Development and validation of zeroand first-order derivative area under curve spectrophotometric methods for the determination of entacapone in bulk material and in tablets

摘要

Aim: The aim of this work is to establish two simple, economical, and rapidspectrophotometric methods for the quantification of entacapone in bulk material andin tablets. Further, this study is designed to validate the developed methods as perICH guidelines. Materials and Methods: In Methods I and II, a stock standard solutionwas prepared by dissolving 10 mg of entacapone in 100 mL of 10% v/v acetonitrile toobtain a concentration of 100 μg/mL. After suitable dilution, 10 μg/mL of entacaponewas prepared and scanned in the UV-visible range 500–200 nm; entacapone showeda maximum absorbance at 384.40 nm. In Method I, area under curve (AUC) of thezero-order spectrum was recorded between 348.00 and 410.20 nm. While, in Method II,zero-order spectra were derivatized into first-order, and the AUC was recordedbetween 386.40 and 460.20 nm. For a linearity study, series of dilutions were preparedfrom stock solutions. Results: In Method I, and II, entacapone followed linearity inthe concentration range of 2–12 μg/mL and 5–30 μg/mL with (r2>0.999). The amountsof entacapone estimated by both these methods were found to be 99.24 ± 0.054 and98.68 ± 1.04, respectively. Conclusion: The developed methods are simple, precise,rugged, robust, and economical. Both these methods can be used for routine analysisof entacapone from its tablet formulation.