Vijay Parmar

Publications (14) View all

• Article: Hydrochloride salt co-crystals: preparation, characterization and physicochemical studies.

  Vijaykumar K Parmar, Shailesh A Shah
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  ABSTRACT: Co-crystallization approach for modification of physicochemical properties of hydrochloride salt is presented. The objective of this investigation was to study the effect of co-crystallization with different co-crystal formers on physicochemical properties of fluoxetine hydrochloride (FH). FH was screened for co-crystallization with a series of carboxylic acid co-formers by slow evaporation method. Photomicrographs and melting points of crystalline phases were determined. The co-crystals were characterized by FTIR, DSC and PXRD methods. Solubility of co-crystals was determined in water and buffer solutions. Powder and intrinsic dissolution profiles were assessed for co-crystals. Physical mixtures of drug and co-formers were used for comparisons at characterizations and physicochemical properties evaluation stages. Four co-crystals of FH viz. Fluoxetine hydrochloride-maleic acid (FH-MA), Fluoxetine hydrochloride-glutaric acid (FH-GA), Fluoxetine hydrochloride-L-tartaric acid (FH-LTA) and Fluoxetine hydrochloride-DL-tartaric acid (FH-DLTA) were obtained from screening experiments. Physical characterization showed that they have unique crystal morphology, thermal, spectroscopic and X-ray diffraction properties. Solubility and dissolution studies showed that Fluoxetine hydrochloride-maleic acid co-crystal possess high aqueous solubility in distilled water, pH 4.6, 7.0 buffer solutions and dissolution rate in distilled water than that of pure drug. Co-crystal formation approach can be used for ionic API to tailor its physical properties.
  Pharmaceutical Development and Technology 06/2012; · 1.36 Impact Factor
• Article: RP-HPLC Method for Estimation of Nitazoxanide in Oral Suspension Formulation

  Jimish R Patel, Harpreet Singh Bedi, Anil Middha, Laxaman M Prajapati, Vijay K Parmar
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  ABSTRACT: A simple, precise, accurate, rapid and reproducible reverse phase high performance liquid chromatographic method was developed for estimation of Nitazoxanide in oral suspension formulation. The mixture of acetonitrile: ammonium dihydrogen phosphate buffer (0.075 M) in the ratio 45:55 (% v/v) adjusted to pH 3.0 with ortho-phosphoric acid was used as mobile phase. The detection of the Nitazoxanide in oral suspension formulation was carried out at 240 nm and flow rate was set to 1.5 ml/min. Linearity was obtained in the concentration range of 5 to 25 µg/mL of Nitazoxanide with correlation coefficients of 0.997. The results of the analysis were validated statistically and recovery studies confirmed the accuracy of the proposed method.
  Der Pharma Chemica 0975-413X. 01/2012; 4(3):1140-1144.
• Article: Development of QSAR model for prediction of fold selectivity of phenyl benzoxazole as estrogen receptor inhibitors

  Laxman M Prajapati, Vijay K Parmar, Manish J Patel, Jimish R Patel
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  ABSTRACT: QSAR model development of 37 phenyl benzoxazole was carried out to predict the fold selectivity for estrogen receptor. The ratio of IC50 for estrogen receptor-α and estrogen receptor-β (fold selectivity) was taken as biological activity. Physicochemical parameters were calculated using Dragon software, version 1.11. Sequential multiple linear regression analysis was carried out to derive QSAR models, which were further evaluated for statistical significance and predictive power by internal and external validation. The best quantitative structure activity relationship model was selected having a correlation coefficient (R2) of 0.948, cross-validated correlation coefficient (Q2) of 0.921 and, R2pred of 0.853. The predictive ability of the selected model was also confirmed by leave one-out cross-validation. The QSAR model indicates that the descriptors (H1p, R5u, RTe) play an important role in estrogen receptor-β binding. The information generated from the present study may be useful in the design of more potent substituted phenyl benzoxazole derivatives as estrogen receptor ligands.
  Medicinal Chemistry Research 11/2011; · 1.27 Impact Factor
• Article: Development of QSAR model for indoyl aryl sulfone derivatives as reverse transcriptase inhibitors

  Laxman M Prajapati, Vijay K Parmar, Manish J Patel, Jimish R Patel
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  ABSTRACT: QSAR model development of 39 indoyl aryl sulfones was carried out to predict reverse transcriptase inhibition activity. EC50 for reverse transcriptase binding was taken as biological activity. Physicochemical parameters were calculated using PaDEL descriptor software, version 2.1. Stepwise multiple linear regression analysis was applied to derive QSAR models, which were further evaluated for statistical significance and predictive power by internal and external validation. The best quantitative structure activity relationship model was selected having a correlation coefficient (R2) of 0.835, cross-validated correlation coefficient (Q2) of 0780 and, R2pred of 0.830. The predictive ability of the selected model was also confirmed by leave one-out cross-validation. The QSAR model indicates that the descriptors (nHBint, SaaNH, MDEO-11 and minaaaC) play an important role in enzyme binding. The information derived from the present study may be useful in the design of more potent substituted indoyl aryl sulfones.
  Der Pharma Chemica. 06/2011; 6(3-ISSN 0975-413X):53-61.
• Article: A simple high-performance liquid chromatographic method for the estimation of boswellic acids from the market formulations containing Boswellia serrata extract.

  Shailesh A Shah, Ishwarsinh S Rathod, Bhanubhai N Suhagia, Saurabh S Pandya, Vijay K Parmar
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  ABSTRACT: A simple, rapid, and reproducible reverse-phase high-performance liquid chromatographic method is developed for the estimation of boswellic acids, the active constituents in Boswellia serrata oleo-gum resin. The chromatographic separation is performed using a mobile phase consisting of acetonitrile-water (90:10, % v/v) adjusted to pH 4 with glacial acetic acid on a Kromasil 100 C18 analytical column with flow rate of 2.0 mL/min and detection at 260 nm. The elution times are 4.30 and 7.11 min for 11-keto beta-boswellic acid (11-KBA) and 3-acetyl 11-keto beta-boswellic acid (A-11-KBA), respectively. The calibration curve is linear in the 11.66-58.30 microg/mL and 6.50-32.50 microg/mL range for 11-KBA and A-11-KBA, respectively. The limits of detection are 2.33 microg/mL and 1.30 microg/mL for 11-KBA and A-11-KBA, respectively. The mean recoveries are 98.24% to 104.17% and 94.12% to 105.92% for 11-KBA and A-11-KBA, respectively. The inter- and intra-day variation coefficients are less than 5%. The present method is successfully applied for the estimation of boswellic acids from the market formulations containing Boswellia serrata extract.
  Journal of chromatographic science 10/2008; 46(8):735-8. · 0.88 Impact Factor