Determination of phenolic sympathomimetic drugs in pharmaceutical samples and biological fluids by flow-injection chemiluminescence.

A rapid and highly sensitive flow-injection chemiluminometric method was developed for determination of 3 sympathomimetic drugs, namely, etilefrine hydrochloride, isoxsuprine hydrochloride, and prenalterol hydrochloride. The method is based on chemiluminescence induced by oxidation of drugs with acidified potassium permanganate in the presence of formic acid as a carrier. The calibration graphs were linear over the concentration ranges 0.2-9, 0.2-12.5, and 0.025-1.25 microg/mL for the 3 compounds, respectively. The method was applied successfully in determining the drugs in dosage forms and in biological fluids. A proposal for the reaction pathway is suggested.