Pharmaceutica Analytica Acta

Abstract

New Kinetic Spectrophotometric Method for Determination of Atorvastatin in Pure and Pharmaceutical Dosage Forms

Safwan Ashour

New, accurate, sensitive and reliable kinetic spectrophotometric method for the assay of atorvastatin calcium (AVS) in pure form and pharmaceutical formulations has been developed. The method involves the oxidative coupling reaction of AVS with 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) in the presence of Ce(IV) in an acidic medium to form colored product with lambdamax at 566 nm. The reaction is followed spectrophotometrically by measuring the increase in absorbance at 566 nm as a function of time. The initial rate and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 2.0-20.0 ?g/mL for initial rate and fixed time methods. The limit of detection for initial rate and fixed time methods is 0.093 and 0.064 ?g/mL, respectively. Molar absorptivity for the method was found to be 3.36×104 L/ mol cm. Statistical treatment of the experimental results indicates that the methods are precise and accurate. Both methods have been applied successfully for the estimation of pravastatin sodium in commercial dosage forms with no interference from the excipients. The results are compared with the pharmacopoeial method.