Evaluation of a rapid oral fluid point-of-care test for MDMA.

Cozart Bioscience Limited has developed novel lateral flow technology that allows the detection of drugs of abuse in biological fluids and suspect powders. This paper describes the application of this technology for the detection of 3,4-methylenedioxymethamphetamine (MDMA) in oral fluid. Samples (N = 370) were obtained from the analytical laboratory at Cozart Bioscience Limited following their routine analysis for drugs of abuse. Oral fluid samples were screened for the presence of MDMA and methamphetamine using the Cozart RapiScan System (CRS) and then confirmed for the presence of amphetamines (amphetamine, methamphetamine, MDA, MDMA, MDEA, and MBDB) by gas chromatography-mass spectrometry (GC-MS). In addition to the detection of MDMA and methamphetamine, the CRS cross-reacts with high levels of amphetamine to give a positive result. One hundred and twenty-one samples screened positive using the CRS. Six of these samples were confirmed negative for MDMA and methamphetamine, but contained very high levels of amphetamine. Employing a screening cutoff of 45 ng/mL for the CRS and a confirmation cutoff of 30 ng/mL for GC-MS, the sensitivity, specificity, and accuracy were 96.6, 96.8, and 96.8%, respectively. When applying the Substance Abuse and Mental Health Services Administration recommended confirmation cutoff for amphetamines of 50 ng/mL, the sensitivity, specificity, and accuracy increased marginally to 98.3, 96.9, and 97.3%, respectively.

Determination of enalapril and enalaprilat by enzyme linked immunosorbent assays: application to pharmacokinetic and pharmacodynamic analysis.

We have developed two enzyme linked immunosorbent assay (ELISA) methods for determining enalapril and enalaprilat in plasma. In this study, 48 healthy subjects received an oral dose of either 10 or 20 mg of enalapril and plasma concentrations of enalapril and enalaprilat were determined by their specific ELISA methods. These plasma concentrations and blood pressure measurements were applied to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) parameters of both enalapril and enalaprilat. The enalapril values for the area under the curve (AUC(0)--> infinity ) were 480 +/- 216 and 832 +/- 325 ngh/mL, maximum plasma concentrations (C(max)) were 310 +/- 187 and 481 +/- 185 ng/mL, and times required to reach the maximum concentration t(max) were 1.13 +/- 0.22 and 1.09 +/- 0.33 h for 10 and 20 mg doses, respectively. The enalaprilat values for AUC(0)--> infinity were 256 +/- 122 and 383 +/- 158 ngh/mL, C(max) values were 57 +/- 29 and 72.9 +/- 33.6 ng/mL and t(max) values were 4.28 +/- 1.45 and 4.05 +/- 01.22 h for 10 and 20 mg doses, respectively. The C(max) values of enalapril were approximately 10 times higher than those in the literature, which were determined by angiotensin converting enzyme (ACE) inhibition assays following alkaline hydrolysis, but similar to those of enalaprilat. The PD profiles revealed a significant correlation between enalaprilat concentrations in plasma and the decrease in systolic and diastolic blood pressures (r = -0.95 with P < 0.001 and r = -0.95 with P < 0.001), respectively, following a single oral dose of enalapril. These ELISA methods have the advantage of being simple, accurate, sensitive, and do not depend on enalaprilat binding to ACE. Such methods can be used for analysis and kinetic testing of enalapril and enalaprilat in biological fluids.