Separation and determination of lamivudine, tenofovir disoproxil fumarate and efavirenz in tablet dosage form by thin-layer chromatographic-densitometric method

Abstract

Summary This paper describes the development and validation of high-performance thin-layer chromatography (HPTLC) method for the simultaneous determination of lamivudine (LAM), tenofovir disoproxil fumarate (TDF) and efavirenz (EFV). The separation was carried out on Merck HPTLC aluminum plates precoated with silica gel G60 F 254 (20 × 10 cm) with 250-μm thickness using chloroform–methanol–toluene (9:1.2:0.3, v/v) as mobile phase. HPTLC separation of the three drugs followed by densitometric measurement was carried out in the absorbance mode at 260 nm. The drugs were resolved satisfactorily with R F values of 0.20 ± 0.02, 0.61 ± 0.01 and 0.73 ± 0.02 for LAM, TDF and EFV, respectively. The linear regression analysis data for the calibration plots showed good linear relationship with r 2 = 0.9997, 0.9991 and 0.9990 for LAM, TDF and EFV, respectively, in the concentration range of 400–800 ng spot – 1 for LAM and TDF and 800–1600 ng spot –1 for EFV. The limit of detection and quantitation were 180 and 300 ng spot – 1 , respectively for LAM, 150 and 210 ng spot – 1 , respectively for TDF and 300 and 400 ng spot –1, respectively, for EFV. The method was validated for precision, robustness, limit of detection (LOD), limit of quantitation (LOQ), specificity and accuracy. The method can be used for routine analysis of these drugs in various formulations in quality control laboratories.