A New Method Development and Validation of 5α Reductase Inhibitor (Dutasteride) Using R-HPLC In Bulk and Pharmaceutical Dosage Form (Dexamethasone Use as An Internal Standard)

The proposed HPLC Method was found to be simple,precise,accurate and economicalfor the estimation of dutasteride in Bulk and tablet dosage form. The present work, developed HPLC method was found suitable and validated. Luna – C-18 (250 mm x 4.6 mm, 20 µL) column was used for the assay. Mobile phase was Acetonitrile and Water in the ratio 80:20. Linearity was established in the range of 5-100 µg/ml with a coefficient correlation of 0.9998 and eluents were monitored at 242 nm and at 1 ml/min. flow rate. The Retention time was found to be 5.9 min. The efficiency of the column, expressed as the number of theoretical plates for six replicate injections was 11566 ± 119.695 (%CV1.03%) and USP tailing factor was 1.25 ± 0.012 (%CV 0.79). The regression equation for the calibration plot was Y = 0.0618 X – 0.008. Intra-day precision from 0.166 to 1.449 and Inter-day precision from 0.186 to 1.449. The% recovery of dutasteride from API and dosage form were 100.70% and 99.66%. The drug was subjected to stress conditions such as Oxidative and Photodegradation, Considerable degradation was found to occure in acidic and basic medium on heating at 100°C but no degradation was observed at room temperature. The drug was exposed to 10% H2O2{heating at 100°C forming degradation product at RT: 2.557}. The LOD and LOQ was 0.257µg and 0.779 µg respectively.When the flow rate was reduced, the retention time of dutasteride increased.The assay result with analyst #1 and Analyst #2 were % Assay = 98.40% (%RSD = 0.13%) and % Assay = 99.07% (%RSD =0.53) respectively. Robustness and ruggednesswasobserved that results were well within acceptance limits of 98–102%, with %RSD ±2.0%, indicating the method is rugged and provides consistent and reliable results which are not affected by small changes in experimental conditions. This method can be used for routine analysis of dutasteride. Running Title: A New Method Development and Validation of 5α-Reductase inhibitor using R-HPLC.