Abstrait

New Colorimetric Methods for the Estimation of Abacavir Sulphate in Bulk and Dosage Forms

B. Rajitha, S. Prashanthi, K. Ram Subha Reddy, S. K. Gulati and G. Tuljarani

Four simple, sensitive, rapid and accurate visible spectrophotometric methods (designated as A, B, C and D) have been developed for the estimation of abacavir sulphate in pharmaceutical formulations. Methods A and B are based on the ion pair complex formation of abacavir sulphate with dyes erichrome black -T and orange–G in acetate buffer followed by their extraction with chloroform. The absorbance of organic layer was measured for the above complexes at 510 nm and 484 nm, respectively. Method C is based on oxidative coupling between abacavir sulphate and 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in presence of cerric ammonium sulphate (CAS) to form a colored product with absorption maxima at 630 nm. Method D is based on the oxidation/reduction reaction between the abacavir sulphate and Folin-ciocalteau reagent (F.C. reagent) to form blue color chromogen having absorption maxima at 752 nm. All the variables have been optimized. The concentrations of measurements are reproducible within a relative standard deviation of less than 1% .The linearity was found to be 5 to 60, 2.5 to 15, 10 to 50 and 10 to 70 µg/mL for method A, B, C and D, respectively. The proposed methods were validated statistically. Recovery studies were carried out by standard addition method.