Development and validation of analytical method for quantitation of Emtricitabine, Tenofovir, Efavirenz based on HPLC

This paper describes the development and validation of a HPLC method for the quantitation of Emtricitabine, Tenofovir, and Efavirenz in pure form and pharmaceutical formulations. The Zorbax SB CN, (250 × 4.6 mm, 5 μm) column was used. UV detection was performed at 260 nm. The mobile phase consisted of methanol (A) and buffer at pH 4.5(B) using the gradient: 0-10 min (90% B), 10-22 min (35% B), and 22-25 min (90% B). The flow rate was 1.5 ml/min in ambient temperature. The injection volume of sample was 20 μl. The method showed to be linear (r2 > 0.999), precise (RSD < 0.76%), accurate (recovery of 100.09% for Emtricitabine, 99.88% for Tenofovir and 100.04% for Efavirenz), specific and robust. Three batches of Emtricitabine, Tenofovir, and Efavirenz tablets were assayed by the validated method. The Emtricitabine contents in the tablet samples varied from 99.94 to 101.60%. The Tenofovir content in the tablet samples varied from 99.13 to 101.81% while Efavirenz content varied from 100.01 to 101.67%.