Eddp [BSA]

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed, validated and applied to simultaneous analysis of oral fluid samples for the following 10 analytes: methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), buprenorphine, norbuprenorphine, morphine, codeine, 6-acetylmorphine, 6-acetylcodeine, amphetamine, and methamphetamine. The oral fluid sample was briefly centrifuged and the supernatant was directly injected into the LC-MS-MS system operated under reverse-phase chromatography and electrospray ionization (ESI). Deuterated analogs of the analytes were adopted as the internal standards and found to be effective (except for buprenorphine) to compensate for potential matrix effects. Each analytical run took <10 min. Linearity range (r(2) > 0.99) established for buprenorphine and the other nine analytes were 5-100 and 1-100 ng/mL. Intra- and interday precision (% CV) ranges for the 10 analytes were 0.87-12.2% and 1.27-12.8%, while the corresponding accuracy (%) ranges were 91.8-113% and 91.9-111%. Limits of detection and quantitation established for these 10 analytes were in the ranges of 0.1-1.0 and 0.25-1.0 ng/mL (5 ng/mL for buprenorphine). The method was successfully applied to the analysis of 62 oral fluid specimens collected from patients participating in methadone and buprenorphine substitution therapy programs. Analytical results of methadone and buprenorphine were compared with data derived from GC-MS analysis and found to be compatible. Overall, the direct injection LC-MS-MS method performed well, permitting rapid analysis of oral fluid samples for simultaneous quantification of methadone, buprenorphine, opiate and amphetamine drug categories without extensive sample preparation steps.

A reversed-phase high performance liquid chromatographic (RP-HPLC) method is developed and validated for the determination of methadone, a substitute of heroin used for drug addicts under heroin detoxication treatment in therapeutic communities, as well as its main metabolite EDDP in biological fluids. The analytical column, a Kromasil C-18 , 5 mu m, 250 x 4 mm, was operated at ambient temperature using isocratic elution with a mixture of CH3CN - 0.025 M CH3COONH4 (90-10 v/v) at a flow rate 1.2 mL/min. Anthracene (1 ng/mu L) was used as the internal standard. Inlet pressure was 220 kg/cm(2) . A DAD detector was monitoring the column eluant at 220 nm. The limit of detection was 10 ng for EDDP and 20 ng for methadone, per 20 mu L injection volume. Linearity held up to 20 ng/mu L for methadone and 15 ng/mu L for its metabolite. The statistical evaluation of the method was performed in terms of within-day (n = 6) and between-day (n=8) precision and accuracy, and was found to be satisfactory, with high accuracy and precision results. The method was successfully applied to biological fluids. Blood serum samples after deproteinization with acetonitrile and solid phase extraction, yielded high recovery rates: 101.5% for EDDP and 103.3% for methadone. Direct analysis of urine provided recovery rates at 97.9% for EDDP and 94.9% for methadone. The developed method can be readily applied to monitoring the levels of methadone and EDDP in biological samples from patients undergoing methadone maintenance therapy, in order to individualize treatment.