oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Development and Validation of RP-HPLC Method for Azilsartan Medoxomil Potassium Quantitation in Human Plasma by Solid Phase Extraction Procedure  [PDF]
Paras P. Vekariya,Hitendra S. Joshi
ISRN Spectroscopy , 2013, DOI: 10.1155/2013/572170
Abstract: Simple and rapid reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated using solid phase extraction (SPE) technique for the determination of Azilsartan Medoxomil Potassium (AMP) in human plasma; detection was carried out by photo diode array detector. Chromatographic separation of the analyte AMP was achieved within 7.5?min by Waters symmetry C18 (4.6 × 250?mm, 5?μm) column, mobile phase was 25?mM ammonium acetate buffer (pH 5.5): acetonitrile 55?:?45?v/v, flow rate was 1.0?mL/min, and the detection was carried out at 254?nm. Calibration curve was linear (r2 > 0.9985) in the range of 1.0–9.0?μg/mL, limit of detection (LOD) and limit of quantitation (LOQ) were 0.150?μg/mL and 0.400?μg/mL, respectively, and intra- and interday deviations were between 1.53–8.41% and 1.78–4.59%, respectively. The overall mean recovery of AMP was 92.35%. No any endogenous constituents were found to interfere at retention time of the analyte. This new RP-HPLC method was successfully validated and may be applied to conduct bioavailability and bioequivalence studies of AMP. 1. Introduction Azilsartan Medoxomil Potassium is chemically named as (5-Methyl-2-oxo-1,3-dioxol-4yl) methyl 2-ethoxy-1-{[2′-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl) biphenyl-4-yl]methyl}-1H-benzimidazole-7-carboxylate monopotassium salt (Figure 1). It is a white crystalline powder which is practically insoluble in water, freely soluble in methanol, dimethylsulfoxide, and dimethylformamide, soluble in acetic acid, slightly soluble in acetone, and acetonitrile and very slightly soluble in tetrahydrofuran and 1-octanol [1]. Figure 1: Chemical structure of lafutidine hydrochloride salt. The US Food and Drug Administration (FDA) has approved Edarbi tablet (Azilsartan Medoxomil Potassium) on February 25, 2011, to treat hypertension in adults. It is available in 80?mg and 40?mg dosages, with the recommended dosage set at 80?mg once in a day [2]. Angiotensin II hormone plays a vital role in activation of renin-angiotensin-aldosterone system as well as in regulation of blood pressure, fluid-electrolyte balance, and also in pathophysiology of hypertension. Activation of type 1 angiotensin receptor which is a member of G protein coupled receptor efficiently controls the numerous effects of AII which are vasoconstriction, secretion of aldosterone and vasopressin and cellular proliferation. So blocking of AII receptor will also block receptor-1, and it will lead to termination of the whole course of action mentioned above; so AII blocker will be helpful in the management of
METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF OFLOXACIN AND ORNIDAZOLE IN TABLET DOSAGE FORM BY RP-HPLC  [PDF]
B.Dhandapani,,N.Thirumoorthy,Shaik Harun Rasheed,,M.Rama kotaiah
International Journal of Pharmaceutical and Biological Research , 2010,
Abstract: A simple reverse phase liquid chromatographic method has been developed and subsequently validated for simultaneous determination of Ofloxacin and Ornidazole in combination. The separation was carried out using a mobile phase consisting of 2mM phosphate buffer and Acetonitrile with pH 3.5 adjusted with ortho phosphoric acid in the ratio of 70: 30%v/v. The column used was Phenomenex C18, (250 mm x 4.6 mm i.d, 5 m) with flow rate of 1 ml / min using PDA detection at 293 nm. The described method was linear over a concentration range of 5-50 g/ml and 12.5-125 g/ml for the assay of Ofloxacin and Ornidazole respectively. Gatifloxacin (50 g/ml) was used as nternal standard. The retention times of Ofloxacin, Ornidazole and Gatifloxacin were found to be 2.1, 2.5 and 5.5min respectively. Results of analysis were validated statistically and by recovery tudies. The limit of detection (LOD) and the limit of quantification (LOQ) for Ofloxacin and Ornidazole were found to be 5 and10 μg/ml10 and 25 μg/ml respectively. The results of the study showed that the proposed RP-HPLC method is simple, rapid, precise and accurate, which is useful for the routine determination of Ofloxacin and Ornidazole bulk drug and in its pharmaceutical dosage form.
Method Development and Validation for The Simultaneous Estimation of Ofloxacin and Ornidazole in Tablet Dosage Form by Rp-Hplc
B.Dhandapani,,N.Thirumoorthy,Shaik Harun Rasheed,,M.Rama kotaiah
International Journal of Pharma Sciences and Research , 2010,
Abstract: A simple reverse phase liquid chromatographic method has been developed and subsequently validated for simultaneous determination of Ofloxacin and Ornidazole in combination. The separation was carriedout using a mobile phase consisting of 2mM phosphate buffer and Acetonitrile with pH 3.5 adjusted with ortho phosphoric acid in the ratio of 70: 30%v/v. The column used was Phenomenex C18, (250 mm x 4.6 mm i.d, 5 m) with flow rate of 1 ml / min using PDA detection at 293 nm. The described method was linear over a concentration range of 5-50 g/ml and 12.5-125 g/ml for the assay of Ofloxacin and Ornidazole respectively. Gatifloxacin (50 g/ml) was used as internal standard. The retention times of Ofloxacin, Ornidazole and Gatifloxacin were found to be 2.1, 2.5 and 5.5min respectively. Results of analysis were validated statistically and by recovery studies. The limit of detection (LOD) and the limit of quantification (LOQ) for Ofloxacin and Ornidazole were found to be 5 and10 μg/ml 10 and 25 μg/ml respectively. The results of the study showed that the proposed RP-HPLC method is simple, rapid, precise and accurate, which is useful for the routine determination of Ofloxacin and Ornidazolebulk drug and in its pharmaceutical dosage form.
Simultaneous determination of ofloxacin and ornidazole in solid dosage form by RP-HPLC and HPTLC techniques  [cached]
Puranik Manisha,Bhawsar D,Rathi Prachi,Yeole P
Indian Journal of Pharmaceutical Sciences , 2010,
Abstract: The objective of this work was to develop and validate simple, rapid and accurate chromatographic methods for simultaneous determination of ofloxacin and ornidazole in solid dosage form. The first method was based on reversed phase high performance liquid chromatography, on Intersil C 18 column (250 mm, 4.6 i.d.), using acetonitrile:methanol: 0.025M phosphate buffer, pH 3.0 (30:10:60 % v/v/v) as the mobile phase, at a flow rate of 1 ml/min at ambient temperature. Quantification was achieved with UV detection at 318 nm over a concentration range of 2-40 μg/ml for ofloxacin and 5-100 μg/ml for ornidazole. The mean retention time of ofloxacin and ornidazole was found to be 4.04 min and 5.83 min, 6.77 min (isomers), respectively. The amount of ofloxacin and ornidazole estimated as percentage of label claimed was found to be 100.23 and 99.61%, with mean percent recoveries 100.20 and 100.93%, respectively. The second method was based on TLC separation of these drugs using silica gel 60F 254 aluminium sheets and dichloromethane:methanol:25% ammonia solution (9.5:1:3 drops v/v) as mobile phase. Detection was carried out at 318 nm over the concentration range of 20-100 ng/spot for ofloxacin and 50-250 ng/spot for ornidazole. The mean R f value of ofloxacin and ornidazole was found to be 0.16 and 0.56, 0.78 (isomers), respectively. The amount of ofloxacin and ornidazole estimated as percentage of label claimed was found to be 100.23 and 99.61% with mean percent recoveries 100.47 and 99.32%, respectively. Both these methods were found to be simple, precise, accurate, selective and rapid and could be successfully applied for the determination of pure laboratory prepared mixtures and tablets.
PHARMACOKINETIC STUDY OF RISPERIDONE: APPLICATION OF A HPLC METHOD WITH SOLID PHASE EXTRACTION
TORRES V,PABLO; SEPúLVEDA C,M. JACQUELINE; VON PLESSING R,CARLOS;
Journal of the Chilean Chemical Society , 2011, DOI: 10.4067/S0717-97072011000100019
Abstract: a new, simplified solid phase extraction procedure for the determination of risperidone and 9-hydroxyrisperidone in human plasma has been developed. this method involves the use of an optimized extraction protocol developed in waters oasis? hlb 30mg 1cc extraction columns using 1 ml of human serum. separation was performed by hplc using a waters xterra rp-18 (5 μm, 150x4,6 mm) column with a mobile phase consisting in acetonitrile - potassium dihydrogen phosphate 50 mm ph 3.4 (27/73). uv detection at 278 nm was used to quantify analytes, encountering good linearity (r2 > 0.999) in the 2-100 ng/ml concentration range. the mean recovery was 92.4 % and 92.8 % for risperidone and 9-hydroxyrisperidone respectively, with an intraday - interday precision below 7%, and accuracy below 115 %. the method has been successfully applied in pharmacokinetic studies that require a large sample number.
PHARMACOKINETIC STUDY OF RISPERIDONE: APPLICATION OF A HPLC METHOD WITH SOLID PHASE EXTRACTION  [cached]
PABLO TORRES V,M. JACQUELINE SEPúLVEDA C,CARLOS VON PLESSING R
Journal of the Chilean Chemical Society , 2011,
Abstract: A new, simplified solid phase extraction procedure for the determination of risperidone and 9-hydroxyrisperidone in human plasma has been developed. This method involves the use of an optimized extraction protocol developed in Waters OASIS HLB 30mg 1cc extraction columns using 1 mL of human serum. Separation was performed by HPLC using a Waters XTerra RP-18 (5 μm, 150x4,6 mm) column with a mobile phase consisting in acetonitrile - potassium dihydrogen phosphate 50 mM pH 3.4 (27/73). UV detection at 278 nm was used to quantify analytes, encountering good linearity (r2 > 0.999) in the 2-100 ng/mL concentration range. The mean recovery was 92.4 % and 92.8 % for risperidone and 9-hydroxyrisperidone respectively, with an intraday - interday precision below 7%, and accuracy below 115 %. The method has been successfully applied in pharmacokinetic studies that require a large sample number.
Determination of Ofloxacin in Plasma by HPLC with UV Detection  [PDF]
M. Amini,Kh. Abdi,M. Darabi,A. Shafiee
Journal of Applied Sciences , 2005,
Abstract: A simple, sensitive isocratic method for detection and quantification of ofloxacin in plasma has been developed. The assay consisted of reversed HPLC with UV detection. Separation was achieved on a C18 column. The detection limit was 10 ng mL-1 in plasma. The validation data has been studied. This method provides sufficient sensitivity for pharmacokinetic studies and dose control in veterinary as well as in human medicine.
Validation of a method using solid phase extraction and liquid chromatography for the determination of pesticide residues in groundwaters
Caldas, Sergiane S.;Demoliner, Adriana;Primel, Ednei G.;
Journal of the Brazilian Chemical Society , 2009, DOI: 10.1590/S0103-50532009000100020
Abstract: a method is described for the determination of the pesticides carbofuran, clomazone, 2,4-d and tebuconazole in groundwaters. the method involves solid phase extraction (spe) with c18 cartridges and quantification by high performance liquid chromatography with diode array detector (hplc-dad). after the optimization of the extraction and separation parameters, the method was validated by evaluating the analytical curve, linearity, limits of detection and quantification, precision and accuracy (recovery). the method presents an average recovery of 87.9% and 96.9%, in repeatability and intermediate precision conditions, respectively, with adequate precision (rsd from 0.8 to 20.7%), for all compounds. the method will be applied to determine pesticides in groundwater samples with limit of quantification of 0.2 μg l-1.
Optimization of Analytical Conditions to Determine Steroids and Pharmaceuticals Drugs in Water Samples Using Solid Phase-Extraction and HPLC  [PDF]
Ramiro Vallejo-Rodríguez, Alberto Lopez-Lopez, Hugo Saldarriaga-Nore?a, Mario Murillo-Tovar, Leonel Hernández-Mena
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.28099
Abstract: Two reliable methods were optimized to determine two steroids (17?-Estradiol and 17?-Ethinylestradiol) and two pharmaceutical drugs (ibuprofen and naproxen) using Solid-Phase Extraction (SPE) for sample preparation and High Performance Liquid Chromatography (HPLC) for analysis. SPE (C18) conditions were evaluated varying elution solvent volume, pH conditions and sample mass in the cartridge and reduction techniques of the extract. The efficiency of the analytical methods was evaluated by spiking ultrapure water samples with compounds at three and four levels of concentration for steroids and pharmaceutical drugs, re- spectively. The recoveries were independent (P > 0.05) of added mass of target analytes with a repeatability lower than 6.5% for steroids and 12.1% for pharmaceutical compounds. The recovery factor (coefficient of variation, CV) was higher than 83% for steroids (CV < 3.8%) and >93% for pharmaceuticals (CV < 5.2%). The optimized analytical method was applied for the evaluation of a steroid degradation test using ozone, finding that the estimated limit of detection is sufficient to determine the residual mass (μg?L–1) of 17β-Estradiol after the experiment.
Optimization and validation of the solid-liquid extraction technique for determination of picloram in soils by high performance liquid chromatography
Assis, E.C;Silva, A.A;Barbosa, L.C;Queiroz, M.E.L.R;D'Antonino, L;Gon?alves, V.A;
Planta Daninha , 2011, DOI: 10.1590/S0100-83582011000300023
Abstract: the objective of this study was to optimize and validate the solid-liquid extraction (esl) technique for determination of picloram residues in soil samples. at the optimization stage, the optimal conditions for extraction of soil samples were determined using univariate analysis. ratio soil/solution extraction, type and time of agitation, ionic strength and ph of extraction solution were evaluated. based on the optimized parameters, the following method of extraction and analysis of picloram was developed: weigh 2.00 g of soil dried and sieved through a sieve mesh of 2.0 mm pore, add 20.0 ml of kcl concentration of 0.5 mol l-1, shake the bottle in the vortex for 10 seconds to form suspension and adjust to ph 7.00, with alkaline koh 0.1 mol l-1. homogenate the system in a shaker system for 60 minutes and then let it stand for 10 minutes. the bottles are centrifuged for 10 minutes at 3,500 rpm. after the settlement of the soil particles and cleaning of the supernatant extract, an aliquot is withdrawn and analyzed by high performance liquid chromatography. the optimized method was validated by determining the selectivity, linearity, detection and quantification limits, precision and accuracy. the esl methodology was efficient for analysis of residues of the pesticides studied, with percentages of recovery above 90%. the limits of detection and quantification were 20.0 and 66.0 mg kg-1 soil for the pva, and 40.0 and 132.0 mg kg-1 soil for the vla. the coefficients of variation (cv) were equal to 2.32 and 2.69 for pva and th soils, respectively. the methodology resulted in low organic solvent consumption and cleaner extracts, as well as no purification steps for chromatographic analysis were required. the parameters evaluated in the validation process indicated that the esl methodology is efficient for the extraction of picloram residues in soils, with low limits of detection and quantification.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.