Rapid colorimetric analysis of chlorhexidine in pharmaceutical preparations.

A colorimetric determination of chlorhexidine is described. The method is based on the formation of a yellow complex between the drug and bromcresol green. The absorption peak of this complex, extracted by chloroform, is at 410 nm, and linear response is obtained from 2.5 to 30 micrograms of chlorhexidine/ml. The accuracy and reproducibility of this rapid method make it useful for chlorhexidine determination in the manufacturing control of pharmaceutical mixtures.