Determination of the active ingredient loperamide hydrochloride in pharmaceutical caplets by high performance thin layer chromatography with ultraviolet absorption densitometry of fluorescence quenched zones.

ABSTRACT

A quantitative method using silica gel HPTLC plates with fluorescent indicator, automated sample application, and automated UV absorption densitometry of the fluorescence quenching zones was developed and validated for determination of loperamide hydrochloride in anti-diarrheal medications. Samples of three brands of caplets assayed within 96.0-105% of the 2 mg label value. Repeatability was 3.3%, 1.6%, and 2.8% (RSD) for replicate analyses (n=6) of three tablets. The errors of a blank-spike and standard analyses performed to evaluate accuracy were 2.00% and 2.02%, respectively. The method is suitable for application in a drug manufacturing quality control or regulatory analysis laboratory.