New visible spectrophometric methods for the assay of cintapride

Abstract

In this study, four new simple, accurate and highly sensitive spectrophotometric methods have been developed for the determination of Cinitapride (CIN), in both pure and in pharmaceutical preparations. The method M₁ [Metol-Cr (VI)] and M₂ (DMPD – CAT) are direct methods. The method M₃ (NBS/Br-/metol - SA) where the drug is oxidised with excess of N-bromosuccunimide in acid medium, followed by the determination of unreacted N-bromosuccunimide with the dye Celestin Blue and M₄ (EDDP/KIO₃), where the coloured species formation appears to be due to the formation of coloured charge-transfer complex are indirect methods. Regresion analysis of Beer’s law plots show good correlation in the concentration range of 4.0-16, 2.0-12.0, 4.0-14 and 2-10 µg/mL for methods M_1, M₂, M₃ and M₄ respectively, and the corresponding molar absorptivity values are 0.6741 × 10⁴, 3.3708 × 10⁴, 2.5155 × 10⁴ and 2.435×10⁴ L mol^-1cm^-1. All variables have been optimized and the results were statistically compared with those of literature methods by employing the student’s <i>T</i>-test and <i>F</i>-test. No interference has been observed from excipients normally added to the tablets. All the methods are new and superior to the existing methods in terms of λ max and molar absorpitivity. The methods can be applied to the routine pharmaceutical analysis of cinitapride in the formulations.