The Disposition of Cocaine and Opiate Analytes in Hair and Fingernails of Humans Following Cocaine and Codeine Administration

Abstract

This study investigated the disposition patterns of cocaine and opiates into hair and fingernail specimens collected from 8 volunteers enrolled in a 10-week inpatient clinical study. All subjects were African-American males with a confirmed drug use history. Scalp hair and fingernail scrapings were collected weekly throughout the course of the study. Head hair was collected from the posterior vertex region, and fingernail scrapings were collected along the entire ventral surface of the nail plate. The specimens were introduced to successive decontamination washes including an isopropanol wash and three phosphate buffer washes. All decontamination washes were collected and analyzed. All specimens were enzymatically digested prior to being subjected to solid-phase extraction and derivatization. Analyses were performed using electron impact gas chromatography-mass spectrometry. Analytes investigated included eight cocaine analytes and five codeine analytes. The limit of quantitation for all analytes ranged from 0.1 to 0.5 ng/mg for both matrices. Cocaine was present at the highest concentrations of any analyte in both hair and nail. Benzoylecgonine and ecgonine methyl ester were the primary metabolites in both matrices and were typically less than 15% of cocaine concentrations. Codeine was the only opiate analyte identified in either hair or nail. Observed drug disposition profiles were different for hair and nails. A significant dose-response relationship was observed for hair specimens. The mean peak concentrations in hair after low dosing were half the concentration observed after high-dose administration. Generally, no clear relationship was evident between nail drug concentrations and dose. Decontamination washes removed less than 20% of the total drug present in hair, but removed most of the drug concentrations (60-100%) in nail. This investigation demonstrated that higher concentrations of drug were found in the subjects' hair than in their fingernails and that cocaine was found in both matrices at a greater concentration than codeine. Although both hair and nail have similar physical and chemical properties and may share common mechanisms of drug incorporation, this clinical study suggests that there are distinct differences in their disposition profiles.

Dose-Related Distribution of Codeine, Cocaine, and Metabolites into Human Hair following Controlled Oral Codeine and Subcutaneous Cocaine Administration

“…This study corroborates previous animal and human studies that reported dose-related cocaine concentrations in hair Hubbard et al, 2000;Ropero-Miller et al, 2000). Hubbard et al (2000) found dose-related concentrations of cocaine, ecgonine methyl ester, benzoylecgonine, TABLE 1 Average maximum codeine, cocaine, and metabolite concentrations in hair samples from 10 participants during a controlled codeine and cocaine administration study Baseline hair shavings were collected at the end of the 3-week washout period, immediately preceding the start of drug dosing, representing previously selfadministered cocaine (mean Ϯ S.E.M.).…”

“…Codeine hair concentrations in this study were similar to those previously reported and demonstrate dose relationship Joseph et al, 1999;Kronstrand et al, 1999;Ropero-Miller et al, 2000). Greater than 83 pg/mg norcodeine was found in 5 of 10 subjects after the high dose; however, only semiquantification was possible due to matrix effects compounded by the lack of commercially available deuterated norcodeine for use as an internal standard (Scheidweiler and Huestis, 2004).…”

Nail analysis for the detection of drugs of abuse and pharmaceuticals: a review

“…For both finger-and toenails, the concentrations in the washes were less than in the nails themself. In contrast, after a decontamination procedure consisting of washing with isopropanol for 15 min and phosphate buffer for 30 min, higher concentrations were present in the washes than in the nail scrapings [10]. Concentrations in the nail scrapings were 5-40 % of those in the washes, and in many samples compounds were only detected in the washes and not in the scrapings.…”

“…Concentrations in the nail scrapings were 5-40 % of those in the washes, and in many samples compounds were only detected in the washes and not in the scrapings. Thus, it is likely that this decontamination procedure not only eliminated external contamination, but also removed cocaine incorporated into the nail matrix [10]. The possible degradation, mainly by hydrolysis, of cocaine analytes during extraction from the nail matrix was evaluated in several studies.…”

“…1). Other mechanisms of incorporation that have been proposed are incorporation through diffusion from biological fluids such as sweat, sebum, and saliva [10][11][12], and incorporation Fig. 1 Structure of the nail: a sagittal section of the fingertip (adapted from [14]) through diffusion from the external environment [13].…”