Visible spectrophotometric determination of Rosuvastatin in bulk and pharmaceutical formulations

Two simple and sensitive methods have been developed for the estimation of rosvastatin in bulk and in pharmaceutical dosage forms. Method A is based on the oxidative coupling of rosvastatin with MBTH in presence of oxidant cerric ammonium sulphate and the λmax of the colored species was found to be 658 nm. Method B is based on the formation of co-ordination complex between rosvastatin and cobalt thiocyanate and the blue colored complex formed is extracted into nitrobenzene which posses characteristic absorption maxima 626 nm. The colored species obeyed Beer’s Law in the concentration range 2-14 μg/mL and 50-250 μg/mL for method A and method B respectively. Marketed pharmaceutical preparations were analyzed and the results obtained by the proposed methods were in agreement with labeled amount. Recovery studies were carried out by standard addition method. The results of analysis have been validated by application of statistical principles to the data obtained and the methods were found to be satisfactory. Both the proposed methods were simple, rapid, and economical and can be used for routine analysis of rosvastatin in bulk and pharmaceutical dosage forms.