Impurity profiling of methamphetamine hydrochloride drugs seized in the Philippines.

Methamphetamine hydrochloride is one of the most widely used illicit drugs in the Philippines. In this study, we describe the application of cluster analysis of trace impurities in the profiling of the seized methamphetamine drug samples. Thirty milligrams of a homogenized drug sample were dissolved in 1 mL of pH 10.5 buffer solution and extracted with ethyl acetate containing three internal standards. The trace impurities were identified using gas chromatography-mass spectrometry (GC-MS) and quantified by gas chromatography with a flame ionization detector (GC-FID). Following previously reported methodologies, 30 impurity peaks were selected from the GC-FID chromatograms. The peak areas and retention times were referenced to the internal standards. The peak areas of the selected peaks were then grouped for cluster analysis. In order to check for consistency of clustering, two further cluster analyses were performed using 40 and 50 impurity peaks. Changes in clustering were observed in going from 30 to 40 impurity peaks, while analyses using 40 and 50 impurity peaks gave similar results. Thus, for the seized drug samples used in this study, cluster analysis using at least 40 impurity peaks showed better consistency of clustering as compared to analysis using 30 peaks only. Ten of the impurity peaks were identified, of which four were identified for the first time in methamphetamine drug samples. These are p-bromotoluene, N-benzyl amphetamine, N-ethyl amphetamine, and N-ethyl methamphetamine. The presence of phenyl-2-propanone (P2P), N,N-dimethyl amphetamine, and N-formyl amphetamine is indicative that these casework samples were synthesized using the Leuckart method.

Hair analysis for drugs of abuse. XI. Disposition of benzphetamine and its metabolites into hair and comparison of benzphetamine use and methamphetamine use by hair analysis.

In order to study the disposition of benzphetamine (BZP) and its metabolites, desmethyl benzphetamine (norBZP), p-hydroxy desmethyl benzphetamine (OHnorBZP), methamphetamine (MA) and amphetamine (AP), from plasma to hair in rats, an analytical method for identifying these drugs in plasma, urine and hair was developed with selected ion monitoring of gas chromatograph/mass spectrometry (GC/MS-SIM) results. After the intraperitoneal administration of BZP to rats (10 mg/kg/d, 10d, n = 3), concentrations of BZP and its metabolites in rat hair newly grown for 4 weeks were compared to the areas under the concentration versus time curve (AUCs) of these drugs in the rat plasma. The concentrations of BZP, norBZP, OHnorBZP, MA and AP in the rat hair were 14.8 +/- 1.4, 6.1 +/- 0.3, 2.6 +/- 0.5, 2.3 +/- 0.1 and 9.2 +/- 0.3 ng/mg, and the ratio of the concentrations in the hair to AUCs in the rat plasma was 3.0:0.1:0.1:0.6:0.2, respectively. This fact suggested that BZP tends to be readily incorporated into hair from blood. The method was applied to the determination of the metabolites in scalp hair and pubic hair of humans who orally ingested BZP (30 mg/d, 5d, n = 2). BZP, norBZP, MA and AP were detected at 0.14-0.56, 0.29-0.63, 0.10 and 1.06-1.66 ng/mg in the scalp hair and at 0.10-0.20, 0.13-0.18, trace-0.15 and 0.23 ng/mg in the pubic hair, respectively. It was shown that BZP use could be retrospectively distinguished from MA use by the detection of BZP and/or norBZP in hair.