Determination of Terazosin by MBTH and BPB reagents using Spectrophotometric Technique

A simple, sensitive, selective rapid spectrophotometric method has been developed for the determination of terazosin in pure form, pharmaceutical formulations and blood sample based on the oxidative coupling reaction with MBTH (3-methyl-2-benzothiazolone hydrazone hydrochlorideMethod-A), and Ion association reaction with BPB(Bromophenol Blue-Method-B) reagents at P H_ 4.0 which is extractable at 620 nm (Method-A) and 410nm (Method-B) respectively. Beer’s law is obeyed in the concentration ranges 10-60 μg ml -1 and 5-30 μg ml -1 for formulations, 4-24 μg ml -1 and 3-18 μg ml -1 for blood sample respectively. The developed method was applied directly and easily for the analysis of the pharmaceutical formulations and blood samples. % R.S.D was found between 0.09699%-0.38910% (Method-A), and 0.45101%-0.75718% (Method-B), respectively and recovery was found between 99.85%-99.98% (Method-A), and 98.62%-99.86% (Method-B), respectively. The proposed methods were applied successfully for the analysis of terazosin. No interference was observed from common pharmaceutical excipients.