Enzymic micro-determination of bronopol and its application to pharmaceuticals

Abstract

A procedure is described for the rapid micro-determination of bronopol, based on the measurement of inhibition of a thiol protease, papain. The inhibition follows a linear relationship with concentration in the range 0.8–4.0 µg ml^–1. The method utilizes the property of bronopol that is primarily responsible for its antimicrobial activity (ability to form disulfide bonds) and hence is also indicative of its antimicrobial potency. The method showed sensitivity towards the degradation of bronopol and can, therefore, be used in stability analysis. Results for the determination of bronopol in the presence of various pharmaceutical ingredients and also in the presence of much higher amounts of some antibiotics and anti-histamine and anti-inflammatory drugs confirmed the validity of the method in the determination of bronopol in complex pharamaceuticals.