LC-MS/MS Analysis of Δ9-THC, CBN and CBD in Hair: Investigation of Artefacts

Associations between hair-derived cannabinoid levels, self-reported use, and cannabis-related problems

RATIONALE

As cannabis potency and cannabis use are increasing in newly legalized markets, it is increasingly important to measure and examine the effects of cannabinoid exposure.

OBJECTIVES

The current study aims to assess how hair-derived cannabinoid concentrations - offering insight into three-month cumulative exposure - are associated with common self-report measures of cannabis use and cannabis use-related problems.

METHODS

74 near-daily dependent cannabis users self-reported their quantity of cannabis use, cannabis use-related problems, and estimated cannabis potency. Hair samples were provided to quantify Δ9-THC, CBD, and CBN using LC-MS/MS and THC-consumption was verified by analyzing THC-COOH in hair using GC-MS/MS.

RESULTS

Cannabinoids were detectable in 95.95% of the hair samples from individuals who tested positive on a urine screen for cannabis. Δ9-THC concentrations were positively associated with measures of self-reported potency (relative potency, potency category, and perceived 'high'), but Δ9-THC, CBD, CBN concentrations and THC/CBD ratio were not associated with self-reported quantity of use. Self-reported potency, but not hair-derived concentrations, were associated with withdrawal and craving. Self-reported quantity of cannabis use, but not cannabinoid concentrations, were associated with cannabis use-related problems.

CONCLUSIONS

The use of hair-derived cannabinoid quantification is supported for detecting cannabis use in near-daily users, but the lack of associations between hair-derived cannabinoid concentrations and self-report measures of use does not support the use of hair analyses alone for quantification of cannabinoid exposure. Further research comparing hair-derived cannabinoid concentrations with other biological matrices (e.g. plasma) and self-report is necessary to further evaluate the validity of hair analyses for this purpose.

Tacrolimus monitoring in hair samples of kidney transplant recipients

Background

Calcineurin inhibitors, including tacrolimus, remain a cornerstone of immunosuppressive therapy after kidney transplantation. However, the therapeutic window is narrow, and nephrotoxic side effects occur with overdose, while the risk of alloimmunization and graft rejection increases with underdose. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) allows quantification of tacrolimus in biological samples from patients. This study investigates the feasibility of quantifying tacrolimus in scalp hair from kidney transplant (KT) recipients and correlates hair tacrolimus concentrations with tacrolimus dosage and blood trough levels. The aim was to provide proof-of-principle for hair tacrolimus drug monitoring in KT recipients.

Method

Single-center prospective study between September 9, 2021 and December 4, 2021, including KT recipients under tacrolimus. Minors, patients with active skin or hair diseases, and patients with scalp hair shorter than 4 cm were excluded from participation. Scalp hair was collected from the posterior vertex of patients, cut into segments, and analyzed for tacrolimus by LC-MS/MS. Patients filled out a questionnaire on hair treatments and washing habits. In parallel, tacrolimus trough levels were measured in whole blood and correlated with hair tacrolimus concentrations.

Results

In total, 39 consenting KT recipients were included, and hair samples were collected at 53 visits. Tacrolimus was detected in 98% of hair samples from patients exposed to the drug. Tacrolimus hair levels and whole blood trough levels were correlated with a beta coefficient of 0.42 (95% CI: -0.22-1.1, p = n.s.). Age and dark hair affected hair tacrolimus measurements, while different tacrolimus formulations (immediate release vs. extended release), hair washes, and permanent coloring did not. Longitudinal measurements in a subgroup of patients indicate that long-term measurement of hair tacrolimus levels is feasible.

Conclusion

Measuring tacrolimus in hair is a potentially reliable method to monitor drug exposure in KT patients. Rapid wash-in effects and consistent concentrations over time indicate that tacrolimus is incorporated into the hair matrix, allowing temporal resolution in the analysis of recent exposure and exposure history. This method provides a simple and low-risk alternative to regular blood sampling, sparing patients from frequent hospital visits through the self-collection of hair samples.

Single sample preparation for the simultaneous extraction of drugs, pharmaceuticals, cannabinoids and endogenous steroids in hair

Recently, we published a multi-analyte method for the simultaneous analysis of 116 drugs and pharmaceuticals including different substance groups like opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics based on a single sample workup followed by a single analytical measurement with LC-MS/MS. However, in some cases, additional analysis of further substance groups, such as cannabinoids and endogenous steroids, is required, which are analyzed in our laboratory using separate sample preparation and separate analytical methods. The goal of this study was to use the knowledge from the different sample preparations and combine them into a single sample preparation and extraction workflow for the simultaneous extraction of drugs, pharmaceuticals, cannabinoids, and endogenous steroids to be analyzed with the appropriate analytical methods. A partial validation of selected parameters such as selectivity, linearity, limit of quantification (LOQ), accuracy, precision and robustness for the different analytical methods was carried out and revalidated. In addition, comparative measurements of quality controls and authentic pools were performed and statistically evaluated using the unpaired t-test or the non-parametric Mann-Whitney test. The results using the newly established sample preparation and extraction were in good agreement with the original data. In conclusion, the newly established sample preparation is suitable for the combined extraction of drugs, pharmaceuticals, cannabinoids and endogenous steroids, and gives reliable results for quantification of various substances.

An Optimized Terpene Profile for a New Medical Cannabis Oil

The purpose of this analytical study was to develop an advanced formulation of medical Cannabis oil (MCO) comparing the chemical profile of different extracts obtained with two existing methods (SIFAP and CALVI) and one original upgraded (CERFIT) method. Preparation methods were applied with varying solvent, temperature, and duration of the decarboxylation and extraction steps. HPLC-MS/MS TSQ and GC/FID-HS analyses were performed to investigate cannabinoid and terpene contents in the three oil extracts. Cannabinoids profile remained comparable between the formulations. CERFIT extracts exhibited a superior quantity of total terpene hydrocarbon forms (e.g., limonene and α-pinene) with no degradation occurrence (i.e., oxidized terpenes not quantifiable). Thus, this new method optimized the phytochemical profile of the MCO presenting a value opportunity to obtain a standardized high-level therapeutic product.