Effects of natural environments on drug contents in nails: comparison of drug residual rates between nails and hair to determine the drug-use history of corpses in unnatural death cases using micro-segmental analysis.

PURPOSE: We previously developed evaluation methods using micro-segmental analysis (MSA) to examine the effects of external environments on drug content in hair and nails. In this study, the effects of the natural environmental factors (water, temperature, humidity, light, and soil) on drug contents in nails were examined and compared with our previous experimental data on hair. METHODS: Four hay-fever medicines were used as model drugs (fexofenadine, epinastine, cetirizine, and desloratadine) to evaluate drug stability in the nails. Reference nails containing the four medicines were collected from patients with hay fever who ingested the medicines daily for four months. The nails were exposed to various natural environments for up to four months. RESULTS: The effects of temperature, humidity, and light on drug contents in the nails were comparatively small. Soil significantly decomposed the nail surfaces and decreased the drug content of the nails (up to 17 %). Water also decreased the drug content (up to 12 %), although no apparent changes in nail surfaces were observed. CONCLUSIONS: In comparison with hair data obtained under the same environmental conditions, light affected drugs in the hair rather than in nails, whereas water and soil greatly affected drugs in the nails rather than in hair. Although the disposition of drugs incorporated in the tissues differed between nails and hair, the analytes were detected in nails and hair strands left in severe natural environments. MSA could be useful for estimating drug-use histories and personal profiles using the nails and hair of a corpse.

Development of a method to evaluate the effects of external environments on drug stability in nails using micro-segmental analysis.

Nails can be used as an alternative to hair for examining past drug use. However, daily hand-and-nail care can eliminate the internal drugs. Therefore, we developed an evaluation method to examine the effects of the external environment on drug stability in nails using micro-segmental analysis. First, reference nails containing drugs were prepared by collecting fingernails from participants who had consumed hay-fever medicines continuously for 4 months. Next, the entire free edge of a reference nail was cut into halves at the centerline; one side was stored as an untreated block, and the other was treated with various hand/nail care products. Both nail blocks were washed and segmented at 0.5-mm intervals in the width direction. Each segment in the extraction solution was crushed with stainless-steel beads, sonicated, and soaked in the solution for 24 h. The analytes in extracts were quantified by LC-MS/MS, and the drug concentrations between the treated and untreated blocks were compared. The drug concentrations decreased slightly in nails treated with manicure and gel-nail products. The analytes in nails tended to be lower in water-rich products such as hand soap and hand cream than in oil-rich products such as nailcare oil and acetone-free remover. The developed method using micro-segmental analysis enabled the evaluation of the effects of various hand/nail care products on drug stability in a limited number of nails. This would also be useful for examining the effects of severe environments on drugs in nails collected from cases of unnatural death.

Micro-segmental analysis of the entry pathway and distribution of zolpidem in hair from different scalp regions after a single dose.

Introduction: Hair testing is well established for the assessment of past drug exposure; however, more research is needed to understand drug incorporation mechanisms and drug entry pathways into hair. Method: In this study, a micro-segmental LC-MS/MS method was used to analyze a 0.4 mm segment of hair after a single oral administration of zolpidem. Five single hairs were plucked at 1 day, 3 days, 7 days, and 28 days after administration from the vertex posterior of three subjects, and 5 single hairs were also plucked from the parietal, left temporal, and right temporal regions of the head at 28 days. Results and discussion: Proximal S1 (0-0.4 mm) in hair plucked at 1 day had the highest level of zolpidem at 1.5-2.4 pg/mm; much lower concentrations (< 1 pg/mm) were detected at proximal S2-S8 (0.4-3.2 mm). The drug concentration decreased gradually in S1 for 7 days after drug intake and disappeared by 28 days, suggesting that the drug from the bloodstream initially combined with the hair follicle and then gradually moved to the hair tip as the hair grew. The zolpidem concentration-hair segment profiles exhibited a large peak (root side) and a small peak (tip side) for the four sampling times in all three subjects, indicating that drug incorporation in the hair bulb occurred mainly from the blood but probably also entered the hair through sweat and sebum. Zolpidem was also detected in all hairs from the vertex posterior in all three subjects but was not detected in 1 hair from the parietal region and 2 hairs from the left temporal region. The consistency in drug detection, drug concentration level, and peak position was better in hair from the vertex posterior than from the other three regions, indicating that the vertex posterior is a suitable sampling region for estimating drug intake.

Evaluation of applicability of micro-segmental analysis to hair treated with heat and haircare products.

PURPOSE: Micro-segmental analysis (MSA), which enables the measurement of detailed drug distributions in hair by segmenting a single hair strand at 0.4 mm intervals, is indispensable for estimating the day of drug ingestion. However, haircare with dryers and various products can influence drug concentrations in hair. Therefore, the applicability of MSA to hair that was treated with heat or various haircare products was evaluated. METHODS: Reference hair strands containing drugs consistently along the hair shafts were collected from patients who ingested four hay-fever medicines (fexofenadine, epinastine, cetirizine, and loratadine) daily for 4 months. The hair strands were divided into eight 4 mm regions from the proximal end, and each region was placed on an electric hot plate at 100-200 °C or soaked in haircare products, such as shampoo and bleaching agent. The hair regions were subjected to MSA. Moreover, after a patient was administered midazolam at a single dose and the hair was bleached, the day of midazolam administration was estimated using MSA. RESULTS: Repetitive heating for 1 min and daily haircare products, such as shampoo, hardly affected the drugs in hair, whereas bleaching products containing H2O2 decreased the amounts of hay-fever medicines in the hair up to 58%. However, the amount of midazolam did not decrease in bleached hair and the day of midazolam administration was successfully estimated. CONCLUSIONS: The analytes used in this study were minimally affected by ordinary haircare and could be detected even in bleached hair. Therefore, MSA can be applicable regardless of haircare history.

Micro-segmental hair analysis: detailed procedures and applications in forensic toxicology.

PURPOSE: Since the 1980s, the detection sensitivity of mass spectrometers has increased by improving the analysis of drugs in hair. Accordingly, the number of hair strands required for the analysis has decreased. The length of the hair segment used in the analysis has also shortened. In 2016, micro-segmental hair analysis (MSA), which cuts a single hair strand at a 0.4-mm interval corresponding to a hair growth length of approximately one day, was developed. The advantage of MSA is that the analytical results provide powerful evidence of drug use in the investigation of drug-related crimes and detailed information about the mechanism of drug uptake into hair. This review article focuses on the MSA technique and its applications in forensic toxicology. METHODS: Multiple databases, such as SciFinder, PubMed, and Google, were utilized to collect relevant reports referring to MSA and drug analysis in hair. The experiences of our research group on the MSA were also included in this review. RESULTS: The analytical results provide a detailed drug distribution profile in a hair strand, which is useful for examining the mechanism of drug uptake into hair in detail. Additionally, the analytical method has been used for various scenarios in forensic toxicology, such as the estimation of days of drug consumption and death. CONCLUSIONS: The detailed procedures are summarized so that beginners can use the analytical method in their laboratories. Moreover, some application examples are presented, and the limitations of the current analytical method and future perspectives are described.

Estimation of day of death using micro-segmental hair analysis based on drug use history: a case of lidocaine use as a marker.

During investigations of unnatural death, the time of death is generally estimated using anatomical examinations. However, it can be difficult to accurately determine the day of death, because postmortem changes in the body tissues can be greatly affected by the circumstances of the location of the corpse. We recently developed a method to estimate the day of drug ingestion, using micro-segmental hair analysis based on internal temporal markers (ITMs). In this method, ITMs are ingested at a specific time interval before hair collection to mark timescales within individual hair strands. A single hair strand is segmented at 0.4-mm intervals, corresponding to average daily hair growth. The day of drug ingestion is eventually estimated by calculating the distances between segments containing the drug and ITMs in a hair strand. In the present study, the method was applied to estimate the day of death. A corpse was discovered with a documented medical history of lidocaine administration for surgery 57 days before the discovery. Micro-segmental analysis of a hair plucked from the corpse was performed using lidocaine as an ITM. Lidocaine was detected at specific regions in the hair strands. The day of death was estimated using the known surgery day, the distance from the hair root to the lidocaine peak in the hair strand, and the average hair growth rate. The novel estimation method using a hair enabled us to narrow the estimated time range of death up to the day of death, unlike the conventional anatomical examination. The micro-segmental hair analysis based on drug use history can be extremely helpful in determining the time of an unnatural death.

Micro-segmental hair analysis for proving drug-facilitated crimes: Evidence that a victim ingested a sleeping aid, diphenhydramine, on a specific day.

Sleeping aids are often abused in the commission of drug-facilitated crimes. Generally, there is little evidence that a victim ingested a spiked drink unknowingly because the unconscious victim cannot report the situation to the police immediately after the crime occurred. Although conventional segmental hair analysis can estimate the number of months since a targeted drug was ingested, this analysis cannot determine the specific day of ingestion. We recently developed a method of micro-segmental hair analysis using internal temporal markers (ITMs) to estimate the day of drug ingestion. This method was based on volunteer ingestion of ITMs to determine a timescale within individual hair strands, by segmenting a single hair strand at 0.4-mm intervals, corresponding to daily hair growth. This study assessed the ability of this method to estimate the day of ingestion of an over-the-counter sleeping aid, diphenhydramine, which can be easily abused. To model ingestion of a diphenhydramine-spiked drink unknowingly, each subject ingested a dose of diphenhydramine, followed by ingestion of two doses of the ITM, chlorpheniramine, 14days apart. Several hair strands were collected from each subject's scalp several weeks after the second ITM ingestion. Diphenhydramine and ITM were detected at specific regions within individual hair strands. The day of diphenhydramine ingestion was estimated from the distances between the regions and the days of ITM ingestion. The error between estimated and actual ingestion day ranged from -0.1 to 1.9days regardless of subjects and hair collection times. The total time required for micro-segmental analysis of 96 hair segments (hair length: 3.84cm) was approximately 2days and the cost was almost the same as in general drug analysis. This procedure may be applicable to the investigation of crimes facilitated by various drugs.