Colorimetric estimation of few pharmaceutical agents miglitol, carvedilol and alverine citrate in pure and tablet dosage forms using MBTH

摘要

The objective of the present work is to develop simple, precise and accurate colorimetric methods for the estimation of miglitol (MIG), carvedilol (CRV) and alverine citrate (ALV) using MBTH reagent. The method was developed on Perkin Elmer LAMBDA 25 UV –VIS spectrophotometer with 1cm quartz cells. MBTH (3-methyl benzothiazolin-2- one-hydrazone), in the presence of acidified ferric chloride for MIG and CRV; cerric ammonium sulphate for ALV undergoes oxidative coupling and forms electrophilic intermediate; active coupling species. The drugs reacts with the active coupling species to give greenish blue coloured solution with maximum absorbance measured at 623 nm for MIG; 635 nm for ALV, blue coloured solution monitored at 561 nm for CRV. The order of addition followed is CRV followed by oxidizing agent and MBTH and MIG/ALV followed by MBTH and oxidizing agent. The linearity was assessed and found to be in 10-30 μg/mL for MIG, 20-100 μg/mL for CRV and 50-250 μg/mL for ALV, respectively. The colorimetric methods were extensively validated as per ICH guidelines and all the parameters were within the acceptance criteria with correlation of 0.999 and percentage RSD less than 2 for all the three methods. The methods were proved to be more accurate, simple, precise and rapid by statistical analysis.