High-pressure liquid chromatographic analysis of phenylpropanolamine in human plasma following derivatization with O-phthalaldehyde.

A high-pressure liquid chromatographic analysis of phenylpropanolamine in human plasma following extraction, back-extraction, and O-phthalaldehyde derivatization is presented. Using fluorescence detection, the method was sufficiently sensitive to quantitate as little as 5 ng of drug/ml of plasma; the coefficient of variation below 100 ng/ml ranged between 5.7 and 2.8%. Plasma concentration data following a single 25-mg dose of phenylpropanolamine hydrochloride in 12 healthy volunteers demonstrate the application of the analytical method.