DEVELOPMENT AND VALIDATION OF A BIO-ANALYTICAL METHOD FOR TAMSULOSIN AND DEFLAZACORT IN RAT PLASMA BY RP-HPLC.

Abstract: A bio-analytical method utilizing reverse phase high-performance liquid chromatography (RP-HPLC) method was developed for the simultaneous estimation of tamsulosin and deflazacort in rat plasma. The method employed a mobile phase of acetonitrile and water (70:30%v/v) at a flow rate of 1 ml/min with detection at 234 nm. Symmetrical peaks with acceptable tailing factors were observed for tamsulosin and deflazacort at retention times of 3.8 and 5.1 minutes, respectively. Linearity, interday, and intraday precision analyses met established criteria, with relative recoveries demonstrating satisfactory precision. Limits of detection (LOD) and quantification (LOQ) were determined as 0.325 ng/ml and 3.258 ng/ml for tamsulosin, and 120.36 ng/ml and 364.74 ng/ml for deflazacort, respectively. Maximum plasma concentrations (Cmax) were found to be 32.257 ng/ml for tamsulosin and 152.98 ng/ml for deflazacort, with corresponding times to reach Tmax at 4 and 6 hours. Peak purity studies yielded high index values (0.9999), confirming method specificity. Sample preparation involved protein precipitation followed by chromatographic separation and photodiode array detection. The method showed no interfering peaks, demonstrating accuracy, reproducibility, and specificity over concentration ranges suitable for pharmacokinetic studies in rats. The developed bio analytical RP- HPLC method provides a reliable approach for the simultaneous determination of tamsulosin and deflazacort in rat plasma, essential for pharmacokinetic investigations.