Spectrophotometric Determination of Tenofovir Disoproxil FumarateAuthor(s): S. M. Mallipatil, S. Noola, M. A. Nandedkar, Prakash S. Sarsambi and Abhay Sonawane
Three simple, sensitive, rapid and accurate spectrophotometric methods (A, B and C) in the visible region have been developed for the estimation of tenofovir disoproxil fumarate (TDF) in bulk drug and pharmaceutical formulations. Methods A and B are based on reduction of ferric ions to ferrous ion by TDF, which in presence of 1,10-phenanthroline and 2, 2-bipyridyl form orange red and blood red colored chromogens with absorption maxima at 500.2 and 511.2 nm, respectively. The Beer’s law was obeyed in the concentration range of 2-10 and 5-25 µg/mL. Method C is based on the oxidation followed by coupling of 3-methyl-2-benzothiazolinone hydrazone (MBTH) with TDF in presence of ferric chloride to form green color chromogen with absorption maxima at 640 nm. The Beer’s law was obeyed in the concentration range of 5-25 µg/mL. The results of analysis for these methods have been validated statistically and by recovery studies. The results are compared with those obtained by using UV spectrophotometric methods developed in our laboratory with double distilled water at 260 nm.