Efavirenz is non-nucleotide reverse transcriptase inhibitor and used in the treatment of immunodeficiency virus. A simple, selective, precise and stability-indicating high-performance thin- layer chromatographic method for densitometric determination of efavirenz both as a bulk drug and in formulation was developed and validated as per the International Conference on Harmonisation guidelines. The method employed TLC aluminium plates precoated with silica gel 60F 254 as the stationary phase. The solvent system consisted of dichloroethane: ethyl acetate: ammonia (4.5:0.5:0.2 v/v). Densitometric measurement of efavirenz was performed in the absorbance mode at 247 nm. The system was found to give compact spot for efavirenz (Rf value of 0.48 ± 0.02). The calibration curve of the drug was linear in the range of 500 – 3000 ng/spot with r2= 0.9995 ± 0.0001. The mean value ± SD of slope and intercept were 3.4369 ± 0.0393 and 755.16 ± 62.479 with respect to peak area respectively. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. As the proposed method can effectively separate the drug from its degradation products, it can be employed as stability- indicating method
