Development and validation of a reversed-phase HPLC method for simultaneous analysis of butylhydroxyanisol, simvastatin and its impurities in tablet dosage forms.

A simple, rapid, and sensitive RP-HPLC method using photodiode array detection was developed and validated for the simultaneous determination of butylhydroxyanisol and simvastatin with its impurities in tablet forms. Chromatographic separation was achieved on a Phenomenex Hypersil (250×4.6 mm, 5 μm) column using the mobile phase acetonitrile-sodium acetate (12 mM) buffered to 4.2 with glacial acetic acid. The flow rate was 1.7 mL/min, and the UV detection were made at 238 nm for simvastatin and its impurities and at 290 nm for butylhydroxyanisol. The system suitability solution used for peak impurity identification was generated in-situ without use of any impurity reference standard. The method was validated according to ICH Q2(R1) guidelines, and the acceptance criteria for accuracy, precision, linearity, specificity, robustness, LOD, and LOQ, were met in all cases. Moreover, the reproducibility results obtained by 22 Official Medicines Control Laboratories (OMCL) of European Directorate were satisfactory. The compounds selected for impurity validation were based on those found during long term and accelerate stability studies carried out on several formulation tablets from Moroccan and other markets. The described method was robust and successfully applied in quality control laboratories for routine analysis to determine the butylhydroxyanisol and simvastatin with its impurities content in tablet dosage forms.