Abstract
Substandard and falsified medicines threaten global health and require reliable data and screening technologies to combat their spread. This study examined the quality of 241 samples containing azithromycin, cefixime, esomeprazole and losartan collected from licenced private vendors in the Saptari (121 samples; convenience sampling) and Kathmandu (120 samples; randomised sampling) districts of Nepal. Nearly 10% (24 samples; 95% CI 6.5-14.5) of samples failed pharmacopoeial quality analysis and were classified as 'substandard' or 'probably substandard'. No falsified medicines were identified. Small-scale dissolution acceptance criteria were applied to all 20 three-unit combinations of 213 samples tested in the first stage of the United States Pharmacopoeia dissolution test. Approximately 1% of these results were false positives when compared with the final United States Pharmacopoeia dissolution test results, suggesting the test's usefulness in encouraging dissolution testing in resource-limited contexts. In the narrow sense of presence/absence, two portable Raman spectrometers reliably detected azithromycin, cefixime and losartan in most samples based on effective methods for detecting falsified medicines; however, none of the substandard samples were identified. The findings suggest that falsified medicines are less prevalent in Nepal and the surrounding region than suggested by regional concerns about Nepal and global concerns about low- and middle-income countries. Nevertheless, the Nepalese government should continue to ensure the quality of all distributed medicines.