Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) procedure for screening of urine specimens for 100 analytes relevant in drug-facilitated crime (DFC).

In recent years, drug-facilitated crime (DFC) has become an increasing problem. A minimum list of 80 analytes to be monitored in such cases has been proposed by the Society of Forensic Toxicologists (SOFT) including the recommended minimum performance limits (RMPL). In the present study, two liquid chromatography-tandem mass spectrometry-based screening procedures, one in positive (method I) and one in negative (method II) electrospray ionization mode were developed and validated. Gradient elution was performed on a ZORBAX Eclipse XDB-C18 column after protein precipitation of the urine samples. Detection was carried out in the scheduled multiple reaction monitoring (MRM) mode monitoring two transitions per compound. A total of 100 analytes (91 basic in method I and nine acidic in method II) could be identified using the described procedure. No interferences were observed in 30 tested blank urine samples. The RMPLs were achieved for all analytes and ranged from 1 ng/mL for fentanyl to 10 µg/mL for γ-hydroxybutyrate (GHB). Matrix effects (ME) were evaluated using the same 30 urine samples and ranged from -90 % for tetrazepam to >6,000 % for the 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH). The relative standard deviations of ME were below 25 % for the vast majority of analytes. Results for urine specimens from nine authentic DFC cases were always negative with exception of drugs prescribed to the victims. Reanalysis with the developed procedure of 24 urine samples, with a positive screening result during routine clinical toxicology analysis, confirmed the routine findings. In an excretion study after a single oral doxylamine dose (30 mg), the parent drug and its nor metabolite could be detected in urine specimens from a young female volunteer for 10 days. The developed procedure allows a selective and sensitive screening of urine samples for almost all recommended analytes relevant in DFC cases.

[Chemicotoxicological evaluation of doxylamine].

The conditions of doxilamine isolation from biological fluids are studied. The method of its extraction with a mixture of organic solvents in pH 9 is proposed. Identification of doxilamine with techniques of thin layer chromatography, UV-, IR-spectroscopy, chromato-mass-spectrometry, densitometry, gas-liquid chromatography is described. UV-spectrometry, gas chromatography and densitometry can be used for quantitation of doxilamine.

[Detection of reladorm and donormil in forensic-medical examination of cadavers].

A method was suggested for identifying reladorm and donormil in pharmaceutical drugs and biological objects. The above substances are isolated by 96% ethanol or by mixture of chloroform and isopropanol. 7 color reactions, 3 microcrystalloscopic reactions and chromatography in thin sorbent layer are suggested for identification.

Metabolism of doxylamine succinate in Fischer 344 rats. Part I: Distribution and excretion.

Experiments were conducted with male and female rats (12 per group) dosed by gavage with 2 or 20 mg (based on the free amine) doxylamine succinate containing about 10 microCi 14C-doxylamine succinate to determine distribution and excretion of the activity as a function of dose and sex with time. Urine and feces were collected at intervals up to 72 hr. Most of the dose (approximately equal to 70%) was eliminated in the first 24 hr after dosing and 95 to 100% of the dose was recovered during the 72-hr course of the experiments with both sexes and dose levels. Less than 1% of the total dose remained in the rats at the end of the test period. The urinary route of elimination was more predominant than the fecal route in both sexes given the 20-mg dose. The fecal route predominates in low-dose males whereas there is no significant difference between urinary and fecal routes of elimination in low-dose females. Preliminary characterization of urinary metabolite form using extraction techniques shows 99% of the metabolites to be in the polar conjugated form.

Metabolism of doxylamine succinate in Fischer 344 rats. Part III: Conjugated urinary and fecal metabolites.

Elimination and metabolic profiles of the glucuronide products of doxylamine and its N-demethylated metabolites were determined after the oral administration of (14C)-doxylamine succinate (13.3 and 133 mg/kg doses) to male and female Fischer 344 rats. The cumulative urinary and fecal eliminations of these conjugated doxylamine metabolites at the 13.3 mg/kg dose were 44.4 +/- 4.2% and 47.3 +/- 8.1% of the total recovered dose for male and female rats, respectively. The cumulative urinary and fecal eliminations of conjugated doxylamine metabolites at the 133 mg/kg dose were 55.2 +/- 2.6% and 47.9 +/- 2.5% of the total recovered dose for male and female rats, respectively. The conjugated doxylamine metabolites that were isolated, quantitated, and identified are doxylamine O-glucuronide, N-desmethyl-doxylamine O-glucuronide, and N,N-didesmethyldoxylamine O-glucuronide.

Trace analysis of doxylamine succinate in animal feed, human, urine, and wastewater by GC using a rubidium-sensitized nitrogen detector.

Doxylamine succinate, a drug used as a sleep-inducing agent, an antihistamine, and in a therapeutic formulation taken by pregnant women as an antinauseant, was scheduled for toxicological evaluation as part of a structure activity relationship study, with rats and mice, because a deficiency of such data exists with regard to many antihistamines. Analytical chemical procedures that ensure proper concentration, homogeneity, and stability of the drug in dosed feed, as well as the safety of personnel and the environment, were prerequisites for the toxicological tests. GC methods using a rubidium-sensitized nitrogen detector were developed for analysis of doxylamine succinate in animal feed, human urine, and wastewater at levels as low as 1 ppm, 100 ppb, and 100 ppb, respectively. Sample extracts were cleaned up by liquid-liquid partitioning, followed by additional cleanup on a column of silica gel. Data are presented concerning the stability of the drug in animal feed, extraction efficiencies, and the use of the silica gel cleanup column to separate the caffeine interference from doxylamine in extracts of human urine. Partition values and ancillary data concerning analysis of the drug in feed, by HPLC at levels as low as 10 ppm, are also reported.

Chemometrics optimization of six antihistamines separations by capillary electrophoresis with electrochemiluminescence detection.

This work expanded the knowledge of the use of chemometric experimental design in optimizing of six antihistamines separations by capillary electrophoresis with electrochemiluminescence detection. Specially, central composite design was employed for optimizing the three critical electrophoretic variables (Tris-H(3)PO(4) buffer concentration, buffer pH value and separation voltage) using the chromatography resolution statistic function (CRS function) as the response variable. The optimum conditions were established from empirical model: 24.2mM Tris-H(3)PO(4) buffer (pH 2.7) with separation voltage of 15.9 kV. Applying theses conditions, the six antihistamines (carbinoxamine, chlorpheniramine, cyproheptadine, doxylamine, diphenhydramine and ephedrine) could be simultaneous separated in less than 22 min. Our results indicate that the chemometrics optimization method can greatly simplify the optimization procedure for multi-component analysis. The proposed method was also validated for linearity, repeatability and sensitivity, and was successfully applied to determine these antihistamine drugs in urine.

Multiple-drug toxicity caused by the coadministration of 4-methylmethcathinone (mephedrone) and heroin.

An accidental death caused by the combined use of a new designer drug, 4-methylmethcathinone (mephedrone), and heroin is reported. A 22-year-old Caucasian male was found unresponsive in his living quarters and was transported to the hospital where he died. During autopsy, needle marks were found along the decedent's lower legs and ankles. Investigators discovered the decedent and his roommate had been using "Black Tar" heroin and mephedrone. Routine toxicological analysis detected morphine in the decedent's blood at 0.06 mg/L. Additionally, 6-acetylmorphine, morphine, codeine, and doxylamine were detected in his urine. A designer drug screen, employing a basic liquid-liquid extraction followed by pentafluropropionic anhydride derivatization, was used to isolate mephedrone from both blood and urine specimens. The derivatized extracts were analyzed by gas chromatography- mass spectrometry (GC-MS) operating in full-scan mode. Quantitative analysis of mephedrone was performed by GC-MS operating in selective ion monitoring mode using methamphetamine-d(14) as an internal standard. Mephedrone was confirmed in the decedent's blood and urine at 0.50 and 198 mg/L, respectively. The physiological and pharmacological effects of mephedrone and any associated toxicity have not been reported. However, because of its structural similarities with methcathinone and the high concentration in the decedent's blood, the overall contribution of mephedrone to the death could not be minimized. Therefore, the medical examiner reported the cause of death as multiple-drug toxicity and the manner of death as accidental.

[Biotransformation of doxylamine: isolation, identification and synthesis of some metabolites (author's transl)]. / Zum Stoffwechsel des Doxylamin: Isolierung, Identifizierung und Syntheseeiniger Metabolite.

After administration of therapeutic doses of doxylamine, the unchanged drug(I) and five degradation products were detected in human urine; their chemical structures are discussed and - to some extent - confirmed by synthesis. The results show that biotransformation of doxylamine in man takes place by the following routes: successive dealkylations at the nitrogen atom, giving N-demethyl-doxylamine(II) and N.N-didemethyl-doxylamine(II); cleavage at the benzhydrylether-function, resulting in the formation of 1-phenyl-1-(2-pyridyl)-ethanol(V), 1-phenyl-1-(2-pyridyl)-ethane(VI) and 1-phenyl-1-(2-pyridyl)-ethene(VII). VI and VII may be artefacts. Identification of an additional degradation product(=IV) was not possible, because the isolated quantities were too small. The analytical properties (hydrolysis!) of the pure substance and free base are thoroughly discussed, as well as the role of Chemical Ionization Mass Spectrometry with various reagent gases for the examination of biological extracts.

Doxylamine: a cause for false-positive gas chromatographic assay for phencyclidine.

A 25-year-old white woman ingested an unknown quantity of doxylamine succinate and flurazepam. Urine immunoassay screen (EMIT-dau) was positive for benzodiazopine and negative for phencyclidine. Subsequent gas chromatographic assay of the urine revealed a markedly positive assay for phencyclidine. Doxylamine was ultimately found to be the cause for the false-positive gas chromatographic assay for phencyclidine.

Identification in in vivo acetylation pathway for N-dealkylated metabolites of doxylamine in humans.

1. Metabolites of doxylamine in human urine were separated by g.l.c. and h.p.l.c. and tentatively identified by their mass spectrometric behaviour. 2. N-Desmethyldoxylamine, N,N-didesmethyldoxylamine and their N-acetyl conjugates were identified. This is believed to be the first report of acetylation in vivo of primary and secondary aliphatic amines in man.

Desorption chemical ionization and fast atom bombardment mass spectrometric studies of the glucuronide metabolites of doxylamine.

Three glucuronide metabolites of doxylamine succinate were collected in a single fraction using high-performance liquid chromatography (HPLC) from the urine of dosed male Fischer 344 rats. The metabolites were then separated using an additional HPLC step into fractions containing predominantly a single glucuronide metabolite. Analysis of the metabolites by methane and ammonia desorption chemical ionization, with and without derivatization, revealed fragment ions suggestive of a hydroxylated doxylamine moiety. Identification of the metabolites as glucuronides of doxylamine, desmethyldoxylamine and didesmethyldoxylamine was accomplished, based on determination of the molecular weight and exact mass of each metabolite using fast atom bombardment (FAB) ionization. This assignment was confirmed by the fragmentation observed in FAB mass spectrometric and tandem mass spectrometric experiments. Para-substitution of the glucuronide on the phenyl moiety was observed by 500-MHz nuclear magnetic resonance (NMR) spectrometry. A fraction containing all three glucuronide metabolites, after a single stage of HPLC separation, was also analysed by FAB mass spectrometry, and the proton- and potassium-containing quasimolecular ions for all three metabolites were observed.