Evidence for toxic precursors in illicit phencyclidine preparations

Piperidinocyclohexanecarbonitrile (PCC) is a toxic precursor of phencyclidine (PCP) and is employed in the illicit syntheses of PCP. Also, PCC and homologs are used for syntheses of other PCP derivatives. Conflicting reports on the presence of the cyclohexanecarbonitrile (CC) compound in street drug preparations led us to assess the toxicity of three precursors and to develop analytical methods for the detection and measurement of PCP precursors and homologs. Four hour acute LD₅₀'s (i.p., mg/kg) in male Swiss Webster mice were as follows: PCP 79.0; PCC, 29.0; pyrrolidino-CC, 36.5; morpholino-CC, 39.0. Analytical measurement of these compounds was made by gas chromatography (3% OV-17) with a nitrogen detector. The presence of about 0.5% of PCC in PCP preparations can be detected. Structural confirmation was made by methane chemical ionization mass spectrometry. All compounds (M) exhibited a unique (M+1)⁺, M⁺, (M-1)⁺ ion pattern by solid probe analysis. Analyses of 9 PCP street samples revealed the presence of PCC in 1 sample (2% of sample wt.). PCP content of tablets ranged from 1.1 - 6.8 mg, wherease powders contained 4.2 - 58.6%. Other components in the street samples were identified as sugars and steric and palmitic acid. N-ethyl-1-phenylcyclohexylamine and 1-[2-(2-thienyl)cyclohexyl]-piperidine also were identified in other street drug samples.