respectively. The results proved the method was fast (analysis time less than 7 min), precise, reproducible, and accurate for analysis of ADV over a wide range of concentration. The proposed specific method was used for routine quantification of ADV in pharmaceutical bulk and a tablet dosage form.

  13. Stability-indicating HPLC-DAD methods for determination of two binary mixtures: Rabeprazole sodium-mosapride citrate and rabeprazole sodium-itopride hydrochloride.

    Science.gov (United States)

    El-Fatatry, Hamed M; Mabrouk, Mokhtar M; Hewala, Ismail I; Emam, Ehab H

    2014-08-01

    Two selective stability-indicating HPLC methods are described for determination of rabeprazole sodium (RZ)-mosapride citrate (MR) and RZ-itopride hydrochloride (IO) mixtures in the presence of their ICH-stress formed degradation products. Separations were achieved on X-Bridge C18 column using two mobile phases: the first for RZ-MR mixture consisted of acetonitrile: 0.025 M KH 2 PO 4 solution: TEA (30:69:1 v/v; pH 7.0); the second for RZ-IO mixture was at ratio of 25:74:1 (v/v; pH 9.25). The detection wavelength was 283 nm. The two methods were validated and validation acceptance criteria were met in all cases. Peak purity testing using contrast angle theory, relative absorbance and log  A versus the wavelengths plots were presented. The % recoveries of the intact drugs were between 99.1% and 102.2% with RSD% values less than 1.6%. Application of the proposed HPLC methods indicated that the methods could be adopted to follow the stability of their formulations.

  14. Stability-Indicating TLC-Densitometric and HPLC Methods for the Simultaneous Determination of Piracetam and Vincamine in the Presence of Their Degradation Products.

    Science.gov (United States)

    Ahmed, Amal B; Abdelrahman, Maha M; Abdelwahab, Nada S; Salama, Fathy M

    2016-11-01

    Newly established TLC-densitometric and RP-HPLC methods were developed and validated for the simultaneous determination of Piracetam (PIR) and Vincamine (VINC) in their pharmaceutical formulation and in the presence of PIR and VINC degradation products, PD and VD, respectively. The proposed TLC-densitometric method is based on the separation and quantitation of the studied components using a developing system that consists of chloroform-methanol-glacial acetic acid-triethylamine (8 + 2 + 0.1 + 0.1, v/v/v/v) on TLC silica gel 60 F254 plates, followed by densitometric scanning at 230 nm. On the other hand, the developed RP-HPLC method is based on the separation of the studied components using an isocratic elution of 0.05 M KH2PO4 (containing 0.1% triethylamine adjusted to pH 3 with orthophosphoric acid)-methanol (95 + 5, v/v) on a C8 column at a flow rate of 1 mL/min with diode-array detection at 230 nm. The developed methods were validated according to International Conference on Harmonization guidelines and demonstrated good accuracy and precision. Moreover, the developed TLC-densitometric and RP-HPLC methods are suitable as stability-indicating assay methods for the simultaneous determination of PD and VD either in bulk powder or pharmaceutical formulation. The results were statistically compared with those obtained by the reported RP-HPLC method using t- and F-tests.

  15. ICH Guidelines-compliant HPLC-UV Method for Pharmaceutical ...

    African Journals Online (AJOL)

    NICOLAAS

    samples; (2) the method devoted to analysis of plasma samples is relying on intensive and costly ... by Saudi Food & Drug Authority Laboratories (Riyadh, Saudi. Arabia). .... The ruggedness of the method was evaluated by altering the .... PDGFRb+ perivascular progenitor cells in tumours regulate pericyte differentiation and ...

  16. Stability-indicating RP-HPLC method for simultaneous determination of gatifloxacin and flurbiprofen in binary combination

    Directory of Open Access Journals (Sweden)

    Islam Ullah Khan

    2014-04-01

    Full Text Available A stability-indicating RP-HPLC method is presented for determination of gatifloxacin and flurbiprofen in binary combination. Gatifloxacin, flurbiprofen and their degradation products were detected at 254 nm using a BDS Hypersil C8 (250 X 4.6 mm, 5 µm column and mixture of 20 mM phosphate buffer (pH 3.0 and methanol 30:70 v/v as mobile phase. Response was linear over the range of 15-105 mg mL-1 for gatifloxacin (r² > 0.998 and of 1.5-10.5 mg mL-1 for flurbiprofen (r² > 0.999. The developed method efficiently separated the analytical peaks from degradation products (peak purity index > 0.9999. The method developed can be applied successfully for determination of gatifloxacin and flurbiprofen in human serum, urine, pharmaceutical formulations, and their stability studies.

  17. Application of quality by design concept to develop a dual gradient elution stability-indicating method for cloxacillin forced degradation studies using combined mixture-process variable models.

    Science.gov (United States)

    Zhang, Xia; Hu, Changqin

    2017-09-08

    Penicillins are typical of complex ionic samples which likely contain large number of degradation-related impurities (DRIs) with different polarities and charge properties. It is often a challenge to develop selective and robust high performance liquid chromatography (HPLC) methods for the efficient separation of all DRIs. In this study, an analytical quality by design (AQbD) approach was proposed for stability-indicating method development of cloxacillin. The structures, retention and UV characteristics rules of penicillins and their impurities were summarized and served as useful prior knowledge. Through quality risk assessment and screen design, 3 critical process parameters (CPPs) were defined, including 2 mixture variables (MVs) and 1 process variable (PV). A combined mixture-process variable (MPV) design was conducted to evaluate the 3 CPPs simultaneously and a response surface methodology (RSM) was used to achieve the optimal experiment parameters. A dual gradient elution was performed to change buffer pH, mobile-phase type and strength simultaneously. The design spaces (DSs) was evaluated using Monte Carlo simulation to give their possibility of meeting the specifications of CQAs. A Plackett-Burman design was performed to test the robustness around the working points and to decide the normal operating ranges (NORs). Finally, validation was performed following International Conference on Harmonisation (ICH) guidelines. To our knowledge, this is the first study of using MPV design and dual gradient elution to develop HPLC methods and improve separations for complex ionic samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Stability-Indicating RP-UPLC Method for the Simultaneous Determination of Potential Degradation and Process Impurities of Amlodipine Basylate and Benazepril HCl in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Gajanan B. Kasawar

    2014-10-01

    Full Text Available A stability-indicating RP-UPLC method was developed for the quantification of related impurities of amlodipine basylate (AB and Benazepril hydrochloride (BH in solid pharmaceutical dosages form. The chromatographic separation employs a C18 column using a gradient elution, being solvent-A (1.36 g of potassium dihydrogen phosphate dissolved in one liter of water, adjusted to pH 3.0 with orthophosphoric acid and solvent-B (acetonitrile delivered at a flow rate of 0.3 mL min-1. The analytes were detected and quantified at 217 nm and 240 nm using photo diode-array detector. The method was validated demonstrating to be accurate and precise within the corresponding linear range of all components. The stability of the method was investigated under different stress conditions including hydrolytic, oxidative, exposed to photolytic, humidity and thermal as recommended by ICH guidelines. Relevant degradation was found under hydrolytic and oxidative conditions. Robustness against small modification in mobile phase pH, column oven temperature, flow rate and percentage of the mobile phase composition was ascertained. Lower limit of quantification and detection was also determined. The peak purity indices (purity angle < purity threshold obtained with the aid of PDA detector and satisfactory resolution between related impurities established the specificity of the determination.

  19. Stress degradation studies and development of stability-indicating TLC-densitometry method for determination of prednisolone acetate and chloramphenicol in their individual and combined pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    Musharraf Syed

    2012-01-01

    Full Text Available Abstract A rapid and reproducible stability indicating TLC method was developed for the determination of prednisolone acetate and chloramphenicol in presence of their degraded products. Uniform degradation conditions were maintained by refluxing sixteen reaction mixtures for two hours at 80°C using parallel synthesizer including acidic, alkaline and neutral hydrolysis, oxidation and wet heating degradation. Oxidation at room temperature, photochemical and dry heating degradation studies were also carried out. Separation was done on TLC glass plates, pre-coated with silica gel 60F-254 using chloroform: methanol (14:1 v/v. Spots at Rf 0.21 ± 0.02 and Rf 0.41 ± 0.03 were recognized as chloramphenicol and prednisolone acetate, respectively. Quantitative analysis was done through densitometric measurements at multiwavelength (243 nm, λmax of prednisolone acetate and 278 nm, λmax of chloramphenicol, simultaneously. The developed method was optimized and validated as per ICH guidelines. Method was found linear over the concentration range of 200-6000 ng/spot with the correlation coefficient (r2 ± S.D. of 0.9976 ± 3.5 and 0.9920 ± 2.5 for prednisolone acetate and chloramphenicol, respectively. The developed TLC method can be applied for routine analysis of prednisolone acetate and chloramphenicol in presence of their degraded products in their individual and combined pharmaceutical formulations.

  20. Stability-Indicating Reversed-Phase UHPLC Method Development and Characterization of Degradation Products of Almotriptan Maleate by LC-QTOF-MS/MS.

    Science.gov (United States)

    Saibaba, B; Vishnuvardhan, Ch; Johnsi Rani, P; Satheesh Kumar, N

    2018-01-01

    Almotriptan maleate (ALMT), a highly selective 5-hydroxy tryptamine 1B/1D (5-HT1B/1D) receptor agonist used in the treatment of migraine headache was subjected to various ICH (Q1A (R2)) specified guidelines. The drug underwent significant degradation under hydrolytic (acid, base and neutral), oxidative and photolytic stress conditions, while it was stable under thermal stress condition. A total of seven significant degradation products (DPs) were obtained. A simple, selective and reliable UPLC method has been developed for the separation of ALMT and its DPs using Acquity UPLC HSS Cyano (100 × 2.1 mm, 1.8 μm) column with mobile phase consisting of ammonium acetate (10 mM, pH 4.4) buffer and acetonitrile in gradient elution mode. Chromatographic analysis was performed at a flow rate of 0.3 mL/min using a PDA detector at a wavelength of 230 nm. All the DPs (DP-1 to DP-7) were characterized using UHPLC-ESI-QTOF based on mass fragmentation pattern and accurate m/z values. The developed UPLC method was validated in terms of specificity, linearity, precision and accuracy. The developed stability-indicating method helps in quantification of drug in the presence of DPs. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Support vector regression and artificial neural network models for stability indicating analysis of mebeverine hydrochloride and sulpiride mixtures in pharmaceutical preparation: A comparative study

    Science.gov (United States)

    Naguib, Ibrahim A.; Darwish, Hany W.

    2012-02-01

    A comparison between support vector regression (SVR) and Artificial Neural Networks (ANNs) multivariate regression methods is established showing the underlying algorithm for each and making a comparison between them to indicate the inherent advantages and limitations. In this paper we compare SVR to ANN with and without variable selection procedure (genetic algorithm (GA)). To project the comparison in a sensible way, the methods are used for the stability indicating quantitative analysis of mixtures of mebeverine hydrochloride and sulpiride in binary mixtures as a case study in presence of their reported impurities and degradation products (summing up to 6 components) in raw materials and pharmaceutical dosage form via handling the UV spectral data. For proper analysis, a 6 factor 5 level experimental design was established resulting in a training set of 25 mixtures containing different ratios of the interfering species. An independent test set consisting of 5 mixtures was used to validate the prediction ability of the suggested models. The proposed methods (linear SVR (without GA) and linear GA-ANN) were successfully applied to the analysis of pharmaceutical tablets containing mebeverine hydrochloride and sulpiride mixtures. The results manifest the problem of nonlinearity and how models like the SVR and ANN can handle it. The methods indicate the ability of the mentioned multivariate calibration models to deconvolute the highly overlapped UV spectra of the 6 components' mixtures, yet using cheap and easy to handle instruments like the UV spectrophotometer.

  2. Validation of quantitative method for azoxystrobin residues in green beans and peas.

    Science.gov (United States)

    Abdelraheem, Ehab M H; Hassan, Sayed M; Arief, Mohamed M H; Mohammad, Somaia G

    2015-09-01

    This study presents a method validation for extraction and quantitative analysis of azoxystrobin residues in green beans and peas using HPLC-UV and the results confirmed by GC-MS. The employed method involved initial extraction with acetonitrile after the addition of salts (magnesium sulfate and sodium chloride), followed by a cleanup step by activated neutral carbon. Validation parameters; linearity, matrix effect, LOQ, specificity, trueness and repeatability precision were attained. The spiking levels for the trueness and the precision experiments were (0.1, 0.5, 3 mg/kg). For HPLC-UV analysis, mean recoveries ranged between 83.69% to 91.58% and 81.99% to 107.85% for green beans and peas, respectively. For GC-MS analysis, mean recoveries ranged from 76.29% to 94.56% and 80.77% to 100.91% for green beans and peas, respectively. According to these results, the method has been proven to be efficient for extraction and determination of azoxystrobin residues in green beans and peas. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Stability indicating HPLC-DAD method for analysis of Ketorolac binary and ternary mixtures in eye drops: Quantitative analysis in rabbit aqueous humor.

    Science.gov (United States)

    El Yazbi, Fawzy A; Hassan, Ekram M; Khamis, Essam F; Ragab, Marwa A A; Hamdy, Mohamed M A

    2017-11-15

    Ketorolac tromethamine (KTC) with phenylephrine hydrochloride (PHE) binary mixture (mixture 1) and their ternary mixture with chlorpheniramine maleate (CPM) (mixture 2) were analyzed using a validated HPLC-DAD method. The developed method was suitable for the in vitro as well as quantitative analysis of the targeted mixtures in rabbit aqueous humor. The analysis in dosage form (eye drops) was a stability indicating one at which drugs were separated from possible degradation products arising from different stress conditions (in vitro analysis). For analysis in aqueous humor, Guaifenesin (GUF) was used as internal standard and the method was validated according to FDA regulation for analysis in biological fluids. Agilent 5 HC-C18(2) 150×4.6mm was used as stationary phase with a gradient eluting solvent of 20mM phosphate buffer pH 4.6 containing 0.2% triethylamine and acetonitrile. The drugs were resolved with retention times of 2.41, 5.26, 7.92 and 9.64min for PHE, GUF, KTC and CPM, respectively. The method was sensitive and selective to analyze simultaneously the three drugs in presence of possible forced degradation products and dosage form excipients (in vitro analysis) and also with the internal standard, in presence of aqueous humor interferences (analysis in biological fluid), at a single wavelength (261nm). No extraction procedure was required for analysis in aqueous humor. The simplicity of the method emphasizes its capability to analyze the drugs in vivo (in rabbit aqueous humor) and in vitro (in pharmaceutical formulations). Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Stability-Indicating RP-HPLC Method for Analysis of Paracetamol and Tramadol in a Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Rajesh M. Kamble

    2012-01-01

    Full Text Available A simple, isocratic, rapid and accurate reversed phase high performance liquid chromatography method was developed for the quantitative determination of paracetamol and tramadol in commercial medicinal tablets. The chromatographic separation was achieved on an Intersil C18 (250 mm x 4.6 mm, 5μm column using water pH 3.4 with orthophosphoric acid: methanol (60:40, v/v as a mobile phase, and UV detection at 228 nm. The chromatographic resolutions between paracetamol and tramadol were found greater than five. The linear range for paracetamol and tramadol were 20.8–39.0 μg/ml and 2.4–4.5 μg/ ml was obtained with correlation coefficients ≥0.999 for each analyte. The retention time were found to be 2.1 and 3.9 min for tramadol and paracetamol respectively. Paracetamol and tramadol was subjected to stress conditions (hydrolysis (acid, base oxidation, photolysis and thermal degradation and the stressed samples were analyzed by use of the method. The major degradation was observed in acid and minor in base, thermal, oxidation and photolysis. The forced degradation studies prove the stability indicating power of the method.

  5. Data on corrosion and scaling potential of drinking water resources using stability indices in Jolfa, East Azerbaijan, Iran

    Directory of Open Access Journals (Sweden)

    Mahmood Yousefi

    2018-02-01

    Full Text Available This cross-sectional study was conducted on the drinking water resources of the city of Jolfa (East Azerbaijan province, Iran from samples taken from 30 wells. Calcium hardness, pH, total alkalinity, TDS, temperature and other chemical parameters were measured using standard methods. The Langelier, Rayzner, Puckhorius and aggressive indices were calculated. The results showed that the Langelier, Reynar, Puckorius, Larson-skold and aggressive indices were 1.15 (± 0.43, 6.92 (± 0.54, 6.42 (± 0.9, 0.85 (± 0.72 and 12.79 (± 0.47, respectively. In terms of water classification, 30% of samples fell into the NaCl category and 26.6% in the NaHCO3 category and 43.4% samples in the CaHCO3, MgHCO3 and MgCl category. The sedimentation indices indicated that the water of the wells could be considered as corrosive. Keywords: Corrosion and scaling potential, Stability indices, Ground water, Jolfa

  6. Stability-indicating HPLC–DAD methods for determination of two binary mixtures: Rabeprazole sodium–mosapride citrate and rabeprazole sodium–itopride hydrochloride

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    Hamed M. El-Fatatry

    2014-08-01

    Full Text Available Two selective stability-indicating HPLC methods are described for determination of rabeprazole sodium (RZ–mosapride citrate (MR and RZ–itopride hydrochloride (IO mixtures in the presence of their ICH-stress formed degradation products. Separations were achieved on X-Bridge C18 column using two mobile phases: the first for RZ–MR mixture consisted of acetonitrile: 0.025 M KH2PO4 solution: TEA (30:69:1 v/v; pH 7.0; the second for RZ–IO mixture was at ratio of 25:74:1 (v/v; pH 9.25. The detection wavelength was 283 nm. The two methods were validated and validation acceptance criteria were met in all cases. Peak purity testing using contrast angle theory, relative absorbance and log A versus the wavelengths plots were presented. The % recoveries of the intact drugs were between 99.1% and 102.2% with RSD% values less than 1.6%. Application of the proposed HPLC methods indicated that the methods could be adopted to follow the stability of their formulations. Keywords: Rabeprazole sodium, Mosapride citrate, Itopride hydrochloride, Stability-indicating HPLC–DAD, Peak purity

  7. Development and validation of a dissolution method using HPLC for diclofenac potassium in oral suspension

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    Alexandre Machado Rubim

    2014-04-01

    Full Text Available The present study describes the development and validation of an in vitro dissolution method for evaluation to release diclofenac potassium in oral suspension. The dissolution test was developed and validated according to international guidelines. Parameters like linearity, specificity, precision and accuracy were evaluated, as well as the influence of rotation speed and surfactant concentration on the medium. After selecting the best conditions, the method was validated using apparatus 2 (paddle, 50-rpm rotation speed, 900 mL of water with 0.3% sodium lauryl sulfate (SLS as dissolution medium at 37.0 ± 0.5°C. Samples were analyzed using the HPLC-UV (PDA method. The results obtained were satisfactory for the parameters evaluated. The method developed may be useful in routine quality control for pharmaceutical industries that produce oral suspensions containing diclofenac potassium.

  8. Stability-Indicating RP-HPLC Methods for the Determination of Fluorometholone in Its Mixtures with Sodium Cromoglycate and Tetrahydrozoline Hydrochloride.

    Science.gov (United States)

    El-Bagary, Ramzia I; Fouad, Marwa A; El-Shal, Manal A; Tolba, Enas H

    2016-07-01

    Two stability-indicating reversed-phase liquid chromatographic methods were developed and validated for the determination of fluorometholone (FLU) in its mixtures with sodium cromoglycate (SCG) and tetrahydrozoline hydrochloride (THZ). The first HPLC method (Method 1) was based on isocratic elution of FLU and SCG along with their alkaline degradation products on a reversed phase C18 column (250 × 4.6 mm id)-ACE Generix 5, using a mobile phase consisting of methanol-water (70 : 30, v/v), pH adjusted to 2.5 using orthophosphoric acid at a flow rate of 1.2 mL min(-1) Quantitation was achieved with UV detection at 240 nm. The second HPLC method (Method 2) was based on isocratic elution of FLU, its alkaline degradation product and THZ on a reversed phase C8 column (250 × 4.6 mm)-ACE Generix 5, using a mobile phase consisting of acetonitrile-50 mM potassium dihydrogen orthophosphate (40 : 60, v/v) at a flow rate of 2 mL min(-1) Quantitation was achieved by applying dual-wavelength detection, where FLU and its alkaline degradation product were detected at 240 nm and THZ was detected at 215 nm at ambient temperatures. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5-50 and 10-500 μg mL(-1) for FLU and SCG (Method 1) and over the concentration range of 5-80 and 5-60 μg mL(-1) for FLU and THZ (Method 2), respectively. Besides, the FLU alkaline degradation product was verified using IR, NMR and LC-MS spectroscopy. The two proposed methods could be successfully applied for the routine analysis of the studied drugs either in their pure bulk powders or in their pharmaceutical preparations without any preliminary separation step. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Stability Indicating HPLC Method for the Determination of Chiral Purity of R-(-)-5-[2-aminopropyl]-2-methoxybenzene Sulfonamide

    OpenAIRE

    Kasawar, G. B.; Farooqui, M. N.

    2009-01-01

    A chiral reverse phase liquid chromatographic method was developed for the enantiomeric resolution of racemic mixture of (-)-5-[2-aminopropyl]-2-methoxybenzene sulfonamide in bulk drug. The enantiomeric separation of sulfonamide was resolved on a Crownpak CR (+) column using perchloric acid buffer of pH 1.0 as mobile phase and with UV detection at 226 nm. The method is validated and proved to be robust. The limit of detection and quantification of S (-)-(5)-[2-aminopropyl]-2-methoxyben...

  10. Isolation and characterization of a degradation product in leflunomide and a validated selective stability-indicating HPLC–UV method for their quantification

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    Balraj Saini

    2015-06-01

    Full Text Available Leflunomide (LLM is subjected to forced degradation under conditions of hydrolysis, oxidation, dry heat, and photolysis as recommended by International Conference on Harmonization guideline Q1A(R2. In total, four degradation products (I–IV were formed under different conditions. Products I, II and IV were formed in alkaline hydrolytic, acidic hydrolytic and alkaline photolytic conditions. LLM and all degradation products were optimally resolved by gradient elution over a C18 column. The major degradation product (IV formed in hydrolytic alkaline conditions was isolated through column chromatography. Based on its 1H NMR, IR and mass spectral data, it was characterized as a British Pharmacopoeial impurity B. The HPLC method was found to be linear, accurate, precise, sensitive, specific, rugged and robust for quantification of LLM as well as product IV. Finally, the method was applied to stability testing of the commercially available LLM tablets. Keywords: Leflunomide, Characterization, Forced degradation, Degradation product, HPLC–UV

  11. Stability indicating high performance thin layer chromatographic method for quantitation of venlafaxine in bulk and pharmaceutical dosage form

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    Sunil K Dubey

    2015-01-01

    Full Text Available Background: Venlafaxine (VEN is a phenethylamine bicyclic compound, chemically, 1-(2-[dimethyl amino]-1-[4-methoxy phenyl] ethyl cyclo-hexan-1ol hydrochloride. It is a antidepressant. It inhibits the reuptake of serotonin, nor adrenaline and dopamine to a lesser extent at the presynaptic membrane. Aim: A simple, rapid, precise, accurate, and economical high performance thin layer chromatographic (HPTLC method has been developed and validated for the determination of VEN both as a bulk drug and in formulation. Materials and Methods: The method uses aluminum plates precoated with silica gel 60 F254 as the stationary phase and dichloromethane:acetonitrile:N-hexane:triethylamine: 0.5:0.5:4:0.7 (v/v/v/v as mobile phase. Results: This system gave compact spots for VEN (R f = 0.46 ± 0.05. Forced degradation studies were done by subjecting VEN to acid and alkali hydrolysis, oxidation, and reduction. The peak of the degradation product was well resolved from that of the pure drug and had significant different R f values. Analysis of VEN was performed in the absorbance mode at 225 nm. The limit of detection and quantification were 12.48 and 37.81 ng/spot respectively. Conclusions: The developed method was validated and found to be simple, specific, accurate and precise and can be used for routine quality control analysis of VEN in bulk and pharmaceutical formulation.

  12. Stability Indicating HPLC Method for the Determination of Chiral Purity of R-(-)-5-[2-aminopropyl]-2-methoxybenzene Sulfonamide.

    Science.gov (United States)

    Kasawar, G B; Farooqui, M N

    2009-09-01

    A chiral reverse phase liquid chromatographic method was developed for the enantiomeric resolution of racemic mixture of (-)-5-[2-aminopropyl]-2-methoxybenzene sulfonamide in bulk drug. The enantiomeric separation of sulfonamide was resolved on a Crownpak CR (+) column using perchloric acid buffer of pH 1.0 as mobile phase and with UV detection at 226 nm. The method is validated and proved to be robust. The limit of detection and quantification of S (-)-(5)-[2-aminopropyl]-2-methoxybenzene sulfonamide] was found to be 0.084 and 0.159 mug/ml, respectively for 20 mul injection volume. The percentage recovery of S (-)-(5)-[2-aminopropyl]-2-methoxybenzene sulfonamide] ranged from 99.57 to 101.88 in bulk drug samples of R (-)-(5)-[2- aminopropyl]-2-methoxybenzene sulfonamide].

  13. Stability indicating RP-LC-PDA method for the quantitative analysis of saxagliptin in pharmaceutical dosage form

    Directory of Open Access Journals (Sweden)

    Laís Engroff Scheeren

    2015-06-01

    Full Text Available Saxagliptin is a potent and selective inhibitor of the enzyme dipeptidyl peptidase 4. It is effective in the treatment of type 2 diabetes mellitus because it stimulates the pancreas to produce insulin. In the present study, a liquid chromatography method was developed and validated to quantify the drug in tablets. This method was based on the isocratic elution of saxagliptin, using a mobile phase consisting of 0.1% phosphoric acid at pH 3.0 - methanol (70: 30, v/v at a flow rate of 1 mL.min-1 with UV detection at 225 nm. The chromatographic separation was achieved in 8 minutes on a Waters XBridge C18 column (250 mm x 4.6 mm, 5µm maintained at ambient temperature. The proposed method proved to be specific and robust for the quality control of saxagliptin in pharmaceutical dosage forms, showing good linearity in the range of 15.0 - 100.0 µg.mL-1 (r>0.999, precision (RSD

  14. Polymeric matrix membrane sensors for stability-indicating potentiometric determination of oxybutynin hydrochloride and flavoxate hydrochloride urogenital system drugs.

    Science.gov (United States)

    Heba, Mohamed; Ramadan, Nesrin; El-Laithy, Moustafa

    2008-01-01

    Four polyvinyl chloride (PVC) matrix membrane electrodes responsive to 2 drugs affecting the urogenital system--oxybutynin hydrochloride (OX) and flavoxate hydrochloride (FX)--were developed, described, and characterized. A precipitation-based technique with tungstophosphate (TP) and ammonium reineckate (R) anions as electroactive materials in a PVC matrix with an OX cation was used for electrode 1 and 2 fabrication, respectively. Electrode 3 and 4 fabrication was based on use of the precipitation technique of FX cation with tetrakis (4-chlorophenyl) borate and R anions as electroactive materials. Fast and stable Nernstian responses in the range 1 x 10(-2)-1 x 10(-6) M for the 2 drugs over the pH range 5-8 revealed the performance characteristics of these electrodes, which were evaluated according to International Union of Pure and Applied Chemistry recommendations. The method was applied to FX and OX in their pharmaceutical formulations and in human plasma samples. The 4 proposed sensors were found to be specific for the drugs in the presence of up to 60% of their degradation products. Validation of the method according to the quality assurance standards showed suitability of the proposed electrodes for use in the quality control assessment of these drugs. The recoveries for determination of the drugs by the 4 proposed selective electrodes were 99.5 +/- 0.5, 100.0 +/- 0.4, 99.9 +/- 0.4, and 100.1 +/- 0.4% for sensors 1-4, respectively. Statistical comparison between the results obtained by this method and the official method of the drugs was done, and no significant difference found.

  15. Development of RP-HPLC, Stability Indicating Method for Degradation Products of Linagliptin in Presence of Metformin HCl by Applying 2 Level Factorial Design; and Identification of Impurity-VII, VIII and IX and Synthesis of Impurity-VII

    Directory of Open Access Journals (Sweden)

    Sushant B. Jadhav

    2017-06-01

    Full Text Available The novel reverse phase-high performance liquid chromatography (RP-HPLC, stability indicating method was developed for determination of linagliptin (LGP and its related substances in linagliptin and metformin HCl (MET HCl tablets by implementing design of experiment to understand the critical method parameters and their relation with critical method attributes; to ensure robustness of the method. The separation of nine specified impurities was achieved with a Zorbax SB-Aq 250 × 4.6 mm, 5 µm column, using gradient elution and a detector wavelength of 225 nm, and validated in accordance with International Conference on Harmonization (ICH guidelines and found to be accurate, precise, reproducible, robust, and specific. The drug was found to be degrading extensively in heat, humidity, basic, and oxidation conditions and was forming degradation products during stability studies. After slight modification in the buffer and the column, the same method was used for liquid chromatography–mass spectrometry (LC-MS and ultra-performance liquid chromatography -time-of-flight/mass spectrometry UPLC-TOF/MS analysis, to identify m/z and fragmentation of maximum unspecified degradation products i.e., Impurity-VII (7, Impurity-VIII (8, and Impurity-IX (9 formed during stability studies. Based on the results, a degradation pathway for the drug has been proposed and synthesis of Impurity-VII (7 is also discussed to ensure an in-depth understanding of LGP and its related degradation products and optimum performance during the lifetime of the product.

  16. A versatile, stability-indicating and high-throughput ultra-fast liquid chromatography method for the determination of isoflavone aglycones in soybeans, topical formulations, and permeation assays.

    Science.gov (United States)

    Nemitz, Marina C; Yatsu, Francini K J; Bidone, Juliana; Koester, Letícia S; Bassani, Valquiria L; Garcia, Cássia V; Mendez, Andreas S L; von Poser, Gilsane L; Teixeira, Helder F

    2015-03-01

    There is a growing interest in the pharmaceutical field concerning isoflavones topical delivery systems, especially with regard to their skin care properties and antiherpetic activity. In this context, the present work describes an ultra-fast liquid chromatography method (UFLC) for determining daidzein, glycitein, and genistein in different matrices during the development of topical systems containing isoflavone aglycones (IA) obtained from soybeans. The method showed to be specific, precise, accurate, and linear (0.1 to 5 µg mL(-1)) for IA determination in soybean acid extract, IA-rich fraction obtained after the purification process, IA loaded-nanoemulsions, and topical hydrogel, as well as for permeation/retention assays in porcine skin and porcine esophageal mucosa. The matrix effect was determined for all complex matrices, demonstrating low effect during the analysis. The stability indicating UFLC method was verified by submitting IA to acidic, alkaline, oxidative, and thermal stress conditions, and no interference of degradation products was detected during analysis. Mass spectrometry was performed to show the main compounds produced after acid hydrolysis of soybeans, as well as suggest the main degradation products formed after stress conditions. Besides the IA, hydroxymethylfurfural and ethoxymethylfurfural were produced and identified after acid hydrolysis of the soybean extract and well separated by the UFLC method. The method's robustness was confirmed using the Plackett-Burman experimental design. Therefore, the new method affords fast IA analysis during routine processes, extract purification, products development, and bioanalytical assays. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. A validated method using RP-HPLC for quantification of reserpine in the Brazilian tree Rauvolfia sellowii Müll. Arg. (Apocynaceae

    Directory of Open Access Journals (Sweden)

    Leopoldo C. Baratto

    2012-01-01

    Full Text Available This study describes a simple, fast and reproducible method using RP-HPLC-UV, in a gradient system, for quantification of reserpine in Rauvolfia sellowii stem bark. The analysis were carried out on a C18 column; mobile phase was water and acetonitrile, and separations were carried out in 10 min, flow rate of 1.0 mL min-1, 25 ºC and 268 nm. The validation data showed that the method was specific, accurate, precise and robust. Results were linear over a range of 0.625-40.0 μg mL-1, and the mean recovery was 95.1%. The amount of reserpine found in the dried stem bark was 0.01% (m/m.

  18. Stability of 10 mg/mL cefuroxime solution for intracameral injection in commonly used polypropylene syringes and new ready-to-use cyclic olefin copolymer sterile vials using the LC-UV stability-indicating method.

    Science.gov (United States)

    Feutry, Frédéric; Simon, Nicolas; Genay, Stéphanie; Lannoy, Damien; Barthélémy, Christine; Décaudin, Bertrand; Labalette, Pierre; Odou, Pascal

    2016-01-01

    Injecting intracameral cefuroxime has been found beneficial in reducing the risk of postoperative endophthalmitis but its use has been limited through a lack of approved marketing and of ready-to-use single-units as well as the problem of aseptic compounding. Our aim was to assess a new automated primary packaging system which should ensure a higher level of sterility, thanks to its closed, sterile, ready-to-use polymer vial called "Crystal® vial". The chemical stability of a 10 mg/mL cefuroxime solution was compared in 1 mL Crystal® vials and 1 mL Luer-lock polypropylene syringes (actual reference) to eliminate any potential and specific interactions with its cyclic olefin copolymer (COC) body and elastomer stopper. Cefuroxime solution was introduced into vials and syringes and stored at -20 °C, +5 °C and +25°C/60% Relative Humidity. Cefuroxime concentration and the relative amount of the main degradation product (descarbamoyl-cefuroxime) were both determined by an HPLC/UV method indicating stability. Solutions were considered steady if the concentration remained at over 90% of the initial value. In the adapted storage conditions, the evolution of osmolality, pH and sterility was assessed. Stability profiles were identical between vials and syringes in all storage and temperature conditions. The solution was stable (cefuroxime concentration, pH and osmolality) and still sterile for 365 days at -20°C. The concentration fell below 90% after 21 days at +5 °C and after 16 h at +25°C/60%s relative humidity. The COC and thermoplastic elastomer of the vials had no impact on the degradation process confirming its possible use for a ready-to-use cefuroxime solution single-unit dose.

  19. Stability study on an anti-cancer drug 4-(3,5-bis(2-chlorobenzylidene-4-oxo-piperidine-1-yl-4-oxo-2-butenoic acid (CLEFMA using a stability-indicating HPLC method

    Directory of Open Access Journals (Sweden)

    Dhawal Raghuvanshi

    2017-02-01

    Full Text Available CLEFMA, 4-(3,5-bis(2-chlorobenzylidene-4-oxo-piperidine-1-yl-4-oxo-2-butenoic acid, is a new chemical entity with anti-cancer and anti-inflammatory activities. Here, we report its stability in solution against stress conditions of exposure to acid/base, light, oxidant, high temperature, and plasma. The identity of the degradation products was ascertained by mass and proton nuclear magnetic resonance spectroscopy. To facilitate this study, we developed and validated a reverse phase high performance liquid chromatography method for detection of CLEFMA and its degradation. The method was linear over a range of 1–100 µg/mL; the accuracy and precision were within acceptable limits; it was stability-indicating as it successfully separated cis-/trans-isomers of CLEFMA as well as its degradation product. The major degradation product was produced from amide hydrolysis at maleic acid functionality caused by an acidic buffer, oxidant (3% hydrogen peroxide, or temperature stress (40–60 °C. The log k-pH profile showed that CLEFMA was most stable at neutral pH. In accelerated stability study we found that the shelf-life (T90% of CLEFMA at 25 °C and 4 °C was 45 days and 220 days, respectively. Upon exposure to UV-light (365 nm, the normally prevalent trans-CLEFMA attained cis-configuration. This isomerization also involved the maleic acid moiety. CLEFMA was stable in plasma from which it could be efficiently extracted by an acetonitrile precipitation method. These results indicate that CLEFMA is sensitive to hydrolytic cleavage at its maleic acid moiety, and it is recommended that its samples should be stored under refrigerated and light-free conditions, and under inert environment.

  20. Using an innovative combination of quality-by-design and green analytical chemistry approaches for the development of a stability indicating UHPLC method in pharmaceutical products.

    Science.gov (United States)

    Boussès, Christine; Ferey, Ludivine; Vedrines, Elodie; Gaudin, Karen

    2015-11-10

    An innovative combination of green chemistry and quality by design (QbD) approach is presented through the development of an UHPLC method for the analysis of the main degradation products of dextromethorphan hydrobromide. QbD strategy was integrated to the field of green analytical chemistry to improve method understanding while assuring quality and minimizing environmental impacts, and analyst exposure. This analytical method was thoroughly evaluated by applying risk assessment and multivariate analysis tools. After a scouting phase aimed at selecting a suitable stationary phase and an organic solvent in accordance with green chemistry principles, quality risk assessment tools were applied to determine the critical process parameters (CPPs). The effects of the CPPs on critical quality attributes (CQAs), i.e., resolutions, efficiencies, and solvent consumption were further evaluated by means of a screening design. A response surface methodology was then carried out to model CQAs as function of the selected CPPs and the optimal separation conditions were determined through a desirability analysis. Resulting contour plots enabled to establish the design space (DS) (method operable design region) where all CQAs fulfilled the requirements. An experimental validation of the DS proved that quality within the DS was guaranteed; therefore no more robustness study was required before the validation. Finally, this UHPLC method was validated using the concept of total error and was used to analyze a pharmaceutical drug product. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Development of Micellar HPLC-UV Method for Determination of Pharmaceuticals in Water Samples

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    Danielle Cristina da Silva

    2018-01-01

    Full Text Available Method for extraction and determination of amoxicillin, caffeine, ciprofloxacin, norfloxacin, tetracycline, diclofenac, ibuprofen, nimesulide, levonorgestrel, and 17α-ethynylestradiol exploiting micellar liquid chromatography with PDA detector and solid-phase extraction was proposed. The usage of toxic solvents was low; the chromatographic separation of the medicaments was performed using a C18 column and mobile phases A and B containing 15.0% (v/v ethanol, 3.0% (m/v sodium dodecyl sulfate (SDS, and 0.02 mol·L−1 phosphate at pHs 7.0 and 8.0, respectively. The method is simple, selective, and fast, and the analytes were separated in 23.0 min. For extraction, 1000 mL of sample containing 2.0% (v/v ethanol and 0.002 mol·L−1 citric acid at pH 2.50 was loaded through a 1000 mg of C18 cartridge. The analytes were eluted using 3.0 mL of ethanol, which were evaporated and redissolved in 0.5 mL of mobile phase. Concentration factors better than 1200, except amoxicillin (224, were obtained. The analytical curves were linear (R2 better than 0.992; LOD and LOQ n=10 presented values in the range of 0.019–0.247 and 0.058–0.752 mg·L−1, respectively. Recoveries of 99% were obtained, and the results are in agreement with those obtained by the comparative methods.

  2. UAE-HPLC-UV: New Contribution for Fast Determination of Total Isothiocyanates in Brassicaceae Vegetables

    Directory of Open Access Journals (Sweden)

    Cecilia M. Fusari

    2015-01-01

    Full Text Available Total isothiocyanates content (ITC is considered a good indicator of bioactive compounds responsible for beneficial effects related to Brassicaceae vegetables. Analytical performance is a critical factor for routine analysis in plant tissues. The extraction technique for isolating phytochemicals from Brassicaceae vegetables is currently the bottleneck of the methodology. The aim of this work was to optimize this step in the analytical process. Fast and less expensive alternative, based on ultrasound-assisted extraction technique (UAE for direct extraction of GLS into an aqueous phase and further analysis of the hydrolysis product, was optimized. Full factorial (2k design followed by Central Composite Design (CCD was used to obtain the optimum extraction conditions. Selected conditions were homogenization time (9 min; ultrasound bath time (5 min; and sample-to-solvent ratio (1 : 5 w/v mg mL−1. The proposed analytical methodology exhibits satisfactory analytical performance in terms of linearity, precision (RSD < 2.4%, and limits of detection (26 nmol g−1 w.w.. The new analytical methodology was applied to cauliflower, cabbage, watercress, and broccoli samples with recoveries higher than 86%. The UAE extraction technique was showed to be efficient for real samples analysis leading to sensible, selective, and reproducible methodology for ITC analysis.

  3. Determination of Trace Level Triclosan in Water by Online Preconcentration and HPLC-UV Diode Array

    Science.gov (United States)

    An online high performance liquid chromatography (HPLC) method for the detection and quantification of trace levels of triclosan in water is discussed. Triclosan, an anti-bacterial agent, and related compounds have been shown to reach municipal waste waters through the disposal ...

  4. Analysis of Dithiocarbamate Fungicides in Vegetable Matrices Using HPLC-UV Followed by Atomic Absorption Spectrometry.

    Science.gov (United States)

    Al-Alam, Josephine; Bom, Laura; Chbani, Asma; Fajloun, Ziad; Millet, Maurice

    2017-04-01

    A simple method combining ion-pair methylation, high-performance liquid chromatography (HPLC) analysis with detection at 272 nm and atomic absorption spectrometry was developed in order to determine 10 dithiocarbamate fungicides (Dazomet, Metam-sodium, Ferbam, Ziram, Zineb, Maneb, Mancozeb, Metiram, Nabam and Propineb) and distinguish ethylenbisdithiocarbamates (EBDTCs) Zineb, Maneb and Mancozeb in diverse matrices. This method associates reverse phase analysis by HPLC analysis with detection at 272 nm, with atomic absorption spectrometry in order to distinguish, with the same extraction protocol, Maneb, Mancozeb and Zineb. The limits of detection (0.4, 0.8, 0.5, 1.25 and 1.97) and quantification (1.18, 2.5, 1.52, 4.2 and 6.52) calculated in injected nanogram, respectively, for Dazomet, Metam-Na, dimethyldithiocarbamates (DMDTCs), EBDTCs and propylenebisdithiocarbamates (PBDTCs) justify the sensitivity of the method used. The coefficients of determination R2 were 0.9985, 0.9978, 0.9949, 0.988 and 0.9794, respectively, for Dazomet, Metam-Na, DMDTCs, EBDTCs and PBDTCs, and the recovery from fortified apple and leek samples was above 90%. Results obtained with the atomic absorption method in comparison with spectrophotometric analysis focus on the importance of the atomic absorption as a complementary specific method for the distinction between different EBDTCs fungicides. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Authenticity analysis of citrus essential oils by HPLC-UV-MS on oxygenated heterocyclic components

    Directory of Open Access Journals (Sweden)

    Hao Fan

    2015-03-01

    Full Text Available Citrus essential oils are widely applied in food industry as the backbone of citrus flavors. Unfortunately, due to relatively simple chemical composition and tremendous price differences among citrus species, adulteration has been plaguing the industry since its inception. Skilled blenders are capable of making blends that are almost indistinguishable from authentic oils through conventional gas chromatography analysis. A reversed-phase high performance liquid chromatography (HPLC method was developed for compositional study of nonvolatile constituents in essential oils from major citrus species. The nonvolatile oxygenated heterocyclic components identified in citrus oils were proved to be more effective as markers in adulteration detection than the volatile components. Authors are hoping such an analysis procedure can be served as a routine quality control test for authenticity evaluation in citrus essential oils.

  6. Acrylamide in Romanian food using HPLC-UV and a health risk assessment.

    Science.gov (United States)

    Oroian, Mircea; Amariei, Sonia; Gutt, Gheorghe

    2015-01-01

    The aim of this study was to investigate the level of acrylamide from coffee, potato chips and French fries in Romanian food. According to the European Food Safety Authority, coffee beans, potato chips and French fries have the highest levels of acrylamide. For this survey, 50 samples of coffee beans, 50 samples of potato chips and 25 samples of French fries were purchased from different producers from the Romanian market. Acrylamide levels have been quantified using high-performance liquid chromatography with a diode array detector (HPLC-DAD) method, using water as mobile phase. Health risk assessment was achieved by computing the average daily intake, hazard quotient, cumulative risk, carcinogenic risk and cancer risk. For coffee, potato chips and French fries, acrylamide was not shown to pose a health risk in Romanian food.

  7. Development of a stability-indicating UPLC method for determining olanzapine and its associated degradation products present in active pharmaceutical ingredients and pharmaceutical dosage forms.

    Science.gov (United States)

    Krishnaiah, Ch; Vishnu Murthy, M; Kumar, Ramesh; Mukkanti, K

    2011-03-25

    A simple, sensitive and reproducible ultra performance liquid chromatography (UPLC) coupled with a photodiode array detector method was developed for the quantitative determination of olanzapine (OLN) in API and pharmaceutical dosage forms. The method is applicable to the quantification of related substances and assays of drug substances. Chromatographic separation was achieved on Acquity UPLC BEH 100-mm, 2.1-mm, and 1.7-μm C-18 columns, and the gradient eluted within a short runtime, i.e., within 10.0 min. The eluted compounds were monitored at 250 nm, the flow rate was 0.3 mL/min, and the column oven temperature was maintained at 27°C. The resolution of OLN and eight (potential, bi-products and degradation) impurities was greater than 2.0 for all pairs of components. The high correlation coefficient (r(2)>0.9991) values indicated clear correlations between the investigated compound concentrations and their peak areas within the test ranges. The repeatability and intermediate precision, expressed by the RSD, were less than 2.4%. The accuracy and validity of the method were further ascertained by performing recovery studies via a spike method. The accuracy of the method expressed as relative error was satisfactory. No interference was observed from concomitant substances normally added to the tablets. The drug was subjected to the International Conference on Harmonization (ICH)-prescribed hydrolytic, oxidative, photolytic and thermal stress conditions. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness and robustness. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Development of a stability-indicating high performance liquid chromatography method for assay of erythromycin ethylsuccinate in powder for oral suspension dosage form

    Directory of Open Access Journals (Sweden)

    Fahimeh Kamarei

    2014-12-01

    Full Text Available In this study an effective method was developed to assay erythromycin ethylsuccinate for an oral suspension dosage form. The chromatographic separation was achieved on an X-Terra™ C18 analytical column. A mixture of acetonitrile–ammonium dihydrogen phosphate buffer (0.025 mol L-1 (60:40, V/V (pH 7.0 was used as the mobile phase, effluent flow rate monitored at 1.0 mL min−1, and UV detection at 205 nm. In forced degradation studies, the effects of acid, base, oxidation, UV light and temperature were investigated showing no interference in the peak of drug. The proposed method was validated in terms of specificity, linearity, robustness, precision and accuracy. The method was linear at concentrations ranging from 400 to 600 μg mL−1, precise (intra- and inter-day relative standard deviations <0.65, accurate (mean recovery; 99.5%. The impurities and degradation products of erythromycin ethylsuccinate were selectively determined with good resolution in both the raw material and the final suspension forms. The method could be useful for both routine analytical and quality control assays of erythromycin ethylsuccinate in commercial powder for an oral suspension dosage form and it could be a very powerful tool to investigate the chemical stability of erythromycin ethylsuccinate.

  9. Development and validation of NIR-chemometric methods for chemical and pharmaceutical characterization of meloxicam tablets.

    Science.gov (United States)

    Tomuta, Ioan; Iovanov, Rares; Bodoki, Ede; Vonica, Loredana

    2014-04-01

    Near-Infrared (NIR) spectroscopy is an important component of a Process Analytical Technology (PAT) toolbox and is a key technology for enabling the rapid analysis of pharmaceutical tablets. The aim of this research work was to develop and validate NIR-chemometric methods not only for the determination of active pharmaceutical ingredients content but also pharmaceutical properties (crushing strength, disintegration time) of meloxicam tablets. The development of the method for active content assay was performed on samples corresponding to 80%, 90%, 100%, 110% and 120% of meloxicam content and the development of the methods for pharmaceutical characterization was performed on samples prepared at seven different compression forces (ranging from 7 to 45 kN) using NIR transmission spectra of intact tablets and PLS as a regression method. The results show that the developed methods have good trueness, precision and accuracy and are appropriate for direct active content assay in tablets (ranging from 12 to 18 mg/tablet) and also for predicting crushing strength and disintegration time of intact meloxicam tablets. The comparative data show that the proposed methods are in good agreement with the reference methods currently used for the characterization of meloxicam tablets (HPLC-UV methods for the assay and European Pharmacopeia methods for determining the crushing strength and disintegration time). The results show the possibility to predict both chemical properties (active content) and physical/pharmaceutical properties (crushing strength and disintegration time) directly, without any sample preparation, from the same NIR transmission spectrum of meloxicam tablets.

  10. Development and validation of a high-performance liquid chromatographic method for the determination of cyproterone acetate in human skin.

    Science.gov (United States)

    Henry de Hassonville, Sandrine; Chiap, Patrice; Liégeois, Jean-François; Evrard, Brigitte; Delattre, Luc; Crommen, Jacques; Piel, Géraldine; Hubert, Philippe

    2004-09-21

    In the framework of a preliminary study on the transdermal penetration of cyproterone acetate (CPA), a simple and rapid procedure involving an extraction step coupled to a HPLC-UV determination has been developed for the separation and quantification of CPA in the two main skin layers-epidermis and dermis-after local application. The separation of epidermis and dermis layers was carefully carried out by means of a sharp spatula after skin immersion in heated water at 65 degrees C. The two skin layers were then treated separately according to the same process: (1) sample homogenization by vibration after freezing with liquid nitrogen in a Mikro-Dismembrator; (2) CPA extraction with methanol after addition of the internal standard (betamethasone dipropionate); (3) centrifugation; (4) evaporation of a supernatant aliquot; (5) dissolution of the dry residue in methanol and addition of water; (6) centrifugation; (7) injection of a supernatant aliquot into the HPLC system. The separation was achieved on octadecylsilica stationary phase using a mobile phase consisting in a mixture of acetonitrile and water (40:60 (v/v)). The method was then validated using a new approach based on accuracy profiles over a CPA concentration range from 33 to 667 ng/ml for each skin layer. Finally, the method was successfully applied to the determination of CPA to several skin samples after topical application of different gel formulations containing CPA.

  11. A Validated Reverse Phase HPLC Analytical Method for Quantitation of Glycoalkaloids in Solanum lycocarpum and Its Extracts

    Directory of Open Access Journals (Sweden)

    Renata Fabiane Jorge Tiossi

    2012-01-01

    Full Text Available Solanum lycocarpum (Solanaceae is native to the Brazilian Cerrado. Fruits of this species contain the glycoalkaloids solasonine (SN and solamargine (SM, which display antiparasitic and anticancer properties. A method has been developed for the extraction and HPLC-UV analysis of the SN and SM in different parts of S. lycocarpum, mainly comprising ripe and unripe fruits, leaf, and stem. This analytical method was validated and gave good detection response with linearity over a dynamic range of 0.77–1000.00 μg mL−1 and recovery in the range of 80.92–91.71%, allowing a reliable quantitation of the target compounds. Unripe fruits displayed higher concentrations of glycoalkaloids (1.04% ± 0.01 of SN and 0.69% ± 0.00 of SM than the ripe fruits (0.83% ± 0.02 of SN and 0.60% ± 0.01 of SM. Quantitation of glycoalkaloids in the alkaloidic extract gave 45.09% ± 1.14 of SN and 44.37% ± 0.60 of SM, respectively.

  12. Validated high-performance liquid chromatographic method for the standardisation of Ptychopetalum olacoides Benth., Olacaceae, commercial extracts

    Directory of Open Access Journals (Sweden)

    Renata Colombo

    2010-10-01

    Full Text Available Ptychopetalum olacoides Benth., Olacaceae, popularly known as marapuama or muirapuama or miriantã, is a species native to the Amazonian region of Brazil. Extracts of the bark of the plant have been used traditionally for its stimulating and aphrodisiac properties and currently commercialised by the herbal industry as constituents in a wide range of phytomedicines. Fractionation by open column chromatography followed by preparative HPLC-UV/PAD of the stem bark and of three commercial extracts of P. olacoides allowed the isolation of three components that were common to all extracts analysed, and these were identified by NMR to be vanillic acid, protocatechuic acid and theobromine. Vanillic acid, which has been proposed as a phytochemical marker for P. olacoides, was employed as an external standard in the development and validation of a rapid qualitative and quantitative HPLC assay for the analyte. The recoveries values of the developed method were 99.02% and the LOD and LOQ values were 0.033 and 0.11 mg.L-1, respectively. The described method may be applied to the standardisation of herbs, extracts or phytomedicines commercialised as marapuama.

  13. A rapid and simple determination of A77 1726 in human serum by high-performance liquid chromatography and its application for optimization of leflunomide therapy

    NARCIS (Netherlands)

    van Roon, EN; Yska, JP; Raemaekers, J; Jansen, TLTA; van Wanrooy, M; Brouwers, JRBJ

    2004-01-01

    Leflunomide is a disease-modifying antirheumatic drug, which is bioactivated by fort-nation of A77 1726. In this study a rapid and simple quantitative assay using a reversed phase HPLC-UV method is validated for detection of A77 1726 in human serum. The HPLC-UV method uses a mobile phase consisting

  14. Development and Validation of a Bioanalytical Method for Quantification of 2,6-Bis-(4-hydroxy-3-methoxybenzylidene-cyclohexanone (BHMC in Rat Plasma

    Directory of Open Access Journals (Sweden)

    Yu Zhao Lee

    2012-12-01

    Full Text Available A sensitive and accurate high performance liquid chromatography with ultraviolet/visible light detection (HPLC-UV/VIS method for the quantification of 2,6-bis-(4-hydroxy-3-methoxybenzylidene-cyclohexanone (BHMC in rat plasma was developed and validated. BHMC and the internal standard, harmaline, were extracted from plasma samples by a simple liquid–liquid extraction using 95% ethyl acetate and 5% methanol. Plasma concentration of BHMC and internal standard were analyzed by reversed phase chromatography using a C18 column (150 × 4.6 mm I.D., particle size 5 µm and elution with a gradient mobile phase of water and methanol at a flow rate of 1.0 mL/min. Detection of BHMC and internal standard was done at a wavelength of 380 nm. The limit of quantification was 0.02 µg/mL. The calibration curves was linear (R2 > 0.999 over the concentration range of 0.02–2.5 µg/mL. Intra- and inter-day precision were less than 2% coefficient of variation. The validated method was then applied to a pharmacokinetic study in rats by intravenous administration of BHMC at a single dose of 10 mg/kg. Pharmacokinetic parameters such as half-life, maximum plasma concentration, volume of distribution, clearance and elimination rate constant for BHMC were calculated.

  15. Development and validation of a high performance liquid chromatographic method for the determination of oxcarbazepine and its main metabolites in human plasma and cerebrospinal fluid and its application to pharmacokinetic study.

    Science.gov (United States)

    Kimiskidis, Vasilios; Spanakis, Marios; Niopas, Ioannis; Kazis, Dimitrios; Gabrieli, Chrysi; Kanaze, Feras Imad; Divanoglou, Daniil

    2007-01-17

    An isocratic reversed-phase HPLC-UV procedure for the determination of oxcarbazepine and its main metabolites 10-hydroxy-10,11-dihydrocarbamazepine and 10,11-dihydroxy-trans-10,11-dihydrocarbamazepine in human plasma and cerebrospinal fluid has been developed and validated. After addition of bromazepam as internal standard, the analytes were isolated from plasma and cerebrospinal fluid by liquid-liquid extraction. Separation was achieved on a X-TERRA C18 column using a mobile phase composed of 20 mM KH(2)PO(4), acetonitrile, and n-octylamine (76:24:0.05, v/v/v) at 40 degrees C and detected at 237 nm. The described assay was validated in terms of linearity, accuracy, precision, recovery and lower limit of quantification according to the FDA validation guidelines. Calibration curves were linear with a coefficient of variation (r) greater than 0.998. Accuracy ranged from 92.3% to 106.0% and precision was between 2.3% and 8.2%. The method has been applied to plasma and cerebrospinal fluid samples obtained from patients treated with oxcarbazepine, both in monotherapy and adjunctive therapy.

  16. The Validation of an Analytical Method for Sulfentrazone Residue Determination in Soil Using Liquid Chromatography and a Comparison of Chromatographic Sensitivity to Millet as a Bioindicator Species

    Directory of Open Access Journals (Sweden)

    Marcelo Antonio de Oliveira

    2014-07-01

    Full Text Available Commonly used herbicides, such as sulfentrazone, pose the risk of soil contamination due to their persistence, bioaccumulation and toxicity. Phytoremediation by green manure species has been tested using biomarkers, but analytical data are now required to confirm the extraction of sulfentrazone from soil. Thus, the present work was carried out to analyze sulfentrazone residues in soil based on liquid chromatography with a comparison of these values to the sensitivity of the bioindicator Pennisetum glaucum. The soil samples were obtained after cultivation of Crotalaria juncea and Canavalia ensiformis at four seeding densities and with three doses of sulfentrazone. The seedlings were collected into pots, at two different depths, after 75 days of phytoremediator sowing and then were used to determine the herbicide persistence in the soil. A bioassay with P. glaucum was carried out in the same pot. High-performance liquid chromatography (HPLC, using UV-diode array detection (HPLC/UV-DAD, was used to determine the herbicide residues. The HPLC determination was optimized and validated according to the parameters of precision, accuracy, linearity, limit of detection and quantification, robustness and specificity. The bioindicator P. glaucum was more sensitive to sulfentrazone than residue determination by HPLC. Changes in sulfentrazone concentration caused by green manure phytoremediation were accurately identified by the bioindicator. However, a true correlation between the size of the species and the analyte content was not identified.

  17. Validation and evaluation of an HPLC methodology for the quantification of the potent antimitotic compound (+)-discodermolide in the Caribbean marine sponge Discodermia dissoluta.

    Science.gov (United States)

    Valderrama, Katherine; Castellanos, Leonardo; Zea, Sven

    2010-08-01

    The sponge Discodermia dissoluta is the source of the potent antimitotic compound (+)-discodermolide. The relatively abundant and shallow populations of this sponge in Santa Marta, Colombia, allow for studies to evaluate the natural and biotechnological supply options of (+)-discodermolide. In this work, an RP-HPLC-UV methodology for the quantification of (+)-discodermolide from sponge samples was tested and validated. Our protocol for extracting this compound from the sponge included lyophilization, exhaustive methanol extraction, partitioning using water and dichloromethane, purification of the organic fraction in RP-18 cartridges and then finally retrieving the (+)-discodermolide in the methanol-water (80:20 v/v) fraction. This fraction was injected into an HPLC system with an Xterra RP-18 column and a detection wavelength of 235 nm. The calibration curve was linear, making it possible to calculate the LODs and quantification in these experiments. The intra-day and inter-day precision showed relative standard deviations lower than 5%. The accuracy, determined as the percentage recovery, was 99.4%. Nine samples of the sponge from the Bahamas, Bonaire, Curaçao and Santa Marta had concentrations of (+)-discodermolide ranging from 5.3 to 29.3 microg/g(-1) of wet sponge. This methodology is quick and simple, allowing for the quantification in sponges from natural environments, in situ cultures or dissociated cells.

  18. Differentiation of Cuscuta chinensis and Cuscuta australis by HPLC-DAD-MS analysis and HPLC-UV quantitation.

    Science.gov (United States)

    He, Xianghui; Yang, Wenzhi; Ye, Min; Wang, Qing; Guo, Dean

    2011-11-01

    Cuscuta chinensis and Cuscuta australis, the two botanical sources of the Chinese herbal medicine Tu-Si-Zi, were distinguished from each other based on qualitative and quantitative chemical analysis. By HPLC‑DAD‑MS, a total of 36 compounds were characterized from these two Cuscuta species, including 14 flavonoids, 17 quinic acid derivatives, and 5 lignans. In addition, HPLC‑UV was applied to determine seven major compounds (6 flavonoids plus chlorogenic acid) in 27 batches of Tu-Si-Zi. The results revealed that the amounts of the three classes of compounds varied significantly between the species. C. australis contained more flavonoids but less quinic acid derivatives and lignans than C. chinensis. Particularly, the amounts of kaempferol and astragalin in C. australis were remarkably higher than in C. chinensis. This finding could be valuable for the quality control of Tu-Si-Zi. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Determination of amino acid neurotransmitters in rat hippocampi by HPLC-UV using NBD-F as a derivative.

    Science.gov (United States)

    Wu, Xiaomeng; Wang, Rui; Jiang, Qingqing; Wang, Shue; Yao, Yao; Shao, Lihua

    2014-04-01

    A simple, rapid and accurate high-performance liquid chromatography method with ultraviolet-visible detection was developed for the determination of five amino acid neurotransmitters - aspartate, glutamic acid, glycine, taurine and γ-aminobutyric acid - in rat hippocampi with pre-column derivatization with 4-fluoro-7-nitrobenzofurazan. Several conditions which influenced derivatization and separation, such as pH, temperature, acetonitrile percentage mobile phase and flow rate, were optimized to obtain a suitable protocol for amino acids quantification in samples. The separation of the five neurotransmitter derivatives was performed on a C18 column using a mobile phase consisting of phosphate buffer (0.02 mol/L, pH 6.0)-acetonitrile (84:16, v/v) at a flow rate of 1.0 mL/min with the column temperature at 30°C. The detection wavelength was 472 nm. Without gradient elution, the five neurotransmitter derivatives were completely separated within 15 min. The linear relation was good in the range from 0.50 to 500 µmol/L, and the correlation coefficients were ≥0.999. Intra-day precision was between 1.8 and 3.2%, and inter-day precision was between 2.4 and 4.7%. The limits of detection (signal-to-noise ratio 3) were from 0.02 to 0.15 µmol/L. The established method was used to determine amino acid neurotransmitters in rat hippocampi with satisfactory recoveries varying from 94.9 to 105.2%. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Determination of indole alkaloids and highly volatile compounds in Rauvolfia verticillata by HPLC-UV and GC-MS.

    Science.gov (United States)

    Hong, Bo; Li, Wenjing; Song, Aihua; Zhao, Chunjie

    2013-01-01

    Rauvolfia verticillata (Lour.) Baill. (also called Luofumu in Chinese) is commonly used in traditional Chinese medicine for lowering blood pressure. In this study, a high-performance liquid chromatography assay using ultraviolet detection is described for the simultaneous measurement of the five bioactive indole alkaloids (sarpagine, yohimbine, ajmaline, ajmalicine and reserpine) in Rauvolfia. The detection of all five compounds was conducted at 280 nm. In quantitative analysis, the five compounds showed good regressions (R(2) > 0.9988) within the test ranges, and the recovery of the method was in the range of 90.4-101.4%. In addition, a simple gas chromatography mass method using a DB-1 silica capillary column (30 m × 0.25 mm i.d., 0.25 µm) is described for the identification of the highly volatile compounds in Rauvolfia. In qualitative analysis, more than 39 compounds were assayed and identified using the mass function and the National Institute of Standards and Technology database search system. The results demonstrated that the combination of quantitative and qualitative analyses offered an efficient way to evaluate the quality and consistency of Rauvolfia verticillata.

  1. Two-dimensional fingerprinting approach for comparison of complex substances analysed by HPLC-UV and fluorescence detection.

    Science.gov (United States)

    Ni, Yongnian; Liu, Ying; Kokot, Serge

    2011-02-07

    This work is concerned with the research and development of methodology for analysis of complex mixtures such as pharmaceutical or food samples, which contain many analytes. Variously treated samples (swill washed, fried and scorched) of the Rhizoma atractylodis macrocephalae (RAM) traditional Chinese medicine (TCM) as well as the common substitute, Rhizoma atractylodis (RA) TCM were chosen as examples for analysis. A combined data matrix of chromatographic 2-D HPLC-DAD-FLD (two-dimensional high performance liquid chromatography with diode array and fluorescence detectors) fingerprint profiles was constructed with the use of the HPLC-DAD and HPLC-FLD individual data matrices; the purpose was to collect maximum information and to interpret this complex data with the use of various chemometrics methods e.g. the rank-ordering multi-criteria decision making (MCDM) PROMETHEE and GAIA, K-nearest neighbours (KNN), partial least squares (PLS), back propagation-artificial neural networks (BP-ANN) methods. The chemometrics analysis demonstrated that the combined 2-D HPLC-DAD-FLD data matrix does indeed provide more information and facilitates better performing classification/prediction models for the analysis of such complex samples as the RAM and RA ones noted above. It is suggested that this fingerprint approach is suitable for analysis of other complex, multi-analyte substances.

  2. Assay of flavonoid aglycones from the species of genus Sideritis (Lamiaceae) from Macedonia with HPLC-UV DAD.

    Science.gov (United States)

    Janeska, Bisera; Stefova, Marina; Alipieva, Kalina

    2007-09-01

    Flavonoids obtained from Sideritis species (Lamiaceae), S. raeseri and S. scardica, grown in Macedonia were studied. Qualitative and quantitative analyses of the flavonoid aglycones were performed using high-performance liquid chromatography (HPLC) with a UV diode array detector. Extracts were prepared by acid hydrolysis in acetone, re-extraction in ethyl acetate and evaporation to dryness; the residue dissolved in methanol was subjected to HPLC analysis.Isoscutellarein, chryseriol and apigenin were identified in the extracts. Also, a 4'-methyl ether derivative of isoscutellarein was found, together with hypolaetin and its methyl ether derivative, which were identified according to previously isolated glycosides and literature data. Quantitation was performed using calibration with apigenin.According to this screening analysis, the samples of the genus Sideritis from Macedonia are rich in polyhydroxy flavones and analogous with the previously studied Mediterranean Sideritis species from the Ibero-North African and Greek Sideritis species with respect to the presence of 8-OH flavones and their derivatives.

  3. Optimized Analytical Method to Determine Gallic and Picric Acids in Pyrotechnic Samples by Using HPLC/UV (Reverse Phase)

    International Nuclear Information System (INIS)

    Garcia Alonso, S.; Perez Pastor, R. M.

    2013-01-01

    A study on the optimization and development of a chromatographic method for the determination of gallic and picric acids in pyrotechnic samples is presented. In order to achieve this, both analytical conditions by HPLC with diode detection and extraction step of a selected sample were studied. (Author)

  4. Modeling systematic errors: polychromatic sources of Beer-Lambert deviations in HPLC/UV and nonchromatographic spectrophotometric assays.

    Science.gov (United States)

    Galli, C

    2001-07-01

    It is well established that the use of polychromatic radiation in spectrophotometric assays leads to excursions from the Beer-Lambert limit. This Note models the resulting systematic error as a function of assay spectral width, slope of molecular extinction coefficient, and analyte concentration. The theoretical calculations are compared with recent experimental results; a parameter is introduced which can be used to estimate the magnitude of the systematic error in both chromatographic and nonchromatographic spectrophotometric assays. It is important to realize that the polychromatic radiation employed in common laboratory equipment can yield assay errors up to approximately 4%, even at absorption levels generally considered 'safe' (i.e. absorption <1). Thus careful consideration of instrumental spectral width, analyte concentration, and slope of molecular extinction coefficient is required to ensure robust analytical methods.

  5. Explicating Validity

    Science.gov (United States)

    Kane, Michael T.

    2016-01-01

    How we choose to use a term depends on what we want to do with it. If "validity" is to be used to support a score interpretation, validation would require an analysis of the plausibility of that interpretation. If validity is to be used to support score uses, validation would require an analysis of the appropriateness of the proposed…

  6. FACTAR validation

    International Nuclear Information System (INIS)

    Middleton, P.B.; Wadsworth, S.L.; Rock, R.C.; Sills, H.E.; Langman, V.J.

    1995-01-01

    A detailed strategy to validate fuel channel thermal mechanical behaviour codes for use of current power reactor safety analysis is presented. The strategy is derived from a validation process that has been recently adopted industry wide. Focus of the discussion is on the validation plan for a code, FACTAR, for application in assessing fuel channel integrity safety concerns during a large break loss of coolant accident (LOCA). (author)

  7. Development and Validation of a Simultaneous RP-HPLCUV/DAD Method for Determination of Polyphenols in Gels Containing S. terebinthifolius Raddi (Anacardiaceae)

    Science.gov (United States)

    Carvalho, Melina G.; Aragão, Cícero F. S; Raffin, Fernanda N.; de L. Moura, Túlio F. A.

    2017-01-01

    Topical gels containing extracts of Schinus terebinthifolius have been used to treat bacterial vaginosis. It has been reported that this species has antimicrobial, anti-inflammatory and anti-ulcerogenic properties, which can be attributed to the presence of phenolic compounds. In this work, a sensitive and selective reversed-phase HPLC-UV/DAD method for the simultaneous assay of six polyphenols that could be present in S. terebinthifolius was developed. The method was shown to be accurate and precise. Peak purity and similarity index both exceeded 0.99. Calibration curves were linear over the concentration range studied, with correlation coefficients between 0.9931 and 0.9974. This method was used to determine the polyphenol content of a hydroalcoholic extract and pharmacy-compounded vaginal gel. Although the method is useful to assess the 6 phenolic compounds, some compounds could not be detected in the products. SUMMARY A sensitive, selective, accurate and precise reversed-phase HPLC-UV/DAD method for the simultaneous assay of six polyphenols in S. terebinthifolius Raddi Abbreviations used: RP-HPLC-UV/DAD: Reverse Phase High Performance Liquid Chromatograph with Ultraviolet and Diode Array Detector, HPLC: High Performance Liquid Chromatograph, HPLC-UV: High Performance Liquid Chromatograph with Ultraviolet Detector, ANVISA: Brazilian National Health Surveillance Agency, LOD: Limit of detection, LOQ: Limit of quantitation PMID:28539726

  8. Development and Validation of a Simple High Performance Liquid Chromatography/UV Method for Simultaneous Determination of Urinary Uric Acid, Hypoxanthine, and Creatinine in Human Urine

    Directory of Open Access Journals (Sweden)

    Nimanthi Wijemanne

    2018-01-01

    Full Text Available Uric acid and hypoxanthine are produced in the catabolism of purine. Abnormal urinary levels of these products are associated with many diseases and therefore it is necessary to have a simple and rapid method to detect them. Hence, we report a simple reverse phase high performance liquid chromatography (HPLC/UV technique, developed and validated for simultaneous analysis of uric acid, hypoxanthine, and creatinine in human urine. Urine was diluted appropriately and eluted with C-18 column 100 mm × 4.6 mm with a C-18 precolumn 25 mm × 4.6 mm in series. Potassium phosphate buffer (20 mM, pH 7.25 at a flow rate of 0.40 mL/min was employed as the solvent and peaks were detected at 235 nm. Tyrosine was used as the internal standard. The experimental conditions offered a good separation of analytes without interference of endogenous substances. The calibration curves were linear for all test compounds with a regression coefficient, r2>0.99. Uric acid, creatinine, tyrosine, and hypoxanthine were eluted at 5.2, 6.1, 7.2, and 8.3 min, respectively. Intraday and interday variability were less than 4.6% for all the analytes investigated and the recovery ranged from 98 to 102%. The proposed HPLC procedure is a simple, rapid, and low cost method with high accuracy with minimum use of organic solvents. This method was successfully applied for the determination of creatinine, hypoxanthine, and uric acid in human urine.

  9. Validation philosophy

    International Nuclear Information System (INIS)

    Vornehm, D.

    1994-01-01

    To determine when a set of calculations falls within an umbrella of an existing validation documentation, it is necessary to generate a quantitative definition of range of applicability (our definition is only qualitative) for two reasons: (1) the current trend in our regulatory environment will soon make it impossible to support the legitimacy of a validation without quantitative guidelines; and (2) in my opinion, the lack of support by DOE for further critical experiment work is directly tied to our inability to draw a quantitative open-quotes line-in-the-sandclose quotes beyond which we will not use computer-generated values

  10. Revaluation of maturity and stability indices for compost ...

    African Journals Online (AJOL)

    BOD/COD ratio of compost was studied in conjunction with C/N ratio as commonly maturity index. Carbonaceous materials as well as nitrogenous materials declined in open-air conditions during 20 weeks. C/N ratio was correlated with BOD/COD, a couple parameters to qualify the compost was mature and stable.

  11. STABILITY-INDICATING RP-HPLC METHOD FOR SIMULTANEOUS ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    pharmacopoeia, a careful and thorough literature review also showed absence of any reversed phase LC .... cetostearyl alcohol, petroleum jelly) of the ointment and human serum. Synthetic ... acid/base hydrolysis and oxidation. Acid-stress ...

  12. A Stability Indicating HPLC Method for the Determination of ...

    African Journals Online (AJOL)

    4–20μg/ml and the linear regression equation was y = 57257.38x + 3443.07. Accuracy ranged from 99.27 to 100.78% and the % coefficient of variation (CV) for both intra-day and inter-day precision was less than 2%. MLX showed minor degradation peak in acidic conditions at Rt of 2.24min. The LOD and LOQ values were ...

  13. The Effect of Zeolite on Aggregate Stability Indices

    Directory of Open Access Journals (Sweden)

    F. Sohrab

    2016-02-01

    Full Text Available Introduction: Soil structural stability affects the profitability and sustainability of agricultural systems. Particle size distribution (PSD and aggregate stability are the important characteristics of soil. Aggregate stability has a significant impact on the development of the root system, water and carbon cycle and soil resistance against soil erosion. Soil aggregate stability, defined as the ability of the aggregates to remain intact when subject to a given stress, is an important soil property that affects the movement and storage of water, aeration, erosion, biological activity and growth of crops. Dry soil aggregate stability (Mean Weight Diameter (MWD, Geometric Mean Diameter (GMD and Wet Aggregate Stability (WAS are important indices for evaluating soil aggregate stability.To improve soil physical properties, including modifying aggregate, using various additives (organic, inorganic and chemicals, zeolites are among what has been studied.According to traditional definition, zeolites are hydratealuminosilicates of alkaline and alkaline-earth minerals. Their structure is made up of a framework of[SiO4]−4 and [AlO4]−5 tetrahedron linked to each other's cornersby sharing oxygen atoms. The substitution of Si+4 by Al+3 intetrahedral sites results inmore negative charges and a high cation exchange capacity.Zeolites, as natural cation exchangers, are suitable substitutes to remove toxic cations. Among the natural zeolites,Clinoptilolite seems to be the most efficient ion exchanger and ion-selective material forremoving and stabilizing heavy metals.Due to theexisting insufficient technical information on the effects of using different levels of zeolite on physical properties of different types of soils in Iran, the aim of this research was to assess the effects of two different types of zeolite (Clinoptilolite natural zeolite, Z4, and Synthetic zeolite, A4 on aggregate stability indicesof soil. Materials and Methods: In this study at first, after preparation of two different types of soil with light and medium texture and doing identification tests such as determination of gradation and hydrometer tests and Atterberg limits, zeolite in four levels, 0 (control, 1%, 5%, and 10%w/w, was mixed with two soil textures (sandy loam and silty loam in three replications. Then, each treatment was saturated for 48 hours in each month, during 6 months. Dry soil aggregate stability (Mean Weight Diameter (MWD, Geometric Mean Diameter (GMD, and Wet Aggregate Stability (WAS, were determined. The experiment was carried out using factorial method in a randomized complete design. Results and Discussion:The results showed that, in sandy loam texture, there was no significant difference between two types of zeolites, their level of using and their interaction on MWD (p

  14. Stability-Indicating HPLC Method for the Simultaneous ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research May 2014; 13 (5): 809-817. ISSN: 1596-5996 ... indicating method for the simultaneous estimation of valsartan and ezetimibe in combined tablet ... techniques like spectrometric methods [1-3] and.

  15. Depletion of four nitrofuran antibiotics and their tissue-bound metabolites in porcine tissues and determination using LC-MS/MS and HPLC-UV

    NARCIS (Netherlands)

    Cooper, K.M.; Mulder, P.P.J.; Rhijn, van J.A.; Kovacsics, L.; McCracken, R.J.; Young, P.B.; Kennedy, D.G.

    2005-01-01

    Depletion of the nitrofuran antibiotics furazolidone, furaltadone, nitrofurantoin and nitrofurazone and their tissue-bound metabolites AOZ, AMOZ, AHD and SEM from pig muscle, liver and kidney tissues is described. Groups of pigs were given feed medicated with one of the nitrofuran drugs at a

  16. Simultaneous Determination of First-Line 4-FDC Antituberculosis Drugs by UHPLC-UV and HPLC-UV: A Comparative Study.

    Science.gov (United States)

    Franco, Pedro H C; Chellini, Paula R; Oliveira, Marcone A L; Pianetti, Gerson A

    2017-07-01

    Tuberculosis is the second most deadly infectious disease, surpassed only by HIV/AIDS, and has resulted in over 1 billion deaths in the last 200 years. The World Health Organization estimates that in 2014, 9.6 million people were infected by this disease and 1.5 million had died. First-choice treatment consists of fixed-dose combination tablets containing rifampicin, isoniazid, pyrazinamide, and ethambutol hydrochloride (4-FDC). There are pharmacopeial protocols available to test 4-FDC, but they are prolonged, two-step methods. One single-step method in the literature performs the simultaneous determination by HPLC, but requires a long acquisition time. In this context, an ultra-HPLC (UHPLC) method was developed based on the HPLC method with the objective of reducing analysis time. A C18 column (1.9 µm particle size) was used with UV-diode-array detection at 238 and 282 nm. The method was found to be selective, linear, exact, precise, and robust. Samples from two batches were analyzed and the results compared with those obtained by the HPLC method, with no statistically significant differences observed (P > 0.05). This UHPLC method reduced the analysis time from 17 to 4 min, with a more than 90% reduction in sample and reagent consumption and a financial economy of almost 50-fold.

  17. HPLC-UV-ESI-MS analysis of phenolic compounds and antioxidant properties of Hypericum undulatum shoot cultures and wild-growing plants.

    Science.gov (United States)

    Rainha, Nuno; Koci, Kamila; Coelho, Ana Varela; Lima, Elisabete; Baptista, José; Fernandes-Ferreira, Manuel

    2013-02-01

    LC-UV and LC-MS analysis were used to study the phenolic composition of water extracts of Hypericum undulatum (HU) shoot cultures and wild-growing (WG) plants. Total phenolic content (TPC), determined using the Folin-Ciocalteu assay, and the antioxidant activity measured by two complementary methods were also performed for each sample. Mass spectrometry revealed several phenolics acids with quinic acid moieties, flavonols, mostly quercetin, luteolin and apigenin glycosides, flavan-3-ols (catechin and epicatechin) and the xanthonoid mangiferin. Differences in phenolic composition profile and TPC were found between the samples. The major phenolic in HU culture-growing (CG) samples is chlorogenic acid, followed by epicatechin, quercitrin and isoquercitrin. The WG plants presents hyperoside as the main phenolic, followed by isoquercitrin, chlorogenic acid and quercetin. The TPC and antioxidant activity were higher in samples from WG plants. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Three-phase hollow-fiber liquid-phase microextraction combined with HPLC-UV for the determination of isothiazolinone biocides in adhesives used for food packaging materials.

    Science.gov (United States)

    Rosero-Moreano, Milton; Canellas, Elena; Nerín, Cristina

    2014-02-01

    The present study deals with the development of a liquid microextraction procedure for enhancing the sensitivity of the determination of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one in adhesives. The procedure involves a three-phase hollow-fiber liquid-phase microextraction using a semipermeable polypropylene membrane, which contained 1-octanol as the organic phase in the pores of the membrane. The donor and acceptor phases are aqueous acidic and alkaline media, respectively, and the final liquid phase (acceptor) is analyzed by HPLC coupled with diode array detection. The most appropriate conditions were extraction time 20 min, stirring speed 1400 rpm, extraction temperature 50°C. The quantification limits of the method were 0.123 and 0.490 μg/g for 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one, respectively. Three different adhesive samples were successfully analyzed. The procedure was compared to direct analysis using ultra high pressure liquid chromatography coupled with TOF-MS, where the identification of the compounds and the quantification values were confirmed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. An examination of endoparasites and fecal testosterone levels in flying squirrels (Glaucomys spp.) using high performance liquid chromatography-ultra-violet (HPLC-UV)

    OpenAIRE

    Waksmonski, Sarah N.; Huffman, Justin M.; Mahan, Carolyn G.; Steele, Michael A.

    2017-01-01

    The immuno-competence hypothesis proposes that higher levels of testosterone increases the susceptibility to parasitism. Here we examined the testosterone levels in two species of flying squirrels (Glaucomys): one known to regularly host a nematode species (Strongyloides robustus) without ill effects (G. volans) and a closely related species that is considered negatively affected by the parasite. We quantified fecal testosterone levels in northern and southern flying squirrels (G. sabrinus, G...

  20. Simultaneous separation and identification of oligomeric procyanidins and anthocyanin-derived pigments in raw red wine by HPLC-UV-ESI-MSn.

    Science.gov (United States)

    Pati, S; Losito, I; Gambacorta, G; La Notte, E; Palmisano, F; Zambonin, P G

    2006-07-01

    Samples of raw red wine (Primitivo di Manduria, Apulia, Southern Italy) were analysed without any pre-treatment (except 1:2 dilution with water) using HPLC with detection based on UV absorbance and Electrospray Ionisation Sequential Mass Spectrometry (ESI-MSn, with n = 1-3) in a series configuration. In particular, absorbance at 520 nm was monitored for UV detection in order to identify pigments responsible for wine colour. On the other hand, two subsequent stages of MS detection based on positive ions were adopted. The first consisted of an explorative MS acquisition, aimed at the individuation of the m/z ratios for positively charged compounds; the second was based on fragmentation of the detected ions within an ion trap analyser, followed by MS/MS and, if required, MS3 acquisitions. The synergy between UV detection and MSn analysis led to the identification of 41 pigments, which can be classified into five groups: grape anthocyanins, pyranoanthocyanins, vinyl-linked anthocyanin-flavanol pigments, ethyl-bridged anthocyanin-flavanol pigments and flavanol-anthocyanin compounds. Many isomeric and oligomeric structures were found within each group. A further class of compounds, not absorbing in the visible spectrum, could be also characterised by ESI-MSn and corresponded to B-type procyanidins, i.e. proanthocyanidins arising from C4-->C8/C4-->C6 couplings between catechin or epicatechin units. In particular, oligomeric structures (from dimers to pentamers), often present with several isomers, were identified and their fragmentation patterns clarified.

  1. Molecularly imprinted polymer cartridges coupled to high performance liquid chromatography (HPLC-UV) for simple and rapid analysis of fenthion in olive oil.

    Science.gov (United States)

    Bakas, Idriss; Ben Oujji, Najwa; Istamboulié, Georges; Piletsky, Sergey; Piletska, Elena; Ait-Addi, Elhabib; Ait-Ichou, Ihya; Noguer, Thierry; Rouillon, Régis

    2014-07-01

    A combination of molecular modelling and a screening of the library of non-imprinted polymers (NIPs) was used to identify acrylamide as a functional monomer with high affinity towards fenthion, organophosphate insecticide, which is frequently used in the treatment of olives. A good correlation was found between the screening tests and modelling of monomer-template interactions performed using a computational approach. Acrylamide-based molecularly imprinted polymer (MIP) and non-imprinted polymer (NIP) were thermally synthesised in dimethyl formamide (porogen) using ethylene glycol dimethacrylate as a cross-linker and 1,1-azo-bis (isobutyronitrile) as an initiator. The chemical and physical properties of the prepared polymers were characterised. The binding of fenthion by the polymers was studied using solvents with different polarities. The developed MIP showed a high selectivity towards fenthion, compared to other organophosphates (dimethoate, methidathion malalthion), and allowed extraction of fenthion from olive oil samples with a recovery rate of about 96%. The extraction of fenthion using MIPs was much more effective than traditional C18 reverse-phase solid phase extraction and allowed to achieve a low detection limit (LOD) (5 µg L(-1)). Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Extraction and HPLC- UV Analysis of C60, C70, and [6,6]-phenyl C61-butyric acid methyl ester in Synthetic and Natural Waters

    Science.gov (United States)

    Studies have shown that C60 fullerene can form stable colloidal suspensions in water that result in C60 aqueous concentrations many orders of magnitude above C60's aqueous solubility; however, quantitative methods for the analysis of C60 and other fullerenes in environmental medi...

  3. CZE/PAD and HPLC-UV/PAD Profile of Flavonoids from Maytenus aquifolium and Maytenus ilicifolia “espinheira santa” Leaves Extracts

    OpenAIRE

    Diagone, Cristina A.; Colombo, Renata; Lanças, Fernando M.; Yariwake, Janete H.

    2012-01-01

    This paper describes the application of HPLC and CZE to analyze flavonoids in the leaves of Maytenus ilicifolia and Maytenus aquifolium, which are species widely used in Brazilian folk medicine. The two species showed different flavonoid profiles, but acidic hydrolysis of the Maytenus extracts confirmed that all these compounds are quercetin or kaempferol derivatives. A comparison of the CZE and HPLC profiles of Maytenus extracts showed numerous flavonoid peaks using HPLC. However, the advant...

  4. HPLC-UV/DAD and ESI-MS(n) analysis of flavonoids and antioxidant activity of an Algerian medicinal plant: Paronychia argentea Lam.

    Science.gov (United States)

    Sait, Sabrina; Hamri-Zeghichi, Sabrina; Boulekbache-Makhlouf, Lila; Madani, Khodir; Rigou, Peggy; Brighenti, Virginia; Pio Prencipe, Francesco; Benvenuti, Stefania; Pellati, Federica

    2015-01-01

    Paronychia argentea Lam., belonging to the Caryophyllaceae family, is a perennial plant widely distributed in Algeria. Even though this plant is used in the Algerian popular medicine, its phytochemical characterization is incomplete. In this study, the flavonoid profile and the in vitro antioxidant activity of the ethanolic extract, decoction and infusion of P. argentea aerial parts are reported. Flavonoids were analyzed by means of high-performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry. Eleven compounds were identified and six of them, including isorhamnetin-3-O-dihexoside, quercetin-3-O-glucoside, quercetinmethylether-O-hexoside, quercetin, jaceosidin and isorhamnetin, were described in this plant for the first time. The ethanol extract showed the highest flavonoid content, followed by the decoction and the infusion (25.4 ± 0.8 mg/g of DM, 8.4 ± 0.5 mg/g of DM, 0.2 mg/g of DM, respectively), while the best antioxidant activity was shown by the decoction (RC0.5 = 178 μg/mL for reducing power, 72.4% of inhibition of lipid peroxidation, IC50 = 27.38μ g/mL for DPPH radical scavenging activity and 59.7% of inhibition of NO radical). These results showed that P. argentea decoction could be considered as a valuable source of flavonoids and antioxidants that might contribute to the valorization of the phytotherapeutic potential of this plant. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Hollow Fiber Supported Liquid Membrane Extraction Combined with HPLC-UV for Simultaneous Preconcentration and Determination of Urinary Hippuric Acid and Mandelic Acid

    Directory of Open Access Journals (Sweden)

    Abdulrahman Bahrami

    2017-02-01

    Full Text Available This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L−1 sodium chloride, liquid membrane containing 1-octanol with 20% (w/v tributyl phosphate as the carrier, the time of extraction was 150 min, and stirring rate was 500 rpm. The organic phase immobilized in the pores of a hollow fiber was back-extracted into 24 µL of a solution containing sodium carbonate with pH 11, which was placed inside the lumen of the fiber. Under optimized conditions, the high enrichment factors of 172 and 195 folds, detection limit of 0.007 and 0.009 µg·mL−1 were obtained. The relative standard deviation (RSD (% values for intra- and inter-day precisions were calculated at 2.5%–8.2% and 4.1%–10.7%, respectively. The proposed method was successfully applied to the analysis of these metabolites in real urine samples. The results indicated that hollow-fiber liquid-phase microextraction (HF-LPME based on facilitated pH gradient transport can be used as a sensitive and effective method for the determination of mandelic acid and hippuric acid in urine specimens.

  6. Application of Optimized Vortex-Assisted Surfactant-Enhanced DLLME for Preconcentration of Thymol and Carvacrol, and Their Determination by HPLC-UV: Response Surface Methodology.

    Science.gov (United States)

    Ghaedi, Mehrorang; Roosta, Mostafa; Khodadoust, Saeid; Daneshfar, Ali

    2015-08-01

    A novel vortex-assisted surfactant-enhanced dispersive liquid-liquid microextraction combined with high-performance liquid chromatography (VASEDLLME-HPLC) was developed for the determination of thymol and carvacrol (phenolic compound). In this method, the extraction solvent (CHCl3) was dispersed into the aqueous samples via a vortex agitator and addition of the surfactant (Triton X-100). The preliminary experiments were undertaken to select the best extraction solvent and surfactant. The influences of effective variables were investigated using a Plackett-Burman 2(7-4) screening design and then, the significant variables were optimized by using a central composite design combined with desirability function. Working under optimum conditions specified as: 140 µL CHCl3, 0.08% (w/v, Triton X-100), 3 min extraction time, 6 min centrifugation at 4,500 rpm, pH 7, 0.0% (w/v) NaCl permit achievement of high and reasonable linear range over 0.005-4.0 mg L(-1) with R(2) = 0.9998 (n = 10). The separation of thymol and carvacrol was achieved in <14 min using a C18 column and an isocratic binary mobile phase acetonitrile-water (55:45, v/v) with a flow rate of 1.0 mL min(-1). The VASEDLLME is applied for successful determination of carvacrol and thymol in different thyme and pharmaceutical samples with relative standard deviation <4.7% (n = 5). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. A Study of Method Development, Validation, and Forced Degradation for Simultaneous Quantification of Paracetamol and Ibuprofen in Pharmaceutical Dosage Form by RP-HPLC Method

    OpenAIRE

    Jahan, Md. Sarowar; Islam, Md. Jahirul; Begum, Rehana; Kayesh, Ruhul; Rahman, Asma

    2014-01-01

    A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP) guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and...

  8. Construct Validity and Case Validity in Assessment

    Science.gov (United States)

    Teglasi, Hedwig; Nebbergall, Allison Joan; Newman, Daniel

    2012-01-01

    Clinical assessment relies on both "construct validity", which focuses on the accuracy of conclusions about a psychological phenomenon drawn from responses to a measure, and "case validity", which focuses on the synthesis of the full range of psychological phenomena pertaining to the concern or question at hand. Whereas construct validity is…

  9. High-performance liquid chromatography method for the determination of hydrogen peroxide present or released in teeth bleaching kits and hair cosmetic products.

    Science.gov (United States)

    Gimeno, Pascal; Bousquet, Claudine; Lassu, Nelly; Maggio, Annie-Françoise; Civade, Corinne; Brenier, Charlotte; Lempereur, Laurent

    2015-03-25

    This manuscript presents an HPLC/UV method for the determination of hydrogen peroxide present or released in teeth bleaching products and hair products. The method is based on an oxidation of triphenylphosphine into triphenylphosphine oxide by hydrogen peroxide. Triphenylphosphine oxide formed is quantified by HPLC/UV. Validation data were obtained using the ISO 12787 standard approach, particularly adapted when it is not possible to make reconstituted sample matrices. For comparative purpose, hydrogen peroxide was also determined using ceric sulfate titrimetry for both types of products. For hair products, a cross validation of both ceric titrimetric method and HPLC/UV method using the cosmetic 82/434/EEC directive (official iodometric titration method) was performed. Results obtained for 6 commercialized teeth whitening products and 5 hair products point out similar hydrogen peroxide contain using either the HPLC/UV method or ceric sulfate titrimetric method. For hair products, results were similar to the hydrogen peroxide content using the cosmetic 82/434/EEC directive method and for the HPLC/UV method, mean recoveries obtained on spiked samples, using the ISO 12787 standard, ranges from 100% to 110% with a RSDhydrogen peroxide contents higher than the regulated limit. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Development and validation of spectrofluorimetric and LC–MS/MS methods for the determination of hesperidin in human plasma and pharmaceutical forms

    Directory of Open Access Journals (Sweden)

    Pavun Leposava A.

    2012-01-01

    Full Text Available The spectrofluorometric method, based on fluorescence properties of aluminium (III–hesperidin complex, for the determination of hesperidin in human plasma and pharmaceutical forms has been developed and validated. The complex shows strong emission in the presence of surfactant betain sulfonate SB 12 at 476 nm with excitation at 390 nm. Linearity range in pharmaceutical forms of hesperidin was 0.06 – 24.4 μg mL-1 with LOD 0.016 μg mL-1 and LOQ 0.049 μg mL-1. Recovery values in the range 99.3 – 99.7% indicate good accuracy of the method. A linear dependence of the intensity of fluorescence of the complex on the concentration of hesperidin in plasma was obtained in concentration range from 0.1 – 12.2 μg mL-1. The LOD was 0.032 μg mL-1 while LOQ was 0.096 μg mL-1. Recovery values were in the range 98.4 – 99.8%. The reliability of the method was checked by LC-MS/MS method for plasma samples and HPLC/UV method for tablets with direct determination of hesperidin after separation. Linearity range in determination of hesperidin in pharmaceutical forms was obtained in the range from 0.05 to 10.00 μg mL-1. The LOD was 0.01 μg mL-1 and LOQ was 0.03 μg mL-1. Linearity range in plasma determination of hesperidin was 0.02 – 10.00 μg mL-1 with LOD 0.005 μg mL-1 and LOQ 0.015 μg mL-1. Good agreement between two methods indicate the usability of the proposed spectroflurometric method for the simple, precise and accurate determination of hesperidin in clinical and quality control laboratories.

  11. Optimized Analytical Method to Determine Gallic and Picric Acids in Pyrotechnic Samples by Using HPLC/UV (Reverse Phase); Optimizacion del Metodo Analitico mediante HPLC/UV Operando en Fase Inversa para la Determinacion de Acido Galico y Acido Picrico en Muestras de Origen Pirotecnico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.

    2013-10-01

    A study on the optimization and development of a chromatographic method for the determination of gallic and picric acids in pyrotechnic samples is presented. In order to achieve this, both analytical conditions by HPLC with diode detection and extraction step of a selected sample were studied. (Author)

  12. Lesson 6: Signature Validation

    Science.gov (United States)

    Checklist items 13 through 17 are grouped under the Signature Validation Process, and represent CROMERR requirements that the system must satisfy as part of ensuring that electronic signatures it receives are valid.

  13. Principles of Proper Validation

    DEFF Research Database (Denmark)

    Esbensen, Kim; Geladi, Paul

    2010-01-01

    to suffer from the same deficiencies. The PPV are universal and can be applied to all situations in which the assessment of performance is desired: prediction-, classification-, time series forecasting-, modeling validation. The key element of PPV is the Theory of Sampling (TOS), which allow insight......) is critically necessary for the inclusion of the sampling errors incurred in all 'future' situations in which the validated model must perform. Logically, therefore, all one data set re-sampling approaches for validation, especially cross-validation and leverage-corrected validation, should be terminated...

  14. Validity in Qualitative Evaluation

    OpenAIRE

    Vasco Lub

    2015-01-01

    This article provides a discussion on the question of validity in qualitative evaluation. Although validity in qualitative inquiry has been widely reflected upon in the methodological literature (and is still often subject of debate), the link with evaluation research is underexplored. Elaborating on epistemological and theoretical conceptualizations by Guba and Lincoln and Creswell and Miller, the article explores aspects of validity of qualitative research with the explicit objective of con...

  15. Validation of HEDR models

    International Nuclear Information System (INIS)

    Napier, B.A.; Simpson, J.C.; Eslinger, P.W.; Ramsdell, J.V. Jr.; Thiede, M.E.; Walters, W.H.

    1994-05-01

    The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computer models for estimating the possible radiation doses that individuals may have received from past Hanford Site operations. This document describes the validation of these models. In the HEDR Project, the model validation exercise consisted of comparing computational model estimates with limited historical field measurements and experimental measurements that are independent of those used to develop the models. The results of any one test do not mean that a model is valid. Rather, the collection of tests together provide a level of confidence that the HEDR models are valid

  16. Validation of simulation models

    DEFF Research Database (Denmark)

    Rehman, Muniza; Pedersen, Stig Andur

    2012-01-01

    In philosophy of science, the interest for computational models and simulations has increased heavily during the past decades. Different positions regarding the validity of models have emerged but the views have not succeeded in capturing the diversity of validation methods. The wide variety...

  17. Model Validation Status Review

    International Nuclear Information System (INIS)

    E.L. Hardin

    2001-01-01

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M and O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  18. Model Validation Status Review

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2001-11-28

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M&O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  19. Development, Validation and Application of RP-HPLC Method: Simultaneous Determination of Antihistamine and Preservatives with Paracetamol in Liquid Formulations and Human Serum

    OpenAIRE

    Hasan, Najmul; Chaiharn, Mathurot; Toor, Umair Ali; Mirani, Zulfiqar Ali; Sajjad, Ghulam; Sher, Nawab; Aziz, Mubashir; Siddiqui, Farhan Ahmed

    2016-01-01

    In this article we describe development and validation of stability indicating, accurate, specific, precise and simple Ion-pairing RP-HPLC method for simultaneous determination of paracetamol and cetirizine HCl along with preservatives i.e. propylparaben, and methylparaben in pharmaceutical dosage forms of oral solution and in serum. Acetonitrile: Buffer: Sulfuric Acid (45:55:0.3 v/v/v) was the mobile phase at flow rate 1.0 mL min-1 using a Hibar? Lichrosorb? C18 column and monitored at wavel...

  20. Development and validation of simple RP-HPLC-PDA analytical protocol for zileuton assisted with Design of Experiments for robustness determination

    OpenAIRE

    Saurabh B. Ganorkar; Dinesh M. Dhumal; Atul A. Shirkhedkar

    2017-01-01

    A simple, rapid, sensitive, robust, stability-indicating RP-HPLC-PDA analytical protocol was developed and validated for the analysis of zileuton racemate in bulk and in tablet formulation. Development of method and resolution of degradation products from forced; hydrolytic (acidic, basic, neutral), oxidative, photolytic (acidic, basic, neutral, solid state) and thermal (dry heat) degradation was achieved on a LC – GC Qualisil BDS C18 column (250 mm × 4.6 mm × 5 μm) by isocratic mode at ambie...

  1. Validity in Qualitative Evaluation

    Directory of Open Access Journals (Sweden)

    Vasco Lub

    2015-12-01

    Full Text Available This article provides a discussion on the question of validity in qualitative evaluation. Although validity in qualitative inquiry has been widely reflected upon in the methodological literature (and is still often subject of debate, the link with evaluation research is underexplored. Elaborating on epistemological and theoretical conceptualizations by Guba and Lincoln and Creswell and Miller, the article explores aspects of validity of qualitative research with the explicit objective of connecting them with aspects of evaluation in social policy. It argues that different purposes of qualitative evaluations can be linked with different scientific paradigms and perspectives, thus transcending unproductive paradigmatic divisions as well as providing a flexible yet rigorous validity framework for researchers and reviewers of qualitative evaluations.

  2. Cross validation in LULOO

    DEFF Research Database (Denmark)

    Sørensen, Paul Haase; Nørgård, Peter Magnus; Hansen, Lars Kai

    1996-01-01

    The leave-one-out cross-validation scheme for generalization assessment of neural network models is computationally expensive due to replicated training sessions. Linear unlearning of examples has recently been suggested as an approach to approximative cross-validation. Here we briefly review...... the linear unlearning scheme, dubbed LULOO, and we illustrate it on a systemidentification example. Further, we address the possibility of extracting confidence information (error bars) from the LULOO ensemble....

  3. Verification and validation benchmarks.

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-02-01

    Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of

  4. Transient FDTD simulation validation

    OpenAIRE

    Jauregui Tellería, Ricardo; Riu Costa, Pere Joan; Silva Martínez, Fernando

    2010-01-01

    In computational electromagnetic simulations, most validation methods have been developed until now to be used in the frequency domain. However, the EMC analysis of the systems in the frequency domain many times is not enough to evaluate the immunity of current communication devices. Based on several studies, in this paper we propose an alternative method of validation of the transients in time domain allowing a rapid and objective quantification of the simulations results.

  5. HEDR model validation plan

    International Nuclear Information System (INIS)

    Napier, B.A.; Gilbert, R.O.; Simpson, J.C.; Ramsdell, J.V. Jr.; Thiede, M.E.; Walters, W.H.

    1993-06-01

    The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computational ''tools'' for estimating the possible radiation dose that individuals may have received from past Hanford Site operations. This document describes the planned activities to ''validate'' these tools. In the sense of the HEDR Project, ''validation'' is a process carried out by comparing computational model predictions with field observations and experimental measurements that are independent of those used to develop the model

  6. Verification and validation benchmarks

    International Nuclear Information System (INIS)

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-01-01

    Verification and validation (V and V) are the primary means to assess the accuracy and reliability of computational simulations. V and V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V and V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the

  7. Verification and validation benchmarks

    International Nuclear Information System (INIS)

    Oberkampf, William L.; Trucano, Timothy G.

    2008-01-01

    Verification and validation (V and V) are the primary means to assess the accuracy and reliability of computational simulations. V and V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V and V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the

  8. Validation suite for MCNP

    International Nuclear Information System (INIS)

    Mosteller, Russell D.

    2002-01-01

    Two validation suites, one for criticality and another for radiation shielding, have been defined and tested for the MCNP Monte Carlo code. All of the cases in the validation suites are based on experiments so that calculated and measured results can be compared in a meaningful way. The cases in the validation suites are described, and results from those cases are discussed. For several years, the distribution package for the MCNP Monte Carlo code1 has included an installation test suite to verify that MCNP has been installed correctly. However, the cases in that suite have been constructed primarily to test options within the code and to execute quickly. Consequently, they do not produce well-converged answers, and many of them are physically unrealistic. To remedy these deficiencies, sets of validation suites are being defined and tested for specific types of applications. All of the cases in the validation suites are based on benchmark experiments. Consequently, the results from the measurements are reliable and quantifiable, and calculated results can be compared with them in a meaningful way. Currently, validation suites exist for criticality and radiation-shielding applications.

  9. Containment Code Validation Matrix

    International Nuclear Information System (INIS)

    Chin, Yu-Shan; Mathew, P.M.; Glowa, Glenn; Dickson, Ray; Liang, Zhe; Leitch, Brian; Barber, Duncan; Vasic, Aleks; Bentaib, Ahmed; Journeau, Christophe; Malet, Jeanne; Studer, Etienne; Meynet, Nicolas; Piluso, Pascal; Gelain, Thomas; Michielsen, Nathalie; Peillon, Samuel; Porcheron, Emmanuel; Albiol, Thierry; Clement, Bernard; Sonnenkalb, Martin; Klein-Hessling, Walter; Arndt, Siegfried; Weber, Gunter; Yanez, Jorge; Kotchourko, Alexei; Kuznetsov, Mike; Sangiorgi, Marco; Fontanet, Joan; Herranz, Luis; Garcia De La Rua, Carmen; Santiago, Aleza Enciso; Andreani, Michele; Paladino, Domenico; Dreier, Joerg; Lee, Richard; Amri, Abdallah

    2014-01-01

    The Committee on the Safety of Nuclear Installations (CSNI) formed the CCVM (Containment Code Validation Matrix) task group in 2002. The objective of this group was to define a basic set of available experiments for code validation, covering the range of containment (ex-vessel) phenomena expected in the course of light and heavy water reactor design basis accidents and beyond design basis accidents/severe accidents. It was to consider phenomena relevant to pressurised heavy water reactor (PHWR), pressurised water reactor (PWR) and boiling water reactor (BWR) designs of Western origin as well as of Eastern European VVER types. This work would complement the two existing CSNI validation matrices for thermal hydraulic code validation (NEA/CSNI/R(1993)14) and In-vessel core degradation (NEA/CSNI/R(2001)21). The report initially provides a brief overview of the main features of a PWR, BWR, CANDU and VVER reactors. It also provides an overview of the ex-vessel corium retention (core catcher). It then provides a general overview of the accident progression for light water and heavy water reactors. The main focus is to capture most of the phenomena and safety systems employed in these reactor types and to highlight the differences. This CCVM contains a description of 127 phenomena, broken down into 6 categories: - Containment Thermal-hydraulics Phenomena; - Hydrogen Behaviour (Combustion, Mitigation and Generation) Phenomena; - Aerosol and Fission Product Behaviour Phenomena; - Iodine Chemistry Phenomena; - Core Melt Distribution and Behaviour in Containment Phenomena; - Systems Phenomena. A synopsis is provided for each phenomenon, including a description, references for further information, significance for DBA and SA/BDBA and a list of experiments that may be used for code validation. The report identified 213 experiments, broken down into the same six categories (as done for the phenomena). An experiment synopsis is provided for each test. Along with a test description

  10. Groundwater Model Validation

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed E. Hassan

    2006-01-24

    Models have an inherent uncertainty. The difficulty in fully characterizing the subsurface environment makes uncertainty an integral component of groundwater flow and transport models, which dictates the need for continuous monitoring and improvement. Building and sustaining confidence in closure decisions and monitoring networks based on models of subsurface conditions require developing confidence in the models through an iterative process. The definition of model validation is postulated as a confidence building and long-term iterative process (Hassan, 2004a). Model validation should be viewed as a process not an end result. Following Hassan (2004b), an approach is proposed for the validation process of stochastic groundwater models. The approach is briefly summarized herein and detailed analyses of acceptance criteria for stochastic realizations and of using validation data to reduce input parameter uncertainty are presented and applied to two case studies. During the validation process for stochastic models, a question arises as to the sufficiency of the number of acceptable model realizations (in terms of conformity with validation data). Using a hierarchical approach to make this determination is proposed. This approach is based on computing five measures or metrics and following a decision tree to determine if a sufficient number of realizations attain satisfactory scores regarding how they represent the field data used for calibration (old) and used for validation (new). The first two of these measures are applied to hypothetical scenarios using the first case study and assuming field data consistent with the model or significantly different from the model results. In both cases it is shown how the two measures would lead to the appropriate decision about the model performance. Standard statistical tests are used to evaluate these measures with the results indicating they are appropriate measures for evaluating model realizations. The use of validation

  11. Validation of Serious Games

    Directory of Open Access Journals (Sweden)

    Katinka van der Kooij

    2015-09-01

    Full Text Available The application of games for behavioral change has seen a surge in popularity but evidence on the efficacy of these games is contradictory. Anecdotal findings seem to confirm their motivational value whereas most quantitative findings from randomized controlled trials (RCT are negative or difficult to interpret. One cause for the contradictory evidence could be that the standard RCT validation methods are not sensitive to serious games’ effects. To be able to adapt validation methods to the properties of serious games we need a framework that can connect properties of serious game design to the factors that influence the quality of quantitative research outcomes. The Persuasive Game Design model [1] is particularly suitable for this aim as it encompasses the full circle from game design to behavioral change effects on the user. We therefore use this model to connect game design features, such as the gamification method and the intended transfer effect, to factors that determine the conclusion validity of an RCT. In this paper we will apply this model to develop guidelines for setting up validation methods for serious games. This way, we offer game designers and researchers handles on how to develop tailor-made validation methods.

  12. Checklists for external validity

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke

    2014-01-01

    to an implementation setting. In this paper, currently available checklists on external validity are identified, assessed and used as a basis for proposing a new improved instrument. METHOD: A systematic literature review was carried out in Pubmed, Embase and Cinahl on English-language papers without time restrictions....... The retrieved checklist items were assessed for (i) the methodology used in primary literature, justifying inclusion of each item; and (ii) the number of times each item appeared in checklists. RESULTS: Fifteen papers were identified, presenting a total of 21 checklists for external validity, yielding a total...... of 38 checklist items. Empirical support was considered the most valid methodology for item inclusion. Assessment of methodological justification showed that none of the items were supported empirically. Other kinds of literature justified the inclusion of 22 of the items, and 17 items were included...

  13. Shift Verification and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Tara M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Evans, Thomas M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Gregory G [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Godfrey, Andrew T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-07

    This documentation outlines the verification and validation of Shift for the Consortium for Advanced Simulation of Light Water Reactors (CASL). Five main types of problems were used for validation: small criticality benchmark problems; full-core reactor benchmarks for light water reactors; fixed-source coupled neutron-photon dosimetry benchmarks; depletion/burnup benchmarks; and full-core reactor performance benchmarks. We compared Shift results to measured data and other simulated Monte Carlo radiation transport code results, and found very good agreement in a variety of comparison measures. These include prediction of critical eigenvalue, radial and axial pin power distributions, rod worth, leakage spectra, and nuclide inventories over a burn cycle. Based on this validation of Shift, we are confident in Shift to provide reference results for CASL benchmarking.

  14. Validating Animal Models

    Directory of Open Access Journals (Sweden)

    Nina Atanasova

    2015-06-01

    Full Text Available In this paper, I respond to the challenge raised against contemporary experimental neurobiology according to which the field is in a state of crisis because of the multiple experimental protocols employed in different laboratories and strengthening their reliability that presumably preclude the validity of neurobiological knowledge. I provide an alternative account of experimentation in neurobiology which makes sense of its experimental practices. I argue that maintaining a multiplicity of experimental protocols and strengthening their reliability are well justified and they foster rather than preclude the validity of neurobiological knowledge. Thus, their presence indicates thriving rather than crisis of experimental neurobiology.

  15. Validation Process Methods

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, John E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); English, Christine M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gesick, Joshua C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mukkamala, Saikrishna [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2018-01-04

    This report documents the validation process as applied to projects awarded through Funding Opportunity Announcements (FOAs) within the U.S. Department of Energy Bioenergy Technologies Office (DOE-BETO). It describes the procedures used to protect and verify project data, as well as the systematic framework used to evaluate and track performance metrics throughout the life of the project. This report also describes the procedures used to validate the proposed process design, cost data, analysis methodologies, and supporting documentation provided by the recipients.

  16. Validated high-performance liquid chromatographic method for the standardisation of Ptychopetalum olacoides Benth., Olacaceae, commercial extracts Validação de método de cromatografia líquida de alta performance para padronização de extratos comerciais de Ptychopetalum olacoides Benth., Olacaceae

    Directory of Open Access Journals (Sweden)

    Renata Colombo

    2010-11-01

    Full Text Available Ptychopetalum olacoides Benth., Olacaceae, popularly known as marapuama or muirapuama or miriantã, is a species native to the Amazonian region of Brazil. Extracts of the bark of the plant have been used traditionally for its stimulating and aphrodisiac properties and currently commercialised by the herbal industry as constituents in a wide range of phytomedicines. Fractionation by open column chromatography followed by preparative HPLC-UV/PAD of the stem bark and of three commercial extracts of P. olacoides allowed the isolation of three components that were common to all extracts analysed, and these were identified by NMR to be vanillic acid, protocatechuic acid and theobromine. Vanillic acid, which has been proposed as a phytochemical marker for P. olacoides, was employed as an external standard in the development and validation of a rapid qualitative and quantitative HPLC assay for the analyte. The recoveries values of the developed method were 99.02% and the LOD and LOQ values were 0.033 and 0.11 mg.L-1, respectively. The described method may be applied to the standardisation of herbs, extracts or phytomedicines commercialised as marapuama.Ptychopetalum olacoides Benth., Olacaceae, popularmente conhecida como marapuama, muirapuama ou miriantã, é uma espécie nativa da região da Amazônia do Brasil. Extratos das cascas da planta são tradicionalmente usados por suas propriedades estimulantes e afrodisíacas, e frequentemente comercializados como constituinte de uma grande variedade de formulações fitoterápicas. O fracionamento por coluna cromatográfica aberta seguida por CLAE-UV/PAD das cascas do caule de três extratos comerciais de P. olacoides permitiram o isolamento de três substâncias comuns em todos os extratos analisados. Os compostos foram identificados por RMN como ácido vanílico, ácido protocatecuíco e teobromina. O ácido vanílico foi utilizado como marcador fitoquímico para P. olacoides e empregado como padr

  17. The dialogic validation

    DEFF Research Database (Denmark)

    Musaeus, Peter

    2005-01-01

    This paper is inspired by dialogism and the title is a paraphrase on Bakhtin's (1981) "The Dialogic Imagination". The paper investigates how dialogism can inform the process of validating inquiry-based qualitative research. The paper stems from a case study on the role of recognition...

  18. A valid licence

    NARCIS (Netherlands)

    Spoolder, H.A.M.; Ingenbleek, P.T.M.

    2010-01-01

    A valid licence Tuesday, April 20, 2010 Dr Hans Spoolder and Dr Paul Ingenbleek, of Wageningen University and Research Centres, share their thoughts on improving farm animal welfare in Europe At the presentation of the European Strategy 2020 on 3rd March, President Barroso emphasised the need for

  19. The Chimera of Validity

    Science.gov (United States)

    Baker, Eva L.

    2013-01-01

    Background/Context: Education policy over the past 40 years has focused on the importance of accountability in school improvement. Although much of the scholarly discourse around testing and assessment is technical and statistical, understanding of validity by a non-specialist audience is essential as long as test results drive our educational…

  20. Validating year 2000 compliance

    NARCIS (Netherlands)

    A. van Deursen (Arie); P. Klint (Paul); M.P.A. Sellink

    1997-01-01

    textabstractValidating year 2000 compliance involves the assessment of the correctness and quality of a year 2000 conversion. This entails inspecting both the quality of the conversion emph{process followed, and of the emph{result obtained, i.e., the converted system. This document provides an

  1. Validation and test report

    DEFF Research Database (Denmark)

    Pedersen, Jens Meldgaard; Andersen, T. Bull

    2012-01-01

    . As a consequence of extensive movement artefacts seen during dynamic contractions, the following validation and test report consists of a report that investigates the physiological responses to a static contraction in a standing and a supine position. Eight subjects performed static contractions of the ankle...

  2. Statistical Analysis and validation

    NARCIS (Netherlands)

    Hoefsloot, H.C.J.; Horvatovich, P.; Bischoff, R.

    2013-01-01

    In this chapter guidelines are given for the selection of a few biomarker candidates from a large number of compounds with a relative low number of samples. The main concepts concerning the statistical validation of the search for biomarkers are discussed. These complicated methods and concepts are

  3. Validity and Fairness

    Science.gov (United States)

    Kane, Michael

    2010-01-01

    This paper presents the author's critique on Xiaoming Xi's article, "How do we go about investigating test fairness?," which lays out a broad framework for studying fairness as comparable validity across groups within the population of interest. Xi proposes to develop a fairness argument that would identify and evaluate potential fairness-based…

  4. Development and validation of an rp-hplc method for simultaneous determination of Ramipril and Amlodipine in tablets

    Directory of Open Access Journals (Sweden)

    Shi-Ying Dai

    2013-12-01

    Full Text Available An rp-hplc method for the simultaneous determination of Ramipril (RP and Amlodipine (AL in tablets was developed and validated by Chinese Pharmacopoeia 2010. The linearity of the proposed method was investigated in the range of 0.01–0.25 mg/mL (r2=0.9998 for RP and 0.014–0.36 mg/mL (r2=0.9997 for AL. The limits of detection (LOD were 0.06 μg/mL and 0.02 μg/mL for RP and AL, and the limits of quantitation (LOQ were 0.2 μg/mL and 0.07 μg/mL, respectively. Some major impurities and degradation products did not disturb the detection of RP and AL and the assay can thus be considered stability-indicating. Keywords: Ramipril, Amlodipine, RP-HPLC, Stability-indicating

  5. EOS Terra Validation Program

    Science.gov (United States)

    Starr, David

    2000-01-01

    The EOS Terra mission will be launched in July 1999. This mission has great relevance to the atmospheric radiation community and global change issues. Terra instruments include Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Clouds and Earth's Radiant Energy System (CERES), Multi-Angle Imaging Spectroradiometer (MISR), Moderate Resolution Imaging Spectroradiometer (MODIS) and Measurements of Pollution in the Troposphere (MOPITT). In addition to the fundamental radiance data sets, numerous global science data products will be generated, including various Earth radiation budget, cloud and aerosol parameters, as well as land surface, terrestrial ecology, ocean color, and atmospheric chemistry parameters. Significant investments have been made in on-board calibration to ensure the quality of the radiance observations. A key component of the Terra mission is the validation of the science data products. This is essential for a mission focused on global change issues and the underlying processes. The Terra algorithms have been subject to extensive pre-launch testing with field data whenever possible. Intensive efforts will be made to validate the Terra data products after launch. These include validation of instrument calibration (vicarious calibration) experiments, instrument and cross-platform comparisons, routine collection of high quality correlative data from ground-based networks, such as AERONET, and intensive sites, such as the SGP ARM site, as well as a variety field experiments, cruises, etc. Airborne simulator instruments have been developed for the field experiment and underflight activities including the MODIS Airborne Simulator (MAS) AirMISR, MASTER (MODIS-ASTER), and MOPITT-A. All are integrated on the NASA ER-2 though low altitude platforms are more typically used for MASTER. MATR is an additional sensor used for MOPITT algorithm development and validation. The intensive validation activities planned for the first year of the Terra

  6. Validation of analytical methods for the stability studies of naproxen suppositories for infant and adult use

    International Nuclear Information System (INIS)

    Rodriguez Hernandez, Yaslenis; Suarez Perez, Yania; Garcia Pulpeiro, Oscar

    2011-01-01

    Analytical and validating studies were performed in this paper, with a view to using them in the stability studies of the future formulations of naproxen suppositories for children and adults. The most influential factors in the naproxen stability were determined, that is, the major degradation occurred in acid medium, oxidative medium and by light action. One high-performance liquid chromatography-based method was evaluated, which proved to be adequate to quantify naproxen in suppositories and was selective against degradation products. The quantification limit was 3,480 μg, so it was valid for these studies. Additionally, the parameters specificity for stability, detection and quantification limits were evaluated for the direct semi-aqueous acid-base method, which was formerly validated for the quality control and showed satisfactory results. Nevertheless, the volumetric methods were not regarded as stability indicators; therefore, this method will be used along with the chromatographic methods of choice, that is, thin-layer chromatography and highperformance liquid chromatography, to determine the degradation products

  7. Flight code validation simulator

    Science.gov (United States)

    Sims, Brent A.

    1996-05-01

    An End-To-End Simulation capability for software development and validation of missile flight software on the actual embedded computer has been developed utilizing a 486 PC, i860 DSP coprocessor, embedded flight computer and custom dual port memory interface hardware. This system allows real-time interrupt driven embedded flight software development and checkout. The flight software runs in a Sandia Digital Airborne Computer and reads and writes actual hardware sensor locations in which Inertial Measurement Unit data resides. The simulator provides six degree of freedom real-time dynamic simulation, accurate real-time discrete sensor data and acts on commands and discretes from the flight computer. This system was utilized in the development and validation of the successful premier flight of the Digital Miniature Attitude Reference System in January of 1995 at the White Sands Missile Range on a two stage attitude controlled sounding rocket.

  8. Software Validation in ATLAS

    International Nuclear Information System (INIS)

    Hodgkinson, Mark; Seuster, Rolf; Simmons, Brinick; Sherwood, Peter; Rousseau, David

    2012-01-01

    The ATLAS collaboration operates an extensive set of protocols to validate the quality of the offline software in a timely manner. This is essential in order to process the large amounts of data being collected by the ATLAS detector in 2011 without complications on the offline software side. We will discuss a number of different strategies used to validate the ATLAS offline software; running the ATLAS framework software, Athena, in a variety of configurations daily on each nightly build via the ATLAS Nightly System (ATN) and Run Time Tester (RTT) systems; the monitoring of these tests and checking the compilation of the software via distributed teams of rotating shifters; monitoring of and follow up on bug reports by the shifter teams and periodic software cleaning weeks to improve the quality of the offline software further.

  9. CIPS Validation Data Plan

    Energy Technology Data Exchange (ETDEWEB)

    Nam Dinh

    2012-03-01

    This report documents analysis, findings and recommendations resulted from a task 'CIPS Validation Data Plan (VDP)' formulated as an POR4 activity in the CASL VUQ Focus Area (FA), to develop a Validation Data Plan (VDP) for Crud-Induced Power Shift (CIPS) challenge problem, and provide guidance for the CIPS VDP implementation. The main reason and motivation for this task to be carried at this time in the VUQ FA is to bring together (i) knowledge of modern view and capability in VUQ, (ii) knowledge of physical processes that govern the CIPS, and (iii) knowledge of codes, models, and data available, used, potentially accessible, and/or being developed in CASL for CIPS prediction, to devise a practical VDP that effectively supports the CASL's mission in CIPS applications.

  10. CIPS Validation Data Plan

    International Nuclear Information System (INIS)

    Dinh, Nam

    2012-01-01

    This report documents analysis, findings and recommendations resulted from a task 'CIPS Validation Data Plan (VDP)' formulated as an POR4 activity in the CASL VUQ Focus Area (FA), to develop a Validation Data Plan (VDP) for Crud-Induced Power Shift (CIPS) challenge problem, and provide guidance for the CIPS VDP implementation. The main reason and motivation for this task to be carried at this time in the VUQ FA is to bring together (i) knowledge of modern view and capability in VUQ, (ii) knowledge of physical processes that govern the CIPS, and (iii) knowledge of codes, models, and data available, used, potentially accessible, and/or being developed in CASL for CIPS prediction, to devise a practical VDP that effectively supports the CASL's mission in CIPS applications.

  11. Validating MEDIQUAL Constructs

    Science.gov (United States)

    Lee, Sang-Gun; Min, Jae H.

    In this paper, we validate MEDIQUAL constructs through the different media users in help desk service. In previous research, only two end-users' constructs were used: assurance and responsiveness. In this paper, we extend MEDIQUAL constructs to include reliability, empathy, assurance, tangibles, and responsiveness, which are based on the SERVQUAL theory. The results suggest that: 1) five MEDIQUAL constructs are validated through the factor analysis. That is, importance of the constructs have relatively high correlations between measures of the same construct using different methods and low correlations between measures of the constructs that are expected to differ; and 2) five MEDIQUAL constructs are statistically significant on media users' satisfaction in help desk service by regression analysis.

  12. DDML Schema Validation

    Science.gov (United States)

    2016-02-08

    XML schema govern DDML instance documents. For information about XML, refer to RCC 125-15, XML Style Guide.2 Figure 4 provides an XML snippet of a...we have documented three main types of information .  User Stories: A user story describes a specific requirement of the schema in the terms of a...instance document is a schema -valid XML file that completely describes the information in the test case in a manner that satisfies the user story

  13. What is validation

    International Nuclear Information System (INIS)

    Clark, H.K.

    1985-01-01

    Criteria for establishing the validity of a computational method to be used in assessing nuclear criticality safety, as set forth in ''American Standard for Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors,'' ANSI/ANS-8.1-1983, are examined and discussed. Application of the criteria is illustrated by describing the procedures followed in deriving subcritical limits that have been incorporated in the Standard

  14. Stability-indicating liquid Chromatographic assaymethod for Opthalmic solutions containing combination of Dexamethasone and Chloramphenicol

    International Nuclear Information System (INIS)

    Rao, R.M.; Al-Ashban, R.M.; Shah, A.H.

    2004-01-01

    A selective high-performance chromatographic procedure for the stability monitoring of ophthalmic solutions containing a combination of dexamethasone and chloramphenicolis demonstrated. The separation of the active components and the degradation product of chloramphenicol (1-amino-1-(4-nitrophenyl)-propane-1, 3diol) was achieved on a u-Bondapack C-18 column ( 5 um, 300 mm x 3.9 mm) maintained at ambient temperature (15-20C) by utilizing a mobile phase consisting acidified water (5% actified water with glacial acetic acid ) : acetonitrile : triethyl amine 700 : 300 : 2and pH was adjusted to 5.0 by using 10 M Na OH. The flow rate was 1.5 ml min-1; and elutes were followed with UV-detection at 254 nm. Complete resolution of dexamethasone, chloramphenicol and its hydrolytic product could be attained. The sensitivity, accuracy and specificity were tested. The method was successfully applied in post-marketing stability of the commercial batches of ophthalmic solutions. (author)

  15. The use of stability indices in predicting asphaltene problems in upstream and downstream oil operations

    Energy Technology Data Exchange (ETDEWEB)

    Asomaning, S. [Baker Petrolite, Sugar Land, TX (United States)

    2003-07-01

    A series of test methods have been developed to determine the stability of asphaltenes in crude oils. They were developed due to the high cost of remediating asphaltene deposition in offshore operations. This study described the characteristics of the Oliensis Spot Test, two saturates, aromatics, resins and asphaltenes (SARA)-based screens (the Colloidal Instability Index and Asphaltene-Resin ratio), a solvent titration method with near infrared radiation (NIR) solids detection, and live oil depressurization. Each method is used to predict the stability of asphaltenes in crude oils with different API gravity. A complete description of the test methods was provided along with experimental data. The effectiveness of the different tests in predicting the stability of asphaltenes in crude oils was also assessed. Results indicate that the prediction of a crude oil's tendency towards asphaltene precipitation was more accurate with the Colloidal Instability Index and the solvent titration method. Live oil depressurization proved to be very effective in predicting the stability of asphaltenes for light oils, where most stability tests fail. tabs., figs.

  16. Stability indicating RP-HPLC method for simultaneous determination of piroxicam and ofloxacin in binary combination.

    Science.gov (United States)

    John, Peter; Azeem, Waqar; Ashfaq, Muhammad; Khan, Islam Ullah; Razzaq, Syed Naeem

    2015-09-01

    A simple and precise RP-HPLC method was developed for simultaneous determination of piroxicam and ofloxacin in pharmaceutical formulations and human serum. Optimum separations of piroxicam, ofloxacin and stress-induced degradation products were achieved by use of Hypersil BDS C8 column (250 x 4.6mm, 5 μm). The mobile phase was a mixture of acetonitrile: 0.012M K2HPO4: 0.008M sodium citrate (both buffers mixed and pH adjusted to 2.8) (50:25:25 v/v/v) delivered at flow rate of 1.5 mL min⁻¹ using DAD at 254 nm. Response was linear function of concentration over the ranges of 70-130 mg mL⁻¹ for piroxicam and ofloxacin (r² ≥ 0.999). The method efficiently separated the analytical peaks from degradation products with acceptable tailing and resolution. The developed method was successfully used for concurrent analysis of piroxicam and ofloxacin in pharmaceutical formulations, human serum and in vitro drug interaction studies.

  17. Effectiveness of Stability Indices for Bread Wheat Genotypes Selection to Water Deficit Tolerant

    Directory of Open Access Journals (Sweden)

    A Naderi

    2013-12-01

    Full Text Available In countries such as Iran which will be faced water deficit as the main challenge in the future and the food production is going to be dependent to water recourses, wheat water-deficit tolerant and adapted genotypes release is one of the most important strategies under such a condition. In order to study the adaptation and terminal water deficit stress tolerance, fifteen bread wheat lines and Chamran cultivar as the check were evaluated. This research was carried out at Ahvaz, Dezfool, Zabol and Darab, south warm region research stations, in 2007-08 and 2008-09, in two separated experiments (1-well-watered and 2- terminal water deficit stress, using complete randomized block design with three replications. Data were analyzed and genotypes response was evaluated based on tolerance indices. Results showed that the difference among stations, years, genotypes and double and triple effects of source variations were significant at 1% probability level. Mean grain yield was 4300 Kg/ha in first year, while grain yield increased significantly in second year and reached to 5692 Kg/ha. Mean grain yield were 5840 and 4591Kg/ha under well-watered and terminal water deficit stress conditions, respectively. Correlation coefficients among STI, GMP ،MP and K1STI were significant. Correlation coefficient between slop of linear regression of grain yield in response to drought stress intensity and grain yield under terminal water deficit stress was positively and, with K2STI, TOL and SSI was negatively significant. Grain yield index, (YIR the proportion of grain yield of each genotype to grand mean of grain yield of all genotypes was the most important components to define grain yield in stepwise regression under both experiment conditions. According to the results of this research and based on tolerance indices, lines No. 2, 14 and 15 were selected as the high potential- terminal water deficit stress tolerant genotypes.

  18. Stability-indicating spectrofluorimetric method for determination of itopride hydrochloride in raw material and pharmaceutical formulations.

    Science.gov (United States)

    Walash, Mohamed I; Ibrahim, Fawzia; Eid, Manal I; El Abass, Samah Abo

    2013-11-01

    A simple, sensitive and rapid spectrofluorimetric method for determination of itopride hydrochloride in raw material and tablets has been developed. The proposed method is based on the measurement of the native fluorescence of the drug in water at 363 nm after excitation at 255 nm. The relative fluorescence intensity-concentration plot was rectilinear over the range of 0.1-2 μg/mL (2.5 × 10(-7)-5.06 × 10(-6) mole/L), with good correlation (r = 0.9999), limit of detection of 0.015 μg/mL and a lower limit of quantification of 0.045 μg/mL. The described method was successfully applied for the determination of itopride hydrochloride in its commercial tablets with average percentage recovery of 100.11 ± 0.32 without interference from common excipients. Additionally, the proposed method can be applied for determination of itopride in combined tablets with rabeprazole or pantoprazole without prior separation. The method was extended to stability study of itopride. The drug was exposed to acidic, alkaline, oxidative and photolytic degradation according to ICH guidelines. Moreover, the method was utilized to investigate the kinetics of the alkaline, acidic and oxidative degradation of the drug. A proposal for the degradation pathways was postulated.

  19. Relative performance of three stream bed stability indices as indicators of stream health.

    Science.gov (United States)

    Kusnierz, Paul C; Holbrook, Christopher M

    2017-10-16

    Bed stability is an important stream habitat attribute because it affects geomorphology and biotic communities. Natural resource managers desire indices of bed stability that can be used under a wide range of geomorphic conditions, are biologically meaningful, and are easily incorporated into sampling protocols. To eliminate potential bias due to presence of instream wood and increase precision of stability values, we modified a stream bed instability index (ISI) to include measurements of bankfull depth (d bf ) and median particle diameter (D 50 ) only in riffles and increased the pebble count to decrease variability (i.e., increase precision) in D 50 . The new riffle-based instability index (RISI) was compared to two established indices: ISI and the riffle stability index (RSI). RISI and ISI were strongly associated with each other but neither was closely associated with RSI. RISI and ISI were closely associated with both a diatom- and two macrovertebrate-based stream health indices, but RSI was only weakly associated with the macroinvertebrate indices. Unexpectedly, precision of D 50 did not differ between RISI and ISI. Results suggest that RISI is a viable alternative to both ISI and RSI for evaluating bed stability in multiple stream types. With few data requirements and a simple protocol, RISI may also better conform to riffle-based sampling methods used by some water quality practitioners.

  20. Mirror trends of plasticity and stability indicators in primate prefrontal cortex.

    Science.gov (United States)

    García-Cabezas, Miguel Á; Joyce, Mary Kate P; John, Yohan J; Zikopoulos, Basilis; Barbas, Helen

    2017-10-01

    Research on plasticity markers in the cerebral cortex has largely focused on their timing of expression and role in shaping circuits during critical and normal periods. By contrast, little attention has been focused on the spatial dimension of plasticity-stability across cortical areas. The rationale for this analysis is based on the systematic variation in cortical structure that parallels functional specialization and raises the possibility of varying levels of plasticity. Here, we investigated in adult rhesus monkeys the expression of markers related to synaptic plasticity or stability in prefrontal limbic and eulaminate areas that vary in laminar structure. Our findings revealed that limbic areas are impoverished in three markers of stability: intracortical myelin, the lectin Wisteria floribunda agglutinin, which labels perineuronal nets, and parvalbumin, which is expressed in a class of strong inhibitory neurons. By contrast, prefrontal limbic areas were enriched in the enzyme calcium/calmodulin-dependent protein kinase II (CaMKII), known to enhance plasticity. Eulaminate areas have more elaborate laminar architecture than limbic areas and showed the opposite trend: they were enriched in markers of stability and had lower expression of the plasticity-related marker CaMKII. The expression of glial fibrillary acidic protein (GFAP), a marker of activated astrocytes, was also higher in limbic areas, suggesting that cellular stress correlates with the rate of circuit reshaping. Elevated markers of plasticity may endow limbic areas with flexibility necessary for learning and memory within an affective context, but may also render them vulnerable to abnormal structural changes, as seen in neurologic and psychiatric diseases. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  1. Different Stability-Indicating Chromatographic Techniques for the Determination of Netobimin

    Science.gov (United States)

    Ramadan, Nesrin K.; Mohamed, Afaf O.; Shawky, Sara E.; Salem, Maissa Y.

    2012-01-01

    Two simple, accurate, and sensitive methods were developed for the determination of netobimin in the presence of its degradation product. Method (A) was an HPLC method, performed on C18 column using acetonitrile/methanol/0.01 M potassium dihydrogen phosphate (56 : 14 : 30 by volume) as a mobile phase with a flow rate of 0.5 mL/min. Detection was performed at 254 nm. Method (B) was a TLC method, using silica gel 60 F254 plates; the optimized mobile phase was toluene/methanol/chloroform/ammonium hydroxide (5 : 4 : 6 : 0.1 by volume). The spots were scanned densitometrically at 346 nm. Linearity ranges were 1–10 μg/mL for method (A) and 0.5–5 μg/band for method (B), and the mean percentage recoveries were 99.3 ± 0.7% and 99.7 ± 0.7% for methods (A) and (B), respectively. The proposed methods were found to be specific for netobimin in the presence of up to 90% of its degradation product. Statistical comparison between the results obtained by these methods and the manufacturer method was done, and no significance difference was obtained. PMID:22567566

  2. Different Stability-Indicating Chromatographic Techniques for the Determination of Netobimin

    Directory of Open Access Journals (Sweden)

    Nesrin K. Ramadan

    2012-01-01

    Full Text Available Two simple, accurate, and sensitive methods were developed for the determination of netobimin in the presence of its degradation product. Method (A was an HPLC method, performed on C18 column using acetonitrile/methanol/0.01 M potassium dihydrogen phosphate (56 : 14 : 30 by volume as a mobile phase with a flow rate of 0.5 mL/min. Detection was performed at 254 nm. Method (B was a TLC method, using silica gel 60 F254 plates; the optimized mobile phase was toluene/methanol/chloroform/ammonium hydroxide (5 : 4 : 6 : 0.1 by volume. The spots were scanned densitometrically at 346 nm. Linearity ranges were 1–10 μg/mL for method (A and 0.5–5 μg/band for method (B, and the mean percentage recoveries were 99.3±0.7% and 99.7±0.7% for methods (A and (B, respectively. The proposed methods were found to be specific for netobimin in the presence of up to 90% of its degradation product. Statistical comparison between the results obtained by these methods and the manufacturer method was done, and no significance difference was obtained.

  3. An Analysis of Financial Stability Indicators in European Banking: The Role of Common Factors

    NARCIS (Netherlands)

    Kool, C.J.M.

    2006-01-01

    In this paper, we investigate the information content of three market indicators of financial instability using daily data on subordinated debt spreads (SND), credit default swap spreads (CDS) and implied option volatility (IV) over the period January 2001 – January 2004 for a sample of twenty major

  4. Content validity and its estimation

    Directory of Open Access Journals (Sweden)

    Yaghmale F

    2003-04-01

    Full Text Available Background: Measuring content validity of instruments are important. This type of validity can help to ensure construct validity and give confidence to the readers and researchers about instruments. content validity refers to the degree that the instrument covers the content that it is supposed to measure. For content validity two judgments are necessary: the measurable extent of each item for defining the traits and the set of items that represents all aspects of the traits. Purpose: To develop a content valid scale for assessing experience with computer usage. Methods: First a review of 2 volumes of International Journal of Nursing Studies, was conducted with onlyI article out of 13 which documented content validity did so by a 4-point content validity index (CV! and the judgment of 3 experts. Then a scale with 38 items was developed. The experts were asked to rate each item based on relevance, clarity, simplicity and ambiguity on the four-point scale. Content Validity Index (CVI for each item was determined. Result: Of 38 items, those with CVIover 0.75 remained and the rest were discarded reSulting to 25-item scale. Conclusion: Although documenting content validity of an instrument may seem expensive in terms of time and human resources, its importance warrants greater attention when a valid assessment instrument is to be developed. Keywords: Content Validity, Measuring Content Validity

  5. Validering av Evolution 220

    OpenAIRE

    Krakeli, Tor-Arne

    2013-01-01

    - Det har blitt kjøpt inn et nytt spektrofotometer (Evolution 220, Thermo Scientific) til BioLab Nofima. I den forbindelsen har det blitt utført en validering som involverer kalibreringsstandarder fra produsenten og en test på normal distribusjon (t-test) på to metoder (Total fosfor, Tryptofan). Denne valideringen fant Evolution 220 til å være et akseptabelt alternativ til det allerede benyttede spektrofotometeret (Helios Beta). På bakgrunn av noen instrumentbegrensninger må de aktuelle an...

  6. Simulation Validation for Societal Systems

    National Research Council Canada - National Science Library

    Yahja, Alex

    2006-01-01

    .... There are however, substantial obstacles to validation. The nature of modeling means that there are implicit model assumptions, a complex model space and interactions, emergent behaviors, and uncodified and inoperable simulation and validation knowledge...

  7. Influência de desproteinizantes ácidos na quantificação da glutationa reduzida eritrocitária por CLAE-UV Influence of deproteinizing acids in erythrocytic reduced glutathione quantification by HPLC-UV

    Directory of Open Access Journals (Sweden)

    Karen L. Schott

    2007-06-01

    Full Text Available Large differences in reduced glutathione (GSH levels have been found in different investigations, also in healthy people. GSH oxidation in vitro has been associated with sample acidification in the presence of oxihemoglobin. In this work, the influence of different acids on GSH determination utilizing HPLC with UV detection was evaluated. The results showed that metaphosphoric acid and sulfosalicylic acid were inadequate for analysis, because metaphosphoric acid showed to be inefficient for deproteinization and with sulfosalicylic acid loss of GSH was observed. Trichloroacetic acid did not effect GSH quantification, since the deproteinized form was immediately derivatized with 5, 5´-dithio-bis (2-nitrobenzoic acid. Methods with TCA deproteinization presented linear results from 0.5 to 3.0 mM. The correlation coefficient between aqueous curves and GSH spiked RBC exceeded 0.99. Precision calculations showed CV lower than 10% and bias within ± 10% for concentrations of 0.5; 1.5 and 3.0 mM GSH. The recovery was higher than 94%. Moreover, GSH blood concentrations were independent of hemoglobin concentrations.

  8. HPLC-UV ATMOSPHERIC-PRESSURE IONIZATION MASS-SPECTROMETRIC DETERMINATION OF THE DOPAMINE-D2 AGONIST N-0923 AND ITS MAJOR METABOLITES AFTER OXIDATIVE-METABOLISM BY RAT-LIVER, MONKEY LIVER, AND HUMAN LIVER-MICROSOMES

    NARCIS (Netherlands)

    SWART, PJ; BRONNER, GM; BRUINS, AP; ENSING, K; TEPPER, PG; DEZEEUW, RA

    1993-01-01

    An innovative custom-built atmospheric ionization source afforded an opportunity to perform on-line LC/MS analysis and to obtain identification of metabolites without need to rely on radioactive profiling. An HPLC with a UV detector coupled to a modified R 3010 triple quadrupole mass spectrometer

  9. Rapid in situ growth of oriented titanium-nickel oxide composite nanotubes arrays coated on a nitinol wire as a solid-phase microextraction fiber coupled to HPLC-UV.

    Science.gov (United States)

    Zhen, Qi; Zhang, Min; Song, Wenlan; Wang, Huiju; Wang, Xuemei; Du, Xinzhen

    2016-10-01

    An oriented titanium-nickel oxide composite nanotubes coating was in situ grown on a nitinol wire by direct electrochemical anodization in ethylene glycol with ammonium fluoride and water for the first time. The morphology and composition of the resulting coating showed that the anodized nitinol wire provided a titania-rich coating. The titanium-nickel oxide composite nanotubes coated fiber was used for solid-phase microextraction of different aromatic compounds coupled to high-performance liquid chromatography with UV detection. The titanium-nickel oxide composite nanotubes coating exhibited high extraction capability, good selectivity, and rapid mass transfer for weakly polar UV filters. Thereafter the important parameters affecting extraction efficiency were investigated for solid-phase microextraction of UV filters. Under the optimized conditions, the calibration curves were linear in the range of 0.1-300 μg/L for target UV filters with limits of detection of 0.019-0.082 μg/L. The intraday and interday precision of the proposed method with the single fiber were 5.3-7.2 and 5.9-7.9%, respectively, and the fiber-to-fiber reproducibility ranged from 6.3 to 8.9% for four fibers fabricated in different batches. Finally, its applicability was evaluated by the extraction and determination of target UV filters in environmental water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Desenvolvimento e validação de método analítico empregando DLLME e HPLC/UV para determinação de benzodiazepínicos em amostra de água

    OpenAIRE

    Tamires Valim Marques

    2014-01-01

    Resumo: A crescente preocupação com a poluição das águas por novos poluentes denominados emergentes tem se intensificado, visto que aumentou o número destes compostos detectados em água. Dentre estes compostos encontram-se os fármacos e produtos de higiene pessoal, usados cotidianamente pela população. O presente trabalho teve como objetivo o desenvolvimento de um método simples, rápido e sensível utilizando a microextração líquido líquido (DLLME) combinada com a cromatografia líquida de ultr...

  11. DETERMINAÇÃO DE CORANTES SINTÉTICOS EM BEBIDAS ISOTÔNICAS EMPREGANDO EXTRAÇÃO EM FASE SÓLIDA DISPERSIVA E HPLC-UV/Vis

    OpenAIRE

    Luana Floriano

    2016-01-01

    As bebidas isotônicas são especialmente formuladas para pessoas que praticam atividade física, sendo compostas principalmente por carboidratos, eletrólitos e vitaminas. Os corantes sintéticos são aditivos alimentares comumente utilizados em bebidas isotônicas para aprimorar suas características de consumo e aparência. Além do menor custo de produção em relação aos corantes de origem natural, os corantes sintéticos apresentam diversas vantagens, tais como alta estabilidade à luz, oxigênio e pH...

  12. Audit Validation Using Ontologies

    Directory of Open Access Journals (Sweden)

    Ion IVAN

    2015-01-01

    Full Text Available Requirements to increase quality audit processes in enterprises are defined. It substantiates the need for assessment and management audit processes using ontologies. Sets of rules, ways to assess the consistency of rules and behavior within the organization are defined. Using ontologies are obtained qualifications that assess the organization's audit. Elaboration of the audit reports is a perfect algorithm-based activity characterized by generality, determinism, reproducibility, accuracy and a well-established. The auditors obtain effective levels. Through ontologies obtain the audit calculated level. Because the audit report is qualitative structure of information and knowledge it is very hard to analyze and interpret by different groups of users (shareholders, managers or stakeholders. Developing ontology for audit reports validation will be a useful instrument for both auditors and report users. In this paper we propose an instrument for validation of audit reports contain a lot of keywords that calculates indicators, a lot of indicators for each key word there is an indicator, qualitative levels; interpreter who builds a table of indicators, levels of actual and calculated levels.

  13. Validation of thermalhydraulic codes

    International Nuclear Information System (INIS)

    Wilkie, D.

    1992-01-01

    Thermalhydraulic codes require to be validated against experimental data collected over a wide range of situations if they are to be relied upon. A good example is provided by the nuclear industry where codes are used for safety studies and for determining operating conditions. Errors in the codes could lead to financial penalties, to the incorrect estimation of the consequences of accidents and even to the accidents themselves. Comparison between prediction and experiment is often described qualitatively or in approximate terms, e.g. ''agreement is within 10%''. A quantitative method is preferable, especially when several competing codes are available. The codes can then be ranked in order of merit. Such a method is described. (Author)

  14. Método para determinação de carboidratos empregado na triagem de adulterações em café

    OpenAIRE

    Pauli, Elis Daiane; Cristiano, Valderi; Nixdorf, Suzana Lucy

    2011-01-01

    The objective in this work was to validate a chromatography method for the determination of total carbohydrates in soluble coffee, using a HPLC-UV-VIS with postcolumn derivatization system, in order to verify adulterant additions. The validated method was accurate and robust. Adulteration could be observed by increasing xylose and glucose levels in samples with addition of coffee husks and starchy products while decreasing of galactose and mannose characteristic carbohydrates presenting in hi...

  15. Design for validation: An approach to systems validation

    Science.gov (United States)

    Carter, William C.; Dunham, Janet R.; Laprie, Jean-Claude; Williams, Thomas; Howden, William; Smith, Brian; Lewis, Carl M. (Editor)

    1989-01-01

    Every complex system built is validated in some manner. Computer validation begins with review of the system design. As systems became too complicated for one person to review, validation began to rely on the application of adhoc methods by many individuals. As the cost of the changes mounted and the expense of failure increased, more organized procedures became essential. Attempts at devising and carrying out those procedures showed that validation is indeed a difficult technical problem. The successful transformation of the validation process into a systematic series of formally sound, integrated steps is necessary if the liability inherent in the future digita-system-based avionic and space systems is to be minimized. A suggested framework and timetable for the transformtion are presented. Basic working definitions of two pivotal ideas (validation and system life-cyle) are provided and show how the two concepts interact. Many examples are given of past and present validation activities by NASA and others. A conceptual framework is presented for the validation process. Finally, important areas are listed for ongoing development of the validation process at NASA Langley Research Center.

  16. Site characterization and validation

    International Nuclear Information System (INIS)

    Olsson, O.; Eriksson, J.; Falk, L.; Sandberg, E.

    1988-04-01

    The borehole radar investigation program of the SCV-site (Site Characterization and Validation) has comprised single hole reflection measurements with centre frequencies of 22, 45, and 60 MHz. The radar range obtained in the single hole reflection measurements was approximately 100 m for the lower frequency (22 MHz) and about 60 m for the centre frequency 45 MHz. In the crosshole measurements transmitter-receiver separations from 60 to 200 m have been used. The radar investigations have given a three dimensional description of the structure at the SCV-site. A generalized model of the site has been produced which includes three major zones, four minor zones and a circular feature. These features are considered to be the most significant at the site. Smaller features than the ones included in the generalized model certainly exist but no additional features comparable to the three major zones are thought to exist. The results indicate that the zones are not homogeneous but rather that they are highly irregular containing parts of considerably increased fracturing and parts where their contrast to the background rock is quite small. The zones appear to be approximately planar at least at the scale of the site. At a smaller scale the zones can appear quite irregular. (authors)

  17. Spare Items validation

    International Nuclear Information System (INIS)

    Fernandez Carratala, L.

    1998-01-01

    There is an increasing difficulty for purchasing safety related spare items, with certifications by manufacturers for maintaining the original qualifications of the equipment of destination. The main reasons are, on the top of the logical evolution of technology, applied to the new manufactured components, the quitting of nuclear specific production lines and the evolution of manufacturers quality systems, originally based on nuclear codes and standards, to conventional industry standards. To face this problem, for many years different Dedication processes have been implemented to verify whether a commercial grade element is acceptable to be used in safety related applications. In the same way, due to our particular position regarding the spare part supplies, mainly from markets others than the american, C.N. Trillo has developed a methodology called Spare Items Validation. This methodology, which is originally based on dedication processes, is not a single process but a group of coordinated processes involving engineering, quality and management activities. These are to be performed on the spare item itself, its design control, its fabrication and its supply for allowing its use in destinations with specific requirements. The scope of application is not only focussed on safety related items, but also to complex design, high cost or plant reliability related components. The implementation in C.N. Trillo has been mainly curried out by merging, modifying and making the most of processes and activities which were already being performed in the company. (Author)

  18. SHIELD verification and validation report

    International Nuclear Information System (INIS)

    Boman, C.

    1992-02-01

    This document outlines the verification and validation effort for the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system code. Along with its predecessors, SHIELD has been in use at the Savannah River Site (SRS) for more than ten years. During this time the code has been extensively tested and a variety of validation documents have been issued. The primary function of this report is to specify the features and capabilities for which SHIELD is to be considered validated, and to reference the documents that establish the validation

  19. Experimental validation of UTDefect

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, A.S. [ABB Tekniska Roentgencentralen AB, Taeby (Sweden); Bostroem, A.; Wirdelius, H. [Chalmers Univ. of Technology, Goeteborg (Sweden). Div. of Mechanics

    1997-01-01

    This study reports on conducted experiments and computer simulations of ultrasonic nondestructive testing (NDT). Experiments and simulations are compared with the purpose of validating the simulation program UTDefect. UTDefect simulates ultrasonic NDT of cracks and some other defects in isotropic and homogeneous materials. Simulations for the detection of surface breaking cracks are compared with experiments in pulse-echo mode on surface breaking cracks in carbon steel plates. The echo dynamics are plotted and compared with the simulations. The experiments are performed on a plate with thickness 36 mm and the crack depths are 7.2 mm and 18 mm. L- and T-probes with frequency 1, 2 and 4 MHz and angels 45, 60 and 70 deg are used. In most cases the probe and the crack is on opposite sides of the plate, but in some cases they are on the same side. Several cracks are scanned from two directions. In total 53 experiments are reported for 33 different combinations. Generally the simulations agree well with the experiments and UTDefect is shown to be able to, within certain limits, perform simulations that are close to experiments. It may be concluded that: For corner echoes the eight 45 deg cases and the eight 60 deg cases show good agreement between experiments and UTDefect, especially for the 7.2 mm crack. The amplitudes differ more for some cases where the defect is close to the probe and for the corner of the 18 mm crack. For the two 70 deg cases there are too few experimental values to compare the curve shapes, but the amplitudes do not differ too much. The tip diffraction echoes also agree well in general. For some cases, where the defect is close to the probe, the amplitudes differ more than 10-15 dB, but for all but two cases the difference in amplitude is less than 7 dB. 6 refs.

  20. Cleaning Validation of Fermentation Tanks

    DEFF Research Database (Denmark)

    Salo, Satu; Friis, Alan; Wirtanen, Gun

    2008-01-01

    Reliable test methods for checking cleanliness are needed to evaluate and validate the cleaning process of fermentation tanks. Pilot scale tanks were used to test the applicability of various methods for this purpose. The methods found to be suitable for validation of the clenlinees were visula...

  1. The validation of language tests

    African Journals Online (AJOL)

    KATEVG

    Stellenbosch Papers in Linguistics, Vol. ... validation is necessary because of the major impact which test results can have on the many ... Messick (1989: 20) introduces his much-quoted progressive matrix (cf. table 1), which ... argue that current accounts of validity only superficially address theories of measurement.

  2. Validity in SSM: neglected areas

    NARCIS (Netherlands)

    Pala, O.; Vennix, J.A.M.; Mullekom, T.L. van

    2003-01-01

    Contrary to the prevailing notion in hard OR, in soft system methodology (SSM), validity seems to play a minor role. The primary reason for this is that SSM models are of a different type, they are not would-be descriptions of real-world situations. Therefore, establishing their validity, that is

  3. The Consequences of Consequential Validity.

    Science.gov (United States)

    Mehrens, William A.

    1997-01-01

    There is no agreement at present about the importance or meaning of the term "consequential validity." It is important that the authors of revisions to the "Standards for Educational and Psychological Testing" recognize the debate and relegate discussion of consequences to a context separate from the discussion of validity.…

  4. Current Concerns in Validity Theory.

    Science.gov (United States)

    Kane, Michael

    Validity is concerned with the clarification and justification of the intended interpretations and uses of observed scores. It has not been easy to formulate a general methodology set of principles for validation, but progress has been made, especially as the field has moved from relatively limited criterion-related models to sophisticated…

  5. The measurement of instrumental ADL: content validity and construct validity

    DEFF Research Database (Denmark)

    Avlund, K; Schultz-Larsen, K; Kreiner, S

    1993-01-01

    do not depend on help. It is also possible to add the items in a valid way. However, to obtain valid IADL-scales, we omitted items that were highly relevant to especially elderly women, such as house-work items. We conclude that the criteria employed for this IADL-measure are somewhat contradictory....... showed that 14 items could be combined into two qualitatively different additive scales. The IADL-measure complies with demands for content validity, distinguishes between what the elderly actually do, and what they are capable of doing, and is a good discriminator among the group of elderly persons who...

  6. Convergent validity test, construct validity test and external validity test of the David Liberman algorithm

    Directory of Open Access Journals (Sweden)

    David Maldavsky

    2013-08-01

    Full Text Available The author first exposes a complement of a previous test about convergent validity, then a construct validity test and finally an external validity test of the David Liberman algorithm.  The first part of the paper focused on a complementary aspect, the differential sensitivity of the DLA 1 in an external comparison (to other methods, and 2 in an internal comparison (between two ways of using the same method, the DLA.  The construct validity test exposes the concepts underlined to DLA, their operationalization and some corrections emerging from several empirical studies we carried out.  The external validity test examines the possibility of using the investigation of a single case and its relation with the investigation of a more extended sample.

  7. Validation of EAF-2005 data

    International Nuclear Information System (INIS)

    Kopecky, J.

    2005-01-01

    Full text: Validation procedures applied on EAF-2003 starter file, which lead to the production of EAF-2005 library, are described. The results in terms of reactions with assigned quality scores in EAF-20005 are given. Further the extensive validation against the recent integral data is discussed together with the status of the final report 'Validation of EASY-2005 using integral measurements'. Finally, the novel 'cross section trend analysis' is presented with some examples of its use. This action will lead to the release of improved library EAF-2005.1 at the end of 2005, which shall be used as the starter file for EAF-2007. (author)

  8. Validity and validation of expert (Q)SAR systems.

    Science.gov (United States)

    Hulzebos, E; Sijm, D; Traas, T; Posthumus, R; Maslankiewicz, L

    2005-08-01

    At a recent workshop in Setubal (Portugal) principles were drafted to assess the suitability of (quantitative) structure-activity relationships ((Q)SARs) for assessing the hazards and risks of chemicals. In the present study we applied some of the Setubal principles to test the validity of three (Q)SAR expert systems and validate the results. These principles include a mechanistic basis, the availability of a training set and validation. ECOSAR, BIOWIN and DEREK for Windows have a mechanistic or empirical basis. ECOSAR has a training set for each QSAR. For half of the structural fragments the number of chemicals in the training set is >4. Based on structural fragments and log Kow, ECOSAR uses linear regression to predict ecotoxicity. Validating ECOSAR for three 'valid' classes results in predictivity of > or = 64%. BIOWIN uses (non-)linear regressions to predict the probability of biodegradability based on fragments and molecular weight. It has a large training set and predicts non-ready biodegradability well. DEREK for Windows predictions are supported by a mechanistic rationale and literature references. The structural alerts in this program have been developed with a training set of positive and negative toxicity data. However, to support the prediction only a limited number of chemicals in the training set is presented to the user. DEREK for Windows predicts effects by 'if-then' reasoning. The program predicts best for mutagenicity and carcinogenicity. Each structural fragment in ECOSAR and DEREK for Windows needs to be evaluated and validated separately.

  9. Validation of Autonomous Space Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — System validation addresses the question "Will the system do the right thing?" When system capability includes autonomy, the question becomes more pointed. As NASA...

  10. Magnetic Signature Analysis & Validation System

    National Research Council Canada - National Science Library

    Vliet, Scott

    2001-01-01

    The Magnetic Signature Analysis and Validation (MAGSAV) System is a mobile platform that is used to measure, record, and analyze the perturbations to the earth's ambient magnetic field caused by object such as armored vehicles...

  11. Mercury and Cyanide Data Validation

    Science.gov (United States)

    Document designed to offer data reviewers guidance in determining the validity ofanalytical data generated through the USEPA Contract Laboratory Program (CLP) Statement ofWork (SOW) ISM01.X Inorganic Superfund Methods (Multi-Media, Multi-Concentration)

  12. ICP-MS Data Validation

    Science.gov (United States)

    Document designed to offer data reviewers guidance in determining the validity ofanalytical data generated through the USEPA Contract Laboratory Program Statement ofWork (SOW) ISM01.X Inorganic Superfund Methods (Multi-Media, Multi-Concentration)

  13. Contextual Validity in Hybrid Logic

    DEFF Research Database (Denmark)

    Blackburn, Patrick Rowan; Jørgensen, Klaus Frovin

    2013-01-01

    interpretations. Moreover, such indexicals give rise to a special kind of validity—contextual validity—that interacts with ordinary logi- cal validity in interesting and often unexpected ways. In this paper we model these interactions by combining standard techniques from hybrid logic with insights from the work...... of Hans Kamp and David Kaplan. We introduce a simple proof rule, which we call the Kamp Rule, and first we show that it is all we need to take us from logical validities involving now to contextual validities involving now too. We then go on to show that this deductive bridge is strong enough to carry us...... to contextual validities involving yesterday, today and tomorrow as well....

  14. MARS Validation Plan and Status

    International Nuclear Information System (INIS)

    Ahn, Seung-hoon; Cho, Yong-jin

    2008-01-01

    The KINS Reactor Thermal-hydraulic Analysis System (KINS-RETAS) under development is directed toward a realistic analysis approach of best-estimate (BE) codes and realistic assumptions. In this system, MARS is pivoted to provide the BE Thermal-Hydraulic (T-H) response in core and reactor coolant system to various operational transients and accidental conditions. As required for other BE codes, the qualification is essential to ensure reliable and reasonable accuracy for a targeted MARS application. Validation is a key element of the code qualification, and determines the capability of a computer code in predicting the major phenomena expected to occur. The MARS validation was made by its developer KAERI, on basic premise that its backbone code RELAP5/MOD3.2 is well qualified against analytical solutions, test or operational data. A screening was made to select the test data for MARS validation; some models transplanted from RELAP5, if already validated and found to be acceptable, were screened out from assessment. It seems to be reasonable, but does not demonstrate whether code adequacy complies with the software QA guidelines. Especially there may be much difficulty in validating the life-cycle products such as code updates or modifications. This paper presents the plan for MARS validation, and the current implementation status

  15. Validation: an overview of definitions

    International Nuclear Information System (INIS)

    Pescatore, C.

    1995-01-01

    The term validation is featured prominently in the literature on radioactive high-level waste disposal and is generally understood to be related to model testing using experiments. In a first class, validation is linked to the goal of predicting the physical world as faithfully as possible but is unattainable and unsuitable for setting goals for the safety analyses. In a second class, validation is associated to split-sampling or to blind-tests predictions. In the third class of definition, validation focuses on the quality of the decision-making process. Most prominent in the present review is the observed lack of use of the term validation in the field of low-level radioactive waste disposal. The continued informal use of the term validation in the field of high level wastes disposals can become cause for misperceptions and endless speculations. The paper proposes either abandoning the use of this term or agreeing to a definition which would be common to all. (J.S.). 29 refs

  16. Development and Validation of RP-LC Method for the Determination of Cinnarizine/Piracetam and Cinnarizine/Heptaminol Acefyllinate in Presence of Cinnarizine Reported Degradation Products

    Directory of Open Access Journals (Sweden)

    Ola M. EL-Houssini

    2013-01-01

    Full Text Available Specific stability indicating reverse-phase liquid chromatography (RP-LC assay method (SIAM was developed for the determination of cinnarizine (Cinn/piracetam (Pira and cinnarizine (Cinn/heptaminol acefyllinate (Hept in the presence of the reported degradation products of Cinn. A C 18 column and gradient mobile phase was applied for good resolution of all peaks. The detection was achieved at 210 nm and 254 nm for Cinn/Pira and Cinn/Hept, respectively. The responses were linear over concentration ranges of 20-200, 20-1000 and 25-1000 μgmL −1 for Cinn, Pira, and Hept respectively. The proposed method was validated for linearity, accuracy, repeatability, intermediate precision, and robustness via statistical analysis of the data. The method was shown to be precise, accurate, reproducible, sensitive, and selective for the analysis of Cinn/Pira and Cinn/Hept in laboratory prepared mixtures and in pharmaceutical formulations.

  17. Development and Validation of RP-LC Method for the Determination of Cinnarizine/Piracetam and Cinnarizine/Heptaminol Acefyllinate in Presence of Cinnarizine Reported Degradation Products

    Science.gov (United States)

    EL-Houssini, Ola M.; Zawilla, Nagwan H.; Mohammad, Mohammad A.

    2013-01-01

    Specific stability indicating reverse-phase liquid chromatography (RP-LC) assay method (SIAM) was developed for the determination of cinnarizine (Cinn)/piracetam (Pira) and cinnarizine (Cinn)/heptaminol acefyllinate (Hept) in the presence of the reported degradation products of Cinn. A C18 column and gradient mobile phase was applied for good resolution of all peaks. The detection was achieved at 210 nm and 254 nm for Cinn/Pira and Cinn/Hept, respectively. The responses were linear over concentration ranges of 20–200, 20–1000 and 25–1000 μgmL−1 for Cinn, Pira, and Hept respectively. The proposed method was validated for linearity, accuracy, repeatability, intermediate precision, and robustness via statistical analysis of the data. The method was shown to be precise, accurate, reproducible, sensitive, and selective for the analysis of Cinn/Pira and Cinn/Hept in laboratory prepared mixtures and in pharmaceutical formulations. PMID:24137049

  18. Site characterization and validation - validation drift fracture data, stage 4

    International Nuclear Information System (INIS)

    Bursey, G.; Gale, J.; MacLeod, R.; Straahle, A.; Tiren, S.

    1991-08-01

    This report describes the mapping procedures and the data collected during fracture mapping in the validation drift. Fracture characteristics examined include orientation, trace length, termination mode, and fracture minerals. These data have been compared and analysed together with fracture data from the D-boreholes to determine the adequacy of the borehole mapping procedures and to assess the nature and degree of orientation bias in the borehole data. The analysis of the validation drift data also includes a series of corrections to account for orientation, truncation, and censoring biases. This analysis has identified at least 4 geologically significant fracture sets in the rock mass defined by the validation drift. An analysis of the fracture orientations in both the good rock and the H-zone has defined groups of 7 clusters and 4 clusters, respectively. Subsequent analysis of the fracture patterns in five consecutive sections along the validation drift further identified heterogeneity through the rock mass, with respect to fracture orientations. These results are in stark contrast to the results form the D-borehole analysis, where a strong orientation bias resulted in a consistent pattern of measured fracture orientations through the rock. In the validation drift, fractures in the good rock also display a greater mean variance in length than those in the H-zone. These results provide strong support for a distinction being made between fractures in the good rock and the H-zone, and possibly between different areas of the good rock itself, for discrete modelling purposes. (au) (20 refs.)

  19. Validation of a liquid chromatographic method for the pharmaceutical quality control of products containing elacridar

    Directory of Open Access Journals (Sweden)

    Emilia Sawicki

    2016-08-01

    Full Text Available Many anticancer drugs have an impaired bioavailability and poor brain penetration because they are substrates to drug efflux pumps such as P-glycoprotein and Breast Cancer Resistance Protein. Elacridar is a strong inhibitor of these two drug efflux pumps and therefore has great potential to improve oral absorption and brain penetration of many anticancer drugs. Currently, a clinical formulation of elacridar is unavailable and therefore the pharmaceutical development of a drug product is highly warranted. This also necessitates the availability of an analytical method for its quality control. A reverse-phase high-performance liquid chromatographic method with ultraviolet detection was developed for the pharmaceutical quality control of products containing elacridar as the active pharmaceutical ingredient. The analytical method was validated for linearity, accuracy, precision, selectivity, carry-over, stability of stock and reference solutions, stability of the final extract, stability-indicating capability and impurity testing. We found that elacridar is unstable in aqueous solutions that are exposed to light because a hydroxylation product of elacridar is formed. Therefore, sample solutions with elacridar must be protected from light.

  20. A Study of Method Development, Validation, and Forced Degradation for Simultaneous Quantification of Paracetamol and Ibuprofen in Pharmaceutical Dosage Form by RP-HPLC Method

    Directory of Open Access Journals (Sweden)

    Md. Sarowar Jahan

    2014-01-01

    Full Text Available A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and system suitability. Forced degradation study was validated according to International Conference on Harmonisation (ICH. For this, an isocratic condition of mobile phase comprising phosphate buffer (pH 6.8 and acetonitrile in a ratio of 65:35, v/v at a flow rate of 0.7 mL/minute over RP C18 (octadecylsilane (ODS, 150 × 4.6 mm, 5 μm, Phenomenex Inc. column at ambient temperature was maintained. The method showed excellent linear response with correlation coefficient ( R 2 values of 0.999 and 1.0 for paracetamol and ibuprofen respectively, which were within the limit of correlation coefficient ( R 2 > 0.995. The percent recoveries for two drugs were found within the acceptance limit of (97.0-103.0%. Intra-and inter-day precision studies of the new method were less than the maximum allowable limit percentage of relative standard deviation (%RSD ≤ 2.0. Forced degradation of the drug product was carried out as per the ICH guidelines with a view to establishing the stability-indicating property of this method and providing useful information about the degradation pathways, degradation products, and how the quality of a drug substance and drug product changes with time under the influence of various stressing conditions. The degradation of ibuprofen was within the limit (5-20%, according to the guideline of ICH, while paracetamol showed <20% degradation in oxidation and basic condition.

  1. A Study of Method Development, Validation, and Forced Degradation for Simultaneous Quantification of Paracetamol and Ibuprofen in Pharmaceutical Dosage Form by RP-HPLC Method.

    Science.gov (United States)

    Jahan, Md Sarowar; Islam, Md Jahirul; Begum, Rehana; Kayesh, Ruhul; Rahman, Asma

    2014-01-01

    A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP) guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and system suitability. Forced degradation study was validated according to International Conference on Harmonisation (ICH). For this, an isocratic condition of mobile phase comprising phosphate buffer (pH 6.8) and acetonitrile in a ratio of 65:35, v/v at a flow rate of 0.7 mL/minute over RP C18 (octadecylsilane (ODS), 150 × 4.6 mm, 5 μm, Phenomenex Inc.) column at ambient temperature was maintained. The method showed excellent linear response with correlation coefficient (R (2)) values of 0.999 and 1.0 for paracetamol and ibuprofen respectively, which were within the limit of correlation coefficient (R (2) > 0.995). The percent recoveries for two drugs were found within the acceptance limit of (97.0-103.0%). Intra-and inter-day precision studies of the new method were less than the maximum allowable limit percentage of relative standard deviation (%RSD) ≤ 2.0. Forced degradation of the drug product was carried out as per the ICH guidelines with a view to establishing the stability-indicating property of this method and providing useful information about the degradation pathways, degradation products, and how the quality of a drug substance and drug product changes with time under the influence of various stressing conditions. The degradation of ibuprofen was within the limit (5-20%, according to the guideline of ICH), while paracetamol showed degradation in oxidation and basic condition.

  2. Quality data validation: Comprehensive approach to environmental data validation

    International Nuclear Information System (INIS)

    Matejka, L.A. Jr.

    1993-01-01

    Environmental data validation consists of an assessment of three major areas: analytical method validation; field procedures and documentation review; evaluation of the level of achievement of data quality objectives based in part on PARCC parameters analysis and expected applications of data. A program utilizing matrix association of required levels of validation effort and analytical levels versus applications of this environmental data was developed in conjunction with DOE-ID guidance documents to implement actions under the Federal Facilities Agreement and Consent Order in effect at the Idaho National Engineering Laboratory. This was an effort to bring consistent quality to the INEL-wide Environmental Restoration Program and database in an efficient and cost-effective manner. This program, documenting all phases of the review process, is described here

  3. The validation of an infrared simulation system

    CSIR Research Space (South Africa)

    De Waal, A

    2013-08-01

    Full Text Available theoretical validation framework. This paper briefly describes the procedure used to validate software models in an infrared system simulation, and provides application examples of this process. The discussion includes practical validation techniques...

  4. Process validation for radiation processing

    International Nuclear Information System (INIS)

    Miller, A.

    1999-01-01

    Process validation concerns the establishment of the irradiation conditions that will lead to the desired changes of the irradiated product. Process validation therefore establishes the link between absorbed dose and the characteristics of the product, such as degree of crosslinking in a polyethylene tube, prolongation of shelf life of a food product, or degree of sterility of the medical device. Detailed international standards are written for the documentation of radiation sterilization, such as EN 552 and ISO 11137, and the steps of process validation that are described in these standards are discussed in this paper. They include material testing for the documentation of the correct functioning of the product, microbiological testing for selection of the minimum required dose and dose mapping for documentation of attainment of the required dose in all parts of the product. The process validation must be maintained by reviews and repeated measurements as necessary. This paper presents recommendations and guidance for the execution of these components of process validation. (author)

  5. Rapid Robot Design Validation, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Energid Technologies will create a comprehensive software infrastructure for rapid validation of robot designs. The software will support push-button validation...

  6. CASL Verification and Validation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Mousseau, Vincent Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dinh, Nam [North Carolina State Univ., Raleigh, NC (United States)

    2016-06-30

    This report documents the Consortium for Advanced Simulation of LWRs (CASL) verification and validation plan. The document builds upon input from CASL subject matter experts, most notably the CASL Challenge Problem Product Integrators, CASL Focus Area leaders, and CASL code development and assessment teams. This document will be a living document that will track progress on CASL to do verification and validation for both the CASL codes (including MPACT, CTF, BISON, MAMBA) and for the CASL challenge problems (CIPS, PCI, DNB). The CASL codes and the CASL challenge problems are at differing levels of maturity with respect to validation and verification. The gap analysis will summarize additional work that needs to be done. Additional VVUQ work will be done as resources permit. This report is prepared for the Department of Energy’s (DOE’s) CASL program in support of milestone CASL.P13.02.

  7. A validated RP-HPLC method for simultaneous determination of propranolol and valsartan in bulk drug and gel formulation

    Science.gov (United States)

    Imam, Syed Sarim; Ahad, Abdul; Aqil, Mohammed; Sultana, Yasmin; Ali, Asgar

    2013-01-01

    Objective: A simple, precise, and stability indicating high performance liquid chromatography (HPLC) method was developed and validated for the simultaneous determination of propranolol hydrochloride and valsartan in pharmaceutical dosage form. Materials and Methods: The method involves the use of easily available inexpensive laboratory reagents. The separation was achieved on Hypersil ODS C-18 column (250*4.6 mm, i.d., 5 μm particle size) with isocratic flow with UV detector. The mobile phase at a flow rate of 1.0 mL/min consisted of acetonitrile, methanol, and 0.01 M disodium hydrogen phosphate (pH 3.5) in the ratio of 50:35:15 v/v. Results: A linear response was observed over the concentration range 5-50 μg/mL of propranolol and the concentration range 4-32 μg/mL of valsartan. Limit of detection and limit of quantitation for propranolol were 0.27 μg/mL and 0.85 μg/mL, and for valsartan were 0.45 μg/mL and 1.39 μg/mL, respectively. The method was successfully validated in accordance to ICH guidelines acceptance criteria for linearity, accuracy, precision, specificity, robustness. Conclusion: The analysis concluded that the method was selective for simultaneous estimation of propranolol and valsartan can be potentially used for the estimation of these drugs in combined dosage form. PMID:23559826

  8. All Validity Is Construct Validity. Or Is It?

    Science.gov (United States)

    Kane, Michael

    2012-01-01

    Paul E. Newton's article on the consensus definition of validity tackles a number of big issues and makes a number of strong claims. I agreed with much of what he said, and I disagreed with a number of his claims, but I found his article to be consistently interesting and thought provoking (whether I agreed or not). I will focus on three general…

  9. Validering av vattenkraftmodeller i ARISTO

    OpenAIRE

    Lundbäck, Maja

    2013-01-01

    This master thesis was made to validate hydropower models of a turbine governor, Kaplan turbine and a Francis turbine in the power system simulator ARISTO at Svenska Kraftnät. The validation was made in three steps. The first step was to make sure the models was implement correctly in the simulator. The second was to compare the simulation results from the Kaplan turbine model to data from a real hydropower plant. The comparison was made to see how the models could generate simulation result ...

  10. PIV Data Validation Software Package

    Science.gov (United States)

    Blackshire, James L.

    1997-01-01

    A PIV data validation and post-processing software package was developed to provide semi-automated data validation and data reduction capabilities for Particle Image Velocimetry data sets. The software provides three primary capabilities including (1) removal of spurious vector data, (2) filtering, smoothing, and interpolating of PIV data, and (3) calculations of out-of-plane vorticity, ensemble statistics, and turbulence statistics information. The software runs on an IBM PC/AT host computer working either under Microsoft Windows 3.1 or Windows 95 operating systems.

  11. Assessment of juveniles testimonies’ validity

    Directory of Open Access Journals (Sweden)

    Dozortseva E.G.

    2015-12-01

    Full Text Available The article presents a review of the English language publications concerning the history and the current state of differential psychological assessment of validity of testimonies produced by child and adolescent victims of crimes. The topicality of the problem in Russia is high due to the tendency of Russian specialists to use methodical means and instruments developed abroad in this sphere for forensic assessments of witness testimony veracity. A system of Statement Validity Analysis (SVA by means of Criteria-Based Content Analysis (CBCA and Validity Checklist is described. The results of laboratory and field studies of validity of CBCA criteria on the basis of child and adult witnesses are discussed. The data display a good differentiating capacity of the method, however, a high level of error probability. The researchers recommend implementation of SVA in the criminal investigation process, but not in the forensic assessment. New perspective developments in the field of methods for differentiation of witness statements based on the real experience and fictional are noted. The conclusion is drawn that empirical studies and a special work for adaptation and development of new approaches should precede their implementation into Russian criminal investigation and forensic assessment practice

  12. Automatic Validation of Protocol Narration

    DEFF Research Database (Denmark)

    Bodei, Chiara; Buchholtz, Mikael; Degano, Pierpablo

    2003-01-01

    We perform a systematic expansion of protocol narrations into terms of a process algebra in order to make precise some of the detailed checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we...

  13. Validation process of simulation model

    International Nuclear Information System (INIS)

    San Isidro, M. J.

    1998-01-01

    It is presented a methodology on empirical validation about any detailed simulation model. This king of validation it is always related with an experimental case. The empirical validation has a residual sense, because the conclusions are based on comparisons between simulated outputs and experimental measurements. This methodology will guide us to detect the fails of the simulation model. Furthermore, it can be used a guide in the design of posterior experiments. Three steps can be well differentiated: Sensitivity analysis. It can be made with a DSA, differential sensitivity analysis, and with a MCSA, Monte-Carlo sensitivity analysis. Looking the optimal domains of the input parameters. It has been developed a procedure based on the Monte-Carlo methods and Cluster techniques, to find the optimal domains of these parameters. Residual analysis. This analysis has been made on the time domain and on the frequency domain, it has been used the correlation analysis and spectral analysis. As application of this methodology, it is presented the validation carried out on a thermal simulation model on buildings, Esp., studying the behavior of building components on a Test Cell of LECE of CIEMAT. (Author) 17 refs

  14. Validity of Management Control Topoi

    DEFF Research Database (Denmark)

    Nørreklit, Lennart; Nørreklit, Hanne; Israelsen, Poul

    2004-01-01

    The validity of research and company topoi for constructing/analyzing relaity is analyzed as the integration of the four aspects (dimensions): fact, possibility (logic), value and comunication. Main stream, agency theory and social constructivism are critizied for reductivism (incomplete integrat...

  15. NVN 5694 intra laboratory validation. Feasibility study for interlaboratory- validation

    International Nuclear Information System (INIS)

    Voors, P.I.; Baard, J.H.

    1998-11-01

    Within the project NORMSTAR 2 a number of Dutch prenormative protocols have been defined for radioactivity measurements. Some of these protocols, e.g. the Dutch prenormative protocol NVN 5694, titled Methods for radiochemical determination of polonium-210 and lead-210, have not been validated, neither by intralaboratory nor interlaboratory studies. Validation studies are conducted within the framework of the programme 'Normalisatie and Validatie van Milieumethoden 1993-1997' (Standardization and Validation of test methods for environmental parameters) of the Dutch Ministry of Housing, Physical Planning and the Environment (VROM). The aims of this study were (a) a critical evaluation of the protocol, (b) investigation on the feasibility of an interlaboratory study, and (c) the interlaboratory validation of NVN 5694. The evaluation of the protocol resulted in a list of deficiencies varying from missing references to incorrect formulae. From the survey by interview it appeared that for each type of material, there are 4 to 7 laboratories willing to participate in a interlaboratory validation study. This reflects the situation in 1997. Consequently, if 4 or 6 (the minimal number) laboratories are participating and each laboratory analyses 3 subsamples, the uncertainty in the repeatability standard deviation is 49 or 40 %, respectively. If the ratio of reproducibility standard deviation to the repeatability standard deviation is equal to 1 or 2, then the uncertainty in the reproducibility standard deviation increases from 42 to 67 % and from 34 to 52 % for 4 or 6 laboratories, respectively. The intralaboratory validation was established on four different types of materials. Three types of materials (milkpowder condensate and filter) were prepared in the laboratory using the raw material and certified Pb-210 solutions, and one (sediment) was obtained from the IAEA. The ECN-prepared reference materials were used after testing on homogeneity. The pre-normative protocol can

  16. An information architecture for validating courseware

    OpenAIRE

    Melia, Mark; Pahl, Claus

    2007-01-01

    Courseware validation should locate Learning Objects inconsistent with the courseware instructional design being used. In order for validation to take place it is necessary to identify the implicit and explicit information needed for validation. In this paper, we identify this information and formally define an information architecture to model courseware validation information explicitly. This promotes tool-support for courseware validation and its interoperability with the courseware specif...

  17. Methodology for Validating Building Energy Analysis Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Judkoff, R.; Wortman, D.; O' Doherty, B.; Burch, J.

    2008-04-01

    The objective of this report was to develop a validation methodology for building energy analysis simulations, collect high-quality, unambiguous empirical data for validation, and apply the validation methodology to the DOE-2.1, BLAST-2MRT, BLAST-3.0, DEROB-3, DEROB-4, and SUNCAT 2.4 computer programs. This report covers background information, literature survey, validation methodology, comparative studies, analytical verification, empirical validation, comparative evaluation of codes, and conclusions.

  18. Construct Validity: Advances in Theory and Methodology

    OpenAIRE

    Strauss, Milton E.; Smith, Gregory T.

    2009-01-01

    Measures of psychological constructs are validated by testing whether they relate to measures of other constructs as specified by theory. Each test of relations between measures reflects on the validity of both the measures and the theory driving the test. Construct validation concerns the simultaneous process of measure and theory validation. In this chapter, we review the recent history of validation efforts in clinical psychological science that has led to this perspective, and we review f...

  19. CTF Void Drift Validation Study

    Energy Technology Data Exchange (ETDEWEB)

    Salko, Robert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gosdin, Chris [Pennsylvania State Univ., University Park, PA (United States); Avramova, Maria N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gergar, Marcus [Pennsylvania State Univ., University Park, PA (United States)

    2015-10-26

    This milestone report is a summary of work performed in support of expansion of the validation and verification (V&V) matrix for the thermal-hydraulic subchannel code, CTF. The focus of this study is on validating the void drift modeling capabilities of CTF and verifying the supporting models that impact the void drift phenomenon. CTF uses a simple turbulent-diffusion approximation to model lateral cross-flow due to turbulent mixing and void drift. The void drift component of the model is based on the Lahey and Moody model. The models are a function of two-phase mass, momentum, and energy distribution in the system; therefore, it is necessary to correctly model the ow distribution in rod bundle geometry as a first step to correctly calculating the void distribution due to void drift.

  20. Validation of New Cancer Biomarkers

    DEFF Research Database (Denmark)

    Duffy, Michael J; Sturgeon, Catherine M; Söletormos, Georg

    2015-01-01

    BACKGROUND: Biomarkers are playing increasingly important roles in the detection and management of patients with cancer. Despite an enormous number of publications on cancer biomarkers, few of these biomarkers are in widespread clinical use. CONTENT: In this review, we discuss the key steps...... in advancing a newly discovered cancer candidate biomarker from pilot studies to clinical application. Four main steps are necessary for a biomarker to reach the clinic: analytical validation of the biomarker assay, clinical validation of the biomarker test, demonstration of clinical value from performance...... of the biomarker test, and regulatory approval. In addition to these 4 steps, all biomarker studies should be reported in a detailed and transparent manner, using previously published checklists and guidelines. Finally, all biomarker studies relating to demonstration of clinical value should be registered before...

  1. The validated sun exposure questionnaire

    DEFF Research Database (Denmark)

    Køster, B; Søndergaard, J; Nielsen, J B

    2017-01-01

    Few questionnaires used in monitoring sun-related behavior have been tested for validity. We established criteria validity of a developed questionnaire for monitoring population sun-related behavior. During May-August 2013, 664 Danes wore a personal electronic UV-dosimeter for one week...... that measured the outdoor time and dose of erythemal UVR exposure. In the following week, they answered a questionnaire on their sun-related behavior in the measurement week. Outdoor time measured by dosimetry correlated strongly with both outdoor time and the developed exposure scale measured...... in the questionnaire. Exposure measured in SED by dosimetry correlated strongly with the exposure scale. In a linear regression model of UVR (SED) received, 41 percent of the variation was explained by skin type, age, week of participation and the exposure scale, with the exposure scale as the main contributor...

  2. Automatic validation of numerical solutions

    DEFF Research Database (Denmark)

    Stauning, Ole

    1997-01-01

    This thesis is concerned with ``Automatic Validation of Numerical Solutions''. The basic theory of interval analysis and self-validating methods is introduced. The mean value enclosure is applied to discrete mappings for obtaining narrow enclosures of the iterates when applying these mappings...... differential equations, but in this thesis, we describe how to use the methods for enclosing iterates of discrete mappings, and then later use them for discretizing solutions of ordinary differential equations. The theory of automatic differentiation is introduced, and three methods for obtaining derivatives...... are described: The forward, the backward, and the Taylor expansion methods. The three methods have been implemented in the C++ program packages FADBAD/TADIFF. Some examples showing how to use the three metho ds are presented. A feature of FADBAD/TADIFF not present in other automatic differentiation packages...

  3. Drive: Theory and Construct Validation.

    Science.gov (United States)

    Siegling, Alex B; Petrides, K V

    2016-01-01

    This article explicates the theory of drive and describes the development and validation of two measures. A representative set of drive facets was derived from an extensive corpus of human attributes (Study 1). Operationalised using an International Personality Item Pool version (the Drive:IPIP), a three-factor model was extracted from the facets in two samples and confirmed on a third sample (Study 2). The multi-item IPIP measure showed congruence with a short form, based on single-item ratings of the facets, and both demonstrated cross-informant reliability. Evidence also supported the measures' convergent, discriminant, concurrent, and incremental validity (Study 3). Based on very promising findings, the authors hope to initiate a stream of research in what is argued to be a rather neglected niche of individual differences and non-cognitive assessment.

  4. Validation of nursing management diagnoses.

    Science.gov (United States)

    Morrison, R S

    1995-01-01

    Nursing management diagnosis based on nursing and management science, merges "nursing diagnosis" and "organizational diagnosis". Nursing management diagnosis is a judgment about nursing organizational problems. The diagnoses provide a basis for nurse manager interventions to achieve outcomes for which a nurse manager is accountable. A nursing organizational problem is a discrepancy between what should be happening and what is actually happening that prevents the goals of nursing from being accomplished. The purpose of this study was to validate 73 nursing management diagnoses identified previously in 1992: 71 of the 72 diagnoses were considered valid by at least 70% of 136 participants. Diagnoses considered to have high priority for future research and development were identified by summing the mean scores for perceived frequency of occurrence and level of disruption. Further development of nursing management diagnoses and testing of their effectiveness in enhancing decision making is recommended.

  5. Validation of radiation sterilization process

    International Nuclear Information System (INIS)

    Kaluska, I.

    2007-01-01

    The standards for quality management systems recognize that, for certain processes used in manufacturing, the effectiveness of the process cannot be fully verified by subsequent inspection and testing of the product. Sterilization is an example of such a process. For this reason, sterilization processes are validated for use, the performance of sterilization process is monitored routinely and the equipment is maintained according to ISO 13 485. Different aspects of this norm are presented

  6. Satellite imager calibration and validation

    CSIR Research Space (South Africa)

    Vhengani, L

    2010-10-01

    Full Text Available and Validation Lufuno Vhengani*, Minette Lubbe, Derek Griffith and Meena Lysko Council for Scientific and Industrial Research, Defence Peace Safety and Security, Pretoria, South Africa E-mail: * lvhengani@csir.co.za Abstract: The success or failure... techniques specific to South Africa. 1. Introduction The success or failure of any earth observation mission depends on the quality of its data. To achieve optimum levels of reliability most sensors are calibrated pre-launch. However...

  7. Microservices Validation: Methodology and Implementation

    OpenAIRE

    Savchenko, D.; Radchenko, G.

    2015-01-01

    Due to the wide spread of cloud computing, arises actual question about architecture, design and implementation of cloud applications. The microservice model describes the design and development of loosely coupled cloud applications when computing resources are provided on the basis of automated IaaS and PaaS cloud platforms. Such applications consist of hundreds and thousands of service instances, so automated validation and testing of cloud applications developed on the basis of microservic...

  8. SMAP RADAR Calibration and Validation

    Science.gov (United States)

    West, R. D.; Jaruwatanadilok, S.; Chaubel, M. J.; Spencer, M.; Chan, S. F.; Chen, C. W.; Fore, A.

    2015-12-01

    The Soil Moisture Active Passive (SMAP) mission launched on Jan 31, 2015. The mission employs L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Immediately following launch, there was a three month instrument checkout period, followed by six months of level 1 (L1) calibration and validation. In this presentation, we will discuss the calibration and validation activities and results for the L1 radar data. Early SMAP radar data were used to check commanded timing parameters, and to work out issues in the low- and high-resolution radar processors. From April 3-13 the radar collected receive only mode data to conduct a survey of RFI sources. Analysis of the RFI environment led to a preferred operating frequency. The RFI survey data were also used to validate noise subtraction and scaling operations in the radar processors. Normal radar operations resumed on April 13. All radar data were examined closely for image quality and calibration issues which led to improvements in the radar data products for the beta release at the end of July. Radar data were used to determine and correct for small biases in the reported spacecraft attitude. Geo-location was validated against coastline positions and the known positions of corner reflectors. Residual errors at the time of the beta release are about 350 m. Intra-swath biases in the high-resolution backscatter images are reduced to less than 0.3 dB for all polarizations. Radiometric cross-calibration with Aquarius was performed using areas of the Amazon rain forest. Cross-calibration was also examined using ocean data from the low-resolution processor and comparing with the Aquarius wind model function. Using all a-priori calibration constants provided good results with co-polarized measurements matching to better than 1 dB, and cross-polarized measurements matching to about 1 dB in the beta release. During the

  9. Multimicrophone Speech Dereverberation: Experimental Validation

    Directory of Open Access Journals (Sweden)

    Marc Moonen

    2007-05-01

    Full Text Available Dereverberation is required in various speech processing applications such as handsfree telephony and voice-controlled systems, especially when signals are applied that are recorded in a moderately or highly reverberant environment. In this paper, we compare a number of classical and more recently developed multimicrophone dereverberation algorithms, and validate the different algorithmic settings by means of two performance indices and a speech recognition system. It is found that some of the classical solutions obtain a moderate signal enhancement. More advanced subspace-based dereverberation techniques, on the other hand, fail to enhance the signals despite their high-computational load.

  10. Physical standards and valid caibration

    International Nuclear Information System (INIS)

    Smith, D.B.

    1975-01-01

    The desire for improved nuclear material safeguards has led to the development and use of a number and techniques and instruments for the nondestructive assay (NDA) of special nuclear material. Sources of potential bias in NDA measurements are discussed and methods of eliminating the effects of bias in assay results are suggested. Examples are given of instruments in which these methods have been successfully applied. The results of careful attention to potential sources of assay bias are a significant reduction in the number and complexity of standards required for valid instrument calibration and more credible assay results. (auth)

  11. Verification and validation of models

    International Nuclear Information System (INIS)

    Herbert, A.W.; Hodgkinson, D.P.; Jackson, C.P.; Lever, D.A.; Robinson, P.C.

    1986-12-01

    The numerical accuracy of the computer models for groundwater flow and radionuclide transport that are to be used in repository safety assessment must be tested, and their ability to describe experimental data assessed: they must be verified and validated respectively. Also appropriate ways to use the codes in performance assessments, taking into account uncertainties in present data and future conditions, must be studied. These objectives are being met by participation in international exercises, by developing bench-mark problems, and by analysing experiments. In particular the project has funded participation in the HYDROCOIN project for groundwater flow models, the Natural Analogues Working Group, and the INTRAVAL project for geosphere models. (author)

  12. Static Validation of Security Protocols

    DEFF Research Database (Denmark)

    Bodei, Chiara; Buchholtz, Mikael; Degano, P.

    2005-01-01

    We methodically expand protocol narrations into terms of a process algebra in order to specify some of the checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we demonstrate that these techniques ...... suffice to identify several authentication flaws in symmetric and asymmetric key protocols such as Needham-Schroeder symmetric key, Otway-Rees, Yahalom, Andrew secure RPC, Needham-Schroeder asymmetric key, and Beller-Chang-Yacobi MSR...

  13. Software for validating parameters retrieved from satellite

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Sathe, P.V.; Pankajakshan, T.

    -channel Scanning Microwave Radiometer (MSMR) onboard the Indian satellites Occansat-1 during 1999-2001 were validated using this software as a case study. The program has several added advantages over the conventional method of validation that involves strenuous...

  14. Congruent Validity of the Rathus Assertiveness Schedule.

    Science.gov (United States)

    Harris, Thomas L.; Brown, Nina W.

    1979-01-01

    The validity of the Rathus Assertiveness Schedule (RAS) was investigated by correlating it with the six Class I scales of the California Psychological Inventory on a sample of undergraduate students. Results supported the validity of the RAS. (JKS)

  15. CFD validation experiments for hypersonic flows

    Science.gov (United States)

    Marvin, Joseph G.

    1992-01-01

    A roadmap for CFD code validation is introduced. The elements of the roadmap are consistent with air-breathing vehicle design requirements and related to the important flow path components: forebody, inlet, combustor, and nozzle. Building block and benchmark validation experiments are identified along with their test conditions and measurements. Based on an evaluation criteria, recommendations for an initial CFD validation data base are given and gaps identified where future experiments could provide new validation data.

  16. A CFD validation roadmap for hypersonic flows

    Science.gov (United States)

    Marvin, Joseph G.

    1993-01-01

    A roadmap for computational fluid dynamics (CFD) code validation is developed. The elements of the roadmap are consistent with air-breathing vehicle design requirements and related to the important flow path components: forebody, inlet, combustor, and nozzle. Building block and benchmark validation experiments are identified along with their test conditions and measurements. Based on an evaluation criteria, recommendations for an initial CFD validation data base are given and gaps identified where future experiments would provide the needed validation data.

  17. Stability-indicating HPLC-DAD/UV-ESI/MS impurity profiling of the anti-malarial drug lumefantrine.

    Science.gov (United States)

    Verbeken, Mathieu; Suleman, Sultan; Baert, Bram; Vangheluwe, Elien; Van Dorpe, Sylvia; Burvenich, Christian; Duchateau, Luc; Jansen, Frans H; De Spiegeleer, Bart

    2011-02-28

    Lumefantrine (benflumetol) is a fluorene derivative belonging to the aryl amino alcohol class of anti-malarial drugs and is commercially available in fixed combination products with β-artemether. Impurity characterization of such drugs, which are widely consumed in tropical countries for malaria control programmes, is of paramount importance. However, until now, no exhaustive impurity profile of lumefantrine has been established, encompassing process-related and degradation impurities in active pharmaceutical ingredients (APIs) and finished pharmaceutical products (FPPs). Using HPLC-DAD/UV-ESI/ion trap/MS, a comprehensive impurity profile was established based upon analysis of market samples as well as stress, accelerated and long-term stability results. In-silico toxicological predictions for these lumefantrine related impurities were made using Toxtree® and Derek®. Several new impurities are identified, of which the desbenzylketo derivative (DBK) is proposed as a new specified degradant. DBK and the remaining unspecified lumefantrine related impurities are predicted, using Toxtree® and Derek®, to have a toxicity risk comparable to the toxicity risk of the API lumefantrine itself. From unstressed, stressed and accelerated stability samples of lumefantrine API and FPPs, nine compounds were detected and characterized to be lumefantrine related impurities. One new lumefantrine related compound, DBK, was identified and characterized as a specified degradation impurity of lumefantrine in real market samples (FPPs). The in-silico toxicological investigation (Toxtree® and Derek®) indicated overall a toxicity risk for lumefantrine related impurities comparable to that of the API lumefantrine itself.

  18. Stability-Indicating RP-HPLC Method for Analysis of Paracetamol and Tramadol in a Pharmaceutical Dosage Form

    OpenAIRE

    Kamble, Rajesh M.; Singh, Shrawan G.

    2012-01-01

    A simple, isocratic, rapid and accurate reversed phase high performance liquid chromatography method was developed for the quantitative determination of paracetamol and tramadol in commercial medicinal tablets. The chromatographic separation was achieved on an Intersil C18 (250 mm x 4.6 mm, 5μm) column using water pH 3.4 with orthophosphoric acid: methanol (60:40, v/v) as a mobile phase, and UV detection at 228 nm. The chromatographic resolutions between paracetamol and tramadol were found gr...

  19. Data on corrosion and scaling potential of drinking water resources using stability indices in Jolfa, East Azerbaijan, Iran.

    Science.gov (United States)

    Yousefi, Mahmood; Saleh, Hossein Najafi; Mahvi, Amir Hossein; Alimohammadi, Mahmood; Nabizadeh, Ramin; Mohammadi, Ali Akbar

    2018-02-01

    This cross-sectional study was conducted on the drinking water resources of the city of Jolfa (East Azerbaijan province, Iran) from samples taken from 30 wells. Calcium hardness, pH, total alkalinity, TDS, temperature and other chemical parameters were measured using standard methods. The Langelier, Rayzner, Puckhorius and aggressive indices were calculated. The results showed that the Langelier, Reynar, Puckorius, Larson-skold and aggressive indices were 1.15 (± 0.43), 6.92 (± 0.54), 6.42 (± 0.9), 0.85 (± 0.72) and 12.79 (± 0.47), respectively. In terms of water classification, 30% of samples fell into the NaCl category and 26.6% in the NaHCO 3 category and 43.4% samples in the CaHCO 3 , MgHCO 3 and MgCl category. The sedimentation indices indicated that the water of the wells could be considered as corrosive.

  20. Stability-indicating HPLC method for the determination of the stability of oxytocin parenteral solutions prepared in polyolefin bags.

    Science.gov (United States)

    Kaushal, G; Sayre, B E; Prettyman, T

    2012-02-01

    Oxytocin is very commonly used in clinical settings and is a nonapeptide hormone that stimulates the contraction of uterine smooth muscles. In this study the stability of extemporaneously compounded oxytocin solutions was investigated in polyolefin bags. The sterile preparations of oxytocin were compounded to the strength of 0.02 U/mL in accordance with United States Pharmacopeia (USP) standards. In order to carry out the stability testing of these parenteral products, the solutions were stored under three different temperature conditions of -20°C (frozen), 2-6°C (refrigerated), and 22-25°C (room temperature). Three solutions from each temperature were withdrawn and were assessed for stability on days 0, 7, 15, 21, and 30 as per the USP guidelines. The assay of oxytocin was examined by an HPLC method at each time point. No precipitation, cloudiness or color change was observed during this study at all temperatures. The assay content by HPLC revealed that oxytocin retains greater than at least 90% of the initial concentrations for 21 days. There was no significant change in pH and absorbance values for 21 days under all the conditions of storage. Oxytocin parenteral solutions in the final concentration of 0.02 U/mL and diluted in normal saline are stable for at least 30 days under frozen and refrigerated conditions for 30 days. At the room temperature, the oxytocin solutions were stable for at least 21 days. The stability analysis results show that the shelf-life of 21 days observed in this study was far better than their recommended expiration dates.

  1. MODIS Hotspot Validation over Thailand

    Directory of Open Access Journals (Sweden)

    Veerachai Tanpipat

    2009-11-01

    Full Text Available To ensure remote sensing MODIS hotspot (also known as active fire products or hotspots quality and precision in forest fire control and management in Thailand, an increased level of confidence is needed. Accuracy assessment of MODIS hotspots utilizing field survey data validation is described. A quantitative evaluation of MODIS hotspot products has been carried out since the 2007 forest fire season. The carefully chosen hotspots were scattered throughout the country and within the protected areas of the National Parks and Wildlife Sanctuaries. Three areas were selected as test sites for validation guidelines. Both ground and aerial field surveys were also conducted in this study by the Forest Fire Control Division, National Park, Wildlife and Plant Conversation Department, Ministry of Natural Resources and Environment, Thailand. High accuracy of 91.84 %, 95.60% and 97.53% for the 2007, 2008 and 2009 fire seasons were observed, resulting in increased confidence in the use of MODIS hotspots for forest fire control and management in Thailand.

  2. ASTEC validation on PANDA SETH

    International Nuclear Information System (INIS)

    Bentaib, Ahmed; Bleyer, Alexandre; Schwarz, Siegfried

    2009-01-01

    The ASTEC code development by IRSN and GRS is aimed to provide an integral code for the simulation of the whole course of severe accidents in Light-Water Reactors. ASTEC is a complex system of codes for reactor safety assessment. In this validation, only the thermal-hydraulic module of ASTEC code is used. ASTEC is a lumped-parameter code able to represent multi-compartment containments. It uses the following main elements: zones (compartments), junctions (liquids and atmospherics) and structures. The zones are connected by junctions and contain steam, water and non condensable gases. They exchange heat with structures by different heat transfer regimes: convection, radiation and condensation. This paper presents the validation of ASTEC V1.3 on the tests T9 and T9bis, of the PANDA OECD/SETH experimental program, investigating the impact of injection velocity and steam condensation on the plume shape and on the gas distribution. Dedicated meshes were developed to simulate the test facility with the two vessels DW1, DW2 and the interconnection pipe. The obtained numerical results are analyzed and compared to the experiments. The comparison shows a good agreement between experiments and calculations. (author)

  3. Benchmarks for GADRAS performance validation

    International Nuclear Information System (INIS)

    Mattingly, John K.; Mitchell, Dean James; Rhykerd, Charles L. Jr.

    2009-01-01

    The performance of the Gamma Detector Response and Analysis Software (GADRAS) was validated by comparing GADRAS model results to experimental measurements for a series of benchmark sources. Sources for the benchmark include a plutonium metal sphere, bare and shielded in polyethylene, plutonium oxide in cans, a highly enriched uranium sphere, bare and shielded in polyethylene, a depleted uranium shell and spheres, and a natural uranium sphere. The benchmark experimental data were previously acquired and consist of careful collection of background and calibration source spectra along with the source spectra. The calibration data were fit with GADRAS to determine response functions for the detector in each experiment. A one-dimensional model (pie chart) was constructed for each source based on the dimensions of the benchmark source. The GADRAS code made a forward calculation from each model to predict the radiation spectrum for the detector used in the benchmark experiment. The comparisons between the GADRAS calculation and the experimental measurements are excellent, validating that GADRAS can correctly predict the radiation spectra for these well-defined benchmark sources.

  4. Expert system validation in prolog

    Science.gov (United States)

    Stock, Todd; Stachowitz, Rolf; Chang, Chin-Liang; Combs, Jacqueline

    1988-01-01

    An overview of the Expert System Validation Assistant (EVA) is being implemented in Prolog at the Lockheed AI Center. Prolog was chosen to facilitate rapid prototyping of the structure and logic checkers and since February 1987, we have implemented code to check for irrelevance, subsumption, duplication, deadends, unreachability, and cycles. The architecture chosen is extremely flexible and expansible, yet concise and complementary with the normal interactive style of Prolog. The foundation of the system is in the connection graph representation. Rules and facts are modeled as nodes in the graph and arcs indicate common patterns between rules. The basic activity of the validation system is then a traversal of the connection graph, searching for various patterns the system recognizes as erroneous. To aid in specifying these patterns, a metalanguage is developed, providing the user with the basic facilities required to reason about the expert system. Using the metalanguage, the user can, for example, give the Prolog inference engine the goal of finding inconsistent conclusions among the rules, and Prolog will search the graph intantiations which can match the definition of inconsistency. Examples of code for some of the checkers are provided and the algorithms explained. Technical highlights include automatic construction of a connection graph, demonstration of the use of metalanguage, the A* algorithm modified to detect all unique cycles, general-purpose stacks in Prolog, and a general-purpose database browser with pattern completion.

  5. Validity and Reliability in Social Science Research

    Science.gov (United States)

    Drost, Ellen A.

    2011-01-01

    In this paper, the author aims to provide novice researchers with an understanding of the general problem of validity in social science research and to acquaint them with approaches to developing strong support for the validity of their research. She provides insight into these two important concepts, namely (1) validity; and (2) reliability, and…

  6. Validity Semantics in Educational and Psychological Assessment

    Science.gov (United States)

    Hathcoat, John D.

    2013-01-01

    The semantics, or meaning, of validity is a fluid concept in educational and psychological testing. Contemporary controversies surrounding this concept appear to stem from the proper location of validity. Under one view, validity is a property of score-based inferences and entailed uses of test scores. This view is challenged by the…

  7. Validation of the Child Sport Cohesion Questionnaire

    Science.gov (United States)

    Martin, Luc J.; Carron, Albert V.; Eys, Mark A.; Loughead, Todd

    2013-01-01

    The purpose of the present study was to test the validity evidence of the Child Sport Cohesion Questionnaire (CSCQ). To accomplish this task, convergent, discriminant, and known-group difference validity were examined, along with factorial validity via confirmatory factor analysis (CFA). Child athletes (N = 290, M[subscript age] = 10.73 plus or…

  8. The Role of Generalizability in Validity.

    Science.gov (United States)

    Kane, Michael

    The relationship between generalizability and validity is explained, making four important points. The first is that generalizability coefficients provide upper bounds on validity. The second point is that generalization is one step in most interpretive arguments, and therefore, generalizability is a necessary condition for the validity of these…

  9. Site characterization and validation - Inflow to the validation drift

    International Nuclear Information System (INIS)

    Harding, W.G.C.; Black, J.H.

    1992-01-01

    Hydrogeological experiments have had an essential role in the characterization of the drift site on the Stripa project. This report focuses on the methods employed and the results obtained from inflow experiments performed on the excavated drift in stage 5 of the SCV programme. Inflows were collected in sumps on the floor, in plastic sheeting on the upper walls and ceiling, and measured by means of differential humidity of ventilated air at the bulkhead. Detailed evaporation experiments were also undertaken on uncovered areas of the excavated drift. The inflow distribution was determined on the basis of a system of roughly equal sized grid rectangles. The results have highlighted the overriding importance of fractures in the supply of water to the drift site. The validation drift experiment has revealed that in excess of 99% of inflow comes from a 5 m section corresponding to the 'H' zone, and that as much as 57% was observed coming from a single grid square (267). There was considerable heterogeneity even within the 'H' zone, with 38% of such samples areas yielding no flow at all. Model predictions in stage 4 underestimated the very substantial declines in inflow observed in the validation drift when compared to the SDE; this was especially so in the 'good' rock areas. Increased drawdowns in the drift have generated less flow and reduced head responses in nearby boreholes by a similar proportion. This behaviour has been the focus for considerable study in the latter part of the SCV project, and a number of potential processes have been proposed. These include 'transience', stress redistribution resulting from the creation of the drift, chemical precipitation, blast-induced dynamic unloading and related gas intrusion, and degassing. (au)

  10. How valid are commercially available medical simulators?

    Science.gov (United States)

    Stunt, JJ; Wulms, PH; Kerkhoffs, GM; Dankelman, J; van Dijk, CN; Tuijthof, GJM

    2014-01-01

    Background Since simulators offer important advantages, they are increasingly used in medical education and medical skills training that require physical actions. A wide variety of simulators have become commercially available. It is of high importance that evidence is provided that training on these simulators can actually improve clinical performance on live patients. Therefore, the aim of this review is to determine the availability of different types of simulators and the evidence of their validation, to offer insight regarding which simulators are suitable to use in the clinical setting as a training modality. Summary Four hundred and thirty-three commercially available simulators were found, from which 405 (94%) were physical models. One hundred and thirty validation studies evaluated 35 (8%) commercially available medical simulators for levels of validity ranging from face to predictive validity. Solely simulators that are used for surgical skills training were validated for the highest validity level (predictive validity). Twenty-four (37%) simulators that give objective feedback had been validated. Studies that tested more powerful levels of validity (concurrent and predictive validity) were methodologically stronger than studies that tested more elementary levels of validity (face, content, and construct validity). Conclusion Ninety-three point five percent of the commercially available simulators are not known to be tested for validity. Although the importance of (a high level of) validation depends on the difficulty level of skills training and possible consequences when skills are insufficient, it is advisable for medical professionals, trainees, medical educators, and companies who manufacture medical simulators to critically judge the available medical simulators for proper validation. This way adequate, safe, and affordable medical psychomotor skills training can be achieved. PMID:25342926

  11. Convergent Validity of the PUTS

    Directory of Open Access Journals (Sweden)

    Valerie Cathérine Brandt

    2016-04-01

    Full Text Available Premonitory urges are a cardinal feature in Gilles de la Tourette syndrome. Severity of premonitory urges can be assessed with the Premonitory Urge for Tic Disorders Scale (PUTS. However, convergent validity of the measure has been difficult to assess due to the lack of other urge measures.We investigated the relationship between average real-time urge intensity assessed by an in-house developed real-time urge monitor, measuring urge intensity continuously for 5mins on a visual analogue scale, and general urge intensity assessed by the PUTS in 22 adult Tourette patients (mean age 29.8+/- 10.3; 19 male. Additionally, underlying factors of premonitory urges assessed by the PUTS were investigated in the adult sample using factor analysis and were replicated in 40 children and adolescents diagnosed with Tourette syndrome (mean age 12.05 +/- 2.83 SD, 31 male.Cronbach’s alpha for the PUTS10 was acceptable (α = .79 in the adult sample. Convergent validity between average real-time urge intensity scores (as assessed with the real-time urge monitor and the 10-item version of the PUTS (r = .64 and the 9-item version of the PUTS (r = .66 was good. A factor analysis including the 10 items of the PUTS and average real-time urge intensity scores revealed three factors. One factor included the average real-time urge intensity score and appeared to measure urge intensity, while the other two factors can be assumed to reflect the (sensory quality of urges and subjective control, respectively. The factor structure of the 10 PUTS items alone was replicated in a sample of children and adolescents.The results indicate that convergent validity between the PUTS and the real-time urge assessment monitor is good. Furthermore, the results suggest that the PUTS might assess more than one dimension of urges and it may be worthwhile developing different sub-scales of the PUTS assessing premonitory urges in terms of intensity and quality, as well as subjectively

  12. Turbine-99 unsteady simulations - Validation

    International Nuclear Information System (INIS)

    Cervantes, M J; Andersson, U; Loevgren, H M

    2010-01-01

    The Turbine-99 test case, a Kaplan draft tube model, aimed to determine the state of the art within draft tube simulation. Three workshops were organized on the matter in 1999, 2001 and 2005 where the geometry and experimental data were provided as boundary conditions to the participants. Since the last workshop, computational power and flow modelling have been developed and the available data completed with unsteady pressure measurements and phase resolved velocity measurements in the cone. Such new set of data together with the corresponding phase resolved velocity boundary conditions offer new possibilities to validate unsteady numerical simulations in Kaplan draft tube. The present work presents simulation of the Turbine-99 test case with time dependent angular resolved inlet velocity boundary conditions. Different grids and time steps are investigated. The results are compared to experimental time dependent pressure and velocity measurements.

  13. Ultrasonic techniques validation on shell

    International Nuclear Information System (INIS)

    Navarro, J.; Gonzalez, E.

    1998-01-01

    Due to the results obtained in several international RRT during the 80's, it has been necessary to prove the effectiveness of the NDT techniques. For this reason it has been imperative to verify the goodness of the Inspection Procedure over different mock-ups, representative of the inspection area and with real defects. Prior to the revision of the inspection procedure and with the aim of updating the techniques used, it is a good practice to perform different scans on the mock-ups until the validation is achieved. It is at this point, where all the parameters of the inspection at hands are defined; transducer, step, scan direction,... and what it's more important, it will be demonstrated that the technique to be used for the area required to inspection is suitable to evaluate the degradation phenomena that could appear. (Author)

  14. Turbine-99 unsteady simulations - Validation

    Science.gov (United States)

    Cervantes, M. J.; Andersson, U.; Lövgren, H. M.

    2010-08-01

    The Turbine-99 test case, a Kaplan draft tube model, aimed to determine the state of the art within draft tube simulation. Three workshops were organized on the matter in 1999, 2001 and 2005 where the geometry and experimental data were provided as boundary conditions to the participants. Since the last workshop, computational power and flow modelling have been developed and the available data completed with unsteady pressure measurements and phase resolved velocity measurements in the cone. Such new set of data together with the corresponding phase resolved velocity boundary conditions offer new possibilities to validate unsteady numerical simulations in Kaplan draft tube. The present work presents simulation of the Turbine-99 test case with time dependent angular resolved inlet velocity boundary conditions. Different grids and time steps are investigated. The results are compared to experimental time dependent pressure and velocity measurements.

  15. PEMFC modeling and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, J.V.C. [Federal University of Parana (UFPR), Curitiba, PR (Brazil). Dept. of Mechanical Engineering], E-mail: jvargas@demec.ufpr.br; Ordonez, J.C.; Martins, L.S. [Florida State University, Tallahassee, FL (United States). Center for Advanced Power Systems], Emails: ordonez@caps.fsu.edu, martins@caps.fsu.edu

    2009-07-01

    In this paper, a simplified and comprehensive PEMFC mathematical model introduced in previous studies is experimentally validated. Numerical results are obtained for an existing set of commercial unit PEM fuel cells. The model accounts for pressure drops in the gas channels, and for temperature gradients with respect to space in the flow direction, that are investigated by direct infrared imaging, showing that even at low current operation such gradients are present in fuel cell operation, and therefore should be considered by a PEMFC model, since large coolant flow rates are limited due to induced high pressure drops in the cooling channels. The computed polarization and power curves are directly compared to the experimentally measured ones with good qualitative and quantitative agreement. The combination of accuracy and low computational time allow for the future utilization of the model as a reliable tool for PEMFC simulation, control, design and optimization purposes. (author)

  16. Cable SGEMP Code Validation Study

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, William Parker [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Center for CA Weapons Systems Engineering

    2013-05-01

    This report compared data taken on the Modular Bremsstrahlung Simulator using copper jacketed (cujac) cables with calculations using the RHSD-RA Cable SGEMP analysis tool. The tool relies on CEPXS/ONBFP to perform radiation transport in a series of 1D slices through the cable, and then uses a Green function technique to evaluate the expected current drive on the center conductor. The data were obtained in 2003 as part of a Cabana verification and validation experiment using 1-D geometries, but were not evaluated until now. The agreement between data and model is not adequate unless gaps between the dielectric and outer conductor (ground) are assumed, and these gaps are large compared with what is believed to be in the actual cable.

  17. Comparative Validation of Building Simulation Software

    DEFF Research Database (Denmark)

    Kalyanova, Olena; Heiselberg, Per

    The scope of this subtask is to perform a comparative validation of the building simulation software for the buildings with the double skin façade. The outline of the results in the comparative validation identifies the areas where is no correspondence achieved, i.e. calculation of the air flow r...... is that the comparative validation can be regarded as the main argument to continue the validation of the building simulation software for the buildings with the double skin façade with the empirical validation test cases.......The scope of this subtask is to perform a comparative validation of the building simulation software for the buildings with the double skin façade. The outline of the results in the comparative validation identifies the areas where is no correspondence achieved, i.e. calculation of the air flow...

  18. Development and validation of simple RP-HPLC-PDA analytical protocol for zileuton assisted with Design of Experiments for robustness determination

    Directory of Open Access Journals (Sweden)

    Saurabh B. Ganorkar

    2017-02-01

    Full Text Available A simple, rapid, sensitive, robust, stability-indicating RP-HPLC-PDA analytical protocol was developed and validated for the analysis of zileuton racemate in bulk and in tablet formulation. Development of method and resolution of degradation products from forced; hydrolytic (acidic, basic, neutral, oxidative, photolytic (acidic, basic, neutral, solid state and thermal (dry heat degradation was achieved on a LC – GC Qualisil BDS C18 column (250 mm × 4.6 mm × 5 μm by isocratic mode at ambient temperature, employing a mobile phase methanol and (0.2%, v/v orthophosphoric acid in ratio of (80:20, v/v at a flow rate of 1.0 mL min−1 and detection at 260 nm. ‘Design of Experiments’ (DOE employing ‘Central Composite Design’ (CCD and ‘Response Surface Methodology’ (RSM were applied as an advancement to traditional ‘One Variable at Time’ (OVAT approach to evaluate the effects of variations in selected factors (methanol content, flow rate, concentration of orthophosphoric acid as graphical interpretation for robustness and statistical interpretation was achieved with Multiple Linear Regression (MLR and ANOVA. The method succeeded over the validation parameters: linearity, precision, accuracy, limit of detection and limit of quantitation, and robustness. The method was applied effectively for analysis of in-house zileuton tablets.

  19. Study and ICH validation of a reverse-phase liquid chromatographic method for the quantification of the intact monoclonal antibody cetuximab

    Directory of Open Access Journals (Sweden)

    Antonio Martínez-Ortega

    2016-04-01

    Full Text Available Cetuximab (CTX is a potent chimeric mouse/human monoclonal antibody (mAb approved worldwide for treatment of metastatic colorectal cancer. Among the various biological and physical analyses performed for full study on this biopharmaceutic, the determination of the concentration preparations throughout manufacturing and subsequent handling in hospital is particularly relevant. In the present work, the study and validation of a method for quantifying intact CTX by reverse-phase high-performance liquid chromatography with diode array detection ((RPHPLC/DAD is presented. With that end, we checked the performance of a chromatographic method for quantifying CTX and conducted a study to validate the method as stability-indicating in accordance with the International Conference on Harmonization guidelines (ICH for biotechnological drugs; therefore, we evaluated linearity, accuracy, precision, detection and quantification limits, robustness and system suitability. The specificity of the method and the robustness of the mAb formulation against external stress factors were estimated by comprehensive chromatographic analysis by subjecting CTX to several informative stress conditions. As demonstrated, the method is rapid, accurate, and reproducible for CTX quantification. It was also successfully used to quantify CTX in a long-term stability study performed under hospital conditions.

  20. Development and validation of different methods manipulating zero order and first order spectra for determination of the partially overlapped mixture benazepril and amlodipine: A comparative study

    Science.gov (United States)

    Hemdan, A.

    2016-07-01

    Three simple, selective, and accurate spectrophotometric methods have been developed and then validated for the analysis of Benazepril (BENZ) and Amlodipine (AML) in bulk powder and pharmaceutical dosage form. The first method is the absorption factor (AF) for zero order and amplitude factor (P-F) for first order spectrum, where both BENZ and AML can be measured from their resolved zero order spectra at 238 nm or from their first order spectra at 253 nm. The second method is the constant multiplication coupled with constant subtraction (CM-CS) for zero order and successive derivative subtraction-constant multiplication (SDS-CM) for first order spectrum, where both BENZ and AML can be measured from their resolved zero order spectra at 240 nm and 238 nm, respectively, or from their first order spectra at 214 nm and 253 nm for Benazepril and Amlodipine respectively. The third method is the novel constant multiplication coupled with derivative zero crossing (CM-DZC) which is a stability indicating assay method for determination of Benazepril and Amlodipine in presence of the main degradation product of Benazepril which is Benazeprilate (BENZT). The three methods were validated as per the ICH guidelines and the standard curves were found to be linear in the range of 5-60 μg/mL for Benazepril and 5-30 for Amlodipine, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits.

  1. Active Transportation Demand Management (ATDM) Trajectory Level Validation

    Data.gov (United States)

    Department of Transportation — The ATDM Trajectory Validation project developed a validation framework and a trajectory computational engine to compare and validate simulated and observed vehicle...

  2. Benchmarking - a validation of UTDefect

    International Nuclear Information System (INIS)

    Niklasson, Jonas; Bostroem, Anders; Wirdelius, Haakan

    2006-06-01

    New and stronger demands on reliability of used NDE/NDT procedures and methods have stimulated the development of simulation tools of NDT. Modelling of ultrasonic non-destructive testing is useful for a number of reasons, e.g. physical understanding, parametric studies and in the qualification of procedures and personnel. The traditional way of qualifying a procedure is to generate a technical justification by employing experimental verification of the chosen technique. The manufacturing of test pieces is often very expensive and time consuming. It also tends to introduce a number of possible misalignments between the actual NDT situation and the proposed experimental simulation. The UTDefect computer code (SUNDT/simSUNDT) has been developed, together with the Dept. of Mechanics at Chalmers Univ. of Technology, during a decade and simulates the entire ultrasonic testing situation. A thorough validated model has the ability to be an alternative and a complement to the experimental work in order to reduce the extensive cost. The validation can be accomplished by comparisons with other models, but ultimately by comparisons with experiments. This project addresses the last alternative but provides an opportunity to, in a later stage, compare with other software when all data are made public and available. The comparison has been with experimental data from an international benchmark study initiated by the World Federation of NDE Centers. The experiments have been conducted with planar and spherically focused immersion transducers. The defects considered are side-drilled holes, flat-bottomed holes, and a spherical cavity. The data from the experiments are a reference signal used for calibration (the signal from the front surface of the test block at normal incidence) and the raw output from the scattering experiment. In all, more than forty cases have been compared. The agreement between UTDefect and the experiments was in general good (deviation less than 2dB) when the

  3. How valid are commercially available medical simulators?

    Directory of Open Access Journals (Sweden)

    Stunt JJ

    2014-10-01

    Full Text Available JJ Stunt,1 PH Wulms,2 GM Kerkhoffs,1 J Dankelman,2 CN van Dijk,1 GJM Tuijthof1,2 1Orthopedic Research Center Amsterdam, Department of Orthopedic Surgery, Academic Medical Centre, Amsterdam, the Netherlands; 2Department of Biomechanical Engineering, Faculty of Mechanical, Materials and Maritime Engineering, Delft University of Technology, Delft, the Netherlands Background: Since simulators offer important advantages, they are increasingly used in medical education and medical skills training that require physical actions. A wide variety of simulators have become commercially available. It is of high importance that evidence is provided that training on these simulators can actually improve clinical performance on live patients. Therefore, the aim of this review is to determine the availability of different types of simulators and the evidence of their validation, to offer insight regarding which simulators are suitable to use in the clinical setting as a training modality. Summary: Four hundred and thirty-three commercially available simulators were found, from which 405 (94% were physical models. One hundred and thirty validation studies evaluated 35 (8% commercially available medical simulators for levels of validity ranging from face to predictive validity. Solely simulators that are used for surgical skills training were validated for the highest validity level (predictive validity. Twenty-four (37% simulators that give objective feedback had been validated. Studies that tested more powerful levels of validity (concurrent and predictive validity were methodologically stronger than studies that tested more elementary levels of validity (face, content, and construct validity. Conclusion: Ninety-three point five percent of the commercially available simulators are not known to be tested for validity. Although the importance of (a high level of validation depends on the difficulty level of skills training and possible consequences when skills are

  4. Validation of the Danish PAROLE lexicon (upubliceret)

    DEFF Research Database (Denmark)

    Møller, Margrethe; Christoffersen, Ellen

    2000-01-01

    This validation is based on the Danish PAROLE lexicon dated June 20, 1998, downloaded on March 16, 1999. Subsequently, the developers of the lexicon have informed us that they have been revising the lexicon, in particular the morphological level. Morphological entries were originally generated...... automatically from a machine-readable version of the Official Danish Spelling Dictionary (Retskrivningsordbogen 1986, in the following RO86), and this resulted in some overgeneration, which the developers started eliminating after submitting the Danish PAROLE lexicon for validation. The present validation is......, however, based on the January 1997 version of the lexicon. The validation as such complies with the specifications described in ELRA validation manuals for lexical data, i.e. Underwood and Navaretta: "A Draft Manual for the Validation of Lexica, Final Report" [Underwood & Navaretta1997] and Braasch: "A...

  5. Reliability and validity in a nutshell.

    Science.gov (United States)

    Bannigan, Katrina; Watson, Roger

    2009-12-01

    To explore and explain the different concepts of reliability and validity as they are related to measurement instruments in social science and health care. There are different concepts contained in the terms reliability and validity and these are often explained poorly and there is often confusion between them. To develop some clarity about reliability and validity a conceptual framework was built based on the existing literature. The concepts of reliability, validity and utility are explored and explained. Reliability contains the concepts of internal consistency and stability and equivalence. Validity contains the concepts of content, face, criterion, concurrent, predictive, construct, convergent (and divergent), factorial and discriminant. In addition, for clinical practice and research, it is essential to establish the utility of a measurement instrument. To use measurement instruments appropriately in clinical practice, the extent to which they are reliable, valid and usable must be established.

  6. Verifying and Validating Simulation Models

    Energy Technology Data Exchange (ETDEWEB)

    Hemez, Francois M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    This presentation is a high-level discussion of the Verification and Validation (V&V) of computational models. Definitions of V&V are given to emphasize that “validation” is never performed in a vacuum; it accounts, instead, for the current state-of-knowledge in the discipline considered. In particular comparisons between physical measurements and numerical predictions should account for their respective sources of uncertainty. The differences between error (bias), aleatoric uncertainty (randomness) and epistemic uncertainty (ignorance, lack-of- knowledge) are briefly discussed. Four types of uncertainty in physics and engineering are discussed: 1) experimental variability, 2) variability and randomness, 3) numerical uncertainty and 4) model-form uncertainty. Statistical sampling methods are available to propagate, and analyze, variability and randomness. Numerical uncertainty originates from the truncation error introduced by the discretization of partial differential equations in time and space. Model-form uncertainty is introduced by assumptions often formulated to render a complex problem more tractable and amenable to modeling and simulation. The discussion concludes with high-level guidance to assess the “credibility” of numerical simulations, which stems from the level of rigor with which these various sources of uncertainty are assessed and quantified.

  7. Neutron flux control systems validation

    International Nuclear Information System (INIS)

    Hascik, R.

    2003-01-01

    In nuclear installations main requirement is to obtain corresponding nuclear safety in all operation conditions. From the nuclear safety point of view is commissioning and start-up after reactor refuelling appropriate period for safety systems verification. In this paper, methodology, performance and results of neutron flux measurements systems validation is presented. Standard neutron flux measuring chains incorporated into the reactor protection and control system are used. Standard neutron flux measuring chain contains detector, preamplifier, wiring to data acquisition unit, data acquisition unit, wiring to display at control room and display at control room. During reactor outage only data acquisition unit and wiring and displaying at reactor control room is verified. It is impossible to verify detector, preamplifier and wiring to data acquisition recording unit during reactor refuelling according to low power. Adjustment and accurate functionality of these chains is confirmed by start-up rate (SUR) measurement during start-up tests after refuelling of the reactors. This measurement has direct impact to nuclear safety and increase operational nuclear safety level. Briefly description of each measuring system is given. Results are illustrated on measurements performed at Bohunice NPP during reactor start-up tests. Main failures and their elimination are described (Authors)

  8. ISOTHERMAL AIR INGRESS VALIDATION EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Chang H Oh; Eung S Kim

    2011-09-01

    Idaho National Laboratory carried out air ingress experiments as part of validating computational fluid dynamics (CFD) calculations. An isothermal test loop was designed and set to understand the stratified-flow phenomenon, which is important as the initial air flow into the lower plenum of the very high temperature gas cooled reactor (VHTR) when a large break loss-of-coolant accident occurs. The unique flow characteristics were focused on the VHTR air-ingress accident, in particular, the flow visualization of the stratified flow in the inlet pipe to the vessel lower plenum of the General Atomic’s Gas Turbine-Modular Helium Reactor (GT-MHR). Brine and sucrose were used as heavy fluids, and water was used to represent a light fluid, which mimics a counter current flow due to the density difference between the stimulant fluids. The density ratios were changed between 0.87 and 0.98. This experiment clearly showed that a stratified flow between simulant fluids was established even for very small density differences. The CFD calculations were compared with experimental data. A grid sensitivity study on CFD models was also performed using the Richardson extrapolation and the grid convergence index method for the numerical accuracy of CFD calculations . As a result, the calculated current speed showed very good agreement with the experimental data, indicating that the current CFD methods are suitable for predicting density gradient stratified flow phenomena in the air-ingress accident.

  9. CTF Validation and Verification Manual

    Energy Technology Data Exchange (ETDEWEB)

    Salko, Robert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Blyth, Taylor S. [Pennsylvania State Univ., University Park, PA (United States); Dances, Christopher A. [Pennsylvania State Univ., University Park, PA (United States); Magedanz, Jeffrey W. [Pennsylvania State Univ., University Park, PA (United States); Jernigan, Caleb [Holtec International, Marlton, NJ (United States); Kelly, Joeseph [U.S. Nuclear Regulatory Commission (NRC), Rockville, MD (United States); Toptan, Aysenur [North Carolina State Univ., Raleigh, NC (United States); Gergar, Marcus [Pennsylvania State Univ., University Park, PA (United States); Gosdin, Chris [Pennsylvania State Univ., University Park, PA (United States); Avramova, Maria [Pennsylvania State Univ., University Park, PA (United States); Palmtag, Scott [Core Physics, Inc., Cary, NC (United States); Gehin, Jess C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-05-25

    Coolant-Boiling in Rod Arrays- Two Fluids (COBRA-TF) is a Thermal/Hydraulic (T/H) simulation code designed for Light Water Reactor (LWR) analysis. It uses a two-fluid, three-field (i.e. fluid film, fluid drops, and vapor) modeling approach. Both sub-channel and 3D Cartesian forms of nine conservation equations are available for LWR modeling. The code was originally developed by Pacific Northwest Laboratory in 1980 and has been used and modified by several institutions over the last several decades. COBRA-TF is also used at the Pennsylvania State University (PSU) by the Reactor Dynamics and Fuel Management Group (RDFMG), and has been improved, updated, and subsequently became the PSU RDFMG version of COBRA-TF (CTF). One part of the improvement process includes validating the methods in CTF. This document seeks to provide a certain level of certainty and confidence in the predictive capabilities of the code for the scenarios it was designed to model--rod bundle geometries with operating conditions that are representative of prototypical Pressurized Water Reactor (PWR)s and Boiling Water Reactor (BWR)s in both normal and accident conditions. This is done by modeling a variety of experiments that simulate these scenarios and then presenting a qualitative and quantitative analysis of the results that demonstrates the accuracy to which CTF is capable of capturing specific quantities of interest.

  10. Seismic Data Gathering and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    Three recent earthquakes in the last seven years have exceeded their design basis earthquake values (so it is implied that damage to SSC’s should have occurred). These seismic events were recorded at North Anna (August 2011, detailed information provided in [Virginia Electric and Power Company Memo]), Fukushima Daichii and Daini (March 2011 [TEPCO 1]), and Kaswazaki-Kariwa (2007, [TEPCO 2]). However, seismic walk downs at some of these plants indicate that very little damage occurred to safety class systems and components due to the seismic motion. This report presents seismic data gathered for two of the three events mentioned above and recommends a path for using that data for two purposes. One purpose is to determine what margins exist in current industry standard seismic soil-structure interaction (SSI) tools. The second purpose is the use the data to validated seismic site response tools and SSI tools. The gathered data represents free field soil and in-structure acceleration time histories data. Gathered data also includes elastic and dynamic soil properties and structural drawings. Gathering data and comparing with existing models has potential to identify areas of uncertainty that should be removed from current seismic analysis and SPRA approaches. Removing uncertainty (to the extent possible) from SPRA’s will allow NPP owners to make decisions on where to reduce risk. Once a realistic understanding of seismic response is established for a nuclear power plant (NPP) then decisions on needed protective measures, such as SI, can be made.

  11. Validation for chromatographic and electrophoretic methods

    OpenAIRE

    Ribani, Marcelo; Bottoli, Carla Beatriz Grespan; Collins, Carol H.; Jardim, Isabel Cristina Sales Fontes; Melo, Lúcio Flávio Costa

    2004-01-01

    The validation of an analytical method is fundamental to implementing a quality control system in any analytical laboratory. As the separation techniques, GC, HPLC and CE, are often the principal tools used in such determinations, procedure validation is a necessity. The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing, in a general way, the similarities and differences between the guidelines established by the dif...

  12. Redundant sensor validation by using fuzzy logic

    International Nuclear Information System (INIS)

    Holbert, K.E.; Heger, A.S.; Alang-Rashid, N.K.

    1994-01-01

    This research is motivated by the need to relax the strict boundary of numeric-based signal validation. To this end, the use of fuzzy logic for redundant sensor validation is introduced. Since signal validation employs both numbers and qualitative statements, fuzzy logic provides a pathway for transforming human abstractions into the numerical domain and thus coupling both sources of information. With this transformation, linguistically expressed analysis principles can be coded into a classification rule-base for signal failure detection and identification

  13. Earth Science Enterprise Scientific Data Purchase Project: Verification and Validation

    Science.gov (United States)

    Jenner, Jeff; Policelli, Fritz; Fletcher, Rosea; Holecamp, Kara; Owen, Carolyn; Nicholson, Lamar; Dartez, Deanna

    2000-01-01

    This paper presents viewgraphs on the Earth Science Enterprise Scientific Data Purchase Project's verification,and validation process. The topics include: 1) What is Verification and Validation? 2) Why Verification and Validation? 3) Background; 4) ESE Data Purchas Validation Process; 5) Data Validation System and Ingest Queue; 6) Shipment Verification; 7) Tracking and Metrics; 8) Validation of Contract Specifications; 9) Earth Watch Data Validation; 10) Validation of Vertical Accuracy; and 11) Results of Vertical Accuracy Assessment.

  14. Internal Validity: A Must in Research Designs

    Science.gov (United States)

    Cahit, Kaya

    2015-01-01

    In experimental research, internal validity refers to what extent researchers can conclude that changes in dependent variable (i.e. outcome) are caused by manipulations in independent variable. The causal inference permits researchers to meaningfully interpret research results. This article discusses (a) internal validity threats in social and…

  15. Validation of the Netherlands pacemaker patient registry

    NARCIS (Netherlands)

    Dijk, WA; Kingma, T; Hooijschuur, CAM; Dassen, WRM; Hoorntje, JCA; van Gelder, LM

    1997-01-01

    This paper deals with the validation of the information stored in the Netherlands central pacemaker patient database. At this moment the registry database contains information on more than 70500 patients, 85000 pacemakers and 90000 leads. The validation procedures consisted of an internal

  16. Ensuring validity in qualitative International Business Research

    DEFF Research Database (Denmark)

    Andersen, Poul Houman

    2004-01-01

    The purpose of this paper is to provide an account for how the validity issue may be gasped within a qualitative apporach to the IB field......The purpose of this paper is to provide an account for how the validity issue may be gasped within a qualitative apporach to the IB field...

  17. Construct Validity of Neuropsychological Tests in Schizophrenia.

    Science.gov (United States)

    Allen, Daniel N.; Aldarondo, Felito; Goldstein, Gerald; Huegel, Stephen G.; Gilbertson, Mark; van Kammen, Daniel P.

    1998-01-01

    The construct validity of neuropsychological tests in patients with schizophrenia was studied with 39 patients who were evaluated with a battery of six tests assessing attention, memory, and abstract reasoning abilities. Results support the construct validity of the neuropsychological tests in patients with schizophrenia. (SLD)

  18. 77 FR 27135 - HACCP Systems Validation

    Science.gov (United States)

    2012-05-09

    ... validation, the journal article should identify E.coli O157:H7 and other pathogens as the hazard that the..., or otherwise processes ground beef may determine that E. coli O157:H7 is not a hazard reasonably... specifications that require that the establishment's suppliers apply validated interventions to address E. coli...

  19. Validity in assessment of prior learning

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Aarkrog, Vibe

    2015-01-01

    , the article discusses the need for specific criteria for assessment. The reliability and validity of the assessment procedures depend on whether the competences are well-defined, and whether the teachers are adequately trained for the assessment procedures. Keywords: assessment, prior learning, adult...... education, vocational training, lifelong learning, validity...

  20. Validation of the Classroom Behavior Inventory

    Science.gov (United States)

    Blunden, Dale; And Others

    1974-01-01

    Factor-analytic methods were used toassess contruct validity of the Classroom Behavior Inventory, a scale for rating behaviors associated with hyperactivity. The Classroom Behavior Inventory measures three dimensions of behavior: Hyperactivity, Hostility, and Sociability. Significant concurrent validity was obtained for only one Classroom Behavior…

  1. DESIGN AND VALIDATION OF A CARDIORESPIRATORY ...

    African Journals Online (AJOL)

    UJA

    This study aimed to validate the 10x20m test for children aged 3 to 6 years in order ... obtained adequate parameters of reliability and validity in healthy children aged 3 ... and is a determinant of cardiovascular risk in preschool children (Bürgi et al., ... (Seca 222, Hamburg, Germany), and weight (kg) that was recorded with a ...

  2. DESCQA: Synthetic Sky Catalog Validation Framework

    Science.gov (United States)

    Mao, Yao-Yuan; Uram, Thomas D.; Zhou, Rongpu; Kovacs, Eve; Ricker, Paul M.; Kalmbach, J. Bryce; Padilla, Nelson; Lanusse, François; Zu, Ying; Tenneti, Ananth; Vikraman, Vinu; DeRose, Joseph

    2018-04-01

    The DESCQA framework provides rigorous validation protocols for assessing the quality of high-quality simulated sky catalogs in a straightforward and comprehensive way. DESCQA enables the inspection, validation, and comparison of an inhomogeneous set of synthetic catalogs via the provision of a common interface within an automated framework. An interactive web interface is also available at portal.nersc.gov/project/lsst/descqa.

  3. Structural Validation of the Holistic Wellness Assessment

    Science.gov (United States)

    Brown, Charlene; Applegate, E. Brooks; Yildiz, Mustafa

    2015-01-01

    The Holistic Wellness Assessment (HWA) is a relatively new assessment instrument based on an emergent transdisciplinary model of wellness. This study validated the factor structure identified via exploratory factor analysis (EFA), assessed test-retest reliability, and investigated concurrent validity of the HWA in three separate samples. The…

  4. Linear Unlearning for Cross-Validation

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Larsen, Jan

    1996-01-01

    The leave-one-out cross-validation scheme for generalization assessment of neural network models is computationally expensive due to replicated training sessions. In this paper we suggest linear unlearning of examples as an approach to approximative cross-validation. Further, we discuss...... time series prediction benchmark demonstrate the potential of the linear unlearning technique...

  5. Validation of self-reported erythema

    DEFF Research Database (Denmark)

    Petersen, B; Thieden, E; Lerche, C M

    2013-01-01

    Most epidemiological data of sunburn related to skin cancer have come from self-reporting in diaries and questionnaires. We thought it important to validate the reliability of such data.......Most epidemiological data of sunburn related to skin cancer have come from self-reporting in diaries and questionnaires. We thought it important to validate the reliability of such data....

  6. Validity of a Measure of Assertiveness

    Science.gov (United States)

    Galassi, John P.; Galassi, Merna D.

    1974-01-01

    This study was concerned with further validation of a measure of assertiveness. Concurrent validity was established for the College Self-Expression Scale using the method of contrasted groups and through correlations of self-and judges' ratings of assertiveness. (Author)

  7. Empirical Validation of Listening Proficiency Guidelines

    Science.gov (United States)

    Cox, Troy L.; Clifford, Ray

    2014-01-01

    Because listening has received little attention and the validation of ability scales describing multidimensional skills is always challenging, this study applied a multistage, criterion-referenced approach that used a framework of aligned audio passages and listening tasks to explore the validity of the ACTFL and related listening proficiency…

  8. Theory and Validation for the Collision Module

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1999-01-01

    This report describes basic modelling principles, the theoretical background and validation examples for the Collision Module for the computer program DAMAGE.......This report describes basic modelling principles, the theoretical background and validation examples for the Collision Module for the computer program DAMAGE....

  9. Is intercessory prayer valid nursing intervention?

    Science.gov (United States)

    Stang, Cecily Wellelr

    2011-01-01

    Is the use of intercessory prayer (IP) in modern nursing a valid practice? As discussed in current healthcare literature, IP is controversial, with authors offering support for and against the efficacy of the practice. This article reviews IP literature and research, concluding IP is a valid intervention for Christian nurses.

  10. Promoting Rigorous Validation Practice: An Applied Perspective

    Science.gov (United States)

    Mattern, Krista D.; Kobrin, Jennifer L.; Camara, Wayne J.

    2012-01-01

    As researchers at a testing organization concerned with the appropriate uses and validity evidence for our assessments, we provide an applied perspective related to the issues raised in the focus article. Newton's proposal for elaborating the consensus definition of validity is offered with the intention to reduce the risks of inadequate…

  11. The Treatment Validity of Autism Screening Instruments

    Science.gov (United States)

    Livanis, Andrew; Mouzakitis, Angela

    2010-01-01

    Treatment validity is a frequently neglected topic of screening instruments used to identify autism spectrum disorders. Treatment validity, however, should represent an important aspect of these instruments to link the resulting data to the selection of interventions as well as make decisions about treatment length and intensity. Research…

  12. Terminology, Emphasis, and Utility in Validation

    Science.gov (United States)

    Kane, Michael T.

    2008-01-01

    Lissitz and Samuelsen (2007) have proposed an operational definition of "validity" that shifts many of the questions traditionally considered under validity to a separate category associated with the utility of test use. Operational definitions support inferences about how well people perform some kind of task or how they respond to some kind of…

  13. Validating Measures of Mathematical Knowledge for Teaching

    Science.gov (United States)

    Kane, Michael

    2007-01-01

    According to Schilling, Blunk, and Hill, the set of papers presented in this journal issue had two main purposes: (1) to use an argument-based approach to evaluate the validity of the tests of mathematical knowledge for teaching (MKT), and (2) to critically assess the author's version of an argument-based approach to validation (Kane, 2001, 2004).…

  14. Robust Object Tracking Using Valid Fragments Selection.

    Science.gov (United States)

    Zheng, Jin; Li, Bo; Tian, Peng; Luo, Gang

    Local features are widely used in visual tracking to improve robustness in cases of partial occlusion, deformation and rotation. This paper proposes a local fragment-based object tracking algorithm. Unlike many existing fragment-based algorithms that allocate the weights to each fragment, this method firstly defines discrimination and uniqueness for local fragment, and builds an automatic pre-selection of useful fragments for tracking. Then, a Harris-SIFT filter is used to choose the current valid fragments, excluding occluded or highly deformed fragments. Based on those valid fragments, fragment-based color histogram provides a structured and effective description for the object. Finally, the object is tracked using a valid fragment template combining the displacement constraint and similarity of each valid fragment. The object template is updated by fusing feature similarity and valid fragments, which is scale-adaptive and robust to partial occlusion. The experimental results show that the proposed algorithm is accurate and robust in challenging scenarios.

  15. Validity evidence based on test content.

    Science.gov (United States)

    Sireci, Stephen; Faulkner-Bond, Molly

    2014-01-01

    Validity evidence based on test content is one of the five forms of validity evidence stipulated in the Standards for Educational and Psychological Testing developed by the American Educational Research Association, American Psychological Association, and National Council on Measurement in Education. In this paper, we describe the logic and theory underlying such evidence and describe traditional and modern methods for gathering and analyzing content validity data. A comprehensive review of the literature and of the aforementioned Standards is presented. For educational tests and other assessments targeting knowledge and skill possessed by examinees, validity evidence based on test content is necessary for building a validity argument to support the use of a test for a particular purpose. By following the methods described in this article, practitioners have a wide arsenal of tools available for determining how well the content of an assessment is congruent with and appropriate for the specific testing purposes.

  16. Validation of models with multivariate output

    International Nuclear Information System (INIS)

    Rebba, Ramesh; Mahadevan, Sankaran

    2006-01-01

    This paper develops metrics for validating computational models with experimental data, considering uncertainties in both. A computational model may generate multiple response quantities and the validation experiment might yield corresponding measured values. Alternatively, a single response quantity may be predicted and observed at different spatial and temporal points. Model validation in such cases involves comparison of multiple correlated quantities. Multiple univariate comparisons may give conflicting inferences. Therefore, aggregate validation metrics are developed in this paper. Both classical and Bayesian hypothesis testing are investigated for this purpose, using multivariate analysis. Since, commonly used statistical significance tests are based on normality assumptions, appropriate transformations are investigated in the case of non-normal data. The methodology is implemented to validate an empirical model for energy dissipation in lap joints under dynamic loading

  17. Assessment of teacher competence using video portfolios: reliability, construct validity and consequential validity

    NARCIS (Netherlands)

    Admiraal, W.; Hoeksma, M.; van de Kamp, M.-T.; van Duin, G.

    2011-01-01

    The richness and complexity of video portfolios endanger both the reliability and validity of the assessment of teacher competencies. In a post-graduate teacher education program, the assessment of video portfolios was evaluated for its reliability, construct validity, and consequential validity.

  18. Validation of Symptom Validity Tests Using a "Child-model" of Adult Cognitive Impairments

    NARCIS (Netherlands)

    Rienstra, A.; Spaan, P. E. J.; Schmand, B.

    2010-01-01

    Validation studies of symptom validity tests (SVTs) in children are uncommon. However, since children's cognitive abilities are not yet fully developed, their performance may provide additional support for the validity of these measures in adult populations. Four SVTs, the Test of Memory Malingering

  19. Validation of symptom validity tests using a "child-model" of adult cognitive impairments

    NARCIS (Netherlands)

    Rienstra, A.; Spaan, P.E.J.; Schmand, B.

    2010-01-01

    Validation studies of symptom validity tests (SVTs) in children are uncommon. However, since children’s cognitive abilities are not yet fully developed, their performance may provide additional support for the validity of these measures in adult populations. Four SVTs, the Test of Memory Malingering

  20. Método para determinação de carboidratos empregado na triagem de adulterações em café

    Directory of Open Access Journals (Sweden)

    Elis Daiane Pauli

    2011-01-01

    Full Text Available The objective in this work was to validate a chromatography method for the determination of total carbohydrates in soluble coffee, using a HPLC-UV-VIS with postcolumn derivatization system, in order to verify adulterant additions. The validated method was accurate and robust. Adulteration could be observed by increasing xylose and glucose levels in samples with addition of coffee husks and starchy products while decreasing of galactose and mannose characteristic carbohydrates presenting in high concentration in soluble coffees produced by arabica and robusta coffee beans.

  1. Estimating uncertainty of inference for validation

    Energy Technology Data Exchange (ETDEWEB)

    Booker, Jane M [Los Alamos National Laboratory; Langenbrunner, James R [Los Alamos National Laboratory; Hemez, Francois M [Los Alamos National Laboratory; Ross, Timothy J [UNM

    2010-09-30

    We present a validation process based upon the concept that validation is an inference-making activity. This has always been true, but the association has not been as important before as it is now. Previously, theory had been confirmed by more data, and predictions were possible based on data. The process today is to infer from theory to code and from code to prediction, making the role of prediction somewhat automatic, and a machine function. Validation is defined as determining the degree to which a model and code is an accurate representation of experimental test data. Imbedded in validation is the intention to use the computer code to predict. To predict is to accept the conclusion that an observable final state will manifest; therefore, prediction is an inference whose goodness relies on the validity of the code. Quantifying the uncertainty of a prediction amounts to quantifying the uncertainty of validation, and this involves the characterization of uncertainties inherent in theory/models/codes and the corresponding data. An introduction to inference making and its associated uncertainty is provided as a foundation for the validation problem. A mathematical construction for estimating the uncertainty in the validation inference is then presented, including a possibility distribution constructed to represent the inference uncertainty for validation under uncertainty. The estimation of inference uncertainty for validation is illustrated using data and calculations from Inertial Confinement Fusion (ICF). The ICF measurements of neutron yield and ion temperature were obtained for direct-drive inertial fusion capsules at the Omega laser facility. The glass capsules, containing the fusion gas, were systematically selected with the intent of establishing a reproducible baseline of high-yield 10{sup 13}-10{sup 14} neutron output. The deuterium-tritium ratio in these experiments was varied to study its influence upon yield. This paper on validation inference is the

  2. Verification, validation, and reliability of predictions

    International Nuclear Information System (INIS)

    Pigford, T.H.; Chambre, P.L.

    1987-04-01

    The objective of predicting long-term performance should be to make reliable determinations of whether the prediction falls within the criteria for acceptable performance. Establishing reliable predictions of long-term performance of a waste repository requires emphasis on valid theories to predict performance. The validation process must establish the validity of the theory, the parameters used in applying the theory, the arithmetic of calculations, and the interpretation of results; but validation of such performance predictions is not possible unless there are clear criteria for acceptable performance. Validation programs should emphasize identification of the substantive issues of prediction that need to be resolved. Examples relevant to waste package performance are predicting the life of waste containers and the time distribution of container failures, establishing the criteria for defining container failure, validating theories for time-dependent waste dissolution that depend on details of the repository environment, and determining the extent of congruent dissolution of radionuclides in the UO 2 matrix of spent fuel. Prediction and validation should go hand in hand and should be done and reviewed frequently, as essential tools for the programs to design and develop repositories. 29 refs

  3. Validation of Yoon's Critical Thinking Disposition Instrument.

    Science.gov (United States)

    Shin, Hyunsook; Park, Chang Gi; Kim, Hyojin

    2015-12-01

    The lack of reliable and valid evaluation tools targeting Korean nursing students' critical thinking (CT) abilities has been reported as one of the barriers to instructing and evaluating students in undergraduate programs. Yoon's Critical Thinking Disposition (YCTD) instrument was developed for Korean nursing students, but few studies have assessed its validity. This study aimed to validate the YCTD. Specifically, the YCTD was assessed to identify its cross-sectional and longitudinal measurement invariance. This was a validation study in which a cross-sectional and longitudinal (prenursing and postnursing practicum) survey was used to validate the YCTD using 345 nursing students at three universities in Seoul, Korea. The participants' CT abilities were assessed using the YCTD before and after completing an established pediatric nursing practicum. The validity of the YCTD was estimated and then group invariance test using multigroup confirmatory factor analysis was performed to confirm the measurement compatibility of multigroups. A test of the seven-factor model showed that the YCTD demonstrated good construct validity. Multigroup confirmatory factor analysis findings for the measurement invariance suggested that this model structure demonstrated strong invariance between groups (i.e., configural, factor loading, and intercept combined) but weak invariance within a group (i.e., configural and factor loading combined). In general, traditional methods for assessing instrument validity have been less than thorough. In this study, multigroup confirmatory factor analysis using cross-sectional and longitudinal measurement data allowed validation of the YCTD. This study concluded that the YCTD can be used for evaluating Korean nursing students' CT abilities. Copyright © 2015. Published by Elsevier B.V.

  4. Tracer travel time and model validation

    International Nuclear Information System (INIS)

    Tsang, Chin-Fu.

    1988-01-01

    The performance assessment of a nuclear waste repository demands much more in comparison to the safety evaluation of any civil constructions such as dams, or the resource evaluation of a petroleum or geothermal reservoir. It involves the estimation of low probability (low concentration) of radionuclide transport extrapolated 1000's of years into the future. Thus models used to make these estimates need to be carefully validated. A number of recent efforts have been devoted to the study of this problem. Some general comments on model validation were given by Tsang. The present paper discusses some issues of validation in regards to radionuclide transport. 5 refs

  5. Development of a validated HPLC method for the quantitative determination of trelagliptin succinate and its related substances in pharmaceutical dosage forms.

    Science.gov (United States)

    Luo, Zhiqiang; Chen, Xinjing; Wang, Guopeng; Du, Zhibo; Ma, Xiaoyun; Wang, Hao; Yu, Guohua; Liu, Aoxue; Li, Mengwei; Peng, Wei; Liu, Yang

    2018-01-01

    Trelagliptin succinate is a dipeptidyl peptidase IV (DPP-4) inhibitor which is used as a new long-acting drug for once-weekly treatment of type 2 diabetes mellitus (DM). In the present study, a rapid, sensitive and accurate high-performance liquid chromatography (HPLC) method was developed and validated for separation and determination of trelagliptin succinate and its eight potential process-related impurities. The chromatographic separation was achieved on a Waters Xselect CSH™ C 18 (250mm×4.6mm, 5.0μm) column. The mobile phases comprised of 0.05% trifluoroacetic acid in water as well as acetonitrile containing 0.05% trifluoroacetic acid. The compounds of interest were monitored at 224nm and 275nm. The stability-indicating capability of this method was evaluated by performing stress test studies. Trelagliptin succinate was found to degrade significantly in acid, base, oxidative and thermal stress conditions and only stable in photolytic degradation condition. The degradation products were well resolved from the main peak and its impurities. In addition, the major degradation impurities formed under acid, base, oxidative and thermal stress conditions were characterized by ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). The method was validated to fulfill International Conference on Harmonisation (ICH) requirements and this validation included specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision and robustness. The developed method in this study could be applied for routine quality control analysis of trelagliptin succinate tablets, since there is no official monograph. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Base Flow Model Validation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is the systematic "building-block" validation of CFD/turbulence models employing a GUI driven CFD code (RPFM) and existing as well as new data sets to...

  7. The validation of Huffaz Intelligence Test (HIT)

    Science.gov (United States)

    Rahim, Mohd Azrin Mohammad; Ahmad, Tahir; Awang, Siti Rahmah; Safar, Ajmain

    2017-08-01

    In general, a hafiz who can memorize the Quran has many specialties especially in respect to their academic performances. In this study, the theory of multiple intelligences introduced by Howard Gardner is embedded in a developed psychometric instrument, namely Huffaz Intelligence Test (HIT). This paper presents the validation and the reliability of HIT of some tahfiz students in Malaysia Islamic schools. A pilot study was conducted involving 87 huffaz who were randomly selected to answer the items in HIT. The analysis method used includes Partial Least Square (PLS) on reliability, convergence and discriminant validation. The study has validated nine intelligences. The findings also indicated that the composite reliabilities for the nine types of intelligences are greater than 0.8. Thus, the HIT is a valid and reliable instrument to measure the multiple intelligences among huffaz.

  8. Ensuring validity in qualitative international business research

    DEFF Research Database (Denmark)

    Andersen, Poul Houman; Skaates, Maria Anne

    2002-01-01

    The purpose of this paper is to provide an account of how the validity issue related to qualitative research strategies within the IB field may be grasped from an at least partially subjectivist point of view. In section two, we will first assess via the aforementioned literature review the extent...... to which the validity issue has been treated in qualitative research contributions published in six leading English-language journals which publish IB research. Thereafter, in section three, we will discuss our findings and relate them to (a) various levels of a research project and (b) the existing...... literature on potential validity problems from a more subjectivist point of view. As a part of this step, we will demonstrate that the assumptions of objectivist and subjectivist ontologies and their corresponding epistemologies merit different canons for assessing research validity. In the subsequent...

  9. Convergent Validity of Four Innovativeness Scales.

    Science.gov (United States)

    Goldsmith, Ronald E.

    1986-01-01

    Four scales of innovativeness were administered to two samples of undergraduate students: the Open Processing Scale, Innovativeness Scale, innovation subscale of the Jackson Personality Inventory, and Kirton Adaption-Innovation Inventory. Intercorrelations indicated the scales generally exhibited convergent validity. (GDC)

  10. Validity of Sensory Systems as Distinct Constructs

    OpenAIRE

    Su, Chia-Ting; Parham, L. Diane

    2014-01-01

    Confirmatory factor analysis testing whether sensory questionnaire items represented distinct sensory system constructs found, using data from two age groups, that such constructs can be measured validly using questionnaire data.

  11. Regulatory perspectives on human factors validation

    International Nuclear Information System (INIS)

    Harrison, F.; Staples, L.

    2001-01-01

    Validation is an important avenue for controlling the genesis of human error, and thus managing loss, in a human-machine system. Since there are many ways in which error may intrude upon system operation, it is necessary to consider the performance-shaping factors that could introduce error and compromise system effectiveness. Validation works to this end by examining, through objective testing and measurement, the newly developed system, procedure or staffing level, in order to identify and eliminate those factors which may negatively influence human performance. It is essential that validation be done in a high-fidelity setting, in an objective and systematic manner, using appropriate measures, if meaningful results are to be obtained, In addition, inclusion of validation work in any design process can be seen as contributing to a good safety culture, since such activity allows licensees to eliminate elements which may negatively impact on human behaviour. (author)

  12. Validation of the reactor dynamics code HEXTRAN

    International Nuclear Information System (INIS)

    Kyrki-Rajamaeki, R.

    1994-05-01

    HEXTRAN is a new three-dimensional, hexagonal reactor dynamics code developed in the Technical Research Centre of Finland (VTT) for VVER type reactors. This report describes the validation work of HEXTRAN. The work has been made with the financing of the Finnish Centre for Radiation and Nuclear Safety (STUK). HEXTRAN is particularly intended for calculation of such accidents, in which radially asymmetric phenomena are included and both good neutron dynamics and two-phase thermal hydraulics are important. HEXTRAN is based on already validated codes. The models of these codes have been shown to function correctly also within the HEXTRAN code. The main new model of HEXTRAN, the spatial neutron kinetics model has been successfully validated against LR-0 test reactor and Loviisa plant measurements. Connected with SMABRE, HEXTRAN can be reliably used for calculation of transients including effects of the whole cooling system of VVERs. Further validation plans are also introduced in the report. (orig.). (23 refs., 16 figs., 2 tabs.)

  13. Verification and validation in computational fluid dynamics

    Science.gov (United States)

    Oberkampf, William L.; Trucano, Timothy G.

    2002-04-01

    Verification and validation (V&V) are the primary means to assess accuracy and reliability in computational simulations. This paper presents an extensive review of the literature in V&V in computational fluid dynamics (CFD), discusses methods and procedures for assessing V&V, and develops a number of extensions to existing ideas. The review of the development of V&V terminology and methodology points out the contributions from members of the operations research, statistics, and CFD communities. Fundamental issues in V&V are addressed, such as code verification versus solution verification, model validation versus solution validation, the distinction between error and uncertainty, conceptual sources of error and uncertainty, and the relationship between validation and prediction. The fundamental strategy of verification is the identification and quantification of errors in the computational model and its solution. In verification activities, the accuracy of a computational solution is primarily measured relative to two types of highly accurate solutions: analytical solutions and highly accurate numerical solutions. Methods for determining the accuracy of numerical solutions are presented and the importance of software testing during verification activities is emphasized. The fundamental strategy of validation is to assess how accurately the computational results compare with the experimental data, with quantified error and uncertainty estimates for both. This strategy employs a hierarchical methodology that segregates and simplifies the physical and coupling phenomena involved in the complex engineering system of interest. A hypersonic cruise missile is used as an example of how this hierarchical structure is formulated. The discussion of validation assessment also encompasses a number of other important topics. A set of guidelines is proposed for designing and conducting validation experiments, supported by an explanation of how validation experiments are different

  14. An information architecture for courseware validation

    OpenAIRE

    Melia, Mark; Pahl, Claus

    2007-01-01

    A lack of pedagogy in courseware can lead to learner rejec- tion. It is therefore vital that pedagogy is a central concern of courseware construction. Courseware validation allows the course creator to specify pedagogical rules and principles which courseware must conform to. In this paper we investigate the information needed for courseware valida- tion and propose an information architecture to be used as a basis for validation.

  15. Italian Validation of Homophobia Scale (HS)

    OpenAIRE

    Ciocca, Giacomo; Capuano, Nicolina; Tuziak, Bogdan; Mollaioli, Daniele; Limoncin, Erika; Valsecchi, Diana; Carosa, Eleonora; Gravina, Giovanni L.; Gianfrilli, Daniele; Lenzi, Andrea; Jannini, Emmanuele A.

    2015-01-01

    Introduction: The Homophobia Scale (HS) is a valid tool to assess homophobia. This test is self‐reporting, composed of 25 items, which assesses a total score and three factors linked to homophobia: behavior/negative affect, affect/behavioral aggression, and negative cognition. Aim: The aim of this study was to validate the HS in the Italian context. Methods: An Italian translation of the HS was carried out by two bilingual people, after which an English native translated the test back i...

  16. VAlidation STandard antennas: Past, present and future

    DEFF Research Database (Denmark)

    Drioli, Luca Salghetti; Ostergaard, A; Paquay, M

    2011-01-01

    designed for validation campaigns of antenna measurement ranges. The driving requirements of VAST antennas are their mechanical stability over a given operational temperature range and with respect to any orientation of the gravity field. The mechanical design shall ensure extremely stable electrical....../V-band of telecom satellites. The paper will address requirements for future VASTs and possible architecture for multi-frequency Validation Standard antennas....

  17. Methodology for testing and validating knowledge bases

    Science.gov (United States)

    Krishnamurthy, C.; Padalkar, S.; Sztipanovits, J.; Purves, B. R.

    1987-01-01

    A test and validation toolset developed for artificial intelligence programs is described. The basic premises of this method are: (1) knowledge bases have a strongly declarative character and represent mostly structural information about different domains, (2) the conditions for integrity, consistency, and correctness can be transformed into structural properties of knowledge bases, and (3) structural information and structural properties can be uniformly represented by graphs and checked by graph algorithms. The interactive test and validation environment have been implemented on a SUN workstation.

  18. Empirical Validation of Building Simulation Software

    DEFF Research Database (Denmark)

    Kalyanova, Olena; Heiselberg, Per

    The work described in this report is the result of a collaborative effort of members of the International Energy Agency (IEA), Task 34/43: Testing and validation of building energy simulation tools experts group.......The work described in this report is the result of a collaborative effort of members of the International Energy Agency (IEA), Task 34/43: Testing and validation of building energy simulation tools experts group....

  19. Verification and Validation in Systems Engineering

    CERN Document Server

    Debbabi, Mourad; Jarraya, Yosr; Soeanu, Andrei; Alawneh, Luay

    2010-01-01

    "Verification and validation" represents an important process used for the quality assessment of engineered systems and their compliance with the requirements established at the beginning of or during the development cycle. Debbabi and his coauthors investigate methodologies and techniques that can be employed for the automatic verification and validation of systems engineering design models expressed in standardized modeling languages. Their presentation includes a bird's eye view of the most prominent modeling languages for software and systems engineering, namely the Unified Model

  20. The Legality and Validity of Administrative Enforcement

    Directory of Open Access Journals (Sweden)

    Sergei V. Iarkovoi

    2018-01-01

    Full Text Available The article discusses the concept and content of the validity of adopted by the executive authorities and other bodies of public administration legal acts and committed by them legal actions as an important characteristic of law enforcement by these bodies. The Author concludes that the validity of the administrative law enforcement is not an independent requirement for it, and acts as an integral part of its legal requirements.

  1. A theory of cross-validation error

    OpenAIRE

    Turney, Peter D.

    1994-01-01

    This paper presents a theory of error in cross-validation testing of algorithms for predicting real-valued attributes. The theory justifies the claim that predicting real-valued attributes requires balancing the conflicting demands of simplicity and accuracy. Furthermore, the theory indicates precisely how these conflicting demands must be balanced, in order to minimize cross-validation error. A general theory is presented, then it is developed in detail for linear regression and instance-bas...

  2. DTU PMU Laboratory Development - Testing and Validation

    OpenAIRE

    Garcia-Valle, Rodrigo; Yang, Guang-Ya; Martin, Kenneth E.; Nielsen, Arne Hejde; Østergaard, Jacob

    2010-01-01

    This is a report of the results of phasor measurement unit (PMU) laboratory development and testing done at the Centre for Electric Technology (CET), Technical University of Denmark (DTU). Analysis of the PMU performance first required the development of tools to convert the DTU PMU data into IEEE standard, and the validation is done for the DTU-PMU via a validated commercial PMU. The commercial PMU has been tested from the authors' previous efforts, where the response can be expected to foll...

  3. Verification and validation for waste disposal models

    International Nuclear Information System (INIS)

    1987-07-01

    A set of evaluation criteria has been developed to assess the suitability of current verification and validation techniques for waste disposal methods. A survey of current practices and techniques was undertaken and evaluated using these criteria with the items most relevant to waste disposal models being identified. Recommendations regarding the most suitable verification and validation practices for nuclear waste disposal modelling software have been made

  4. Feature Extraction for Structural Dynamics Model Validation

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles [Los Alamos National Laboratory; Nishio, Mayuko [Yokohama University; Hemez, Francois [Los Alamos National Laboratory; Stull, Chris [Los Alamos National Laboratory; Park, Gyuhae [Chonnam Univesity; Cornwell, Phil [Rose-Hulman Institute of Technology; Figueiredo, Eloi [Universidade Lusófona; Luscher, D. J. [Los Alamos National Laboratory; Worden, Keith [University of Sheffield

    2016-01-13

    As structural dynamics becomes increasingly non-modal, stochastic and nonlinear, finite element model-updating technology must adopt the broader notions of model validation and uncertainty quantification. For example, particular re-sampling procedures must be implemented to propagate uncertainty through a forward calculation, and non-modal features must be defined to analyze nonlinear data sets. The latter topic is the focus of this report, but first, some more general comments regarding the concept of model validation will be discussed.

  5. Validating presupposed versus focused text information.

    Science.gov (United States)

    Singer, Murray; Solar, Kevin G; Spear, Jackie

    2017-04-01

    There is extensive evidence that readers continually validate discourse accuracy and congruence, but that they may also overlook conspicuous text contradictions. Validation may be thwarted when the inaccurate ideas are embedded sentence presuppositions. In four experiments, we examined readers' validation of presupposed ("given") versus new text information. Throughout, a critical concept, such as a truck versus a bus, was introduced early in a narrative. Later, a character stated or thought something about the truck, which therefore matched or mismatched its antecedent. Furthermore, truck was presented as either given or new information. Mismatch target reading times uniformly exceeded the matching ones by similar magnitudes for given and new concepts. We obtained this outcome using different grammatical constructions and with different antecedent-target distances. In Experiment 4, we examined only given critical ideas, but varied both their matching and the main verb's factivity (e.g., factive know vs. nonfactive think). The Match × Factivity interaction closely resembled that previously observed for new target information (Singer, 2006). Thus, readers can successfully validate given target information. Although contemporary theories tend to emphasize either deficient or successful validation, both types of theory can accommodate the discourse and reader variables that may regulate validation.

  6. Assessment of validity with polytrauma Veteran populations.

    Science.gov (United States)

    Bush, Shane S; Bass, Carmela

    2015-01-01

    Veterans with polytrauma have suffered injuries to multiple body parts and organs systems, including the brain. The injuries can generate a triad of physical, neurologic/cognitive, and emotional symptoms. Accurate diagnosis is essential for the treatment of these conditions and for fair allocation of benefits. To accurately diagnose polytrauma disorders and their related problems, clinicians take into account the validity of reported history and symptoms, as well as clinical presentations. The purpose of this article is to describe the assessment of validity with polytrauma Veteran populations. Review of scholarly and other relevant literature and clinical experience are utilized. A multimethod approach to validity assessment that includes objective, standardized measures increases the confidence that can be placed in the accuracy of self-reported symptoms and physical, cognitive, and emotional test results. Due to the multivariate nature of polytrauma and the multiple disciplines that play a role in diagnosis and treatment, an ideal model of validity assessment with polytrauma Veteran populations utilizes neurocognitive, neurological, neuropsychiatric, and behavioral measures of validity. An overview of these validity assessment approaches as applied to polytrauma Veteran populations is presented. Veterans, the VA, and society are best served when accurate diagnoses are made.

  7. Ground-water models: Validate or invalidate

    Science.gov (United States)

    Bredehoeft, J.D.; Konikow, Leonard F.

    1993-01-01

    The word validation has a clear meaning to both the scientific community and the general public. Within the scientific community the validation of scientific theory has been the subject of philosophical debate. The philosopher of science, Karl Popper, argued that scientific theory cannot be validated, only invalidated. Popper’s view is not the only opinion in this debate; however, many scientists today agree with Popper (including the authors). To the general public, proclaiming that a ground-water model is validated carries with it an aura of correctness that we do not believe many of us who model would claim. We can place all the caveats we wish, but the public has its own understanding of what the word implies. Using the word valid with respect to models misleads the public; verification carries with it similar connotations as far as the public is concerned. Our point is this: using the terms validation and verification are misleading, at best. These terms should be abandoned by the ground-water community.

  8. [Validation of the IBS-SSS].

    Science.gov (United States)

    Betz, C; Mannsdörfer, K; Bischoff, S C

    2013-10-01

    Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterised by abdominal pain, associated with stool abnormalities and changes in stool consistency. Diagnosis of IBS is based on characteristic symptoms and exclusion of other gastrointestinal diseases. A number of questionnaires exist to assist diagnosis and assessment of severity of the disease. One of these is the irritable bowel syndrome - severity scoring system (IBS-SSS). The IBS-SSS was validated 1997 in its English version. In the present study, the IBS-SSS has been validated in German language. To do this, a cohort of 60 patients with IBS according to the Rome III criteria, was compared with a control group of healthy individuals (n = 38). We studied sensitivity and reproducibility of the score, as well as the sensitivity to detect changes of symptom severity. The results of the German validation largely reflect the results of the English validation. The German version of the IBS-SSS is also a valid, meaningful and reproducible questionnaire with a high sensitivity to assess changes in symptom severity, especially in IBS patients with moderate symptoms. It is unclear if the IBS-SSS is also a valid questionnaire in IBS patients with severe symptoms because this group of patients was not studied. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Development and validation of an improved LC-MS/MS method for the quantification of desloratadine and its metabolite in human plasma using deutrated desloratadine as internal standard

    Directory of Open Access Journals (Sweden)

    M Saquib Hasnain

    2013-01-01

    Full Text Available Purpose: For the determination of desloratadine (DES and 3-OH desloratadine (3-OHD in human plasma using deutrated desloratadine (DESD5 as internal standard (IS, a novel stability indicating liquid chromatography-tandem mass spectrometric method was developed and validated to support the clinical advancement. Materials and Methods: The solid-phase extraction method used for sample preparation and calibration range was 100-11,000 pg/ml, for which a quadratic regression (1/x 2 was best fitted. The blank plasma was screened and observed free from any endogenous interference. Results: The accuracy (% nominal at low limit of quantification LLOQ level for DES and 3-OHD was 100.4% and 99.9% whereas precision (%CV was 4.6 and 5.1%. They (DES and 3-OHD were stable in human plasma after five freeze-thaw cycles, at room temperature for 23.8 hour, bench top stability for 6.4 hour. Conclusion: This method fulfills all the regulatory requirements for selectivity, sensitivity, precision, accuracy, stability, goodness of fit, and ruggedness of the method for the determination of DES and 3-OHD in human plasma.

  10. Development and Validation of a Precise, Single HPLC Method for the Determination of Tolperisone Impurities in API and Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Raju, Thummala Veera Raghava; Seshadri, Raja Kumar; Arutla, Srinivas; Mohan, Tharlapu Satya Sankarsana Jagan; Rao, Ivaturi Mrutyunjaya; Nittala, Someswara Rao

    2013-01-01

    A novel, sensitive, stability-indicating HPLC method has been developed for the quantitative estimation of Tolperisone-related impurities in both bulk drugs and pharmaceutical dosage forms. Effective chromatographic separation was achieved on a C18 stationary phase with a simple mobile phase combination delivered in a simple gradient programme, and quantitation was by ultraviolet detection at 254 nm. The mobile phase consisted of a buffer and acetonitrile delivered at a flow rate 1.0 ml/min. The buffer consisted of 0.01 M potassium dihydrogen phosphate with the pH adjusted to 8.0 by using diethylamine. In the developed HPLC method, the resolution between Tolperisone and its four potential impurities was found to be greater than 2.0. Regression analysis showed an R value (correlation coefficient) of greater than 0.999 for the Tolperisone impurities. This method was capable of detecting all four impurities of Tolperisone at a level of 0.19 μg/mL with respect to the test concentration of 1000 μg/mL for a 10 µl injection volume. The tablets were subjected to the stress conditions of hydrolysis, oxidation, photolysis, and thermal degradation. Considerable degradation was found to occur in base hydrolysis, water hydrolysis, and oxidation. The stress samples were assayed against a qualified reference standard and the mass balance was found to be close to 100%. The established method was validated and found to be linear, accurate, precise, specific, robust, and rugged.

  11. Validation of a liquid chromatography method for the simultaneous determination of sulfadimethoxine and trimethoprim and application to a stability study.

    Science.gov (United States)

    Louati, K; Mistiri, F; Kallel, M; Safta, F

    2010-03-01

    A liquid chromatography method is described for the simultaneous determination of sulfadimetoxine and trimethoprim from a veterinary formulation at the proportion of 187 mg and 40 mg respectively in presence of some excipient. The solution was subjected to different International Conference On Harmonisation prescribed stress conditions (hydrolysis, oxidation and photolysis). A stability-indicating high-performance liquid chromatography method was developed for the analysis of active substances in presence of their major degradation products. It involved a Knauer Eurospher C18 thermostated column at 25 degrees C, and 9.57 mM phosphate buffer (pH adjusted to 2.0 with orthophosphoric acid)-acetonitrile (70:30 v/v) as mobile phase. The mobile phase flow rate and sample volume injected were 1.2 mL/min and 20 microL, respectively. The selected wavelength for the determination was 248 nm. The method was validated for linearity, precision, accuracy and specificity, and then applied to a stability study of sulfadimetoxine and trimethoprim in the veterinary solution packaged in high density polyethylene plastic bottles of 1 L and 100 mL thermosealed and no thermosealed and corked by a white cap, at both accelerated and long-term conditions required by the International Conference On Harmonisation. The method developed, which separates all of the most degradation products formed under variety of conditions, proved to be simple, accurate, precise and specific. The results of the stress degradation show that the solution is more sensitive to hydrolysis. The stability studies carried out on three batches of each presentation show that the finished product remains stable for six months. Copyright 2010 Elsevier Masson SAS. All rights reserved.

  12. Development and validation of a UV-spectrophotometric method for the determination of pheniramine maleate and its stability studies

    Science.gov (United States)

    Raghu, M. S.; Basavaiah, K.; Ramesh, P. J.; Abdulrahman, Sameer A. M.; Vinay, K. B.

    2012-03-01

    A sensitive, precise, and cost-effective UV-spectrophotometric method is described for the determination of pheniramine maleate (PAM) in bulk drug and tablets. The method is based on the measurement of absorbance of a PAM solution in 0.1 N HCl at 264 nm. As per the International Conference on Harmonization (ICH) guidelines, the method was validated for linearity, accuracy, precision, limits of detection (LOD) and quantification (LOQ), and robustness and ruggedness. A linear relationship between absorbance and concentration of PAM in the range of 2-40 μg/ml with a correlation coefficient (r) of 0.9998 was obtained. The LOD and LOQ values were found to be 0.18 and 0.39 μg/ml PAM, respectively. The precision of the method was satisfactory: the value of relative standard deviation (RSD) did not exceed 3.47%. The proposed method was applied successfully to the determination of PAM in tablets with good accuracy and precision. Percentages of the label claims ranged from 101.8 to 102.01% with the standard deviation (SD) from 0.64 to 0.72%. The accuracy of the method was further ascertained by recovery studies via a standard addition procedure. In addition, the forced degradation of PAM was conducted in accordance with the ICH guidelines. Acidic and basic hydrolysis, thermal stress, peroxide, and photolytic degradation were used to assess the stability-indicating power of the method. A substantial degradation was observed during oxidative and alkaline degradations. No degradation was observed under other stress conditions.

  13. The ALICE Software Release Validation cluster

    International Nuclear Information System (INIS)

    Berzano, D; Krzewicki, M

    2015-01-01

    One of the most important steps of software lifecycle is Quality Assurance: this process comprehends both automatic tests and manual reviews, and all of them must pass successfully before the software is approved for production. Some tests, such as source code static analysis, are executed on a single dedicated service: in High Energy Physics, a full simulation and reconstruction chain on a distributed computing environment, backed with a sample “golden” dataset, is also necessary for the quality sign off. The ALICE experiment uses dedicated and virtualized computing infrastructures for the Release Validation in order not to taint the production environment (i.e. CVMFS and the Grid) with non-validated software and validation jobs: the ALICE Release Validation cluster is a disposable virtual cluster appliance based on CernVM and the Virtual Analysis Facility, capable of deploying on demand, and with a single command, a dedicated virtual HTCondor cluster with an automatically scalable number of virtual workers on any cloud supporting the standard EC2 interface. Input and output data are externally stored on EOS, and a dedicated CVMFS service is used to provide the software to be validated. We will show how the Release Validation Cluster deployment and disposal are completely transparent for the Release Manager, who simply triggers the validation from the ALICE build system's web interface. CernVM 3, based entirely on CVMFS, permits to boot any snapshot of the operating system in time: we will show how this allows us to certify each ALICE software release for an exact CernVM snapshot, addressing the problem of Long Term Data Preservation by ensuring a consistent environment for software execution and data reprocessing in the future. (paper)

  14. Validation in the Absence of Observed Events.

    Science.gov (United States)

    Lathrop, John; Ezell, Barry

    2016-04-01

    This article addresses the problem of validating models in the absence of observed events, in the area of weapons of mass destruction terrorism risk assessment. We address that problem with a broadened definition of "validation," based on stepping "up" a level to considering the reason why decisionmakers seek validation, and from that basis redefine validation as testing how well the model can advise decisionmakers in terrorism risk management decisions. We develop that into two conditions: validation must be based on cues available in the observable world; and it must focus on what can be done to affect that observable world, i.e., risk management. That leads to two foci: (1) the real-world risk generating process, and (2) best use of available data. Based on our experience with nine WMD terrorism risk assessment models, we then describe three best use of available data pitfalls: SME confidence bias, lack of SME cross-referencing, and problematic initiation rates. Those two foci and three pitfalls provide a basis from which we define validation in this context in terms of four tests--Does the model: … capture initiation? … capture the sequence of events by which attack scenarios unfold? … consider unanticipated scenarios? … consider alternative causal chains? Finally, we corroborate our approach against three validation tests from the DOD literature: Is the model a correct representation of the process to be simulated? To what degree are the model results comparable to the real world? Over what range of inputs are the model results useful? © 2015 Society for Risk Analysis.

  15. Calibration, validation, and sensitivity analysis: What's what

    International Nuclear Information System (INIS)

    Trucano, T.G.; Swiler, L.P.; Igusa, T.; Oberkampf, W.L.; Pilch, M.

    2006-01-01

    One very simple interpretation of calibration is to adjust a set of parameters associated with a computational science and engineering code so that the model agreement is maximized with respect to a set of experimental data. One very simple interpretation of validation is to quantify our belief in the predictive capability of a computational code through comparison with a set of experimental data. Uncertainty in both the data and the code are important and must be mathematically understood to correctly perform both calibration and validation. Sensitivity analysis, being an important methodology in uncertainty analysis, is thus important to both calibration and validation. In this paper, we intend to clarify the language just used and express some opinions on the associated issues. We will endeavor to identify some technical challenges that must be resolved for successful validation of a predictive modeling capability. One of these challenges is a formal description of a 'model discrepancy' term. Another challenge revolves around the general adaptation of abstract learning theory as a formalism that potentially encompasses both calibration and validation in the face of model uncertainty

  16. Validation studies of nursing diagnoses in neonatology

    Directory of Open Access Journals (Sweden)

    Pavlína Rabasová

    2016-03-01

    Full Text Available Aim: The objective of the review was the analysis of Czech and foreign literature sources and professional periodicals to obtain a relevant comprehensive overview of validation studies of nursing diagnoses in neonatology. Design: Review. Methods: The selection criterion was studies concerning the validation of nursing diagnoses in neonatology. To obtain data from relevant sources, the licensed professional databases EBSCO, Web of Science and Scopus were utilized. The search criteria were: date of publication - unlimited; academic periodicals - full text; peer-reviewed periodicals; search language - English, Czech and Slovak. Results: A total of 788 studies were found. Only 5 studies were eligible for content analysis, dealing specifically with validation of nursing diagnoses in neonatology. The analysis of the retrieved studies suggests that authors are most often concerned with identifying the defining characteristics of nursing diagnoses applicable to both the mother (parents and the newborn. The diagnoses were validated in the domains Role Relationship; Coping/Stress tolerance; Activity/Rest, and Elimination and Exchange. Diagnoses represented were from the field of dysfunctional physical needs as well as the field of psychosocial and spiritual needs. The diagnoses were as follows: Parental role conflict (00064; Impaired parenting (00056; Grieving (00136; Ineffective breathing pattern (00032; Impaired gas exchange (00030; and Impaired spontaneous ventilation (00033. Conclusion: Validation studies enable effective planning of interventions with measurable results and support clinical nursing practice.

  17. A validated battery of vocal emotional expressions

    Directory of Open Access Journals (Sweden)

    Pierre Maurage

    2007-11-01

    Full Text Available For a long time, the exploration of emotions focused on facial expression, and vocal expression of emotion has only recently received interest. However, no validated battery of emotional vocal expressions has been published and made available to the researchers’ community. This paper aims at validating and proposing such material. 20 actors (10 men recorded sounds (words and interjections expressing six basic emotions (anger, disgust, fear, happiness, neutral and sadness. These stimuli were then submitted to a double validation phase: (1 preselection by experts; (2 quantitative and qualitative validation by 70 participants. 195 stimuli were selected for the final battery, each one depicting a precise emotion. The ratings provide a complete measure of intensity and specificity for each stimulus. This paper provides, to our knowledge, the first validated, freely available and highly standardized battery of emotional vocal expressions (words and intonations. This battery could constitute an interesting tool for the exploration of prosody processing among normal and pathological populations, in neuropsychology as well as psychiatry. Further works are nevertheless needed to complement the present material.

  18. Establishing model credibility involves more than validation

    International Nuclear Information System (INIS)

    Kirchner, T.

    1991-01-01

    One widely used definition of validation is that the quantitative test of the performance of a model through the comparison of model predictions to independent sets of observations from the system being simulated. The ability to show that the model predictions compare well with observations is often thought to be the most rigorous test that can be used to establish credibility for a model in the scientific community. However, such tests are only part of the process used to establish credibility, and in some cases may be either unnecessary or misleading. Naylor and Finger extended the concept of validation to include the establishment of validity for the postulates embodied in the model and the test of assumptions used to select postulates for the model. Validity of postulates is established through concurrence by experts in the field of study that the mathematical or conceptual model contains the structural components and mathematical relationships necessary to adequately represent the system with respect to the goals for the model. This extended definition of validation provides for consideration of the structure of the model, not just its performance, in establishing credibility. Evaluation of a simulation model should establish the correctness of the code and the efficacy of the model within its domain of applicability. (24 refs., 6 figs.)

  19. Italian version of Dyspnoea-12: cultural-linguistic validation, quantitative and qualitative content validity study.

    Science.gov (United States)

    Caruso, Rosario; Arrigoni, Cristina; Groppelli, Katia; Magon, Arianna; Dellafiore, Federica; Pittella, Francesco; Grugnetti, Anna Maria; Chessa, Massimo; Yorke, Janelle

    2018-01-16

    Dyspnoea-12 is a valid and reliable scale to assess dyspneic symptom, considering its severity, physical and emotional components. However, it is not available in Italian version due to it was not yet translated and validated. For this reason, the aim of this study was to develop an Italian version Dyspnoea-12, providing a cultural and linguistic validation, supported by the quantitative and qualitative content validity. This was a methodological study, divided into two phases: phase one is related to the cultural and linguistic validation, phase two is related to test the quantitative and qualitative content validity. Linguistic validation followed a standardized translation process. Quantitative content validity was assessed computing content validity ratio (CVR) and index (I-CVIs and S-CVI) from expert panellists response. Qualitative content validity was assessed by the narrative analysis on the answers of three open-ended questions to the expert panellists, aimed to investigate the clarity and the pertinence of the Italian items. The translation process found a good agreement in considering clear the items in both the six involved bilingual expert translators and among the ten voluntary involved patients. CVR, I-CVIs and S-CVI were satisfactory for all the translated items. This study has represented a pivotal step to use Dyspnoea-12 amongst Italian patients. Future researches are needed to deeply investigate the Italian version of  Dyspnoea-12 construct validity and its reliability, and to describe how dyspnoea components (i.e. physical and emotional) impact the life of patients with cardiorespiratory diseases.

  20. Validation of the prosthetic esthetic index

    DEFF Research Database (Denmark)

    Özhayat, Esben B; Dannemand, Katrine

    2014-01-01

    OBJECTIVES: In order to diagnose impaired esthetics and evaluate treatments for these, it is crucial to evaluate all aspects of oral and prosthetic esthetics. No professionally administered index currently exists that sufficiently encompasses comprehensive prosthetic esthetics. This study aimed...... to validate a new comprehensive index, the Prosthetic Esthetic Index (PEI), for professional evaluation of esthetics in prosthodontic patients. MATERIAL AND METHODS: The content, criterion, and construct validity; the test-retest, inter-rater, and internal consistency reliability; and the sensitivity...... furthermore distinguish between participants and controls, indicating sufficient sensitivity. CONCLUSION: The PEI is considered a valid and reliable instrument involving sufficient aspects for assessment of the professionally evaluated esthetics in prosthodontic patients. CLINICAL RELEVANCE...

  1. Network Security Validation Using Game Theory

    Science.gov (United States)

    Papadopoulou, Vicky; Gregoriades, Andreas

    Non-functional requirements (NFR) such as network security recently gained widespread attention in distributed information systems. Despite their importance however, there is no systematic approach to validate these requirements given the complexity and uncertainty characterizing modern networks. Traditionally, network security requirements specification has been the results of a reactive process. This however, limited the immunity property of the distributed systems that depended on these networks. Security requirements specification need a proactive approach. Networks' infrastructure is constantly under attack by hackers and malicious software that aim to break into computers. To combat these threats, network designers need sophisticated security validation techniques that will guarantee the minimum level of security for their future networks. This paper presents a game-theoretic approach to security requirements validation. An introduction to game theory is presented along with an example that demonstrates the application of the approach.

  2. Validation of comprehensive space radiation transport code

    International Nuclear Information System (INIS)

    Shinn, J.L.; Simonsen, L.C.; Cucinotta, F.A.

    1998-01-01

    The HZETRN code has been developed over the past decade to evaluate the local radiation fields within sensitive materials on spacecraft in the space environment. Most of the more important nuclear and atomic processes are now modeled and evaluation within a complex spacecraft geometry with differing material components, including transition effects across boundaries of dissimilar materials, are included. The atomic/nuclear database and transport procedures have received limited validation in laboratory testing with high energy ion beams. The codes have been applied in design of the SAGE-III instrument resulting in material changes to control injurious neutron production, in the study of the Space Shuttle single event upsets, and in validation with space measurements (particle telescopes, tissue equivalent proportional counters, CR-39) on Shuttle and Mir. The present paper reviews the code development and presents recent results in laboratory and space flight validation

  3. Valid Competency Assessment in Higher Education

    Directory of Open Access Journals (Sweden)

    Olga Zlatkin-Troitschanskaia

    2017-01-01

    Full Text Available The aim of the 15 collaborative projects conducted during the new funding phase of the German research program Modeling and Measuring Competencies in Higher Education—Validation and Methodological Innovations (KoKoHs is to make a significant contribution to advancing the field of modeling and valid measurement of competencies acquired in higher education. The KoKoHs research teams assess generic competencies and domain-specific competencies in teacher education, social and economic sciences, and medicine based on findings from and using competency models and assessment instruments developed during the first KoKoHs funding phase. Further, they enhance, validate, and test measurement approaches for use in higher education in Germany. Results and findings are transferred at various levels to national and international research, higher education practice, and education policy.

  4. Entropy Evaluation Based on Value Validity

    Directory of Open Access Journals (Sweden)

    Tarald O. Kvålseth

    2014-09-01

    Full Text Available Besides its importance in statistical physics and information theory, the Boltzmann-Shannon entropy S has become one of the most widely used and misused summary measures of various attributes (characteristics in diverse fields of study. It has also been the subject of extensive and perhaps excessive generalizations. This paper introduces the concept and criteria for value validity as a means of determining if an entropy takes on values that reasonably reflect the attribute being measured and that permit different types of comparisons to be made for different probability distributions. While neither S nor its relative entropy equivalent S* meet the value-validity conditions, certain power functions of S and S* do to a considerable extent. No parametric generalization offers any advantage over S in this regard. A measure based on Euclidean distances between probability distributions is introduced as a potential entropy that does comply fully with the value-validity requirements and its statistical inference procedure is discussed.

  5. DTU PMU Laboratory Development - Testing and Validation

    DEFF Research Database (Denmark)

    Garcia-Valle, Rodrigo; Yang, Guang-Ya; Martin, Kenneth E.

    2010-01-01

    This is a report of the results of phasor measurement unit (PMU) laboratory development and testing done at the Centre for Electric Technology (CET), Technical University of Denmark (DTU). Analysis of the PMU performance first required the development of tools to convert the DTU PMU data into IEEE...... standard, and the validation is done for the DTU-PMU via a validated commercial PMU. The commercial PMU has been tested from the authors' previous efforts, where the response can be expected to follow known patterns and provide confirmation about the test system to confirm the design and settings....... In a nutshell, having 2 PMUs that observe same signals provides validation of the operation and flags questionable results with more certainty. Moreover, the performance and accuracy of the DTU-PMU is tested acquiring good and precise results, when compared with a commercial phasor measurement device, PMU-1....

  6. Model validation: a systemic and systematic approach

    International Nuclear Information System (INIS)

    Sheng, G.; Elzas, M.S.; Cronhjort, B.T.

    1993-01-01

    The term 'validation' is used ubiquitously in association with the modelling activities of numerous disciplines including social, political natural, physical sciences, and engineering. There is however, a wide range of definitions which give rise to very different interpretations of what activities the process involves. Analyses of results from the present large international effort in modelling radioactive waste disposal systems illustrate the urgent need to develop a common approach to model validation. Some possible explanations are offered to account for the present state of affairs. The methodology developed treats model validation and code verification in a systematic fashion. In fact, this approach may be regarded as a comprehensive framework to assess the adequacy of any simulation study. (author)

  7. Orthorexia nervosa: validation of a diagnosis questionnaire.

    Science.gov (United States)

    Donini, L M; Marsili, D; Graziani, M P; Imbriale, M; Cannella, C

    2005-06-01

    To validate a questionnaire for the diagnosis of orhorexia oervosa, an eating disorder defined as "maniacal obsession for healthy food". 525 subjects were enrolled. Then they were randomized into two samples (sample of 404 subjects for the construction of the test for the diagnosis of orthorexia ORTO-15; sample of 121 subjects for the validation of the test). The ORTO-15 questionnaire, validated for the diagnosis of orthorexia, is made-up of 15 multiple-choice items. The test we proposed for the diagnosis of orthorexia (ORTO 15) showed a good predictive capability at a threshold value of 40 (efficacy 73.8%, sensitivity 55.6% and specificity 75.8%) also on verification with a control sample. However, it has a limit in identifying the obsessive disorder. For this reason we maintain that further investigation is necessary and that new questions useful for the evaluation of the obsessive-compulsive behavior should be added to the ORTO-15 questionnaire.

  8. A broad view of model validation

    International Nuclear Information System (INIS)

    Tsang, C.F.

    1989-10-01

    The safety assessment of a nuclear waste repository requires the use of models. Such models need to be validated to ensure, as much as possible, that they are a good representation of the actual processes occurring in the real system. In this paper we attempt to take a broad view by reviewing step by step the modeling process and bringing out the need to validating every step of this process. This model validation includes not only comparison of modeling results with data from selected experiments, but also evaluation of procedures for the construction of conceptual models and calculational models as well as methodologies for studying data and parameter correlation. The need for advancing basic scientific knowledge in related fields, for multiple assessment groups, and for presenting our modeling efforts in open literature to public scrutiny is also emphasized. 16 refs

  9. Validation of Visual Caries Activity Assessment

    DEFF Research Database (Denmark)

    Guedes, R S; Piovesan, C; Ardenghi, T M

    2014-01-01

    We evaluated the predictive and construct validity of a caries activity assessment system associated with the International Caries Detection and Assessment System (ICDAS) in primary teeth. A total of 469 children were reexamined: participants of a caries survey performed 2 yr before (follow-up rate...... of 73.4%). At baseline, children (12-59 mo old) were examined with the ICDAS and a caries activity assessment system. The predictive validity was assessed by evaluating the risk of active caries lesion progression to more severe conditions in the follow-up, compared with inactive lesions. We also...... assessed if children with a higher number of active caries lesions were more likely to develop new lesions (construct validity). Noncavitated active caries lesions at occlusal surfaces presented higher risk of progression than inactive ones. Children with a higher number of active lesions and with higher...

  10. Validation of dengue infection severity score

    Directory of Open Access Journals (Sweden)

    Pongpan S

    2014-03-01

    Full Text Available Surangrat Pongpan,1,2 Jayanton Patumanond,3 Apichart Wisitwong,4 Chamaiporn Tawichasri,5 Sirianong Namwongprom1,6 1Clinical Epidemiology Program, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; 2Department of Occupational Medicine, Phrae Hospital, Phrae, Thailand; 3Clinical Epidemiology Program, Faculty of Medicine, Thammasat University, Bangkok, Thailand; 4Department of Social Medicine, Sawanpracharak Hospital, Nakorn Sawan, Thailand; 5Clinical Epidemiology Society at Chiang Mai, Chiang Mai, Thailand; 6Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand Objective: To validate a simple scoring system to classify dengue viral infection severity to patients in different settings. Methods: The developed scoring system derived from 777 patients from three tertiary-care hospitals was applied to 400 patients in the validation data obtained from another three tertiary-care hospitals. Percentage of correct classification, underestimation, and overestimation was compared. The score discriminative performance in the two datasets was compared by analysis of areas under the receiver operating characteristic curves. Results: Patients in the validation data were different from those in the development data in some aspects. In the validation data, classifying patients into three severity levels (dengue fever, dengue hemorrhagic fever, and dengue shock syndrome yielded 50.8% correct prediction (versus 60.7% in the development data, with clinically acceptable underestimation (18.6% versus 25.7% and overestimation (30.8% versus 13.5%. Despite the difference in predictive performances between the validation and the development data, the overall prediction of the scoring system is considered high. Conclusion: The developed severity score may be applied to classify patients with dengue viral infection into three severity levels with clinically acceptable under- or overestimation. Its impact when used in routine

  11. Human Factors methods concerning integrated validation of nuclear power plant control rooms; Metodutveckling foer integrerad validering

    Energy Technology Data Exchange (ETDEWEB)

    Oskarsson, Per-Anders; Johansson, Bjoern J.E.; Gonzalez, Natalia (Swedish Defence Research Agency, Information Systems, Linkoeping (Sweden))

    2010-02-15

    The frame of reference for this work was existing recommendations and instructions from the NPP area, experiences from the review of the Turbic Validation and experiences from system validations performed at the Swedish Armed Forces, e.g. concerning military control rooms and fighter pilots. These enterprises are characterized by complex systems in extreme environments, often with high risks, where human error can lead to serious consequences. A focus group has been performed with representatives responsible for Human Factors issues from all Swedish NPP:s. The questions that were discussed were, among other things, for whom an integrated validation (IV) is performed and its purpose, what should be included in an IV, the comparison with baseline measures, the design process, the role of SSM, which methods of measurement should be used, and how the methods are affected of changes in the control room. The report brings different questions to discussion concerning the validation process. Supplementary methods of measurement for integrated validation are discussed, e.g. dynamic, psychophysiological, and qualitative methods for identification of problems. Supplementary methods for statistical analysis are presented. The study points out a number of deficiencies in the validation process, e.g. the need of common guidelines for validation and design, criteria for different types of measurements, clarification of the role of SSM, and recommendations for the responsibility of external participants in the validation process. The authors propose 12 measures for taking care of the identified problems

  12. Further Validation of the IDAS: Evidence of Convergent, Discriminant, Criterion, and Incremental Validity

    Science.gov (United States)

    Watson, David; O'Hara, Michael W.; Chmielewski, Michael; McDade-Montez, Elizabeth A.; Koffel, Erin; Naragon, Kristin; Stuart, Scott

    2008-01-01

    The authors explicated the validity of the Inventory of Depression and Anxiety Symptoms (IDAS; D. Watson et al., 2007) in 2 samples (306 college students and 605 psychiatric patients). The IDAS scales showed strong convergent validity in relation to parallel interview-based scores on the Clinician Rating version of the IDAS; the mean convergent…

  13. Validation of Multilevel Constructs: Validation Methods and Empirical Findings for the EDI

    Science.gov (United States)

    Forer, Barry; Zumbo, Bruno D.

    2011-01-01

    The purposes of this paper are to highlight the foundations of multilevel construct validation, describe two methodological approaches and associated analytic techniques, and then apply these approaches and techniques to the multilevel construct validation of a widely-used school readiness measure called the Early Development Instrument (EDI;…

  14. Marketing Plan for Demonstration and Validation Assets

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2008-05-30

    The National Security Preparedness Project (NSPP), is to be sustained by various programs, including technology demonstration and evaluation (DEMVAL). This project assists companies in developing technologies under the National Security Technology Incubator program (NSTI) through demonstration and validation of technologies applicable to national security created by incubators and other sources. The NSPP also will support the creation of an integrated demonstration and validation environment. This report documents the DEMVAL marketing and visibility plan, which will focus on collecting information about, and expanding the visibility of, DEMVAL assets serving businesses with national security technology applications in southern New Mexico.

  15. Italian Validation of Homophobia Scale (HS

    Directory of Open Access Journals (Sweden)

    Giacomo Ciocca, PsyD, PhD

    2015-09-01

    Conclusions: The Italian validation of the HS revealed the use of this self‐report test to have good psychometric properties. This study offers a new tool to assess homophobia. In this regard, the HS can be introduced into the clinical praxis and into programs for the prevention of homophobic behavior. Ciocca G, Capuano N, Tuziak B, Mollaioli D, Limoncin E, Valsecchi D, Carosa E, Gravina GL, Gianfrilli D, Lenzi A, and Jannini EA. Italian validation of Homophobia Scale (HS. Sex Med 2015;3:213–218.

  16. Validating the passenger traffic model for Copenhagen

    DEFF Research Database (Denmark)

    Overgård, Christian Hansen; VUK, Goran

    2006-01-01

    The paper presents a comprehensive validation procedure for the passenger traffic model for Copenhagen based on external data from the Danish national travel survey and traffic counts. The model was validated for the years 2000 to 2004, with 2004 being of particular interest because the Copenhagen...... matched the observed traffic better than those of the transit assignment model. With respect to the metro forecasts, the model over-predicts metro passenger flows by 10% to 50%. The wide range of findings from the project resulted in two actions. First, a project was started in January 2005 to upgrade...

  17. Validating Acquisition IS Integration Readiness with Drills

    DEFF Research Database (Denmark)

    Wynne, Peter J.

    2017-01-01

    To companies, mergers and acquisitions are important strategic tools, yet they often fail to deliver their expected value. Studies have shown the integration of information systems is a significant roadblock to the realisation of acquisition benefits, and for an IT department to be ready......), to understand how an IT department can use them to validate their integration plans. The paper presents a case study of two drills used to validate an IT department’s readiness to carry out acquisition IS integration, and suggests seven acquisition IS integration drill characteristics others could utilise when...

  18. Reliability and validity of risk analysis

    International Nuclear Information System (INIS)

    Aven, Terje; Heide, Bjornar

    2009-01-01

    In this paper we investigate to what extent risk analysis meets the scientific quality requirements of reliability and validity. We distinguish between two types of approaches within risk analysis, relative frequency-based approaches and Bayesian approaches. The former category includes both traditional statistical inference methods and the so-called probability of frequency approach. Depending on the risk analysis approach, the aim of the analysis is different, the results are presented in different ways and consequently the meaning of the concepts reliability and validity are not the same.

  19. Method Validation Procedure in Gamma Spectroscopy Laboratory

    International Nuclear Information System (INIS)

    El Samad, O.; Baydoun, R.

    2008-01-01

    The present work describes the methodology followed for the application of ISO 17025 standards in gamma spectroscopy laboratory at the Lebanese Atomic Energy Commission including the management and technical requirements. A set of documents, written procedures and records were prepared to achieve the management part. The technical requirements, internal method validation was applied through the estimation of trueness, repeatability , minimum detectable activity and combined uncertainty, participation in IAEA proficiency tests assure the external method validation, specially that the gamma spectroscopy lab is a member of ALMERA network (Analytical Laboratories for the Measurements of Environmental Radioactivity). Some of these results are presented in this paper. (author)

  20. Plant monitoring and signal validation at HFIR

    International Nuclear Information System (INIS)

    Mullens, J.A.

    1991-01-01

    This paper describes a monitoring system for the Oak Ridge National Laboratory's (ORNL'S) High Flux Isotope Reactor (HFIR). HFIR is an 85 MW pressurized water reactor designed to produce isotopes and intense neutron beams. The monitoring system is described with respect to plant signals and computer system; monitoring overview; data acquisition, logging and network distribution; signal validation; status displays; reactor condition monitoring; reactor operator aids. Future work will include the addition of more plant signals, more signal validation and diagnostic capabilities, improved status display, integration of the system with the RELAP plant simulation and graphical interface, improved operator aids, and an alarm filtering system. 8 refs., 7 figs. (MB)