High-performance liquid chromatographic determination of MEN 935 in human plasma, a highly specific and sensitive analytical method for a new antihypertensive drug.

A sensitive and specific HPLC method based on fluorescence detection was developed for the determination of the new antihypertensive agent, 1-[3-[3- [[3-(1-napthoxy)-2-hydroxypropyl]-amino]-3, 3-dimethylpropyl]-2-benzimidazolinone hydrochloride (MEN 935) in human plasma. Selective extraction and back-extraction of the drug and a structurally related internal standard was followed by high-performance chromatographic separation on a reversed-phase column. The method was sufficiently sensitive to quantify as little as 0.5 ng of drug/ml of plasma. Experimental tests of accuracy, precision and linearity of the assay are presented. The method was applied to measure plasma concentration time curves in man after single oral doses of 5-50 mg MEN 935.