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Author

Vishnu P. Choudhari

Other affiliations: Sinhgad college of Pharmacy
Bio: Vishnu P. Choudhari is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: Drotaverine & Chromatography. The author has an hindex of 9, co-authored 46 publications receiving 230 citations. Previous affiliations of Vishnu P. Choudhari include Sinhgad college of Pharmacy.


Papers
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Journal ArticleDOI
TL;DR: In this article, two methods for the simultaneous determination of Emtricitabine and Tenofovir by spectroscopy have been developed: Area Under the Curve (AUC) method and Dual Wavelength Method.
Abstract: Two methods for the simultaneous determination of Emtricitabine and Tenofovir by spectroscopy have been developed. These two simple, accurate and precise methods include Area Under the Curve (AUC) method and Dual Wavelength Method. From a solvent effect studies and the spectral behaviours of Emtricitabine and Tenofovir, methanol was selected as solvent. Emtricitabine shows maximum absorbance at 281 nm and Tenofovir shows maximum absorbance at 259 nm. For the AUC method, the wavelength ranges between 242-248 nm and 269-275 nm were selected with reference to the absorbance curves plotted between the wavelengths of 200-400 nm. In the second method i.e. Dual method in which two wavelengths were selected for each drug in a way so that the difference in absorbance is zero for another drug. Emtricitabine shows equal absorbance at 230.696 nm and 250 nm, where the differences in absorbance were measured for the determination of Tenofovir. Similarly, differences in absorbances at 250 nm and 268.670 nm were measured for determination of Emtricitabine. These methods allows rapid analysis of two drug combination. The results of analysis were validated statistically and by recovery studies. This tablet containing both drugs was assayed using the methods developed, showing a good accuracy and precision.

27 citations

Journal ArticleDOI
TL;DR: Three simple, economical, precise, and accurate methods are described for the simultaneous determination of Tenofovir disoproxil fumarate and Emtricitabine in combined tablet dosage form and absorption corrected method was successfully applied to carry out dissolution study of commercial tablet formulation by using USP II dissolution test apparatus.
Abstract: Three simple, economical, precise, and accurate methods are described for the simultaneous determination of Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM) in combined tablet dosage form. The first method is ratio derivative spectra, second is first-order derivative spectrophotometry and third is absorption corrected method. The amplitudes at 271.07 and 302.17 nm in the ratio derivative method, 224.38 and 306.88 nm in the first order derivative method were selected to determine Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM), respectively, in combined formulation. Beer’s law is obeyed in the concentration range of 3-21 µ g/ml for TE and 2-14 µ g/ml for EM for first two methods and range for third method was 6-30 µ g/ml of TE and 4-20 µ g/ml of EM. The percent assay for commercial formulation was found to be in the range 98.91%–101.72% for both the analytes by the proposed three methods. Absorption corrected method was successfully applied to carry out dissolution study of commercial tablet formulation by using USP II dissolution test apparatus. The methods were validated with respect to linearity, precision, and accuracy. Recoveries by proposed methods were found in the range of 99.06 %-101.34 % for both the analytes.

24 citations

Journal ArticleDOI
TL;DR: It is concluded that the OJ possesses significant antidiabetic and antihyperlipidemic activities in rats, and co-treatment of diabetic rats with OJ and Metformin failed to control blood glucose levels.

21 citations

Journal ArticleDOI
TL;DR: In this article, a reversed phase liquid chromatographic method was developed for simultaneous determination of Atorvastatin, Ezetimibe and Fenofibrate in their ternary mixture of commercial pharmaceutical preparations.
Abstract: A simple, rapid and precise reversed-phase liquid chromatographic method is developed for simultaneous determination of Atorvastatin, Ezetimibe and Fenofibrate in their ternary mixture of commercial pharmaceutical preparations. This method, reported first time for a ternary mixture, uses a Kromasil C18, 250 × 4.6 mm, 5μm analytical column. Analytes were estimated by gradient elution with methanol/water at flow rate of 0.9 mL/min; the column temperature is 40°C and detector wavelength is 240 nm. The sample concentrations are measured on weight basis to avoid the internal standard. The method is validated and shown to be linear. The correlation coefficients for Atorvastatin, Ezetimibe and Fenofibrate are 0.9995, 0.9993 and 0.9996, respectively. The recovery values for Atorvastatin, Ezetimibe and Fenofibrate ranged from 99.7–101.1%, 99.8–101.3% and 99.7–101.7%, respectively. The relative standard deviation for six replicates is always less than 2%. This HPLC method is successfully applied to the simultaneous quantitative analysis of the title drugs in tablets.

19 citations

01 Jan 2010
TL;DR: In this article, a simple, economical, precise and accurate method for simultaneous determination of Atenolol (ATE) and Lercanidipine Hydrochloride (LER) in combined dosage form has been developed.
Abstract: A simple, economical, precise and accurate method for simultaneous determination of Atenolol (ATE) and Lercanidipine Hydrochloride (LER) in combined dosage form has been developed. The first method is based on Ratio Derivative (Method A) and second method is based on Dual Wavelength (Method B). The amplitudes 266.98 nm and 386.97 nm wavelength were selected to determine ATE and LER respectively, by method A. In method B, two wavelengths were selected for each drug in a way so that the difference in absorbance is zero for another drug. At wavelengths 234.01 nm and 238.66 nm Lercanidipine have equal absorbance therefore these two wavelengths were used to determine ATE and on similar basis 253.33 nm and 286.07 nm were selected to determine LER in combined formulation. The drugs obey Beer’s law in the concentration range of 25-125 µg mL -1 for ATE and 5-25 µg mL -1 for LER by the method A and 50-90 µg mL -1 for ATE and 10-18 µg mL -1 for LER by the method B. The % assay of LER and ATE was found to be in the range 99.98 – 101.12 % by the proposed methods. Recovery was found in the range of 98.4 - 101.0 % for both analytes by both methods. The results of analysis have been validated statistically and recovery studies confirmed the accuracy and reproducibility of the proposed methods which were carried out by following ICH guidelines.

15 citations


Cited by
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Book ChapterDOI
01 Jan 2014
TL;DR: In this paper, a revision of the previous edition article by Robert Visser, volume 4, pp 551-560, is presented. But this article is based on the previous version of the article.
Abstract: This article is a revision of the previous edition article by Robert Visser, volume 4, pp 551–560, © 2005, Elsevier Inc.

766 citations

Journal ArticleDOI
TL;DR: Several techniques have been proposed for treatment of spectrophotometric data, with the objective of extracting the largest amount of analytical information from spectra composed of unresolved bands as mentioned in this paper, including zero order absorption, derivative and ratio amplitudes.
Abstract: Several techniques have been proposed for treatment of spectrophotometric data, with the objective of extracting the largest amount of analytical information from spectra composed of unresolved bands. The instrumental development and analytical applications of UV regions absorption spectrophotometry produced in the last 10 y (since 2006) are reviewed. The methods were classified according to the spectra data used, including zero order absorption, derivative and ratio amplitudes. The proposed methods were applied to solve different complex pharmaceutical mixtures and the obtained results were accepted when compared to other reported methods.

45 citations

Journal ArticleDOI
TL;DR: This review addresses the use of modified and cheap materials for antibiotic removal from the environment through several techniques used to remove pollutants.

44 citations

Journal ArticleDOI
TL;DR: A critical review of the literature of the analysis of steroid hormone drugs is presented in this paper based on 213 publications published between 2004 and 2010, where the state of the art of the assay and purity check of bulk drug materials is characterized on the basis of the principal pharmacopoeias supplemented by the literature dealing with their impurity profiling and solid state characterization.

40 citations

Journal ArticleDOI
TL;DR: PP demonstrated an antioxidative effect, suppressed malondialdehyde levels, and restored antioxidant enzyme activities in diabetic rats, and also noticed inhibition of OMP, AGE, and AOPP formation in the rats′ blood plasma.
Abstract: This study was designed to evaluate the effects of purple potato extract of the Blue Congo variety (PP) on diabetes and its antioxidant activities after two-week administration tostreptozotocin (STZ)-induced diabetic rats. The activities of PP were evaluated at a dose of 165 mg/kg body weight (b.w.) by estimating biochemical changes in blood plasma and through a histopathological study of kidney, muscles, and liver tissue. We evaluated the effect of treatment with extract on glucose level, glycated hemoglobin, activities of enzymatic antioxidants (including superoxide dismutase, glutathione peroxidase, and catalase), and lipid peroxidation. Moreover, we determined advanced glycation end-products (AGEs), advanced oxidation protein products (AOPPs), and the level of oxidative modified proteins (OMPs) as markers of carbonyl-oxidative stress in rats with diabetes. Using high-performance liquid chromatography, we identified five anthocyanins and six phenolic acids in the extract from Blue Congo with the dominant acylated anthocyanin as petunidin-3-p-coumaroyl-rutinoside-5-glucoside. The administration of Blue Congo extract lowered blood glucose, improved glucose tolerance, and decreased the amount of glycated hemoglobin. Furthermore, PP demonstrated an antioxidative effect, suppressed malondialdehyde levels, and restored antioxidant enzyme activities in diabetic rats. After administration of PP, we also noticed inhibition of OMP, AGE, and AOPP formation in the rats′ blood plasma.

38 citations