A Novel Stability Indicating Liquid Chromatographic Assay for the Estimation of Rimonabant Hydrochloride in Bulk and Pharmaceutical Dosage Forms

Abstract

A stability indicating HPLC assay method has been developed and validated for the estimation of rimonabant hydrochloride in bulk and pharmaceutical dosage forms. A RP-HPLC isocratic separation was achieved on C₁₈ column (250X4.6 mm i.d., 5 µm) utilizing a mobile phase comprising of methanol and water in the ratio of 90:10 (v/v) and the eluents from the column were monitored using a variable wavelength detector at 280 nm. The stress testing of rimonabant hydrochloride was carried out under acidic, alkaline hydrolysis, oxidation and thermal degradation (dry heat) conditions and rimonabant hydrochloride was well resolved from its degradation products with good resolution. The proposed method has permitted the quantification of rimonabant hydrochloride in the linearity range of 0.2-10 µg/ml and the flow rate was maintained at 1 ml/min. The column was maintained at ambient temperature and the total run time was 10 min. The retention times of rimonabant hydrochloride and saquinavir mesylate were found to be 5.760 min and 4.657 min, respectively and the limit of detection and limit quantification were found to be 0.0113 µg/ml and 0.034 µg/ml, respectively. The percentage recovery was found to be in the range of 100 to 100.22 and the % RSD of intra-day and inter-day precision was found to be 0.572 and 0.549, respectively. The percentage amount of  commercial brand of rimonabant hydrochloride was found to be 100.4. The method was found to be suitable for the routine quality control analysis of rimonabant hydrochloride in bulk drug and formulation as well as for the stability-indicating studies. The method was validated as per ICH (International Conference on Harmonization) guidelines.