Johnson O. Onah and Ukpe Ajima
PURPOSE: Tenofovir disoproxil Fumarate (TDF) is a Nucleoside Reverse Transcriptase Inhibitor (NRTI) used in the management of HIV/AIDS. The drug has not been listed in the Official Pharmacopoeias and monographs. Two simple and sensitive methods for the determination of Tenofovir are described. METHODS: The first method involved the acid hydrolysis of the orthophosphate group of tenofovir disoproxil and its subsequent complexation with ammonium molybdate- Stannous Chloride to form a coloured complex with absorption maximum (ëmax) at 495nm. The second method involves complexation of the hydrolyzed tenofovir with picric acid to form a blue coloured complex that absorbed maximally (ëmax) at 465 nm. RESULTS: Both complexations obeyed Beer-Lamberts Law over the wide range of concentrations investigated. Complexation with ammonium molybdate-stannous Chloride and picric acid gave a mean recovery of 99.20% and 96.12% respectively. Their molar absorptivities were also calculated to be 1,234.09 Mol l-1cm-1 and 12,330.92 Mol l-1cm-1 respectively. The Sandell?s sensitivity were similarly determined as 1.94 and 19.40 respectively. Comparison of the two methods by Student?s t-test suggested that they are not significantly different (t ≥ 5 %). CONCLUSION: This results from this investigation show that both methods are suitable for evaluating the quality of the tenofovir disoproxil formulation and can be used for its routine quality control
