Debela, Asfaw (Asst. Prof.)Moges, Mesfin2022-06-062023-11-092022-06-062023-11-092009-06http://etd.aau.edu.et/handle/12345678/31901HPTLC-densitometry method was developed and validated for simultaneous determination of antiretroviral drugs tenofovir disoproxil fumarate and lamivudine in fixed dose combi nations. The method was based on HPTLC separation of the two drugs followed by densitometric measurements of their spots at 257 nm. Toluene-methanol (6:4, v/v) was used as mobile phase and HPTLC aluminum sheets of si lica gel 60 F254 as stationary phase and detection of the spots were made by observation under short wavelength (254 nm) UV li ght. The system was found to give compact spot for lamivudine (Rr= 0.32 ± 0.02) and tenofovir disoproxil fumarate (Rr = 0.57 ± 0.02). The method was validated for precision, accuracy and robustness. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.998 in the concentration range 100-900 ng/spot for tenofovir disoproxil fumarate and linear relationship with r2 = 0.994 in the concentration range 200-800 ng/spot for lamivudine. The mean value of determination coefficient, slope and intercept were 0.998 ± 0.0012 and 0.994 ± 0.002, 4.80 ± 0.076 and 8. 12 ± 0.21 , 232.80 ± 36.21 and 478.16 ± 72.85 for tenofovir disoproxil fumarate and lamivudine, respectively. The intra-day and inter-day precision was less than 3% relative standard deviation (RSO <3%). The LOO and LOQ were 24.89 and 75.40 ng/spot for tenofovir disoproxil fumarate and 29.60 and 89.72 for lamivudine, respectively. The percentage assay of tenofovir disoproxil fumarate and lamivudine was found 98.63 ± 2. 17 and 100.93 ± 1.32, respectively. The described method has the advantage of being rapid, simple and inexpensive. No chromatographic interferences between the excipients and active ingredients were found. The method therefore could be applied for routine quality control analysis of lamivudine and tenofovir di soproxil flUllarate in fixed dose combination tablet. Key words: Lamivudine; Tenofovir Oisoproxil Fumarate; HPTLC-Oensitometty; Method validationenLamivudineTenofovir Oisoproxil FumarateHPTLC-OensitomettyMethod validationThesis