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.

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.

Paper Millifluidics Lab: Using a Library of Color Tests to Find Adulterated Antibiotics.

A two to three period analytical chemistry experiment has been developed which allows second year students to explore chemical color tests used to detect adulterated pharmaceuticals. Students prepare several paper analytical devices (PADs) to generate positive and negative controls antibiotics, along with cutting agents such as starch and chalk. These PADs are used to identify the active ingredients and excipients in mystery tablets prepared by their classmates. In the second part of the lab, the students select an individual color test and design an experiment to quantify their mystery pill's active pharmaceutical ingredient (API). Nearly all of the student groups were able to successfully identify adulterants present in their mystery tablets. The quantification of the mystery tablets was also successful with all but one group calculating the correct concentration within 6%. In a postlab assessment, the students identified their largest gains in their ability to analyze data and other information, skill in science writing, and learning of laboratory techniques.

Involving Students in the Distributed Pharmaceutical Analysis Laboratory: A Citizen-Science Project to Evaluate Global Medicine Quality.

The distributed pharmaceutical analysis laboratory (DPAL) is a collaboration between 30 academic institutions around the world, whose goal is to determine the quality of medicines collected from partner organizations in low- and middle-income countries (LMICs). Institutions complete system suitability for a high-performance liquid chromatography (HPLC) system using United States Pharmacopeia (USP)-traceable reference standards, and are then approved to analyze batches of samples that are collected in LMICs by covert shoppers. Open Science Framework (OSF) allows DPAL participants access to resources for the program including an HPLC methodology manual, a wiki with HPLC troubleshooting information, detailed checklists and Excel templates for system suitability and sample assay, as well as steps for reporting results. Participants incorporate the DPAL program into their academic curriculum as undergraduate research or via lab activities for analytical chemistry or instrumental analysis courses. Over a thousand samples have been analyzed through DPAL in the last three years, and 168 samples with quality problems have been discovered, including falsified acetaminophen, adulterated amoxicillin-clavulanate and doxycycline, and substandard losartan. These quality problems are reported to the medicine regulatory agencies in the countries of origin and the WHO Rapid Alert System for further action. This real-world program gives students a hands-on opportunity to see the importance of analytical metrics taught in the classroom.

Amoxicillin Quality and Selling Practices in Urban Pharmacies and Drug Stores of Blantyre, Malawi.

This study evaluated a newly developed paper analytical device (PAD) for screening amoxicillin samples in Blantyre urban townships. Covert shoppers attempted to buy amoxicillin from a geographically stratified selection of private pharmacies (N = 22 out of 26) and drug stores (N = 23 out of 103) in the township area. According to the PAD results, all 42 samples obtained by the shoppers contained amoxicillin and none contained suspicious filler materials. Next, the products were assayed using high-performance liquid chromatography. Consistent with the PAD results, all samples contained the correct amount of amoxicillin with no unexpected ingredients. However, one sample was purchased as amoxicillin and contained that ingredient, but was packaged in capsules that are normally used to package ampicillin. Almost every sample failed a simple packaging analysis. Nine in 10 samples were missing their original packaging and/or inserts (52.4% repackaged capsules and 35.7% repackaged blister packs). Only 33.3% of the packages had expiry dates, 16.7% had batch numbers, and 47.6% had the manufacturer's name. Dispensing practices were likewise unsatisfactory. Ninety-five percentage of the sellers sold the amoxicillin without a prescription, even though this medicine is regulated as prescription-only in Malawi. Although the chemical analysis showed that amoxicillin quality was good, our market survey revealed poor adherence to prescription-only medicine dispensing of antibiotics, which threatens antimicrobial stewardship efforts. Furthermore, the wide prevalence of repackaging deprives medicines of important information needed during patient's use, regulatory investigations, and pharmacovigilance reporting.