10.22376/ijpbs.2019.10.1.p1-12 Volume 2 Issue 4 2011 (October - December) Three simple and sensitive Spectrophotometric methods (A, B & C) have been developed for the determination Entecavir (ETV) in pure and pharmaceutical dosage forms. Method A is based on the formation of colored species by nucleophilic substitution of the drug with 1, 2-Napthoquinone-4-sulfonate sodium (NQS) in the presence of alkaline medium (λ lessThan sub greaterThan max lessThan /sub greaterThan :450 nm). Method B is based on formation Schiff's base by the condensation of drug with p-dimethyl amino cinnamaldehyde (PDAC) under acidic conditions (λ lessThan sub greaterThan max lessThan /sub greaterThan :520 nm). Method C is based on oxidation followed by complex formation with 1, 10-Phenanthroline (PTL) in the presence of ferric chloride (λ lessThan sub greaterThan max lessThan /sub greaterThan :500 nm).These methods have been statistically evaluated and found to be precise and accurate. M. Rajeswari, P. Subrahmanyam, G. Devala Rao And G. Sudhakar Sai Babu Entecavir, Spectrophotometry. 91-94