Mitigating the impact of gelatin capsule variability on detection of substandard and falsified pharmaceuticals with near-IR spectroscopy.

Portable NIR spectrometers are effective in detecting authentic pharmaceutical products in intact capsule formulations, which can be used to screen for substandard or falsified versions of those authentic products. However, the chemometric models are trained on libraries of authentic products, and are generally unreliable for detection of quality problems in products from outside their training set, even for products that are nominally the same active pharmaceutical ingredient and same dosage as products in the training set. As part of our research directed at developing better non-brand-specific strategies for pharmaceutical screening, we investigated the impact of capsule composition on NIR modeling. We found that capsule features like gelatin type, color, or thickness, give rise to a similar amount of variance in the NIR spectra as the type of API stored within the capsules. Our results highlight the efficacy of orthogonal projection to latent structures in mitigating the impacts of different types of capsules on the accuracy of NIR chemometric models for classification and regression analysis of lab-made samples. The models showed good performance for classification of field-collected doxycycline capsules as good or bad quality when an NIR-based % w/w metric was used, identifying five samples that were adulterated with talc. However, the % w/w was systematically underestimated, so when evaluating the capsules based on their absolute API content according to the monograph standard, the classification accuracy decreased from 100% to 70%. The underestimation was attributed to an unforeseen variability in the quantities and types of excipients present in the capsules.

Enhancing drug checking services for supply monitoring: perspectives on implementation in syringe service programs in the USA.

BACKGROUND: Shifts in the US drug supply, including the proliferation of synthetic opioids and emergence of xylazine, have contributed to the worsening toll of the overdose epidemic. Drug checking services offer a critical intervention to promote agency among people who use drugs (PWUD) to reduce overdose risk. Current drug checking methods can be enhanced to contribute to supply-level monitoring in the USA, overcoming the selection bias associated with existing supply monitoring efforts and informing public health interventions. METHODS: As a group of analytical chemists, public health researchers, evaluators, and harm reductionists, we used a semi-structured guide to facilitate discussion of four different approaches for syringe service programs (SSPs) to offer drug checking services for supply-level monitoring. Using thematic analysis, we identified four key principles that SSPs should consider when implementing drug checking programs. RESULTS: A number of analytical methods exist for drug checking to contribute to supply-level monitoring. While there is likely not a one-size-fits-all approach, SSPs should prioritize methods that can (1) provide immediate utility to PWUD, (2) integrate seamlessly into existing workflows, (3) balance individual- and population-level data needs, and (4) attend to legal concerns for implementation and dissemination. CONCLUSIONS: Enhancing drug checking methods for supply-level monitoring has the potential to detect emerging threats in the drug supply and reduce the toll of the worsening overdose epidemic.

Metabolites in Urine that Interfere with the Sandell-Kolthoff Assay for Urinary Iodine.

The Sandell-Kolthoff (SK) assay is the main analytical method used to monitor population iodine nutrition in low- and middle-income countries. This assay can distinguish between populations that are iodine-deficient (median urinary iodine levels below 100 ppb), iodine-sufficient (median urinary iodine levels between 100 and 300 ppb), and iodine- excessive(median urinary iodine levels above 300 ppb). However, the analysis of urine samples with the SK reaction is technically challenging, partly because urine samples must be rigorously pretreated to remove interferents. In the literature, the only urinary metabolite that has been identified as an interferent is ascorbic acid. In this study, we used the microplate SK method to screen thirty-three of the major organic metabolites present in urine. We identified four previously unknown interferents: citric acid, cysteine, glycolic acid and urobilin. For each interferent, we investigated the following factors: (1) nature of interference-positive or negative, (2) threshold concentration for interference, and (3) possible mechanisms of interference. While this paper does not attempt to provide an exhaustive list of all interferents, knowledge of the main interferents allows for targeted removal.

Assessment of two brands of fentanyl test strips with 251 synthetic opioids reveals "blind spots" in detection capabilities.

BACKGROUND: Fentanyl test strips (FTS) are a commonly deployed tool in drug checking, used to test for the presence of fentanyl in street drug samples prior to consumption. Previous reports indicate that in addition to fentanyl, FTS can also detect fentanyl analogs like acetyl fentanyl and butyryl fentanyl, with conflicting reports on their ability to detect fentanyl analogs like Carfentanil and furanyl fentanyl. Yet with hundreds of known fentanyl analogs, there has been no large-scale study rationalizing FTS reactivity to different fentanyl analogs. METHODS: In this study, 251 synthetic opioids-including 214 fentanyl analogs-were screened on two brands of fentanyl test strips to (1) assess the differences in the ability of two brands of fentanyl test strips to detect fentanyl-related compounds and (2) determine which moieties in fentanyl analog chemical structures are most crucial for FTS detection. Two FTS brands were assessed in this study: BTNX Rapid Response and WHPM DanceSafe. RESULTS: Of 251 screened compounds assessed, 121 compounds were detectable at or below 20,000 ng/mL by both BTNX and DanceSafe FTS, 50 were not detectable by either brand, and 80 were detectable by one brand but not the other (n = 52 BTNX, n = 28 DanceSafe). A structural analysis of fentanyl analogs screened revealed that in general, bulky modifications to the phenethyl moiety inhibit detection by BTNX FTS while bulky modifications to the carbonyl moiety inhibit detection by DanceSafe FTS. CONCLUSIONS: The different "blind spots" are caused by different haptens used to elicit the antibodies for these different strips. By utilizing both brands of FTS in routine drug checking, users could increase the chances of detecting fentanyl analogs in the "blind spot" of one brand.

Usefulness of medicine screening tools in the frame of pharmaceutical post-marketing surveillance.

The negative consequences of Substandard and falsified (SF) medicines are widely documented nowadays and there is still an urgent need to find them in more efficient ways. Several screening tools have been developed for this purpose recently. In this study, three screening tools were used on 292 samples of ciprofloxacin and metronidazole collected in Cameroon. Each sample was then analyzed by HPLC and disintegration tests. Seven additional samples from the nitro-imidazole (secnidazole, ornidazole, tinidazole) and the fluoroquinolone (levofloxacin, ofloxacin, norfloxacin, moxifloxacin) families were analyzed to mimic falsified medicines. Placebo samples that contained only inert excipients were also tested to mimic falsified samples without active pharmaceutical ingredient (API). The three screening tools implemented were: a simplified visual inspection checklist, a low-cost handheld near infrared (NIR) spectrophotometer and paper analytical devices (PADs). Overall, 61.1% of the samples that failed disintegration and assay tests also failed the visual inspection checklist test. For the handheld NIR, one-class classifier models were built to detect the presence of ciprofloxacin and metronidazole, respectively. The APIs were correctly identified in all the samples with sensitivities and specificities of 100%. However, the importance of a representative and up-to-date spectral database was underlined by comparing models built with different calibration set spanning different variability spaces. The PADs were used only on ciprofloxacin samples and detected the API in all samples in which the presence of ciprofloxacin was confirmed by HPLC. However, these PADs were not specific to ciprofloxacin since they reacted like ciprofloxacin to other fluoroquinolone compounds. The advantages and drawbacks of each screening tool were highlighted. They are promising means in the frame of early detection of SF medicines and they can increase the speed of decision about SF medicines in the context of pharmaceutical post-marketing surveillance.

Current attitudes toward drug checking services and a comparison of expected with actual drugs present in street drug samples collected from opioid users.

BACKGROUND: The opioid epidemic continues to be associated with high numbers of fatalities in the USA and other countries, driven mainly by the inclusion of potent synthetic opioids in street drugs. Drug checking by means of various technologies is being increasingly implemented as a harm reduction strategy to inform users about constituent drugs in their street samples. We assessed how valued drug checking services (DCS) would be for opioid street drug users given the ubiquity of fentanyl and related analogs in the drug supply, the information they would most value from drug checking, and compared expected versus actual constituent drugs in collected samples. METHODS: A convenience sample of opioid street drug users (N = 118) was recruited from two syringe service exchange programs in Chicago between 2021 and 2022. We administered brief surveys asking about overdose history, whether fentanyl was their preferred opioid, and interest in DCS. We also collected drug samples and asked participants what drug(s) they expected were in the sample. Provided samples were analyzed using LC-MS technology and the results compared to their expected drugs. RESULTS: Participants reported an average of 4.4 lifetime overdoses (SD = 4.8, range = 0-20) and 1.1 (SD = 1.8, range = 0-10) past-year overdoses. A majority (92.1%) believed they had recently used drugs containing fentanyl whether intentionally or unintentionally. Opinions about the desirability of fentanyl were mixed with 56.1% indicating they did not and 38.0% indicating they did prefer fentanyl over other opioids, mainly heroin. Attitudes toward DCS indicated a general but not uniform receptiveness with a majority indicating interest in DCS though sizeable minorities believed DCS was "too much trouble" (25.2%) or there was "no point" in testing (35.4%). Participants were especially inaccurate identifying common cutting agents and potentiating drugs such as diphenhydramine in their samples (sensitivity = .17). CONCLUSIONS: Results affirmed street drug users remain interested in using DCS to monitor their drugs and such services should be more widely available. Advanced checking technologies that provide information on the relative quantities and the different drugs present in a given sample available at point-of-care, would be most valuable but remain challenging to implement.

Development and validation of a liquid chromatography tandem mass spectrometry method for the analysis of 53 benzodiazepines in illicit drug samples.

An LC-MS/MS method for the analysis of 53 benzodiazepines, including various designer benzodiazepines, was developed. The developed method was applied to a total of 79 illicit street drug samples collected in Chicago, IL. Of these samples, 68 (84%) had detectable amounts of at least one benzodiazepine. Further, of the 53 benzodiazepines included in the developed method just 14 were measured in samples. Clonazolam, a potent designer benzodiazepine and derivative of clonazepam, was the most frequently measured benzodiazepine in 63% of samples and was measured in the highest concentrations. Other benzodiazepines measured in more than 10% of samples included clonazepam, alprazolam, flualprazolam, and oxazepam. Mixtures of benzodiazepines were frequently measured in samples, with just 24% of samples containing just one benzodiazepine. To determine the response of benzodiazepines on a rapid, point-of-use drug checking tool, all 53 benzodiazepine standards were screened on a lateral flow immunoassay benzodiazepine test strip. Sixty eight percent of standards gave a positive BTS response at a concentration of 20 µg/mL, demonstrating BTS have response to a wide variety of benzodiazepines, including many designer benzodiazepines. A comparison of this data to previous data reported for the same samples demonstrated all samples containing a benzodiazepine also had an opioid present, with fentanyl being present in 94% of benzodiazepine samples. These results highlight high rates of polysubstance drug presence in Chicago, IL illicit drug samples, posing an increased risk of drug overdoses in people who use drugs.

Bis(N,N-diethyl-4-methyl-4-piperazine-1-carboxamide) tetra-kis-(iso-thio-cyanato-κN)-cobalt(II), a model compound for the blue color developed in the Scott test.

The complex, bis-(N,N-diethyl-4-methyl-4-piperazine-1-carboxamide) tetra-kis(iso-thio-cyanato-κN)cobalt(II) (N,N-diethyl-4-methyl-4-piperazine-1-carboxamide = di-ethyl-carbamazine), (C10H22N3O)2[Co(NCS)4], is presented. This com-plex is a blue precipitate, insoluble in water but soluble in organic solvents, that is formed from the reaction of diethylcarbamazine citrate, a protonated tertiary amine, with cobalt(II) and thio-cyanate. This reaction, in the form of the Scott test, is a common presumptive test for cocaine hydro-chloride. The known cobalt compound, [K2Co(NCS)4]·3H2O, has a deep-blue coloration due to the tetra-hedral [Co(NCS)4]2- that is also present in the ion pair with bulky amines, and is similar to the color of other tetra-hedral cobalt(II) complex ions, such as [CoCl4]2-. The structure is consistent with a previous proposal that a hydro-phobic ion pair formed between [Co(NCS)4]2- and two protonated mol-ecules of cocaine is responsible for the blue hydro-phobic products formed by cocaine in the Scott test.

Validated method for the analysis of 22 illicit drugs and their metabolites via liquid chromatography tandem mass spectrometry (LC-MS/MS) in illicit drug samples collected in Chicago, IL.

Drug checking services are being utilized worldwide to provide people who use drugs information on the composition and contents of their drugs as a tool for harm reduction and accidental overdose prevention. Existing drug checking services use a variety of techniques including immunoassay strips and spectroscopic techniques like FTIR and Raman. Few services utilize LC-MS based methods for primary or secondary analysis and few methods exist for direct analysis of illicit drugs. To address this, an LC-MS/MS method was developed for 22 illicit drugs and cutting agents using LC-MS/MS with application to 124 illicit drug samples that were collected from Chicago, IL. Samples were also analyzed using fentanyl and benzodiazepine immunoassay test strips. Fentanyl test strips gave a positive result for 86% of samples with only one sample showing a positive result on a benzodiazepine test strip. LC-MS/MS analysis of samples show that opioids were the most commonly quantified in 96% of samples, followed by stimulants at 12% and benzodiazepines at 1%. Fentanyl was measured in 91% of samples, co-occurring with heroin in 58% of opioid-containing samples. A comparison of the gold-standard LC-MS/MS results to fentanyl test strips shows a high level of accuracy for the fentanyl test strips, with just 5% of samples being classified as false negatives and no false positives. These results demonstrate the strengths and benefits of LC-MS/MS when incorporated as a secondary analysis tool for drug checking.

The air-gap PAD: a roll-to-roll-compatible fabrication method for paper microfluidics.

Paper-based analytical devices (PADs) offer a low-cost, user-friendly platform for rapid point-of-use testing. Without scalable fabrication methods, however, few PADs make it out of the academic laboratory and into the hands of end users. Previously, wax printing was considered an ideal PAD fabrication method, but given that wax printers are no longer commercially available, alternatives are needed. Here, we present one such alternative: the air-gap PAD. Air-gap PADs consist of hydrophilic paper test zones, separated by "air gaps" and affixed to a hydrophobic backing with double-sided adhesive. The primary appeal of this design is its compatibility with roll-to-roll equipment for large-scale manufacturing. In this study, we examine design considerations for air-gap PADs, compare the performance of wax-printed and air-gap PADs, and report on a pilot-scale roll-to-roll production run of air-gap PADs in partnership with a commercial test-strip manufacturer. Air-gap devices performed comparably to their wax-printed counterparts in Washburn flow experiments, a paper-based titration, and a 12-lane pharmaceutical screening device. Using roll-to-roll manufacturing, we produced 2700 feet of air-gap PADs for as little as $0.03 per PAD.

Reciprocal innovation: A new approach to equitable and mutually beneficial global health partnerships.

Global health researchers often discount mutual learning and benefit to address shared health challenges across high and low- and middle-income settings. Drawing from a 30-year partnership called AMPATH that started between Indiana University in the US and Moi University in Kenya, we describe an innovative approach and program for mutual learning and benefit coined 'reciprocal innovation.' Reciprocal innovation harnesses a bidirectional, co-constituted, and iterative exchange of ideas, resources, and innovations to address shared health challenges across diverse global settings. The success of AMPATH in Kenya, particularly in HIV/AIDS and community health, resulted in several innovations being 'brought back' to the US. To promote the bidirectional flow of learning and innovations, the Indiana CTSI reciprocal innovation program hosts annual meetings of multinational researchers and practitioners to identify shared health challenges, supports pilot grants for projects with reciprocal exchange and benefit, and produces educational and training materials for investigators. The transformative power of global health to address systemic health inequities embraces equitable and reciprocal partnerships with mutual benefit across countries and communities of academics, practitioners, and policymakers. Leveraging a long-standing partnership, the Indiana CTSI has built a reciprocal innovation program with promise to redefine global health for shared wellbeing at a global scale.

Iodine status, household salt iodine content, knowledge and practice assessment among pregnant women in Butajira, South Central Ethiopia.

BACKGROUND: Iodine is one of the crucial micronutrients needed by the human body, and is vitally important during pregnancy. This study aimed to determine the relationship between the iodine status of pregnant women and their knowledge, and practices regarding iodized salt. All participants were enrolled in the Butajira nutrition, mental health and pregnancy (BUNMAP) cohort, Butajira, Ethiopia in February-May, 2019. METHODS: In this cross-sectional study, 152 pregnant women without hypertension or known thyroid disease before or during pregnancy were randomly selected from the BUNMAP mother to child cohort (n = 832). Spot urine samples were collected to estimate the level of urinary iodine concentration (UIC). Salt samples were also collected from their homes. The Sandall-Kolthoff (S-K) method was used to measure the level of iodine in the urine samples, and iodometric titration was used to measure the level of iodine in the salt. Data was entered and cleaned using Epi-info version 3.5.3 and then exported to SPSS version 20 for further analysis. Multivariate logistic regression analysis was performed to identify associations in the collected data. RESULTS: The WHO recommended level of iodine for populations of pregnant women is 150-249 F06Dg/L. The median UIC among pregnant women in this study was 151.2 µg/L [interquartile range (IQR) = 85.5-236.2 F06Dg/L], at the low end of this range. About half (49.65%) of the participants were likely to be iodine deficient. There was a significant association between having a formal job (AOR = 2.56; CI = 1.11-5.96) and iodine sufficiency. Based on a cutoff of >15 ppm (mg/kg), 91.7% (95% CI: 87.2-96.2) of the salts collected from the household had adequate iodine content. The median iodine level of the collected salt samples was 34.9 mg/kg (ppm) (IQR = 24.2-44.6 mg/kg). CONCLUSIONS: The UNICEF 2018 guidelines for adequate iodine nutrition in pregnant women include both a recommended median range of 150-249 µg/L, and an upper limit of 20% on the fraction of the population with UIC below 50 µg/L. Because our study population's median level is 151.2 µg/L and the percentage of pregnant women with urinary iodine concentration of less than 50 µg/L is 9.7% (14/145), the women received adequate iodine nutrition. The availability of adequately iodized salt in households is more than 90%, as recommended by WHO. In light of previous iodine deficiency in this region of Ethiopia, the salt iodization program promotes the health of babies and mothers.

Discrimination of Substandard and Falsified Formulations from Genuine Pharmaceuticals Using NIR Spectra and Machine Learning.

Near-infrared (NIR) spectroscopy is a promising technique for field identification of substandard and falsified drugs because it is portable, rapid, nondestructive, and can differentiate many formulated pharmaceutical products. Portable NIR spectrometers rely heavily on chemometric analyses based on libraries of NIR spectra from authentic pharmaceutical samples. However, it is difficult to build comprehensive product libraries in many low- and middle-income countries due to the large numbers of manufacturers who supply these markets, frequent unreported changes in materials sourcing and product formulation by the manufacturers, and general lack of cooperation in providing authentic samples. In this work, we show that a simple library of lab-formulated binary mixtures of an active pharmaceutical ingredient (API) with two diluents gave good performance on field screening tasks, such as discriminating substandard and falsified formulations of the API. Six data analysis models, including principal component analysis and support-vector machine classification and regression methods and convolutional neural networks, were trained on binary mixtures of acetaminophen with either lactose or ascorbic acid. While the models all performed strongly in cross-validation (on formulations similar to their training set), they individually showed poor robustness for formulations outside the training set. However, a predictive algorithm based on the six models, trained only on binary samples, accurately predicts whether the correct amount of acetaminophen is present in ternary mixtures, genuine acetaminophen formulations, adulterated acetaminophen formulations, and falsified formulations containing substitute APIs. This data analytics approach may extend the utility of NIR spectrometers for analysis of pharmaceuticals in low-resource settings.

Rapid, instrument-free colorimetric quantification of DNA using Nile Blue.

The use of nucleic acid tests (NAT) for sensitive and rapid detection of pathogens relevant to human health has increased due to the ubiquity of nucleic acid amplification techniques such as polymerase chain reaction. The use of such tools for detection of amplified nucleic acid (NA) in field and clinical settings is limited by the need for complex instrumentation and trained users. To address these limitations we developed a rapid, robust, and instrument-free colorimetric detection method for nucleic acids using a visible region dye, Nile Blue (NB). NB is a cationic benzophenoxazine dye with well-known binding interactions with NA and has been used in instrumental methods for DNA quantification. When combined with dsDNA, the color of NB shifts from blue to purple. Images of this color shift are collected and are subjected to image analysis. Observed changes in the red and green colorimetric intensities are linked to the ratio of dsDNA to NB. By titrating solutions of dsDNA against a series of NB concentrations, we found it possible to quantitate dsDNA at concentrations ranging from 10-100 µg mL-1 using a k-means cluster analysis method. This range is comparable to that of NA concentrations quantified using gold-standard UV-Visible spectroscopy and to the concentrations of NA in biological samples after amplification. Unknown concentrations of dsDNA from yeast extracts were correctly identified within ±5 µg mL-1 of true concentration. Preliminary experiments demonstrate use of the developed NB method on paper-based analytical devices. As an instrument-free detection method, NB allows for rapid and robust quantification of dsDNA in field settings.

Securing the Chain of Custody and Integrity of Data in a Global North-South Partnership to Monitor the Quality of Essential Medicines.

Substandard and falsified (SF) pharmaceuticals account for an estimated 10% of the pharmaceutical supply chain in low- and middle-income countries (LMICs), where a lack of regulatory and laboratory resources limits the ability to conduct effective post-market surveillance and allows SF products to penetrate the supply chain. The Distributed Pharmaceutical Analysis Laboratory (DPAL) was established in 2014 to expand testing of pharmaceutical dosage forms sourced from LMICs; DPAL is an alliance of academic institutions throughout the United States and abroad that provides high-quality, validated chemical analysis of pharmaceutical dosage forms sourced from partners in LMICs. Results from analysis are reported to relevant regulatory agencies and are used to inform purchasing decisions made by in-country stakeholders. As the DPAL program has expanded to testing more than 1,000 pharmaceutical dosage forms annually, challenges have surfaced regarding data management and sample tracking. Here, we describe a pilot project between DPAL and ARTiFACTs that applies the blockchain to organize and manage key data generated during the DPAL workflow, including a sample's progress through the workflow, its physical location, provenance of metadata, and lab reputability. Recording time and date stamps with these data will create a permanent and verifiable chain of custody for samples. This secure, distributed ledger will be linked to an easy-to-use dashboard, allowing stakeholders to view results and experimental details for each sample in real time and verify the integrity of DPAL analysis data. Introducing this blockchain-based system as a pilot will allow us to test the technology with real users analyzing real samples. Feedback from users will be recorded and necessary adjustments will be made to the system before the implementation of blockchain across all DPAL sites. Anticipated benefits of implementing the blockchain technology for managing DPAL data include efficient management for routing work, increasing throughput, creating a chain of custody for samples and their data in alignment with the distributed nature of DPAL, and using the analysis results to detect patterns of quality within and across brands of products and develop enhanced sampling techniques and best practices.

Community overdose surveillance: Comparing substances collected from the death scene investigation to toxicology results.

BACKGROUND: Recent overdose trends are characterized by increased toxicological detection of stimulants with opioids, yet it is unclear whether these substances are mixed prior to consumption or purposefully used simultaneously. METHODS: Postmortem toxicology data were collected in Marion County, Indiana, from 45 fatal overdose cases involving heroin, fentanyl, methamphetamine, or cocaine. Substances found by death scene investigators at the scene of the fatal overdose (57 samples) were tested using high-pressure liquid chromatography mass-spectrometry (LC-MS) technology. We compared toxicology and LC-MS results to understand whether substances contributing to overdose were found in combination or separately at the scene of the overdose. RESULTS: Comparing toxicology reports with LC-MS results from substances found at the scene of overdose deaths involving opioids and stimulants reveal that deaths are largely the result of the co-use of opioids and stimulants, rather than use of stimulants combined with opioids. CONCLUSIONS: Collecting and testing physical samples from fatal overdose scenes and comparing these to post-mortem toxicology results is a new way to examine polydrug use patterns. This community overdose surveillance method can be used to improve overdose prevention and response efforts.

Cost savings of paper analytical devices (PADs) to detect substandard and falsified antibiotics: Kenya case study.

BACKGROUND: Over 10% of antibiotics in low- and middle-income countries (LMICs) are substandard or falsified. Detection of poor-quality antibiotics via the gold standard method, high-performance liquid chromatography (HPLC), is slow and costly. Paper analytical devices (PADs) and antibiotic paper analytical devices (aPADs) have been developed as an inexpensive way to estimate antibiotic quality in LMICs. AIM: To model the impact of using a rapid screening tools, PADs/aPADs, to improve the quality of amoxicillin used for treatment of childhood pneumonia in Kenya. METHODS: We developed an agent-based model, ESTEEM (Examining Screening Technologies with Economic Evaluations for Medicines), to estimate the effectiveness and cost savings of incorporating PADs and aPADs in amoxicillin quality surveillance in Kenya. We compared the current testing scenario (batches of entire samples tested by HPLC) with an expedited HPLC scenario (testing smaller batches at a time), as well as a screening scenario using PADs/aPADs to identify poor-quality amoxicillin followed by confirmatory analysis with HPLC. RESULTS: Scenarios using PADs/aPADs or expedited HPLC yielded greater incremental benefits than the current testing scenario by annually averting 586 (90% uncertainty range (UR) 364-874) and 221 (90% UR 126-332) child pneumonia deaths, respectively. The PADs/aPADs screening scenario identified and removed poor-quality antibiotics faster than the expedited or regular HPLC scenarios, and reduced costs significantly. The PADs/aPADs scenario resulted in an incremental return of $14.9 million annually compared with the reference scenario of only using HPLC. CONCLUSION: This analysis shows the significant value of PADs/aPADs as a medicine quality screening and testing tool in LMICs with limited resources.

High concentrations of illicit stimulants and cutting agents cause false positives on fentanyl test strips.

BACKGROUND: The opioid epidemic has caused an increase in overdose deaths which can be attributed to fentanyl combined with various illicit substances. Drug checking programs have been started by many harm reduction groups to provide tools for users to determine the composition of their street drugs. Immunoassay fentanyl test strips (FTS) allow users to test drugs for fentanyl by either filling a baggie or cooker with water to dissolve the sample and test. The antibody used in FTS is very selective for fentanyl at high dilutions, a characteristic of the traditional use of urine testing. These street sample preparation methods can lead to mg/mL concentrations of several potential interferents. We tested whether these concentrated samples could cause false positive results on a FTS. METHODS: 20 ng/mL Rapid Response FTS were obtained from BTNX Inc. and tested against 4 different pharmaceuticals (diphenhydramine, alprazolam, gabapentin, and naloxone buprenorphine) and 3 illicit stimulants [cocaine HCl, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA)] in concentrations from 20 to 0.2 mg/mL. The FTS testing pad is divided into 2 sections: the control area and the test area. Control and test area signal intensities were quantified by ImageJ from photographs of the test strips and compared to a threshold set by fentanyl at the FTS limit of detection. RESULTS: False positive results indicating the presence of fentanyl were obtained from samples of methamphetamine, MDMA, and diphenhydramine at concentrations at or above 1 mg/mL. Diphenhydramine is a common cutting agent in heroin. The street sample preparation protocols for FTS use suggested by many online resources would produce such concentrations of these materials. Street samples need to be diluted more significantly to avoid interference from potential cutting agents and stimulants. CONCLUSIONS: Fentanyl test strips are commercially available, successful at detecting fentanyl to the specified limit of detection and can be a valuable tool for harm reduction efforts. Users should be aware that when drugs and adulterants are in high concentrations, FTS can give a false positive result.

"Scentsor": A Whole-Cell Yeast Biosensor with an Olfactory Reporter for Low-Cost and Equipment-Free Detection of Pharmaceuticals.

Portable and inexpensive analytical tools are required to monitor pharmaceutical quality in technology limited settings including low- and middle-income countries (LMICs). Whole cell yeast biosensors have the potential to help meet this need. However, most of the readouts for yeast biosensors require expensive equipment or reagents. To overcome this challenge, we have designed a yeast biosensor that produces a unique scent as a readout. This inducible scent biosensor, or "scentsor", does not require the user to administer additional reagents for reporter development and utilizes only the user's nose to be "read". In this Letter, we describe a scentsor that is responsive to the hormone estradiol (E2). The best estimate threshold (BET) for E2 detection with a panel of human volunteers (n = 49) is 39 nM E2 (15 nM when "non-smellers" are excluded). This concentration of E2 is sensitive enough to detect levels of E2 that would be found in dosage forms. This paper provides evidence that scent has the potential for use in portable yeast biosensors as a readout, particularly for use in LMICs.

idPAD: Paper Analytical Device for Presumptive Identification of Illicit Drugs.

As drug overdose deaths across the United States continue to rise, there is increasing interest in field testing of illicit substances. This work discusses a paper-based analytical device (idPAD) that can run a library of 12 colorimetric tests at the same time, each detecting different chemical functional groups and materials found in illicit drugs, distractor substances, and cutting agents. The idPAD requires no electricity, costs less than $2 USD, and requires minimal training to operate. The results of the 12 tests form a color barcode which is "read" by comparison to standard images. The accuracy of the idPAD was assessed using samples of heroin, cocaine HCl, crack, and methamphetamine at concentrations of 25%-100% in a lactose matrix, as well as pure lactose. Based on 840 "reads" by three different users, the idPAD showed 95% sensitivity and 100% specificity for detecting these drugs; the most common error was mistaking cocaine HCl for crack or crack for cocaine HCl. In a second step, samples of heroin, cocaine, and methamphetamine (n = 30) and distractor substances (pharmaceuticals, cutting agents, and other illicit drugs, n = 64) were tested by two readers, yielding a sensitivity of 100% and specificity of 97%. Targeted substances were detected reliably at 55-180 µg/lane, and the idPAD was found to be stable for at least 3 months when stored at room temperature. The library approach used in the idPAD may provide the accuracy and robustness necessary for a presumptive field drug test.