Visible Spectrophotometric Estimation of Tenofovir Disoproxil Fumarate in Pharmaceutical Formulations

Three simple, accurate, rapid and sensitive methods (A, B and C) have been developed for the estimation of Tenofovir Disoproxil Fumarate in its pharmaceutical dosage form. The Method A is based on the formation of golden yellow colored chromogen, due to ion-association of Tenofovir with Metanil Yellow dye in Chloroform, which exhibits λmax at 425 nm. Method B is based on the formation of reddish brown colored chromogen due to ion-association of Tenofovir with Solochrome Black-T dye in Chloroform, which exhibits λ max at 438 nm. The Method C is based on the formation of blood red colored chromogen with Ferric Chloride and 2,2-Bipyridyl which shows absorption maximum at 523 nm. The absorbance-concentration plot is linear over the range of 10–60 μg/mL for Method A, 10–60 μg/mL for Method B and 20–90 μg/mL for Method C. Results of analysis for all the methods were validated statistically and by recovery studies. The proposed methods are economical and sensitive for the estimation of Tenofovir Disoproxil Fumarate in bulk drug and in its formulations.