Determination of phenylpropanolamine in serum and urine by high-performance liquid chromatography

A high-performance liquid chromatographic analysis of phenylpropanolamine in human serum and urine without prior derivatization is presented. Using direct UV detection the method is sufficiently sensitive to detect 25 ng of drug/ml of serum or urine; the coefficients of variation at 25 ng/ml and 500 ng/ml were 5. 16 and 2.12, respectively, in serum. The method involves serum and urine extraction at a basic pH with chloroform, a single back-extraction, and chromatography on a reverse-phrase column. Serum and urine data following administration of a single 150-mg sustained-release tablet of phenylpropanolamine hydrochloride in six healthy volunteers demonstrates the suitability of the analytical method.