Spectrophotometric Determination of (Atorvastatin Ca) in Pure form and in the Pharmaceutical Formulations

Simple, sensitive and rapid two methods for determination of Atorvastatin Calcium (Atv) in both pure form and pharmaceutical formulations. The first method was based on the oxidation of the studied drug in presence of acidic medium by a known excess of (Potassium bromide: Potassium bromate) (KBr:KBrO3) as an oxidizing agent and subsequent determination of unreacted oxidant by reacting it with Crystal Violet (CV) dye [4 [bis [4 (dimethylamino) phenyl] methylidene] cyclohexa-2,5-dien-1-ylidene]-dimethylazanium;chloride to produce blue at λmax. 594 nm. The second method involved determination of (Atv) using Chromogenic reagent Sodium 1,2-naphthoquine4-sulfonate (NQS) as reagent in an alkaline medium (pH 11.5) to form an orange product at λmax. 456nm, and the linearity range was found to be (10100)μg/mL and (20-80)μg/mL respectively. With molar absorptivity 70.708×10 L/mol.cm and 20.565×10 L/mol.cm, correlation coefficient 0.9992 and 0.9977 and the limit of detection and limit of quantification (0.0178 μg/mL, 0.054 μg/mL) and (0.059 μg/mL, 0.179 μg/mL) respectively. The two methods were successfully applied for the determination of (Atv) in tablet formulation.