Possibility of drug-distribution measurement in the hair of drowned bodies: evaluation of drug stability in water-soaked hair using micro-segmental analysis

Effects of temperature, humidity, light, and soil on drug stability in hair: a preliminary study for estimating personal profiles using micro-segmental analysis of corpse hair

PURPOSE

Micro-segmental hair analysis (MSA), which enables detailed measurement of the distribution of drugs in a single hair strand, is useful for examining the day of death and drug use history of a person. However, corpses are often found in severe environments, such as soil and freezers, which affect the drug contents in hair. Therefore, we examined the effects of temperature, humidity, light, and soil on drug stability in hair as a preliminary study to estimate personal profiles using MSA of corpse hair.

METHODS

Four hay-fever medicines (fexofenadine, epinastine, cetirizine, and desloratadine) were used as model drugs to evaluate drug stability in hair. Reference hair strands consistently containing the four medicines along the hair shaft were collected from patients with hay-fever who ingested the medicines daily for 4 months. The hair strands were placed in chambers with controlled temperatures (- 30 to 60 °C) and relative humidities (ca. 18 % and > 90 %), exposed to light (sunlight and artificial lights) or buried in soil (natural soil and compost).

RESULTS

Sunlight and soil greatly decomposed the hair surfaces and decreased the drug contents in hair (up to 37 %). However, all analytes were successfully detected along the hair shaft, reflecting the intake history, even when the hair was exposed to sunlight for 2 weeks and buried in the soil for 2 months.

CONCLUSIONS

Although the exposure to sunlight and storage in soil for long times made drug-distribution analysis difficult, MSA could be applied even to hair strands collected from corpses left in severe environments.

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.