Work

Quality of antibiotics purchased on Bioko Island and four mainland districts of Equatorial Guinea: a cross-sectional medicine-quality survey

Year: 2026

Type: article

Abstract: Objectives Antibiotics are essential chemotherapeutic agents for treating bacterial infections and vital for curbing mortality and morbidity. However, their misuse, overuse and sub-therapeutic dosing resulting from poor-quality medicines contribute to antimicrobial resistance (AMR), which is recognised as one of the leading global public health threats. Design Cross-sectional medicine-quality survey using mystery-client sampling. Setting Public and private medicine outlets on Bioko Island and four mainland districts of Equatorial Guinea, surveyed in 2018. Participants 424 medicine outlets that were open during the survey window, from which 901 antibiotic samples were purchased. Primary outcome measures The proportion of antibiotic samples (amoxicillin, ampicillin, ciprofloxacin, gentamicin and tetracycline formulations) classified as acceptable, substandard or falsified by active pharmaceutical ingredient content, measured by high-performance liquid chromatography with diode-array detection against US pharmacopoeia tolerance limits; bioavailability was assessed by dissolution testing for a subset of samples. Results The results indicate substantial concern regarding antibiotic quality. Only 33.2% (n=299) of samples were of acceptable quality, while 61.2% (n=551) were substandard and 5.7% (n=51) were falsified. Quality patterns were comparable between Bioko Island and the mainland, with no statistically significant regional differences (overall χ2 p=0.43). The substandard proportion was 62.1% (95% CI 58.2% to 65.9%) on Bioko Island and 59.0% (95% CI 53.2% to 64.6%) on the mainland; the falsified proportion was 6.0% (95% CI 4.4% to 8.1%) and 4.9% (95% CI 3.0% to 8.1%), respectively. Conclusions The findings of this study identify quality concerns affecting the essential antibiotics available in Equatorial Guinea, with comparable patterns observed across both Bioko Island and the mainland. The results support a review of national policies governing the importation and distribution of essential medicines and argue for establishing routine post-market surveillance through the Baney Reference Laboratory, which is well-positioned to serve as the national hub for medicine quality assurance. Strengthening this regulatory capacity will safeguard public health and contribute to global efforts to address AMR.

Source: BMJ Open

DOI: 10.1136/bmjopen-2026-123684