The primary endpoint is to determine average bioequivalence for Test and Reference formulation of efavirenz according to the FDA guidance on bioequivalence testing. The ratio of the Test to Reference formulation mean for efavirenz AUC0-192, AUC0-inf and Cmax and the 90% confidence interval around each mean ratio will be determined. Average bioequivalence will be met if 90% confidence interval around de AUC and Cmax mean ratios for efavirenz falls within the FDA's predefined limits of 0.80 to 1.25.