Conductometric determination of some pharmaceutically important thiol compounds in dosage forms.

A direct semimicro conductometric method is described for the determination of five pharmaceutically-important thiol compounds, namely: N-acetylcysteine, captopril, D-penicillamine, 6-mercaptopurine and thioguanine, in bulk and in dosage forms. The method involves the use of lead nitrate as a titrant in aqueous medium with conductometric detection of the end point. The proposed method was successfully applied to the determination of the studied compounds and the results obtained were found to agree with those given using the official methods. The proposed method is simple, accurate and precise.