STABILITY INDICATING METHOD DEVELOPMENT OF RIMONABANT AND IT's VALIDATION BY RP-HPLC AND HPTLC METHOD

A new simple, accurate, rapid, precise, reproducible and cost effective HPLC and HPTLC method for the quantitative estimation of Rimonabant in bulk and pharmaceutical dosage form. In Method using HPTLC, chromatograms were developed in a mobile phase of 2 mM Sodium dihydrogen orthophosphate (NaH2PO4)-Acetonitrile (38:62) for approximately 25 mins and detected at λmax of 303 nm. Accuracy was found to be in the range of 98.31-102.25 % whereas intraday precision was found to be in the range of 0.03 to 1.60%. Interday precision was found to be 1.36, 0.74 and 0.31 at LQC, MQC and HQC, respectively. Response was found to be linear from concentration range 20-100 µg/ml which was not an improvement over method of estimation by UV spectroscopy. To make more sensitive and suitable for analysis of low concentration samples a method using HPLC with UV detector was developed and validated. In HPLC with UV detector, 20 µl samples were loaded on a Lichrospher, C-18 (250 × 4.6 mm, 5 µm Merck, Germany) and were eluted in a mobile phase of 2 mM Sodium dihydrogen orthophosphate (NaH2PO4)-Acetonitrile (38:62) using an isocratic method at a flow rate of 1 ml/min. Whole eluate was detected at 303 nm. Quality control concentration selected were 2.5, 9 and 10 µg/ml as low, mid and high QC. Accuracy was found to be in the range of 98.03-103.68 % whereas intraday precision was found to be in the range of 0.03 to 1.89%. Inter-day precision was found to be 1.52, 1.04 and 1.18 at LQC, MQC and HQC, respectively. It was found to be specific and linear from 2-20 µg/ml. In nut shell, all three methods developed and validated were accurate and precise. UV method being less cumbersome has its advantage over HPTLC whereas HPTLC method included separation of unwanted ingredients from analyte. HPLC method was more sensitive than other two methods and found suitable to analyze low concentration samples. Keywords: Rimonabant, HPLC, HPTLC, Method development, Validation, ICH guidelines, Sodium dihydrogen orthophasphate , Accuracy, Precisio