Spectrophotometric Estimation of Efavirenz in Formulation and Biological Fluid

A simple, sensitive and accurate spectrophotometric method was developed in ultraviolet region for the estimation of efavirenz (EFA) in pure drug, pharmaceutical formulation. Linear response obtained was in the concentration range of 5-40 μg/ml with correlation coefficient of 0.9993, 0.9989 in solvent and plasma respectively. Excellent recovery proved that the method was sufficiently accurate. There is no interference from any common pharmaceutical additives and diluents. Results of the analysis were validated by recovery studies according to ICH Q2B guidelines and the same method is applied for estimation of efavirenz from plasma and these results were validated according to USFDA guidelines for bioanalytical method.