Yuji Nakahara

Hair analysis for abused and therapeutic drugs.

This review focuses on basic aspects and recent studies of hair analysis for abused and therapeutic drugs and is discussed with 164 references. Firstly, biology of hair and sampling of hair specimens have been commented for the sake of correct interpretation of the results from hair analysis. Then the usual washing methods of hair samples and the extraction methods for drugs in hair have been shown and commented on. Analytical methods for each drug have been discussed by the grouping of three analytical methods, namely immunoassay, HPLC-CE and GC-MS. The outcomes of hair analysis studies have been reviewed by dividing into six groups; morphine and related, cocaine and related, amphetamines, cannabinoids, the other abused drugs and therapeutic drugs. In addition, reports on stability of drugs in the living hair and studies on drug incorporation into hair and dose-hair concentration relationships have been reviewed. Applications of hair analysis to the estimation of drug history, discrimination between OTC drug use and illegal drug use, drug testing for acute poisoning, gestational drug exposure and drug compliance have also been reviewed. Finally, the promising prospects of hair analysis have been described.

Hair Analysis for Drug Abuse: I. Determination of Methamphetamine and Amphetamine in Hair by Stable Isotope Dilution Gas Chromatography/Mass Spectrometry Method

Determination of methamphetamine and amphetamine in hair was performed by gas chromatography/mass spectrometry using stable isotope-labeled internal standards, 2-methylamino-1-phenylpropane-2,3,3,3-d4 and 2-amino-1-phenylpropane-2,3,3,3-d4. Extraction of hair with methanol/5M hydrochloric acid (20:1) using ultrasonication was chosen as the standard method. The calibration curves for amphetamines in the hair were linear from 1 to 100 ng/mg (r greater than 0.99). The detection limit was 0.5 ng/mg at the 95% confidence level. The coefficients of variation (CV) (n = 8) of analysis using the spiked hair with methamphetamine were from 0.7 to 6%. The CV (n = 8) of analysis of the methamphetamine abusers hair was 17.5%. Sectional analysis of monkey and human hair after methamphetamine ingestion suggested a good correlation between the duration of drug use and drug distribution in the hair.

Abuse of Smoking Methamphetamine Mixed with Tobacco: I. Inhalation Efficiency and Pyrolysis Products of Methamphetamine

Experiments of smoking methamphetamine in tobacco have been investigated. Inhalation efficiencies of methamphetamine into tar were 6 to 17% according to the additive amounts, suction volume, and intervals of smoking. Major pyrolysis products of methamphetamine in tar were identified as methamphetamine, amphetamine, phenylacetone, dimethylamphetamine, N-formyl-, N-acetyl-, N-propionyl-, and N-cyanomethyl-methamphetamine by the spectral analysis of infrared spectra (IR), mass spectra (MS), and proton magnetic resonance spectra (PMR), and comparison with the samples synthesized from authentic samples by one step. The largest pyrolysis product was N-cyanomethylmethamphetamine which is a new compound and easily metabolized to methamphetamine in the body. Methamphetamine itself transferred into tar was not so large, but the total active compounds in tar which would be metabolized to methamphetamine in the body were considerably larger.

Detection and diagnostic interpretation of amphetamines in hair.

A review with 22 references on detection and incorporation of amphetamines in hair is presented. This review deals with the detection, incorporation into hair, behavior in the hair shaft, confirmation of past drug use and diagnosis of dependence mainly regarding amphetamine and methamphetamine, along with methoxyphenamine, methylenedioxymethamphetamine, bromomethamphetamine, deprenyl, benzphetamine, fenproporex and mefenorex. First, pretreatment, extraction and analytical methods for amphetamines in hair using immunoassay, HPLC and GC/MS are discussed. This is followed by sections describing the animal experiments, incorporation rates of amphetamines from blood to hair and relationship between drug history and drug distribution in hair. Finally, the diagnosis of amphetamine dependence and confirmation of methamphetamine baby by hair analysis is discussed. The paper concludes with a brief outlook.

Hair analysis for drugs of abuse. V. The facility in incorporation of cocaine into hair over its major metabolites, benzoylecgonine and ecgonine methyl ester.

We studied the incorporation of cocaine (COC), benzoylecgonine (BE) and ecgonine methyl ester (EME) into hair from blood. At first, the time courses of three drugs in rat plasma following i. p. administration of cocaine were investigated over 360 min. AUCs of COC, BE and EME in plasma were 14.2, 60.7 and 53.4 Μg/ml/min, respectively. In contrast, the concentrations of the three compounds in hair were 16.4, 1.7 and 0.8 ng/mg. In spite of that, the AUC of COC in plasma was much lower than that of the other two compounds in plasma, the concentration of COC in hair was much higher than that of the other two compounds. The incorporation of COC into hair was much greater than that of BE and EME. If the incorporation of drugs from blood into hair is compared by [concentration in hair]/[AUC in plasma], that of COC, BE and EME is represented by 77∶1.9∶1. Our results suggest that the incorporation of drugs into hair from blood unexpectedly depends upon the physical properties of each drug.

Hair analysis for drugs of abuse. XIII. Effect of structural factors on incorporation of drugs into hair: the incorporation rates of amphetamine analogs.

Abstract In order to clarify the incorporation mech-anism of drugs from blood into hair, seven effects of structural factors on the incorporation rate (ICR) were studied using 32 amphetamine analogs: (1) effect of a straight chained N-alkyl group; (2) effect of benzene and furan ring at N-position; (3) effect of aliphatic and aromatic hydroxy groups; (4) effect of triple bond group at N-position; (5) effect of N-acyl group and ketone group; (6) effect of methylenedioxy and methoxy groups on benzene ring; and (7) comparison between phenyltertiarybutylamines and phenylisopropylamines. After shaving the back hair and i.p. administration of drugs to Dark-Agouti rats (5 mg/kg, 10 days, n=3), the areas under the concentration versus time curve (AUCs) of drugs in the plasma and the concentrations in hair newly grown for 4 weeks were determined by gas chromatography-mass spectrometry. The ICRs represented by the ratios of hair concentrations to AUCs were compared with those of amphetamine (AP) and methamphetamine (MA). The ICRs of N-alkyl AP increased depending on the length of carbon branches from proton to propyl (C3>C2>C1>H) at N-position. The compounds containing a benzene or furan ring at the N-position (benzphetamine, clobenzorex, norbenzphetamine, prenylamine, furfenorex, and norfurfenorex) had much higher ICRs than those of AP or MA, suggesting that a benzene or furan ring increases their ICRs. The ICRs of deprenyl, nordeprenyl, and fenproporex were significantly low, implying that triple bonds such as of a propargyl or cyano group serve as a negative factor for the ICRs. An ephedrine group (ephedrine, methylephedrine, phenylpropanolamine) showed slightly lower ICRs than the corresponding amphetamine group. However, a hydroxy group on benzene ring apparently decreased the ICRs. Methoxy and methylenedioxy groups on benzene ring distinctly increased their ICRs. The lack of basicity such as N-formyl MA, N-acetyl AP, and N-acetyl MA dramatically lowered their ICRs to zero or nearly zero. Moreover, the compounds containing a ketone group adjacent to benzene ring, e.g., cathinone and amfepramone, showed very low ICRs. Chlorine on propyl group (mefenorex) or benzene ring (clobenzorex) seemed to act positively for the ICR. These results showed that structural factors related to the lipophilicity and basicity clearly affect the drug incorporation into hair from blood.

Optimization of a simple method for the chiral separation of phenethylamines of forensic interest based on cyclodextrin complexation capillary electrophoresis and its preliminary application to the analysis of human urine and hair

Because of the forensic importance of the chiral analysis of amphetamine and other phenethylamines for investigating their synthetic pathways and the metabolic patterns of these compounds, a capillary electrophoresis method has been developed based on the chiral selectivity of beta-cyclodextrin. The influence of different experimental conditions, such as cyclodextrin nature and concentration, voltage, temperature and buffer concentration and pH, on analytical performance has been studied. The optimized analytical conditions are: capillary: bare fused silica, 50 microns I.D., 40 cm effective length; buffer: 150 mM phosphate pH = 2.5, 15 mM beta-cyclodextrin; voltage: 10 kV; temperature: 17.5 degrees C; detection: UV absorption at 200 nm wavelength. Under these conditions, amphetamine, methamphetamine and ephedrine have been easily separated, with baseline resolution of the respective enantiomers. Sensitivity was better than 300 ng per ml. The average precision of migration times of the three analytes was good with RSD = 0.45% and 0.58% in intra-day and day-to-day tests, respectively. Reproducibility of peak heights was also good, with RSD = 2.51% and 3.14% in intra-day and day-to-day tests, respectively. The preliminary analysis of amphetamine in human urine and hair samples, subjected to a simple work-up procedure based on liquid-liquid extraction, showed clean blank electropherograms, excellent chiral resolution and sensitivity, suitable for the analysis of real samples from amphetamine users.

Hair analysis for drug abuse, part II. Hair analysis for monitoring of methamphetamine abuse by isotope dilution gas chromatography/mass spectrometry

Sectional analysis of methamphetamine abusers hair was performed by using stable-isotope dilution GC/MS method. Drug concentrations of hair shaft cut into 2-cm sections from the root side were compared with the self-reported drug histories of 11 cases and the results of experiments on monkeys. It was found that in nine of the 11 cases, the relationship between the results of sectional analysis and drug histories coincided, but the sectional analyses of two cases were not consistent with self-reported drug history. The difference in drug concentrations between the regions of scalp hair was also investigated. Our study suggests that hair analysis, especially sectional analysis, may be useful in determining past drug history even though it is not exact.

Hair analysis for drugs of abuse. VII. The incorporation rates of cocaine, benzoylecgonine and ecgonine methyl ester into rat hair and hydrolysis of cocaine in rat hair.

We studied the incorporation rates of cocaine and its major metabolites, benzoylecgonine (BE) and ecgonine methylester (EME), into hair from blood. It was demonstrated in our previous report (Nakahara et al. 1992a) that the incorporation rate of cocaine from blood into hair was much higher than those of BE and EME following administration of cocaine. In this study, the incorporation rates of these drugs into rat hair were investigated following independent administration of BE and EME at 10 mg/kg per day for 5 days, and co-administration of cocaine, BE-d3 and EME-d3 at 3, 0.5 and 0.5 mg/kg per day for 10 days. When BE and EME were administered to rats independently, levels of both these drugs were hardly detectable or quite low in hair, though their AUCs in plasma were very high. On co-administration of cocaine, BE-d3 and EME-d3, the deuterium labeled metabolites in hair were negligibly lower in comparison with the unlabeled ones and in particular the concentration of BE in rat hair was significantly higher than that of BE-d3 although the AUC of BE-d3 was higher than that of BE. It was concluded that the incorporation rates of BE and EME into hair were very low in comparison with that of cocaine and most of the BE detected in hair would be a hydrolytic product derived from cocaine in hair matrix after incorporation.

Hair analysis for Drug Abuse XV. Disposition of 3,4-methylenedioxymethamphetamine (MDMA) and its related compounds into rat hair and application to hair analysis for MDMA abuse

In order to clarify the mechanism of drug incorporation into hair, disposition of 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA), 3-methoxy-4,5-methylenedioxyamphetamine (MMDA) and metabolites of MDMA, 4-hydroxy-3-methoxyamphetamine (HMAP) and 4-hydroxy-3-methoxymethamphetamine (HMMA), into hair was investigated with an animal model. After the intraperitoneal administration of those six drugs to pigmented hairy rats (5 mg/kg/day, 10 days, n = 3), the parent compounds and their metabolites in the rat plasma (5, 15, 30, 60, 120, 360 min after administration) and in the newly grown rat hair for 4 weeks were determined by GC/MS-SIM. When the ratio of hair concentration to area under the concentration versus time curves (AUCs) in plasma was represented as an index of incorporation rate (ICR) of drugs into hair, the order of ICRs was HMAP < MDA < HMMA < MDMA < MDEA < MMDA. In the comparison between MDA, MDMA and MDEA, their ICRs increased according to the length of carbon branches from proton to ethyl at the N position. From the point of view that the ICRs of MMDA was 2.3 times as much as that of MDA, the methoxy group on the benzene ring seemed to serve as a positive factor for the ICR. However, the ICRs of 4-hydroxy-3-methoxy compounds, HMAP and HMMA, were lower in comparison with those of MDA and MDMA, respectively. On the other hand, the ICRs of MDA, MDMA and MDEA were 5.5-6.1 times larger than those of amphetamine, methamphetamine and ethylamphetamine, suggesting that the methylenedioxy group on the benzene ring raises their ICRs very positively. Moreover, in order to apply the results from the animal experiments to human cases, the scalp hair samples of seven MDMA abusers were analyzed. MDMA and its metabolites, MDA; were simultaneously detected in all the samples by GC/MS. In the two samples, MDEA was found in addition to MDMA and MDA. It was shown that a hair sample is a good specimen for the confirmation of retrospective use of methylenedioxyamphetamines.