Simple Colorimetric Assay for Microgram Determination of Bromhexine Hydrochloride with Mbth and 2, 2’ Bipyridyl

The present work describes two new spectrophotometric methods for the determination of bromhexine hydrochloride in bulk and formulations. Method A is based on the reduction of Fe into Fe by the drug followed by the complex formation of Fe with 2, 2’ bipyridyl to form cherry red colored chromogen having maximum absorbance at 510nm and Method B is based on oxidation of 3-methylbenzothiazolinone-2hydrazone (MBTH) by FeCl3 followed by its coupling with the drug in acidic medium forming an intense green colored chromogen with absorbance maxima at 630nm. Beer’s law is obeyed in the range of 5-25 μg/ml with molar absorptivity of 1.113 x 10 for method A and 2-10 μg/ml with molar absorptivity of 1.128 x 10 for method B. The results were favorably compared with those obtained by reference UV spectrophotometric method. The accuracy, precision, and the linearity ranges of the methods have been determined, and they have been validated by analyzing the title drug. No interference was observed from common pharmaceutical adjuvants. These two methods were successfully applied to the pharmaceutical formulations, capsules, tablets.