# Substandard and Falsified Antibiotics Seized in Belgium: Quality Control Analysis Reveals High Prevalence of WHO Watch List Molecules and Bioavailability Non-Compliance

## TL;DR

This study finds that many seized fake antibiotics in Belgium contain dangerous drugs and fail quality tests, which could worsen antibiotic resistance.

## Contribution

The study provides new insights into the pharmaceutical quality of seized antibiotics and their potential role in promoting antimicrobial resistance.

## Key findings

- 35% of seized antibiotic samples contained WHO watch list molecules.
- 43% of samples failed quality control testing, with dissolution defects being the most common issue.
- Substandard antibiotics may contribute to AMR by exposing bacteria to sub-lethal drug concentrations.

## Abstract

Background: Antimicrobial resistance (AMR) poses a critical global public health challenge requiring comprehensive intervention strategies, including robust antibiotic stewardship programs. The European Commission’s 2017 One Health Action Plan against AMR established guidelines based on WHO’s AWaRe classification system, which categorizes antibiotics into Access, Watch, and Reserve groups to promote prudent use. However, the proliferation of substandard and falsified (SF) medical products increasingly undermines these stewardship efforts, with European regulatory agencies, including Belgium’s Federal Agency for Medicines and Health Products (FAMHP), reporting rising seizures of SF antibiotics. Objective: To assess the pharmaceutical quality of confiscated antibiotic samples and evaluate their potential contribution to AMR development. Methods: We conducted comprehensive pharmaceutical quality control testing on 40 SF antibiotic samples seized by the FAMHP between early 2024 and late 2025. Results: The analysis revealed significant deficiencies: 35% of samples contained antibiotics listed on international watch lists, while nearly 43% failed quality control testing. Dissolution defects represented the predominant failure mode, accounting for 29% of all samples tested. These defects can severely compromise drug bioavailability, clinical efficiency, and expose bacterial populations to sub-lethal concentrations of active pharmaceutical ingredients—a recognized driver of resistance development. Conclusions: Many seized samples appeared to be unregistered/unlicensed medicines that, while prohibited in the EU, may circulate legally elsewhere. This transnational dimension highlights how substandard products threaten global AMR control initiatives beyond individual patient safety. These findings underscore the urgent need to raise more awareness within the EU and for enhanced pharmaceutical quality assurance systems and much more international regulatory cooperation, particularly in low- and middle-income countries where such products circulate more readily.