137VISIBLE SPECTROPHOTOMETRIC DETERMINATION OF ENTECAVIR IN PHARMACEUTICAL DOSAGE FORMSA simple and sensitive method was developed for the determination of Entecavir by visible spectrophotometry using chromogenic reagent, N-(1-naphthyl ethylene diamine). Entecavir forms a red coloured complex with the reagent which shows maximum absorption at 549nm and obeys beer-lamberts law in the concentration range of 25-Simple125μg/ml. The correlation coefficient was calculated 0.9982.subbapharmaco@gmail.comResearch4102014Simple,Spectrophotometer,Maximum,Entecavir,Beers-law,ConcentrationReddy Rambabu, Jampani Subbarao,S Vidyadhara, Battula Sowjanya LakshmiChebrolu Hanumaiah Institute of Pharmaceutical Sciences, Guntur, Andhra Pradesh, India.,Chebrolu Hanumaiah Institute of Pharmaceutical Sciences, Guntur, Andhra Pradesh, India.,Chebrolu Hanumaiah Institute of Pharmaceutical Sciences, Guntur, Andhra Pradesh, India.,Chebrolu Hanumaiah Institute of Pharmaceutical Sciences, Guntur, Andhra Pradesh, India.