European Journal of Biomedical and Pharmaceutical Sciences

DEVELOPMENT AND VALIDATION OF QUANTITATIVE SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF ENTACAPONE IN PHARMACEUTICAL FORMULATION

Khalid Abdel-Salam M. Attia, Mohammed Wafaa Nassar, Mohamed A. Hasan*

ABSTRACT

In the present study, four sensitive, precise and accurate spectrophotometric methods have been developed for the determination of entacapone in pharmaceutical formulation. The first method (method I) is based on the reducing properties of entacapone to Folin-Ciocalteu’s phenol reagent (FCR) in alkaline medium producing blue color which exhibit λ max = 758 nm. The second method (method II) is based on the presence of aketone group of entacapone to reacte with 2,4-Dinitrophenyl Hydrazine (2,4-DNPH) through hydrazine formation producing red color which exhibit λ max = 514 nm. The third method (method III) is based on the reaction of entacapone with 4- Aminoantipyrine (4-AAP) in alkaline medium through formation of quinoid structure producing red color which exhibit λ max = 493 nm. The fourth method (method IV) is based on the reduction of Red Tetrazolium by entacapone in alkaline medium into the corresponding highly colored formazan derivative producing red color with λ max = 486 nm. The validation parameters like linearity, sensitivity, accuracy, precision and robustness were checked by following the ICH guidelines. The proposed methods were applied for the analysis of entacapone in tablet formulation with good results.

Keywords: Entacapone, Folin-ciocalteu’s phenol reagent, 2,4-Dinitrophenyl Hydrazine, hydrazone, 4-Aminoantipyrine, quiniod structure, Red Tetrazolium and formazan derivative.