DEVELOPMENT AND VALIDATION OF A STABILITY-INDICATING LC METHOD FOR SIMULTANEOUS ANALYSIS OF DROTAVERINE HYDROCHLORIDE AND DICLOFENAC POTASSIUM AND ITS APPLICATION FOR FORMULATION ANALYSIS

Simple, sensitive, selective, precise stability indicating chromatographic methods for determination of Drotaverine Hydrochloride and Diclofenac Potassium from pharmaceutical tablets were developed and validated as per the ICH guidelines. A novel stabilityindicating LC assay method was developed and validated for quantitative determination of Drotaverine and Diclofenac in bulk drugs and in pharmaceutical dosage form. An isocratic, reversed phase LC method was developed using an Qualisil BDS C8 column (250 mm x 4.6 mm, 5.0 µ particle size), using methanol: THF: acetate buffer (45:08:17 v/v) pH adjusted to 5.0 with acetic acid mobile phase, flow rate was 0.7 mL min -1 and column was maintained at 50 0 C. The detection was carried out at 292 nm and injection volume was 20 µL. The peak purity was checked with the photodiode array detector. Drotaverine Hydrochloride and Diclofenac Potassium were subjected to acid, alkali and neutral hydrolysis, oxidation, photo degradation and dry heat and wet heat treatment. Degradation products were well separated from the analytes peaks. As the method could effectively separate the drug from its degradation products, it can be employed as stability-indicating one. The developed method was validated with respect to linearity, accuracy (recovery), precision, specificity and robustness.