Biomedical subjects

M S Shingare

Publications and source records attributed to M S Shingare.

6 recordsLinked to original sources

PubMed2007

A validated stability indicating LC method for oxcarbazepine.

The present paper describes the development of a stability indicating reversed phase liquid chromatographic (RPLC) method for oxcarbazepine in the presence of its impurities and degradation products generated from forced decomposition studies. The drug substance was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. The degradation of oxcarbazepine was observed under base hydrolysis. The drug was found to be stable to other stress conditions attempted. Successful separation of the drug from the synthetic impurities and degradation product formed under stress conditions was achieved on a C18 column using mixture of aqueous 0.02 M potassium dihydrogen phosphate-acetonitrile-methanol (45:35:20, v/v/v) as mobile phase. The developed HPLC method was validated with respect to linearity, accuracy, precision, specificity and robustness. The developed HPLC method to determine the related substances and assay determination of oxcarbazepine can be used to evaluate the quality of regular production samples. It can be also used to test the stability samples of oxcarbazepine.

Acetonitriles↗

PubMed2006

Development and validation of enantioselective high performance liquid chromatographic method for Valacyclovir, an antiviral drug in drug substance.

A chiral high performance liquid chromatographic method was developed and validated for the enantiomeric resolution of Valacyclovir, L-valine 2-[(2-amino-1,6-dihydro-6-oxo-9h-purin-9-yl) methoxy] ethyl ester, an antiviral agent in bulk drug substance. The enantiomers of Valacyclovir were resolved on a Chiralpak AD (250 mm x 4.6 mm, 10 microm) column using a mobile phase system containing n-hexane: ethanol: diethylamine (30:70:0.1, v/v/v). The resolution between the enantiomers was found not less than four. The presence of diethylamine in the mobile phase has played an important role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was extensively validated and proved to be robust. The limit of detection and limit of quantification of (D)-enantiomer were found to be 300 and 900 ng/ml, respectively, for 20 microL injection volume. The calibration curve showed excellent linearity over the concentration range of 900 ng/ml (LOQ) to 6000 ng/ml for (D)-enantiomer. The percentage recovery of (D)-enantiomer was ranged from 97.50 to 102.18 in bulk drug samples of Valacyclovir. Valacyclovir sample solution and mobile phase were found to be stable for at least 48 h. The proposed method was found to be suitable and accurate for the quantitative determination of (D)-enantiomer in bulk drugs substance. It can be also used to test the stability samples of Valacyclovir.

Acyclovir↗

PubMed2006

Validated chiral liquid chromatographic method for the enantiomeric separation of Pramipexole dihydrochloride monohydrate.

A chiral liquid chromatographic method was developed for the enantiomeric resolution of Pramipexole dihydrochloride monohydrate, (S)-2-amino-4,5,6,7-tetra-hydro-6-(propylamino) benzothiazole dihydrochloride monohydrate, a dopamine agonist in bulk drugs. The enantiomers of Pramipexole dihydrochloride monohydrate were resolved on a Chiralpak AD (250 mm x 4.6 mm, 10 microm) column using a mobile phase system containing n-hexane:ethanol:diethylamine (70:30:0.1, v/v/v). The resolution between the enantiomers was found not less than eight. The presence of diethylamine in the mobile phase has played an important role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was extensively validated and proved to be robust. The limit of detection and limit of quantification of (R)-enantiomer were found to be 300 and 900 ng/ml, respectively for 20 microl injection volume. The percentage recovery of (R)-enantiomer was ranged from 97.3 to 102.0 in bulk drug samples of Pramipexole dihydrochloride monohydrate. Pramipexole dihydrochloride monohydrate sample solution and mobile phase were found to be stable for at least 48 h. The proposed method was found to be suitable and accurate for the quantitative determination of (R)-enantiomer in bulk drugs.

Antiparkinson Agents↗

PubMed2005

A new stability--indicating RP-HPLC method to determine assay and known impurity of Celecoxib API.

A simple, rapid and accurate Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method was developed to determine assay and known impurity of Celecoxib API. The chromatographic separation was performed on reversed-phase C-18 column. Eluents were monitored on photo-diode array detector at a wavelength of 254 nm using a mixture (40:60) of buffer and acetonitrile. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The method was statistically validated for forced-degradation study, linearity and range, accuracy, precision, stability of analytical solutions, and selectivity. Due to its simplicity, rapid, and accuracy, we believe that the method will be useful to determine assay and known impurity of Celecoxib.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1994

Thin-layer chromatographic spray reagent for the screening of biological materials for the presence of carbaryl.

A spray reagent for the detection of the carbamate insecticide carbaryl was developed, consisting of 1% ammonium cerium(IV) nitrate in 20% v/v hydrochloric acid. This reagent reacts with the hydrolysis product of carbaryl, 1-naphthol, and forms a violet complex. Other carbamate insecticides do not give similar coloured spots. Moreover, organophosphorus, organochlorine and pyrethroid insecticides and constituents of visceral extracts (amino acids, peptides, proteins, etc.) do not interfere. The sensitivity of the reagent is about 0.1 microgram.

Animals↗

PubMedDate not supplied

Synthesis of new pyrroles and their biological activities.

Coumarino acid hydrazides and acid hydrazide of 2-oxy 3, 5, 6-trichloropyridine were prepared in two steps. These acid hydrazides on condensation with Acetonyl acetone i.e. 2,5-hexanedione yields new pyrroles. These pyrroles showed good to moderate antimicrobial activities against Alternaria brassicicola, Aspergillus niger, E. coli and Lactobacillus.

Anti-Infective Agents↗