Determination of Triazolam and  -Hydroxytriazolam in Guinea Pig Hair After a Single Dose

Abstract

A sensitive liquid chromatography-tandem mass spectrometry method is presented for determination of triazolam and alpha-hydroxytriazolam in guinea pig hair after a single dose of triazolam. Eighteen guinea pigs were divided into three dosage groups (10, 100, and 500 microg/kg) and administrated a single dose of triazolam intragastrically. Before administration, drug-free hair was shaved from their back. Newly grown hair in shaved area was collected every seven days after administration. About 20 mg of decontaminated hair was cut into small segments and incubated in 2 mL of phosphate buffer (pH 8.4) at 45 degrees C overnight. Triazolam-d(4) and alpha-hydroxytriazolam-d(4) were used as internal standards, and liquid-liquid extraction was performed with 3 mL of ethyl ether. The sample was separated on an Allure propyl PFP column with a mobile phase of acetonitrile/20 mM ammonium acetate (7:3, v/v). Detection was implemented with multiple reaction monitoring mode by an API4000 triple-quadrupole tandem mass spectrometer. Limits of detection for triazolam and alpha-hydroxytriazolam were 1 and 5 pg/mg, respectively. Triazolam and alpha-hydroxytriazolam could only be detected in the first week, and 100 microg/kg was the minimal dosage detectable in guinea pig hair. The concentration of triazolam in hair was related with administration dosage and hair color. alpha-Hydroxytriazolam has a higher concentration than triazolam in guinea pig hair.

A drug rape case involving triazolam detected in hair and urine

“…The level detected in this particular hair case indicated low intake of triazolam when compared to other similar publications [8,9] although these cases involved administration of triazolam to pigs or prescribed sedative (triazolam) with unknown use/compliance. It is possible that the dark hair of this case improved the detection possibilities since the high melanin content improves absorption of basic drugs such as triazolam.…”

“…The metabolite was not detected in the hair, a finding which could be attributed to the higher LOQ of this more polar compound and lower degree of incorporation of the metabolite into hair. Sun et al [8] found higher concentrations of the metabolite in guinea pig hair than the main drug triazolam. However, their data interpretation was also inhibited by the same less sensitive analysis of the metabolite than the parent drug (five times less), and their observation cannot be used as a general guideline since the study was performed on pigs and only involved four observations.…”

“…The quantitative method met the necessary sensitivity described in the literature for these types of drugs (benzodiazepines) in date rape cases/single dose applications [7,8]. For instance, Sun et al [8] described a LC-MS/MS method for a single dose of triazolam in guinea pig hair with LOD of about 1 and 5 pg/mg of triazolam and metabolite, respectively.…”

“…For instance, Sun et al [8] described a LC-MS/MS method for a single dose of triazolam in guinea pig hair with LOD of about 1 and 5 pg/mg of triazolam and metabolite, respectively. The method presented here is more sensitive than that presented in the study of Sun et al [8]. …”

Validation of a simultaneous analytical method for the detection of 27 benzodiazepines and metabolites and zolpidem in hair using LC–MS/MS and its application to human and rat hair

“…Since the pH in melanocytes is lower than that in plasma, lipophilic and basic drugs enter pigmented hair more than hydrophilic or acidic drugs [2]. The incorporation of selected benzodiazepines into hair has been studied using rat or human hair [3][4][5][6][7]. However, the interpretation of the quantitative results in hair from benzodiazepine, especially diazepam, users is not straightforward because diazepam is metabolized to temazepam and nordiazepam, both of which are further metabolized to oxazepam.…”