Gradient Stability Indicating RP-HPLC Method for Impurity Profiling of Simvastatin in Tablet Dosage Forms

Abstract

Gradient, reversed phase high performance liquid chromatographic (RP-HPLC) method was developed for quantitative estimation and validation of simvastatin impurities which are generated during formulation and storage of simvastatin in tablet dosage forms. The chromatographic separation was achieved on column intersil ODS (150 mm × 4.6 mm, 5 μm) by following gradient flow using mobile phase A and B containing 0.1 % phosphoric acid, acetonitrile in the ratio of 47:53 and 90:10, respectively. Flow rate was 1.0 mL/min. The photo diode array detector was operated at 238 nm. Forced degradation studies were performed on tablets powder which contain simvastatin using acid hydrolysis, base, peroxide, water and UV, thermal, sunlight, humidity degradations. The method was validated for specificity, linearity, precision, accuracy and limit of quantification. The degree of linearity of the calibration curves, the recoveries of simvastatin impurities, the limit of detection and quantification for the HPLC method were determined. The method was found to be simple, specific, precise, accurate and reproducible. The method was applicable for the quality control of commercial simvastatin tablets to quantify the drug and its related substances and to check the formulation content uniformity.