LC–MS determination of triazolam and its hydroxy metabolites in mouse dried blood spots: application to transgenic mouse pharmacokinetic studies

Aim: The objective of this study was to develop a LC–MS/MS method for the simultaneous determination of triazolam (TRZ) and its two hydroxy metabolites in transgenic mouse dried blood spots (DBS) using BALB/c mouse blood as a surrogate biomatrix. Methodology/Results: The DBS method involved spotting volume of 10 μl using Ahlstrom 226 sample collection cards. A ‘whole spot’ analysis (6-mm punch) involved extraction of analytes using water and acetonitrile containing an internal standard. DBS samples were analyzed by a validated LC–MS/MS method with a run time of 4 min. Conclusion: This validated LC–MS/MS method using DBS extraction was applied to quantitation of TRZ, α-hydroxytriazolam and 4-hydroxytriazolam in a CYP3A4 transgenic mouse oral pharmacokinetic study of TRZ.

A comprehensive and sensitive method for hair analysis in drug-facilitated crimes and incorporation of zolazepam and tiletamine into hair after a single exposure

Hair is a highly relevant specimen that is used to verify drug exposure in victims of drug-facilitated crime (DFC) cases. In the present study, a new analytical method involving ultrahigh-performance liquid chromatography-tandem mass spectrometry was developed for determining the presence of model drugs, including zolazepam and tiletamine and their metabolites in hair specimens from DFCs. The incorporation of zolazepam and tiletamine into hair after a single exposure was investigated in Long-Evans rats with the ratio of the hair concentration to the area under the curve. For rapid and simple sample preparation, methanol extraction and protein precipitation were performed for hair and plasma, respectively. No interference was observed in drug-free hair or plasma, except for hair-derived diphenhydramine in blank hair. The coefficients of variance of the matrix effects were below 12%, and the recoveries of the analytes exceeded 70% in all of the matrices. The precision and accuracy results were satisfactory. The limits of quantification ranged from 20 to 50 pg in 10 mg of hair. The drug incorporation rates were 0.03 ± 0.01% for zolazepam and 2.09 ± 0.51% for tiletamine in pigmented hair. We applied the present method to real hair samples in order to determine the drug that was used in seven cases. These results suggest that this comprehensive and sensitive hair analysis method can successfully verify a drug after a single exposure in crimes and can be applied in forensic and clinical toxicology laboratories.