DEVELOPMENT AND VALIDATION OF A NEW RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF EMTRICITABINE, TENOFOVIR, COBICISTAT, ELVITEGRAVIR AND ITS COMPARISION WITH A REPORTED METHOD

A new stability indicating RP HPLC method has been developed and validated for simultaneous estimation of Emtricitabine, Tenofovir, Cobicistat and Elvitegravir in bulk and dosage forms. The method involves separation on Kromasil C18 column (250mm x 4.6mm x5µm particle size). The optimized mobile phase consists of 0.01N KH2PO4(pH 2.5) and Acetonitrile (43:57v/v) with a flow rate of 1ml/min and UV detection at 254nm. Retention time was 2.286 min for Emtricitabine,3.308 min for Tenofovir,5.316 min for Cobicistat,6.638 min for Elvitegravir. RP-HPLC method for the simultaneous estimation of Emtricitabine, Tenofovir, Cobicistat and Elvitegravir in their combine dosage form was developed and validated as per the ICH guidelines. Linearity was observed in the range of 20-120µg/ml for Emtricitabine, 30-180µg/ml for Tenofovir, 15- 90µg/ml for Cobicistat and 15-90µg/ml for Elvitegravir with correlation coefficients (r2=0.999).The percentage recoveries of Emtricitabine, Tenofovir, Cobicistat and Elvitegravir w e r e in the range of 98.55- 101.4% which was withi n the acceptance criteria. The percentage RSD was NMT 2% which proved the precision of the developed method. The developed method is simple, sensitive, rapid, linear, precise, rugged, accurate, specific, and robust. The developed method was found superior in certain respects such as RT and Accuracy. The method was more economical when compared to reported method. Keywords: Emtricitabine, Tenofovir, Cobicistat, Elvitegravir, RP-HPLC Method, Simultaneous estimation, Validation as per ICH guidelines, Forced degradation studies.