Usefulness of combined screening methods for rapid detection of falsified and/or substandard medicines in the absence of a confirmatory method.

BACKGROUND: The influx of substandard and falsified medicines is a global public health challenge and its rapid detection is a key solution to the menace. This study used three screening methods and one confirmatory method for the quality assessment of 25 batches of artemether/lumefantrine dosage forms from the Ghanaian market to test that combined screening methods only can rapidly detect substandard and/or falsified medicines in areas where confirmatory methods may not be available. METHODS: The quality of artemether/lumefantrine tablet products obtained from pharmacies and licensed chemical seller shops within the Accra metropolis in Ghana were analysed using three screening methods (GPHF Minilab, Colorimetry and Counterfeit Drug Indicator) and one confirmatory method (high-performance liquid chromatography). RESULTS: The results showed that 18/25 batches of the artemether/lumefantrine samples passed using the combined screening and confirmatory methods and 5/25 batches of the artemether/lumefantrine samples failed using the combined screening and confirmatory methods. However, 1/25 batch of the artemether/lumefantrine samples failed using the combined screening methods but passed using the confirmatory method. Also, 1/25 batch of the artemether/lumefantrine samples passed using the combined screening methods but failed using the confirmatory method. This notwithstanding, the combined screening methods and the confirmatory method provided equivalent quality assessment profiles for 23/25 (92%) batches of the artemether/lumefantrine tablet products. Out of the 6 samples that failed the confirmatory test, 1/6, 2/6, and 3/6 failed on the high (> 110%), low (< 90%), and no active ingredient (0%), respectively. The sensitivity of Minilab, colorimetric, CoDI, and the combined screening methods at 95% confidence level were 0.5 ± 0.57, 0.83 ± 0.33, 0.75 ± 0.49, and 0.83 ± 0.33, respectively. Also, the specificity of Minilab, colorimetric, CoDI, and the combined screening methods at 95% confidence level were 1.00, 0.95 ± 0.10, 1.00, and 0.95 ± 0.10, respectively. CONCLUSION: The combined screening methods may be used for rapid detection of falsified and/or substandard medicines without using a confirmatory method. However, additional research on the best combinations of screening devices/methods to rapidly detect the quality of medicines is recommended.

Artemether-Lumefantrine Concentrations in Tablets and Powders from Ghana Measured by a New High-Performance Liquid Chromatography Method.

We developed and validated a new analytical method for the simultaneous quantification of artemether and lumefantrine in fixed-dose tablets and powders for reconstitution into pediatric suspensions (PSs). The method showed linearity (r(2) > 0.9947), precision (coefficient of variation < 2%), accuracy (deviation of mean from actual concentrations < 4%), and specificity (peak purities > 99%). The validated method was used to analyze 24 batches of fixed-dose tablets and PSs of artemether and lumefantrine. Of the samples, 23 were obtained using convenience sampling of commonly available brands within Accra in Ghana and one was obtained from Aarhus University Hospital. In all, 83.3% (confidence interval: 80-120%) passed for both artemether and lumefantrine contents, 16.7% failed by the U.S. Pharmacopoeia standards, 8.3% failed for one content, and 8.3% failed for both contents. All four products (16.7%) that failed were PSs, and two (8.3%) showed higher levels of artemether than prescribed (222% and 756%).