Sweat testing for heroin, cocaine, and metabolites

Flux-Type versus Concentration-Type Sensors in Transdermal Measurements

New transdermal biosensors measure analytes that diffuse from the bloodstream through the skin, making it important to reduce the system response time and understand measurement output. While highly customized models have been created for specific sensors, a generalized model for transdermal sensor systems is lacking. Here, a simple one-dimensional diffusion model was used to characterize the measurement system and classify biosensors as either flux types or concentration types. Results showed that flux-type sensors have significantly faster response times than concentration sensors. Furthermore, flux sensors do not measure concentration, but rather have an output measurement that is proportional to skin permeability. These findings should lead to an improved understanding of transdermal measurements and their relation to blood analyte concentration. In the realm of alcohol research, where the majority of commercially available sensors are flux types, our work advocates toward moving away from transdermal alcohol concentration as a metric, and instead suggests embracing transdermal alcohol flux as a more suitable alternative.

Determination of licit and illicit drugs and metabolites in human sweat by liquid chromatography-tandem mass spectrometry

A liquid chromatography-tandem mass spectrometry screening method in sweat was developed for the simultaneous determination of three licit drugs (nicotine, paracetamol, and caffeine); four illicit drugs (cocaine, ketamine, 25I-NBOMe and methamphetamine) and two metabolites (benzoylecgonine and cotinine). Target drugs were liberated from sweat patches with pH 5 sodium acetate buffer and further purified by solid phase extraction (SPE) utilising Strata-X-Drug B cartridges. Optimal solvent constituents for SPE organic wash and elution were 70% v/v methanol in deionised water and 5% v/v ammonium hydroxide in methanol respectively. Chromatographic separation was achieved using a superficially porous particle C18 column with gradient elution, using (A) 0.1% formic acid in water and (B) acetonitrile as mobile phase constituents. Target drugs were identified using a combination of retention time, and the ion ratios for two precursor-product ion transitions for each analyte monitored in multiple reaction monitoring (MRM) mode. The method was linear for all target drugs from 1.0-150.0 ng mL-1 with corresponding limits of quantitation of 1.0 ng mL-1. Limits of detection were found to range from 0.1-0.6 ng per patch. The method was subsequently applied to the analysis of sweat samples from five male and four female participants aged 20-25 years. Sweat was collected from two areas (right forearm and left thigh) using protected layers of gauze. All eighteen patches tested positive for at least one target analyte. The results of this study not only show a multi-substance screening method was achieved but also that sweat patches can be used to indicate an individual's drug use. Therefore, they can provide an alternative non-invasive technique for forensic applications.

Development of analytical method for illegal substances in sweat and comparison of the effectiveness of sweat collection materials

PURPOSE

Sweat analysis can yield valuable information in forensic investigations, diagnosis and treatment. The purpose of this study was to develop a validated gas chromatography-mass spectrometric method for the detection of illegal substances in sweat after optimizing the method by chemometric approach. This study also investigated the effectiveness of alternative sweat-collecting materials.

METHODS

Plackett-Burman screening design was employed to determine the effect of seven process factors on this new method. Then, central composite design (CCD) was used to optimize the method. The method was validated according to the international guidelines. The effectiveness of alternative sweat-collecting materials (cosmetic pads and swabs) was compared with a commercially available collecting device (DrugWipe5A).

RESULTS

Sample pH, ultrasonic bath time, and liquid-liquid extraction (LLE) shaking time were determined as the most significantly effective three parameters with the Plackett- Burman screening design. The validation procedure was successfully performed after optimizing this method. The comparison study demonstrated that cosmetic pads, swabs, and DrugWipe5A can be used interchangeably.

CONCLUSIONS

Our results suggested that the statistical optimum strategy was an effective tool for the optimization of process parameters. Combined with the sensitivity and selectivity of our method, the analysis of sweat collection materials proved to be a useful tool for physicians and health care professionals.

Analysis of Stimulants in Sweat and Urine Using Disposable Pipette Extraction and Gas Chromatography Coupled to Mass Spectrometry in the Context of Doping Control

Urine is initially collected from athletes to screen for the presence of illicit drugs. Sweat is an alternative sample matrix that provides advantages over urine including reduced opportunity for sample adulteration, longer detection-time window and non-invasive collection. Sweat is suitable for analysis of the parent drug and metabolites. In this study, a method was developed and validated to determine the presence of 13 amphetamine- and cocaine-related substances and their metabolites in sweat and urine using disposable pipette extraction (DPX) by gas chromatography coupled to mass spectrometry. The DPX extraction was performed using 0.1 M HCl and dichloromethane:isopropanol:ammonium hydroxide (78:20:2, v/v/v) followed by derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide at 90°C for 20 min. DPX extraction efficiencies ranged between 65.0% and 96.0% in urine and 68.0% and 101.0% in sweat. Method accuracy was from 90.0% to 104.0% in urine and from 89.0% to 105.0% in sweat. Intra-assay precision in urine and in sweat were <15.6% and <17.8%, respectively, and inter-assay precision ranged from 4.70% to 15.3% in urine and from 4.05% to 15.4% in sweat. Calibration curves presented a correlation coefficient -0.99 for all analytes in both matrices. The validated method was applied to urine and sweat samples collected from 40 professional athletes who knowingly took one or more of the target illicit drugs. Thirteen of 40 athletes were positive for at least one drug. All the drugs detected in the urine were also detected in sweat samples indicating that sweat is a viable matrix for screening or confirmatory drug testing.

Avatar-like body imaging of dermal exposure to melamine in factory workers analyzed by ambient mass spectrometry

Ambient mass spectrometry thermal desorption-electrospray ionization/mass spectrometry (TD-ESI/MS) can rapidly identify chemicals without pretreatment of biological samples. This study used a rapid semi-quantitative TD-ESI/MS screening technique for the probe skin sampling of melamine workers occupationally exposed to different ambient melamine concentrations to create avatar-like body images, which were then used to study temporal and dynamic changes in nephrotoxic melamine exposure. We enrolled four voluntary melamine workers from one factory, each from one of four worksites. Melamine exposure was highest in manufacturing and molding, followed by grinding and polishing, packing, and administration, the lowest. Skin samples were collected Friday (end-of-shift) and Monday (pre-shift). Early morning one-spot urine samples were also collected right after skin sampling. 2198 probe skin samples were collected and subjected to semi-quantitative TD-ESI/MS analyses of melamine chemical within 40 h. After normalization, converted body image scores revealed exposure to be highest in the manufacturing worker on Friday and lowest in the administrative worker on Monday. The absolute differences (Friday minus Monday) of normalized body image scores were all significantly positive in each individual worker and across all four workers (permutation test, all p-values < 0.002). The slope estimates of the linear regression line between body image scores and urinary melamine levels were 0.81 (p-value = 0.008). We concluded that this fast and non-invasive technique can potentially be used to study temporal and dynamic changes in exposure to occupational hazards. A future study of developing an automatic and reproducible TD-ESI/MS sampling platform is needed.

Designing, fabrication and evaluation of a rapid, point-of-care and noninvasive system for the detection of lead (Pb2+)

Non-invasive collection of biological sample such as sweat, urine, saliva, hairs and, stool and onsite detection of anlaytes in those samples is an interesting and viable approach for rapid screening of various toxicants in body. Environmental exposure/presence of lead (₈₂Pb) and its rapid detection provide one such opportunity. A chemical spot based colorimetric method and a transdermal patch device based on this spot test, is developed for rapid and qualitative assessment of inorganic lead (Pb²⁺) in non-coloured biological or environmental liquid samples. The transdermal patch system contains two important parts, a chemical spot prepared on a thin glass sheet and, an absorbent paper (11 µm pore size). A one step colour development reaction is able to identify the presence or absence of Pb²⁺. In-vitro evaluation for sensitivity and cut-off value determination, within run and between run precision testing, specificity testing were done. In-vivo evaluation of the developed patch system was performed in occupationally lead-exposed subjects and in control volunteers. In-vivo field testing results were further validated with gold standard test for lead detection. Blood lead levels and patch lead levels were found to be positively correlated (r = 0.57, P < 0.0001). In addition, the sensitivity and specificity of device in identification of Pb²⁺ was found to be 75.93% (95% CI = 62.36%-86.51%) and 95.24% (95% CI = 76.18%-99.88%). The developed system appears as a reliable, non-invasive rapid test with minimum step involve for identification of Pb²⁺ in a given system.

Alternative matrices in forensic toxicology: a critical review

Purpose

The use of alternative matrices in toxicological analyses has been on the rise in clinical and forensic settings. Specimens alternative to blood and urine are useful in providing additional information regarding drug exposure and analytical benefits. The goal of this paper is to present a critical review on the most recent literature regarding the application of six common alternative matrices, i.e., oral fluid, hair, sweat, meconium, breast milk and vitreous humor in forensic toxicology.

Methods

The recent literature have been searched and reviewed for the characteristics, advantages and limitations of oral fluid, hair, sweat, meconium, breast milk and vitreous humor and its applications in the analysis of traditional drugs of abuse and novel psychoactive substances (NPS).

Results

This paper outlines the properties of six biological matrices that have been used in forensic analyses, as alternatives to whole blood and urine specimens. Each of this matrix has benefits in regards to sampling, extraction, detection window, typical drug levels and other aspects. However, theses matrices have also limitations such as limited incorporation of drugs (according to physical–chemical properties), impossibility to correlate the concentrations for effects, low levels of xenobiotics and ultimately the need for more sensitive analysis. For more traditional drugs of abuse (e.g., cocaine and amphetamines), there are already data available on the detection in alternative matrices. However, data on the determination of emerging drugs such as the NPS in alternative biological matrices are more limited.

Conclusions

Alternative biological fluids are important specimens in forensic toxicology. These matrices have been increasingly reported over the years, and this dynamic will probably continue in the future, especially considering their inherent advantages and the possibility to be used when blood or urine are unavailable. However, one should be aware that these matrices have limitations and particular properties, and the findings obtained from the analysis of these specimens may vary according to the type of matrix. As a potential perspective in forensic toxicology, the topic of alternative matrices will be continuously explored, especially emphasizing NPS.

Evidence for the transfer of methadone and EDDP by sweat to children's hair

In cases where there is a question as to whether children have come into contact with drugs, examinations of their scalp hair are frequently carried out. Positive test results are often discussed in the forensic community due to the various possible modes via which drugs and their metabolites can be incorporated into the hair. These include drug uptake by the child (e.g. oral ingestion or inhalation), but also contamination of hair via contact with the sweat from drug users. In this study, the possibility of methadone and its metabolite EDDP being incorporated into children’s hair by contact with sweat from persons undergoing opiate maintenance therapy (methadone) was examined. The transfer of methadone and EDDP via sweat from methadone patients (n = 15) to children’s hair was simulated by close skin contact of drug-free children’s hair, encased in mesh-pouches, for 5 days. Sweat-collecting patches (hereafter referred to as ‘sweat patches’) were applied to the test persons’ skin. One strand of hair and one sweat patch were collected daily from each patient. Analyses were performed using GC–MS/MS (hair) and LC–MS/MS (serum, sweat patches). After 4 days of skin contact, methadone was detectable in the formerly drug-free hair strands in all 15 study participants. EDDP was detectable in 34 of 75 hair strands, with the maximum number of positive results (11 EDDP-positive hair strands) being detected after 5 days. These results show that transfer of methadone and EDDP to drug-free hair is possible through close skin contact with individuals taking part in methadone substitution programmes. A correlation between serum concentration, sweat concentration and substance concentration in hair strands could not be demonstrated, but a tendency towards higher concentrations due to longer contact time is clearly evident.

Findings of illicit drugs in hair of children at different ages

Hair is a preferred material to detect exposure or use of illegal drugs in children. In the present study, we investigated a total of 387 hair samples for commonly applied illegal drugs of children up to 16 years. Analysis was by liquid chromatography/mass spectrometry with LOQs of 0.01 ng/mg hair for all analytes except tetrahydrocannabinol carboxylic acid with an LOQ of 0.1 pg/mg hair. Results were firstly compared with our in-house statics on results from adults' hair, and secondly to literature data. We started from the assumption that drug concentrations decrease with increasing age.Results were assigned to 4 different age groups (< 1 year, 1-< 6 years, 6-< 14 years, 14-16 years). As expected, higher results were obtained in age groups 1 and 2. The lowest concentrations were present in age group 3, whereas an increase could be observed in group 4 except heroin. In babies, positive results may be due to in utero exposure, breast milk feeding, and a close physical contact. All drugs under investigation such as cannabinoids, cocaine, amphetamines, and opiates have been detected in breast milk as well as in skin excretions such as sebum, sweat and cutaneous cells. For most drugs, average concentrations in children hair were lower than in adult hair when compared with our in-house statistics. Interestingly, the increase of cannabinoids, cocaine, and amphetamines concentrations in adolescents' hair points to a deliberate use of these drugs possibly in addition to passive exposure. This observation shows that age groups 1 and 4 are most vulnerable if caregivers or parents are drug users, even if the sources of positive drug findings differ.

Substance Use Disorders and Telehealth in the COVID-19 Pandemic Era: A New Outlook

During the current coronavirus disease 2019 epidemic, many outpatient chemical dependency treatment programs and clinics are decreasing their number of in-person patient contacts. This has widened an already large gap between patients with substance use disorders (SUDs) who need treatment and those who have actually received treatment. For a disorder where group therapy has been the mainstay treatment option for decades, social distancing, shelter in place, and treatment discontinuation have created an urgent need for alternative approaches to addiction treatment. In an attempt to continue some care for patients in need, many medical institutions have transitioned to a virtual environment to promote safe social distancing. Although there is ample evidence to support telemedical interventions, these can be difficult to implement, especially in the SUD population. This article reviews current literature for the use of telehealth interventions in the treatment of SUDs and offers recommendations on safe and effective implementation strategies based on the current literature.

Wearable Electrochemical Sensors for the Monitoring and Screening of Drugs

Wearable electrochemical sensors capable of noninvasive monitoring of chemical markers represent a rapidly emerging digital-health technology. Recent advances toward wearable continuous glucose monitoring (CGM) systems have ignited tremendous interest in expanding such sensor technology to other important fields. This article reviews for the first time wearable electrochemical sensors for monitoring therapeutic drugs and drugs of abuse. This rapidly emerging class of drug-sensing wearable devices addresses the growing demand for personalized medicine, toward improved therapeutic outcomes while minimizing the side effects of drugs and the related medical expenses. Continuous, noninvasive monitoring of therapeutic drugs within bodily fluids empowers clinicians and patients to correlate the pharmacokinetic properties with optimal outcomes by realizing patient-specific dose regulation and tracking dynamic changes in pharmacokinetics behavior while assuring the medication adherence of patients. Furthermore, wearable electrochemical drug monitoring devices can also serve as powerful screening tools in the hands of law enforcement agents to combat drug trafficking and support on-site forensic investigations. The review covers various wearable form factors developed for noninvasive monitoring of therapeutic drugs in different body fluids and toward on-site screening of drugs of abuse. The future prospects of such wearable drug monitoring devices are presented with the ultimate goals of introducing accurate real-time drug monitoring protocols and autonomous closed-loop platforms toward precise dose regulation and optimal therapeutic outcomes. Finally, current unmet challenges and existing gaps are discussed for motivating future technological innovations regarding personalized therapy. The current pace of developments and the tremendous market opportunities for such wearable drug monitoring platforms are expected to drive intense future research and commercialization efforts.

Wearable Devices for Precision Medicine and Health State Monitoring

Wearable technologies will play an important role in advancing precision medicine by enabling measurement of clinically-relevant parameters describing an individual's health state. The lifestyle and fitness markets have provided the driving force for the development of a broad range of wearable technologies that can be adapted for use in healthcare. Here we review existing technologies currently used for measurement of the four primary vital signs: temperature, heart rate, respiration rate, and blood pressure, along with physical activity, sweat, and emotion. We review the relevant physiology that defines the measurement needs and evaluate the different methods of signal transduction and measurement modalities for the use of wearables in healthcare.

Drug screening using the sweat of a fingerprint: lateral flow detection of Δ9-tetrahydrocannabinol, cocaine, opiates and amphetamine

Here, we describe the use of a fluorescence based lateral flow competition assay for the screening of four classes of drugs, viz, Δ9-tetrahydrocannabinol (THC), cocaine (through the detection of benzoylecgonine, BZE), opiates (through the detection of morphine, MOR) and amphetamine (AMP) present in the sweat of a fingerprint. The Drug Screening Cartridge was specifically developed for fingerprint sample collection and analysis. For this study, the cut-offs were set at: 190, 90, 68 and 80 pg/fingerprint for THC, BZE, MOR and AMP, respectively. Working with three UK coroners, the Drug Screening Cartridge, together with its fluorescence reader, was applied to the detection of drugs in the sweat of a fingerprint from deceased individuals. The study shows that there was sufficient sweat present on the fingertips to enable analysis and that the Drug Screening Cartridge could detect the presence, or absence, of each drug. The presence of the drugs was confirmed using LC-MS-MS analysis of a second fingerprint sample collected simultaneously. Excellent correlation was achieved between the results obtained from the Drug Screening Cartridge and the LC-MS-MS analysis of the fingerprint samples obtained from 75 individuals. The accuracy of the results was: 99% for THC; 95% for BZE; 96% for MOR and 93% for AMP. The results obtained using the Drug Screening Cartridge were also compared to toxicological analysis of blood and urine samples with good correlation. The accuracy of the results between the Drug Screening Cartridge and blood was: 96%, 92%, 88% and 97% for THC, BZE, MOR and AMP, respectively. The comparison with urine showed an accuracy ranging between 86% and 92%. This fingerprint sample method has a collection time of just 5 s and a total analysis time of <10 mins. These results show that the lateral flow Drug Screening Cartridge is an excellent screening test to provide information on drug use from the sweat in a single fingerprint sample.

Wearable Sweat Band for Noninvasive Levodopa Monitoring

Levodopa is the standard medication clinically prescribed to patients afflicted with Parkinson's disease. In particular, the monitoring and optimization of levodopa dosage are critical to mitigate the onset of undesired fluctuations in the patients' physical and emotional conditions such as speech function, motor behavior, and mood stability. The traditional approach to optimize levodopa dosage involves evaluating the subjects' motor function, which has many shortcomings due to its subjective and limited quantifiable nature. Here, we present a wearable sweat band on a nanodendritic platform that quantitatively monitors levodopa dynamics in the body. Both stationary iontophoretic induction and physical exercise are utilized as our methods of sweat extraction. The sweat band measures real-time pharmacokinetic profiles of levodopa to track the dynamic response of the drug metabolism. We demonstrated the sweat band's functionalities on multiple subjects with implications toward the systematic administering of levodopa and routine management of Parkinson's disease.

CMOS Interfaces for Internet-of-Wearables Electrochemical Sensors: Trends and Challenges

Smart wearables, among immediate future IoT devices, are creating a huge and fast growing market that will encompass all of the next decade by merging the user with the Cloud in a easy and natural way. Biological fluids, such as sweat, tears, saliva and urine offer the possibility to access molecular-level dynamics of the body in a non-invasive way and in real time, disclosing a wide range of applications: from sports tracking to military enhancement, from healthcare to safety at work, from body hacking to augmented social interactions. The term Internet of Wearables (IoW) is coined here to describe IoT devices composed by flexible smart transducers conformed around the human body and able to communicate wirelessly. In addition the biochemical transducer, an IoW-ready sensor must include a paired electronic interface, which should implement specific stimulation/acquisition cycles while being extremely compact and drain power in the microwatts range. Development of an effective readout interface is a key element for the success of an IoW device and application. This review focuses on the latest efforts in the field of Complementary Metal–Oxide–Semiconductor (CMOS) interfaces for electrochemical sensors, and analyses them under the light of the challenges of the IoW: cost, portability, integrability and connectivity.

Development of surface-enhanced Raman spectroscopy application for determination of illicit drugs: Towards a practical sensor

Surface-enhanced Raman spectroscopy (SERS) has been widely applied to identify or detect illicit drugs, because of the ability for highly specific molecular fingerprint and independence of aqueous solutions impact. We summarize the progress in determination of illicit drugs using SERS, including trace illicit drugs, suspicious objects and drugs or their metabolites in real biological system (urine, saliva and so on). Even though SERS detection of illicit drugs in real samples still remains a huge challenge because of the complex unknown environment, the efficient sample separation and the improved hand-held Raman analyzer will provide the possibility to make SERS a practically analytical technique. Moreover, we put forward a prospective overview for future perspectives of SERS as a practical sensor for illicit drugs determination. Perhaps the review is not exhaustive, we expect to help researchers to understand the evolution and challenges in this field and further interest in promoting Raman and SERS as a practical analyzer for convenient and automated illicit drugs identification.

Noninvasive profiling of sweat-derived lipid mediators for cutaneous research

BACKGROUND AND OBJECTIVE

Recent increases in the use of noninvasive matrices for biomedical analysis has led to interest in the evaluation of sweat for both clinical and research applications. However, despite being one of the two main cutaneous secretions, until very recently, only one study actually analyzed sweat in the context of cutaneous disease. This review attempts to make the case for increased use of sweat in cutaneous research, and discusses lipid mediators as potential analytical targets in sweat.

METHODS

Sweat composition and its relationship with the skin and systemic circulation are discussed, as are practical considerations for sweat sampling and analysis. Previous analyses of lipid mediators in skin biopsies are provided to show that lipid mediators can regulate cutaneous processes and disease pathways. Summaries of recent studies involving the analysis of sweat lipid mediators are provided to demonstrate the utility of sweat lipid mediator testing to support future cutaneous research studies.

RESULTS

Sweat has the potential to reflect both local and systemic biochemical changes in response to disease or intervention, and two recent studies of sweat lipid mediators confirm this ability. Additionally, sweat lipid mediators appear to be temporally stable with individual variability comparable to other matrices, suggesting that these analytes could be useful biomarkers.

CONCLUSIONS

Sweat metabolites may be capable of reporting changes in cutaneous biochemical pathways, thereby providing insight into the immunomodulatory biochemistry of the skin. Lipid mediator analysis of sweat appears to be a non invasive approach that could enhance existing cutaneous research and diagnostic methodologies.

Oral ibuprofen differentially affects plasma and sweat lipid mediator profiles in healthy adult males

Sweat contains a variety of lipid mediators, but whether they originate from the plasma filtrate or from the cutaneous sweat glandular tissues themselves is unknown. To explore this knowledge gap, we collected plasma and sweat from healthy men (n = 9) immediately before and 0.5, 2 and 4 h after oral administration of 400 mg ibuprofen. Of the over 100 lipid mediators assayed by liquid chromatography-tandem mass spectrometry, ∼45 were detected in both plasma and sweat, and 36 were common to both matrices. However, baseline concentrations in each matrix were not correlated and metabolite relative abundances between matrices differed. Oral ibuprofen administration altered sweat lipid mediators, reducing prostaglandin E2, linoleoylethanolamide, and oleoylethanolamide, while increasing 11-hydroxyeicosatetraenoic acid, and causing transient changes in 9-nitrooleate, N-arachidonylglycine and 20-hydroxyeicosatetraenoic acid. Meanwhile, plasma N-acylethanolamide concentrations increased with ibuprofen administration. These results suggest that sweat and plasma differentially reflect biochemical changes due to oral ibuprofen administration, and that plasma is unlikely to be the predominant source of the sweat lipid mediator profile.

Clinical Effects of Regular Dry Sauna Bathing: A Systematic Review

Introduction

Many health benefits are claimed by individuals and facilities promoting sauna bathing; however the medical evidence to support these claims is not well established. This paper aims to systematically review recent research on the effects of repeated dry sauna interventions on human health.

Methods

A systematic search was made of medical databases for studies reporting on the health effects of regular dry sauna bathing on humans from 2000 onwards. Risk of bias was assessed according to the Cochrane Collaboration guidelines.

Results

Forty clinical studies involving a total of 3855 participants met the inclusion criteria. Only 13 studies were randomized controlled trials and most studies were small (n < 40). Reported outcome measures were heterogeneous with most studies reporting beneficial health effects. Only one small study (n = 10) reported an adverse health outcome of disrupted male spermatogenesis, demonstrated to be reversible when ceasing sauna activity.

Conclusions

Regular dry sauna bathing has potential health benefits. More data of higher quality is needed on the frequency and extent of adverse side effects. Further study is also needed to determine the optimal frequency and duration of distinct types of sauna bathing for targeted health effects and the specific clinical populations who are most likely to benefit.

Comparative Evaluation of Drug Deposition in Hair Samples Collected from Different Anatomical Body Sites

In this study, we focused on the validation of a method for the simultaneous detection and quantification of cannabinoids, cocaine and opiates in hair as well as on the distribution of the drugs deposition in hair collected from different anatomical body sites. The proposed analytical procedure was validated for various parameters such as selectivity, linearity, limit of quantification, precision, accuracy, matrix effect and recovery. Four hundred and eighty-one samples were collected during 2010-2015 from 231 drug abusers. A 6-h ultrasonic-assisted methanolic extraction was applied for the isolation of the drugs. The analysis was performed in an liquid chromatography-mass spectrometry system for the opiates and cocaine and in a gas chromatography-mass spectrometry system for the cannabinoids. Cocaine was the most frequent detected drug (68.8-80.5%) followed by cannabinoids (47.6-63.3%) and opiates (34.7-46.7%) depending on the body site that the samples were collected. The mean concentrations of Δ9-tetrahydrocannabinol (THC) were 0.63 ± 2.11 for head, 0.54 ± 1.03 for pubic, 0.34 ± 0.51 for axillary and 0.18 ± 0.18 ng/mg for chest hair samples. The values of cocaine were 6.52 ± 15.98, 4.64 ± 10.77, 6.96 ± 38.21 and 3.94 ± 6.35 ng/mg, while the values of 6-monoacetylmorphine (MAM) were 3.33 ± 5.89, 3.06 ± 9.33, 1.37 ± 1.37 and 16.4 ± 1.77 ng/mg for head, pubic, axillary and chest samples, respectively. Differences between the detected concentrations of cocaine and opiates between the hair samples of different anatomical sites, as well as the ratio of drug metabolites to the parent compounds were observed in some cases. Statistically significant differences in the mean detected levels were noticed for morphine and heroin between head and pubic hair and also for cocaine and benzoylecgonine, between head and axillary hair samples. Moreover, the ratio of MAM to morphine and THC to cannabinol seems to correlate statistically with the total opiate or cannabinoid detected concentrations. The above differences could be attributed to several parameters associated with the structure, morphology, growth rate and other characteristics of the collected hair.

Probing Skin for Metabolites and Topical Drugs with Hydrogel Micropatches

Sampling the skin surface is a convenient way to obtain biological specimens bearing clinically relevant information. Hydrogel micropatches enable noninvasive collection of skin excretion specimens, which can subsequently be subjected to rapid mass spectrometric analysis providing insights into the skin metabolome.

Sweat lipid mediator profiling: a noninvasive approach for cutaneous research

Recent advances in analytical and sweat collection techniques provide new opportunities to identify noninvasive biomarkers for the study of skin inflammation and repair. This study aims to characterize the lipid mediator profile including oxygenated lipids, endocannabinoids, and ceramides/sphingoid bases in sweat and identify differences in these profiles between sweat collected from nonlesional sites on the unflared volar forearm of subjects with and without atopic dermatitis (AD). Adapting routine procedures developed for plasma analysis, over 100 lipid mediators were profiled using LC-MS/MS and 58 lipid mediators were detected in sweat. Lipid mediator concentrations were not affected by sampling or storage conditions. Increases in concentrations of C30-C40 [NS] and [NdS] ceramides, and C18:1 sphingosine, were observed in the sweat of study participants with AD despite no differences being observed in transepidermal water loss between study groups, and this effect was strongest in men (P < 0.05, one-way ANOVA with Tukey's post hoc HSD). No differences in oxylipins and endocannabinoids were observed between study groups. Sweat mediator profiling may therefore provide a noninvasive diagnostic for AD prior to the presentation of clinical signs.

Retrospective monitoring of long-term recreational and dependent cocaine use in toenail clippings/scrapings as an alternative to hair

Background: Toenails were assessed as an alternative matrix to hair for retrospective monitoring of cocaine consumption of recreational and dependent users. Results/methodology: Toenail clippings, scrapings and hair samples from recreational and dependent cocaine users were analyzed for cocaine and metabolites. Dependent users displayed significantly higher concentrations in hair and toenail samples compared to recreational users. Cocaine abstinence could be monitored in hair and toenail samples. One postmortem fingernail was analyzed in layers to investigate the cocaine and metabolite concentration profile. Highest concentrations were observed in the dorsal layer, being indicative of contamination. Conclusion: Having led to comparable results, toenails may be an alternative for retrospective monitoring of cocaine consumption/abstinence. Hair should remain the first choice for assessment of temporal evidence of drug intake.

Hydrogel micropatches for sampling and profiling skin metabolites

Metabolites excreted by skin have a huge potential as disease biomarkers. However, due to the shortage of convenient sampling/analysis methods, the analysis of sweat has not become very popular in the clinical setting (pilocarpine iontophoresis being a prominent exception). In this report, a facile method for sampling and rapid chemical profiling of skin metabolites excreted with sweat is proposed. Metabolites released by skin (primarily the constituents of sweat) are collected into hydrogel (agarose) micropatches. Subsequently, they are extracted in an online analytical setup incorporating nanospray desorption electrospray ionization and an ion trap mass spectrometer. In a series of reference measurements, using bulk sampling and electrospray ionization mass spectrometry, various low-molecular-weight metabolites are detected in the micropatches exposed to skin. The sampling time is as short as 10 min, while the desorption time is 2 min. Technical precision of micropatch analysis varies within the range of 3-42%, depending on the sample and the method of data treatment; the best technical precision (≤10%) has been achieved while using an isotopically labeled internal standard. The limits of detection range from 7 to 278 pmol. Differences in the quantities of extracted metabolites are observed for the samples obtained from healthy individuals (intersubject variabilities: 30-89%; n = 9), which suggests that this method may have the potential to become a semiquantitative assay in clinical analysis and forensics.

Artificial microfluidic skin for in vitro perspiration simulation and testing

To expedite development of any skin wearable material, product, or device, an artificial perspiration (sweat) simulator can provide improved ease, cost, control, flexibility, and reproducibility in comparison to human or animal tests. Reported here is a human perspiration mimicking device including microreplicated skin-texture. A bottom 0.2 μm track etched polycarbonate membrane layer provides flow-rate control while a top photo-curable layer provides skin-like features such as sweat pore density, hydrophobicity, and wetting hysteresis. Key capabilities of this sweat simulator include: constant 'sweat' rate density without bubble-point variation even down to ~1 L h(-1) m(-2); replication of the 2 pores mm(-2) pore-density and the ~50 μm texture of human skin; simple gravity-fed flow control; low-cost and disposable construction.

Sweat testing for the detection of atomoxetine from paediatric patients with attention deficit/ hyperactivity disorder: application to clinical practice

Atomoxetine (ATX) is a selective norepinephrine reuptake inhibitor approved since 2002 for the treatment of attention deficit hyperactivity disorder (ADHD) in children, adolescents, and adults as an alternative treatment to methylphenidate. Within the framework of a project evaluating the use of alternative biological matrices for therapeutic monitoring of psychoactive drugs in paediatric and non-paediatric individuals, the excretion of ATX and its principal metabolites has been recently studied in oral fluid and hair. The aim of this study was to describe the excretion profile of ATX and its metabolites 4-hydroxyatomoxetine (4-OH-ATX) and N-desmethylatomoxetine (N-des-ATX) in sweat following the administration of different dosage regimens (60, 40, 35, and 18 mg/day) of ATX to six paediatric patients. Sweat patches were applied to the back of each participant and removed at timed intervals. ATX and its metabolites were measured in patches using a previously validated liquid chromatography-tandem mass spectrometric (LC-MS/MS) method. Independently from the administered dose, ATX appeared in the sweat patches 1 h post administration and reached its maximum concentration generally at 24 h. Peak ATX concentrations ranged between 2.31 and 40.4 ng/patch and did not correlate with the administered drug dose, or with body surface area. Total ATX excreted in sweat ranged between 0.008 and 0.121 mg, corresponding to 0.02 and 0.3% of the administered drug. Neither 4-OH-ATX, nor N-des-ATX was detected in either of the collected sweat patches. Measuring ATX in sweat patches can provide information on cumulative drug use from patch application until removal.

Refined sewer epidemiology mass balances and their application to heroin, cocaine and ecstasy

The detection of illicit drugs in environmental matrices may be a cause for concern, both from the perspective of their potential environmental impacts and the fact that their presence in detectable concentrations would be an indicator of significant drug use. The primary goal behind recent studies on this subject has been to use measured influent concentrations of selected illicit drugs or their in vivo metabolites in the environment as a means of estimating the abuse level of these drugs and patterns of consumption. Thus-far, such calculations have hinged on the use of solitary excretion estimates from single studies of limited scope and/or studies of limited applicability. Therefore, the need exists to conduct a comprehensive meta-analysis of metabolic disposition studies to construct excretions profiles for the various illicit drugs and their in vivo metabolites. The constructed excretory profiles should not only provide mean excretion values but also indicate the expected variations in excreted fractions that arise due to differences not only in the metabolic capacity of users but also in the efficiencies of various routes of administration for a given illicit drug. Therefore, the primary goal of the research presented here was to refine sewer epidemiology extrapolation mass balances for various illicit drugs of interest by constructing their excretory profiles segregated by route-of-administration. After conducting such a study with a multi-national scope on illicit drugs including cocaine, heroin and ecstasy, the results obtained clearly indicate that extrapolation factors currently being used in literature for these drugs to enumerate prevalence of abuse required significant refinement to increase their reliability.

Bioanalytical procedures and recent developments in the determination of opiates/opioids in human biological samples

The use and abuse of illegal drugs affects all modern societies, and therefore the assessment of drug exposure is an important task that needs to be accomplished. For this reason, the reliable determination of these drugs and their metabolites in biological specimens is an issue of utmost relevance for both clinical and forensic toxicology laboratories in their fields of expertise, including in utero drug exposure, driving under the influence of drugs and drug use in workplace scenarios. Most of the confirmatory analyses for abused drugs in biological samples are performed by gas chromatographic-mass spectrometric methods, but use of the more recent and sensitive liquid chromatography-(tandem) mass spectrometry technology is increasing dramatically. This article reviews recently published articles that describe procedures for the detection of opiates in the most commonly used human biological matrices, blood and urine, and also in unconventional ones, e.g. oral fluid, hair, and meconium. Special attention will be paid to sample preparation and chromatographic analysis.

Simultaneous analysis of buprenorphine, methadone, cocaine, opiates and nicotine metabolites in sweat by liquid chromatography tandem mass spectrometry

A liquid chromatography tandem mass spectrometry method for buprenorphine (BUP), norbuprenorphine (NBUP), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine, benzoylecgonine, ecgonine methyl ester (EME), morphine, codeine, 6-acetylmorphine, heroin, 6-acetylcodeine, cotinine, and trans-3'-hydroxycotinine quantification in sweat was developed and comprehensively validated. Sweat patches were mixed with 6 mL acetate buffer at pH 4.5, and supernatant extracted with Strata-XC-cartridges. Reverse-phase separation was achieved with a gradient mobile phase of 0.1% formic acid and acetonitrile in 15 min. Quantification was achieved by multiple reaction monitoring of two transitions per compound. The assay was a linear 1-1,000 ng/patch, except EME 5-1,000 ng/patch. Intra-, inter-day and total imprecision were <10.1%CV, analytical recovery 87.2-107.7%, extraction efficiency 35.3-160.9%, and process efficiency 25.5-91.7%. Ion suppression was detected for EME (-63.3%) and EDDP (-60.4%), and enhancement for NBUP (42.6%). Deuterated internal standards compensated for these effects. No carryover was detected, and all analytes were stable for 24 h at 22 °C, 72 h at 4 °C, and after three freeze/thaw cycles. The method was applied to weekly sweat patches from an opioid-dependent BUP-maintained pregnant woman; 75.0% of sweat patches were positive for BUP, 93.8% for cocaine, 37.5% for opiates, 6.3% for methadone and all for tobacco biomarkers. This method permits a fast and simultaneous quantification of 14 drugs and metabolites in sweat patches, with good selectivity and sensitivity.

Collection of biological samples in forensic toxicology

Forensic toxicology is the study and practice of the application of toxicology to the purposes of the law. The relevance of any finding is determined, in the first instance, by the nature and integrity of the specimen(s) submitted for analysis. This means that there are several specific challenges to select and collect specimens for ante-mortem and post-mortem toxicology investigation. Post-mortem specimens may be numerous and can endow some special difficulties compared to clinical specimens, namely those resulting from autolytic and putrefactive changes. Storage stability is also an important issue to be considered during the pre-analytic phase, since its consideration should facilitate the assessment of sample quality and the analytical result obtained from that sample. The knowledge on degradation mechanisms and methods to increase storage stability may enable the forensic toxicologist to circumvent possible difficulties. Therefore, advantages and limitations of specimen preservation procedures are thoroughfully discussed in this review. Presently, harmonized protocols for sampling in suspected intoxications would have obvious utility. In the present article an overview is given on sampling procedures for routinely collected specimens as well as on alternative specimens that may provide additional information on the route and timing of exposure to a specific xenobiotic. Last, but not least, a discussion on possible bias that can influence the interpretation of toxicological results is provided. This comprehensive review article is intented as a significant help for forensic toxicologists to accomplish their frequently overwhelming mission.

Excretion of methadone in sweat of pregnant women throughout gestation after controlled methadone administration

Sweat patches (n = 350) were collected throughout gestation from 29 opioid-dependent pregnant women participating in an outpatient methadone-assisted therapy program. Volunteers provided informed consent to participate in institutional review board-approved protocols. Methadone was eluted from sweat patches with sodium acetate buffer, followed by solid-phase extraction and quantification by gas chromatography mass spectrometry (limit of quantification > or = 10 ng/patch). Methadone was present in all weekly patches (n = 311) in concentrations ranging from 10.2 to 12,129.7 nanograms per patch and in 92.3% of short-term patches (n = 39, worn for 12 or 24 hours) in concentrations up to 3303.9 nanograms per patch. Correlation between patch concentrations and total amount of drug administered (r = 0.224), and concentrations and duration of patch wear (r = 0.129) were both weak. Although there were large intra- and intersubject variations in sweat drug concentrations, sweat testing was an effective alternative technique to qualitatively monitor illicit drug use and simultaneously document methadone medication-assisted treatment.

Dermatotoxic effects of orally administered ciprofloxacin in sweating and nonsweating animal models

CONTEXT

Some drugs, such as ciprofloxacin (CFX), that are excreted in sweat may produce some effects/toxicities in the skin structure. In order to differentiate the dermatotoxic effects of drugs due to excretion in sweat, it is essential to perform simultaneous studies in sweating and nonsweating animal models.

OBJECTIVE

To determine the dermatotoxic effects of CFX in sweating (goats) and nonsweating (rabbits) animals and to determine whether there is a relationship between dermatotoxicity and the blood CFX concentration.

MATERIALS AND METHODS

CFX was administered orally at the dose rate of 20 mg/kg body weight to goats (n = 16) and rabbits (n = 16) for 1 and 2 weeks, while control animals were given vehicle (water). Skin biopsies were taken after 1- and 2-week administration of CFX and processed histologically. Similarly, the CFX concentration in the plasma samples was analyzed by high-performance liquid chromatography (HPLC).

RESULTS

Mean ± standard error (SE) epidermal thickness (μm) was 26.2 ± 0.2, 38.6 ± 2.05, and 37.8 ± 1.8 for the control, 1-week-treated, and 2-week-treated goats and 16.06 ± 2.39, 50.67 ± 6.61, and 34.03 ± .12 for the control, 1-week-treated, and 2-week-treated rabbits, respectively. Mean ± SE epidermal cell layers were 2.08 ± 0.08, 3.42 ± 0.16, and 3.25 ± 0.21 in the control, 1-week-treated, and 2-week-treated goats and 1 ± 0, 3.08 ± 0.37, and 1.83 ± 0.35 in the control, 1-week-treated, and 2-week-treated rabbits, respectively. Mean ± SE plasma concentration (μg/mL) of CFX was 0.37 ± 0.06 and 0.30 ± 0.05 in the 1- and 2-week-treated goats and 0.13 ± 0.04 and 0.14 ± 0.09 in the 1- and 2-week-treated rabbits, respectively.

CONCLUSION

Microscopically, increases in epidermal thickness, number of cell layers, and cell infiltration were observed in both sweating and nonsweating animals, indicating that the dermatotoxic effects may not be due to CFX excretion in sweat. No relationship was found between dermatotoxicity and blood CFX concentration in both animal models.

Monitoring pregnant women's illicit opiate and cocaine use with sweat testing

Dependence on illicit drugs during pregnancy is a major public health concern as there may be associated adverse maternal, fetal, and neonatal consequences. Sweat patches (n = 389) were collected from 39 pregnant volunteers who provided written informed consent for this Institutional Review Board-approved protocol and wore patches, replaced approximately weekly, from study entry until delivery. Patches were analyzed for opiates (heroin, 6-acetylmorphine, 6-acetylcodeine, morphine and codeine) and cocaine (cocaine, benzoylecgonine, ecgonine methyl ester, anhydroecgonine methyl ester) by solid phase extraction and gas chromatography mass spectrometry. Seventy-one percent (276) of collected sweat patches were > or =5 ng per patch (limit of quantification) for one or more analytes. Cocaine was present in 254 (65.3%) patches in concentrations ranging from 5.2 to 11,835 ng per patch with 154 of these high enough to satisfy the proposed Substance Abuse and Mental Health Services Administration guidelines for a confirmatory drug test (25 ng per patch). Interestingly, 6-acetylmorphine was the most prominent opiate analyte documented in 134 patches (34.4%) with 11.3% exceeding the proposed opiate Substance Abuse and Mental Health Services Administration cut-off (25 ng per patch). Heroin was identified in fewer patches (77), but in a similar concentration range (5.3-345.4 ng per patch). Polydrug use was evident by the presence of both cocaine and opiate metabolites in 136 (35.0%) patches. Sweat testing is an effective method for monitoring abstinence or illicit drug use relapse in this high-risk population of pregnant opiate- and/or cocaine-dependent women.

Biological testing for drugs of abuse

Testing for drugs of abuse has become commonplace and is used for a variety of indications. Commonly employed testing methods include immunoassay and chromatography. Testing methods vary in their sensitivity, specificity, time, and cost. While urine remains the most common body fluid used for testing of drugs of abuse, over the last several decades the use of alternative matrices such as blood, sweat, oral fluids, and hair has increased dramatically. Each biological matrix offers advantages and disadvantages for drug testing, and the most appropriate matrix frequently depends on the indications for the drug test. Drugs of abuse that are most commonly tested include alcohol, amphetamines, cannabinoids, cocaine, opiates, and phencyclidine. Testing may involve detection of the parent compound or metabolites and sensitivity, specificity, and reliability of drug testing may vary depending on the drug being tested. Toxicologists have a responsibility to understand the strengths and limitations of testing techniques and matrices to be able to critically evaluate the results of a drug test.

Development and validation of a solid-phase extraction gas chromatography-mass spectrometry method for the simultaneous quantification of methadone, heroin, cocaine and metabolites in sweat

A sensitive and specific method is presented to simultaneously quantify methadone, heroin, cocaine and metabolites in sweat. Drugs were eluted from sweat patches with sodium acetate buffer, followed by SPE and quantification by GC/MS with electron impact ionization and selected ion monitoring. Daily calibration for anhydroecgonine methyl ester, ecgonine methyl ester, cocaine, benzoylecgonine (BE), codeine, morphine, 6-acetylcodeine, 6-acetylmorphine (6AM), heroin (5-1000 ng/patch) and methadone (10-1000 ng/patch) achieved determination coefficients of >0.995, and calibrators quantified to within +/-20% of the target concentrations. Extended calibration curves (1000-10,000 ng/patch) were constructed for methadone, cocaine, BE and 6AM by modifying injection techniques. Within (N = 5) and between-run (N = 20) imprecisions were calculated at six control levels across the dynamic ranges with coefficients of variation of <6.5%. Accuracies at these concentrations were +/-11.9% of target. Heroin hydrolysis during specimen processing was <11%. This novel assay offers effective monitoring of drug exposure during drug treatment, workplace and criminal justice monitoring programs.

Methadone in hair and sweat from patients in long-term maintenance therapy

The authors refer to their experience with alternative matrices to supervise the methadone therapy of heroin abusers. For this purpose, hair, sweat, and urine samples were collected from 10 heroin addicts and from a control group and were submitted to gas chromatographic/mass spectroscopic analysis for methadone and its main metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), determination. The advantages of alternative matrices to urine samples in the supervision of methadone maintenance therapy are discussed. In particular, the detection of methadone in sweat could be a preferable option to the urine matrix as a result of the feasibility of sampling that allows noninvasive collection, which is not susceptible to adulteration. The ratio between EDDP and methadone in sweat and hair was also calculated to provide information about program agreement.

Utility of sweat patch testing for drug use monitoring in outpatient treatment for opiate dependence

We evaluated the utility of sweat testing for monitoring of drug use in outpatient clinical settings and compared sweat toxicology with urine toxicology and self-reported drug use during a randomized clinical trial of the efficacy of buprenorphine for treatment of opioid dependence in primary care settings. All study participants (N = 63) were opiate-dependent, treatment-seeking volunteers. The results based on toxicology tests obtained from 188 properly worn and unadulterated patches (out of 536 applied) show that the level of agreement between positive sweat test results and positive urine results was 33% for opiates and 92% for cocaine. The findings of this study, that there is a low acceptability of sweat patch testing by patients (only 54.3% were brought back attached to the skin) and that weekly sweat testing is less sensitive than weekly urine testing in detecting opiate use, suggest limited utility of sweat patch testing in outpatient clinical settings.

Sweat testing in addicts under methadone treatment: an Italian experience

In the last years the interest in monitoring drug exposure with human sweat as alternative biological fluid, is increasing. Sweat collection is convenient, less invasive and difficult to adulterate compared to traditional specimens. The objective of this study was to determine the excretion profile of methadone and other drugs into human sweat. Pharmscope sweat patches (Medical Europe Diagnostic, Madrid, Spain) were used on heroin abusers under methadone treatment. Sweat patches were applied to 10 heroin addicts and 3 drug free volunteers admitted into the study. Sweat patches were worn for about 1 week; urine, saliva and hair samples were collected at the time of the removal of patches. After the extraction, sweat eluates were directly analyzed by GC/MS for the presence of nicotine, cotinine, caffeine, methadone, EDDP and cocaine. The extracts were subsequently derivatized to detect benzoylecgonine, ecgonine methyl ester, morphine, codeine and 6-acetylmorphine. No false positive results were obtained on the drug free samples. All the patches showed positive results for methadone. Cocaine was detected in two cases. Mainly the parent drug was identified rather than the metabolites. The results obtained show the usefulness of sweat as complementary specimen to saliva and urine providing a longer detection window. Moreover, sweat testing offers the advantage of being a non-invasive means of obtaining information about drug exposure.

Application of ion mobility spectrometry in cases of forensic interest

Ion mobility spectrometry (IMS) has been known as an analytical technique since the late 1960s and early 1970s. To date, it has been successfully utilized for the detection of environmental pollutants, warfare agents, explosives, herbicides, pesticides, petroleum products as well as for the detection of prescription and illicit drugs. In this paper the authors describe the use of the IMS technology in cases of forensic interest in Salzburg, Austria. We report the use of the IMS methodology for the rapid analysis of hallucinogenic mushroom material as well as for the analysis of samples taken after an explosion. A new application of the IMS technology for the analysis of postmortem sweat samples for drugs is also presented.

Opioid disposition in human sweat after controlled oral codeine administration

BACKGROUND

Characterization of opioid excretion in sweat is important for accurate interpretation of sweat tests in drug treatment, criminal justice, and workplace drug testing programs.

METHODS

Participants (n=20) received placebo, 3 low (60 mg/70 kg) or 3 high (120 mg/70 kg) codeine sulfate doses (used as a model for opioid excretion) within 1 week. Codeine and metabolites in sweat were collected with PharmChek Sweat Patches; hourly patches were applied for 1 to 15 h (n=775) and weekly patches for 7 days (n=118). Patches were analyzed by solid-phase extraction and gas chromatography-mass spectrometry for codeine, norcodeine, morphine, normorphine, and 6-acetylmorphine. Limits of quantification were 2.5 ng/patch (codeine and morphine) and 5 ng/patch (other analytes).

RESULTS

Codeine was the only analyte identified in 12.6% of hourly patches and 83.3% of weekly sweat patches worn during dosing. Weekly patch concentrations (SD) were 38.6 (59.9) ng/patch [median (range), 15.9 (0-225.1) ng/patch] for low and 34.1 (32.7) ng/patch [24.0 (0-96.2) ng/patch] for high codeine doses. Codeine detected 1 week after dosing was 4.6 (5.3) ng/patch [median (range), 4.0 (0-17.1) ng/patch; n=11] after low and 7.7 (7.1) ng/patch [6.9 (0-20.5) ng/patch; n=10] after high doses. In total, 2.6% of hourly, 38.5% of low-dose, and 45.5% of high-dose weekly patches contained codeine at the proposed Substance Abuse and Mental Health Services Administration cutoff.

CONCLUSIONS

Codeine was the only analyte detected, at highly variable concentrations, up to 2 weeks after dosing. These results are consistent, considering the complex processes of codeine deposition in sweat. Sweat testing is a useful alternative technique for qualitative monitoring of opioid use.

Disposition of Cocaine and Its Metabolites in Human Sweat after Controlled Cocaine Administration

Background: Sweat testing is a noninvasive technique for monitoring drug exposure in treatment, criminal justice, and employment settings.

Methods: We evaluated cocaine excretion in 9 participants’ sweat after they received 3 low doses (75 mg/70 kg) of cocaine HCl subcutaneously within 1 week and, 3 weeks later, 3 high doses (150 mg/70 kg). Six additional participants completed portions of the study. PharmChek® sweat patches (n = 1390) were collected throughout a 3-week washout period, reflecting previously self-administered drugs, and during and after controlled dosing.

Results: Cocaine was the primary analyte detected with 24% of patches positive at the gas chromatography–mass spectrometry limit of quantification of 2.5 ng/patch and 7% of patches at the proposed Substance Abuse and Mental Health Services Administration cutoff of 25 ng/patch. Ecgonine methyl ester (EME) was detected more often and at generally higher concentrations than benzoylecgonine. In patches containing both metabolites, there was no statistically significant difference in the benzoylecgonine/EME ratio based on length of patch wear. During washout, 2 participants’ weekly patches tested positive (≥25 ng/patch) during the first week; one remained positive during week 2; and none were positive during week 3. Cocaine and EME were detectable within 2 h; benzoylecgonine was not detected until 4–8 h after low doses and slightly sooner after high doses. The majority of drug was excreted within 24 h. Over 70% of weekly patches worn during low doses were positive for cocaine (≥25 ng/patch), increasing to 100% during high doses.

Conclusion: Sweat testing is an effective and reliable method of monitoring cocaine exposure.

Validated gas chromatographic-negative ion chemical ionization mass spectrometric method for delta(9)-tetrahydrocannabinol in sweat patches

BACKGROUND

A sensitive gas chromatography-negative ion chemical ionization mass spectrometry (GC/MS-NICI) method was developed and validated for the measurement of Delta(9)-tetrahydrocannabinol (THC) in human sweat patches.

METHODS

THC-d(0) and THC-d(3) were added to worn blank sweat patches (PharmChek; PharmChem Incorporated) and extracted with 3 mL of methanol-0.2 mol/L sodium acetate buffer (pH 5.0, 3:1 by volume) on a reciprocating shaker at ambient temperature for 30 min. Extracted solution (2 mL) was diluted with 8 mL of 0.1 mol/L sodium acetate buffer (pH 4.5) and extracted by use of solid-phase extraction columns (CleanScreen; United Chemical Technologies). Dried extracts were derivatized with trifluoroacetic acid and analyzed with an Agilent 6890 gas chromatograph interfaced with an Agilent 5973 mass selective detector operated in NICI-selected ion-monitoring mode.

RESULTS

The lower limits of detection and quantification for THC in human sweat were 0.2 and 0.4 ng/patch, respectively. The calibration curve was linear from 0.4 to 10 ng/patch (R(2) >0.995). Overall recovery of THC from blank worn patches to which 0.6, 4.0, and 8.0 ng of THC had been added was 44-46%. Assay imprecision, expressed as CV, was <10% for 0.6, 4.0, and 8.0 ng/patch quality-control samples. Twenty-one potential interfering compounds (50 ng/patch) added to low quality-control samples (0.6 ng/patch) did not influence THC quantification.

CONCLUSIONS

This GC/MS-NICI assay for THC in human sweat provides adequate sensitivity and performance characteristics for analyzing THC in sweat patches and meets the requirements of the proposed Substance Abuse and Mental Health Administration's guidelines for sweat testing.

Detecting crack and other cocaine use with fastpatches

A continuing social problem is presented by the large number of individuals who use crack cocaine. Recent research has identified unique pyrolysis products of crack or burned cocaine as anhydroecgonine methylester (AEME) and ecgonidine (ECD) through gas chromatography/mass spectrometry (GC/MS) that allow for the detection of crack use distinct from other cocaine use. However, there have been no large-scale studies to document the presence and prevalence of these substances in sweat. A new sweat-testing appliance called a fastpatch was developed for this study. Through mild heating and a slightly larger collection pad than a standard Pharmchek( trade mark ) sweat patch, this product shows the promise of shorter required wear periods than standard sweat patches, and possibly longer time-periods of detected use. One hundred and eighty subjects wore 360 fastpatch prototypes (one per hand). However, subsequent analysis determined that only one patch per subject was needed to obtain sufficient sweat eluate for GC/MS. Cocaine use was detected in sweat of 92% of subjects through GC/MS, comparing favorably with 91% with EMIT urinalysis. Crack metabolites were detected in 54% of subjects. The predominant analyte detected was AEME. There were no significant differences in detection rates between 15-, 20- and 30-minute wear periods. All wear periods detected both cocaine use in general and crack use successfully. These results suggest that crack use as distinct from other cocaine use can be detected in sweat and that fastpatches are a promising new way to detect drugs of abuse.

Comparison of daily urine, sweat, and skin swabs among cocaine users

This study (1) compares urine, skin swabs, and PharmChek sweat patches for monitoring drug use; (2) measures possible environmental contamination in recent cocaine (COC) users; and (3) evaluates various immunoassays (IA) for screening COC in diverse matrices. Unique aspects include daily urine monitoring of 10 participants for 4 weeks, multiple monitoring methods, analysis for all specimens by IA and gas chromatography (GC)/mass spectrometry (MS), and the potential for continued illicit drug use by participants. Urine served as the "gold standard" specimen for determining drug use. Only cocaine and related substances were detected. Trace amounts of drugs were found on the skin (<50 ng per swab) of urine-negative participants' hands or forehead. In contrast, larger quantities of COC were found on the skin of individuals with BE-positive urines or individuals living with drug users (up to 20 microg per swab). Patch COC amounts among the three regular users (250-9000, 0-240, 160-22,000 ng per patch) exceeded BE (50-950, none, 30-2200 ng per patch). Pre-swabs, valuable for interpreting the source or time frame of positive patch results, contained substantial COC (38-1160, 0-152, 34-762 ng per swab) prior to patch application; therefore, patch results may represent current use, prior use, contamination, or a combination. In three individuals with no indication of cocaine use, false positives (defined as sweat patch positive when urine specimens were <300ng BE/ml) occurred at a 7% rate. Proposed cut-off concentrations of 75 ng cocaine per patch and 300 ng BE/ml urine curtail the incidence of false positives in this limited population. Three immunoassays were compared to screen specimens for cocaine: a modified, manual Microgenics CEDIA; a Cozart ELISA; and an OraSure ELISA. CEDIA's limit of detection (LOD) was 81ng/ml, compared with LODs of 4 ng/ml for the Cozart ELISA and 1.5 ng/ml for the OraSure ELISA. Cozart correlated with OraSure results for COC concentrations <2000 ng per swab (n=117), r(2)=0.79.

Measuring outcome in cocaine clinical trials: a comparison of sweat patches with urine toxicology and participant self-report

AIMS

To evaluate the advantages of using a sweat patch (PharmCheck) for detecting cocaine abuse in cocaine-dependent patients participating in a clinical trial. The utility of the sweat patch was assessed from the following perspectives: the reliability and validity of quantitative sweat patch results, the possible degradation of cocaine to benzoylecgonine (BE) as a function of the length of time that a patch is worn, the completeness of the dataset yielded by thrice-weekly urine toxicology compared with thrice-weekly and weekly sweat patches, and the relative costs associated with sweat patch versus urine measures.

DESIGN

Data were collected during a 10-week out-patient clinical trial in which participants wore two sweat patches, one applied every visit and one applied weekly. Urine samples were collected thrice weekly, as were self-reports of substance use.

SETTING

A multi-site clinical trial conducted in Boston, Cincinnati and New York, USA.

PARTICIPANTS

Twenty-seven participants with comorbid diagnoses of cocaine dependence and adult attention deficit disorder completed the study.

MEASUREMENTS

Sweat patch and urine samples were analyzed by standard methods for cocaine and cocaine metabolites.

FINDINGS

Quantitative sweat patch measures had good reliability in that the correlation between the weekly and per-visit patches was 0.96 (P < 0.0001). The concurrent validity, as judged by the correlation between quantitative urine BE levels and either weekly (0.76, P < 0.0001) or per-visit (0.73, P < 0.0001) cocaine sweat patch levels was reasonable. The correlation between the self-report of cocaine use and these same two patches, however, was lower (0.40, P < 0.05 and 0.30, P < 0.05, respectively). The results revealed no significant degradation of cocaine to BE associated with wearing the patch for a longer time. Finally, the per-visit patch provided cocaine use data on 80.5% of all study days (a total of 70), while urine toxicology and the weekly patch provided 77.4% and 76.1%, respectively.

CONCLUSIONS

The present findings suggest that the PharmCheck patch might be an attractive alternative to urine toxicology for use as an outcome measure in cocaine clinical trials.