Metabolism and toxicological detection of the designer drug N-(1-phenylcyclohexyl)-3-methoxypropanamine (PCMPA) in rat urine using gas chromatography–mass spectrometry

Studies on the metabolism and the toxicological detection of the phencyclidine-derived designer drug N-(1-phenylcyclohexyl)-3-methoxypropanamine (PCMPA) in rat urine are described using gas chromatographic–mass spectrometric (GC–MS) techniques. Based on the identified metabolites, the following metabolic pathways could be postulated: N-dealkylation, O-demethylation partially followed by oxidation of the resulting alcohol to the corresponding carboxylic acid, hydroxylation of the cyclohexyl ring at different positions, and aromatic hydroxylation. The formed metabolites were identical to those of the homologue N-(1-phenylcyclohexyl)-3-ethoxypropanamine (PCEPA) with exception of the mono hydroxyl metabolites of PCEPA. All PCMPA metabolites were partially excreted in conjugated form. An intake of a common drug users’ dose of PCMPA could be detected in rat urine by the authors’ systematic toxicological analysis (STA) procedure using full-scan GC–MS after acid hydrolysis, liquid–liquid extraction and microwave-assisted acetylation. The STA should be suitable for proof of an intake of PCMPA also in human urine assuming similar metabolism.