10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 2 2013 (April - June) Two simple, rapid, sensitive and accurate UV- Spectrophotometric and first order derivative methods have been developed for estimation of Adefovir in bulk and tablets. In methanol: water (3 :7), the λ lessThan sub greaterThan max lessThan /sub greaterThan of Adefovir was found to be 260 nm and the same spectrum was derivatized into first order derivative using UV probe software of instrument (shimadzu 2450), at ∆λ = 2. The amplitude of the trough was recorded at 273 nm. In both these methods, linearity was observed in the concentration range of 4 – 32 µg/mL. The assay results of both these methods were in good agreement with label claim. The methods were validated statistically and recovery studies. CHARUSHILA H. BHIRUD AND SHIVANAND N.HIREMATH Adefovir, UV-Spectrophotometric method, first order derivati spectrophotometry 734-739