A study of the quality of cardiovascular and diabetes medicines in Malang District, Indonesia, using exposure-based sampling

Abstract Background The World Health Organization (WHO) has warned that substandard and falsified medicines threaten health, especially in low- and middle-income countries (LMIC). However, the magnitude of that threat for many medicines in different regions is not well described, and high-quality studies remain rare. Recent reviews of studies of cardiovascular and diabetes medicine quality recorded that 15.4 % of cardiovascular and 6.8% of diabetes samples failed at least one quality test. Review authors warn that study quality was mixed. Because they did not record medicine volume, no study reflected the risk posed to patients. Methods and Findings We investigated the quality of five medicines for cardiovascular disease and diabetes in Malang district, East Java, Indonesia. Our sample frame, based on dispensing volumes by outlet and price category, included sampling from public and private providers and pharmacies, and reflected the potential risk posed to patients. The content of active ingredient was determined by High Performance Liquid Chromatography, and compared with the labelled content. Dissolution testing was also performed. We collected a total of 204 samples: amlodipine (88); captopril (22); furosemide (21); glibenclamide (21); and simvastatin (52), comprising 83 different brands/products. All were manufactured in Indonesia, and all samples met specifications for both assay and dissolution. None was suspected of being falsified. Conclusions While we cannot conclude that the prevalence of poor-quality medicines in Malang district is zero, our sampling method, which reflects likely exposure to specific brands and outlets, suggests that the risk to patients is very low; certainly nothing like the rates found in recent reviews of surveys in LMICs. Our study demonstrates the feasibility of sampling medicines based on likely exposure to specific products, and underlines the dangers of extrapolating results across countries. What is already known on this topic The World Health Organisation suggests that as many as one in 10 medicines in low- and middle-income countries are of poor quality, but studies of the prevalence of substandard and falsified rarely take into account patient exposure. Medicines for non-communicable diseases and studies from large middle-income countries are under-represented in existing studies. What this study adds We showed that it is feasible to sample medicines based on patient exposure. Our exposure-based study of cardiovascular and diabetes medicines in Indonesia, a lower-middle income country that is the world’s fourth most populous, found that all met quality standards. How this study might affect research, practice or policy Adopting exposure-based methods for sampling and/or calculating the prevalence of substandard and falsified medicines would improve our understanding of the potential public health impact of poor-quality products globally.