STABILITY INDICATING RP - HPLC METHOD DEVELOPMENT FOR THE SIMULTANEOUS ESTIMATION OF LAMIVUDINE, TENOFOVIR DISOPROXIL FUMARATE AND EFAVIRENZ IN BULK AND PHARMACEUTICAL FORMULATION

A simple, accurate reverse phase high performance liquid chromatographic method has been developed for the simultaneous estimation of lamivudine, tenofovir disoproxil fumarate and efavirenz in bulk and pharmaceutical formulations. The analytical method development was carried on Agilent make HPLC instrument using RP - C18 column. The mobile phase employed for the estimation is phosphate Buffer pH 4.0 :acetonitrile adjusted to pH 4.0 with glacial acetic acid which was pumped at a flow rate of 1.0 mL min-1 in the ratio of 42:58 v/v. the eluents were monitored at 260 nm. Linearity was obtained in the concentration range of 20-100 μg/mL of lamivudine, tenofovir disoproxil fumarate and 100-500 μg/mL efavirenz. Degradation studies shows that all the three drugs were not degraded under acidic, alkaline, thermal and photolytic conditions.The method was statistically validated and RSD was found to be within limits. Due to its simplicity, rapidness, high precision and accuracy, the proposed HPLC method can be applied for determining lamivudine, tenofovir disoproxil fumarate and efavirenz in bulk and in pharmaceutical dosage form.