DEVELOPMENT AND VALIDATION OF A STABILITY-INDICATING HPLC METHOD FOR THE SIMULTANEOUS DETERMINATION OF PAROXETINE HYDROCHLORIDE AND CLONAZEPAM IN PHARMACEUTICAL DOSAGE FORMS

Geetharam Yanamadala, Praveen Srikumar.P

The study describes development and subsequent validation of a stability indicating reverse-phase high-performance liquid chromatography method for the simultaneous estimation of Paroxetine hydrochloride and clonazepam in tablet dosage forms. A reversed-phase Kromasil ,C18, (150mm x 4.6 mm, particle size) column with mobile phase consisting of Acetonitrile and 0.1 % Orthophosphoric acid buffer 60:40 (v/v) was used. The flow rate was 1.2 mL min-1 and effluents were monitored at 260 nm. The retention times (tR) of Paroxetine and clonazepam were found to be 3.46 min and 4.55 min, respectively. The method was validated in terms of linearity, range, specificity, accuracy, precision, limit of detection (LOD) and limit of quantitation (LOQ). The linearity for both the drugs was found in the range of 125-750 µg/ml and 2.5-15 µg/ml for Paroxetine and clonazepam. The % recoveries of Paroxetine hydrochloride and clonazepam were found to be 99.4 -100.6 and 98.1-101.0 respectively. The utility of the procedure is verified by its application to marketed formulations that were subjected to accelerated degradation studies. The method distinctly separated the drug and degradation products even in actual samples. The products formed in marketed tablet dosage forms are similar to those formed during stress studies.