Post-market quality assessment of antibiotics: findings from a cross-sectional study using standardised patients in Tabalong and Bekasi districts, Indonesia

Objectives: In Indonesia, antibiotics are often purchased without a prescription at community pharmacies, contrary to current regulations. This practice may increase the risk of out-of-specification (OOS) medicines being dispensed, potentially contributing to treatment failure and antibiotic resistance. To address this concern, we assessed the quality of antibiotics purchased without a prescription at private drug retail outlets (PDROs) in Indonesia. Design and setting: We conducted a cross-sectional study in Tabalong and Bekasi, Indonesia, using standardised patients (SPs) who purchased antibiotics without a prescription for three clinical scenarios: upper respiratory tract infection (URTI), tuberculosis (TB) and child diarrhoea. The pharmacies and drug stores were randomly selected from each subdistrict based on the probability proportional method. We measured the active pharmaceutical ingredient (API) content of the antibiotic samples using high-performance liquid chromatography (HPLC). Samples and analysis: The quality of 183 antibiotics including amoxicillin tablets (148/183, 80.9%, 95% CI 74.7% to 86.1%), amoxicillin dry syrup (12/183, 6.6%, 95% CI 3.6% to 10.8%), ampicillin tablets (5/183, 2.7%, 95% CI 1.1% to 5.9%) and ciprofloxacin tablets (18/183, 9.8%, 95% CI 6.2% to 14.8%) obtained from 117/166 (70.5%, 95% CI 62.8 to 77.2) PDROs were tested. Descriptive statistics were used to describe the characteristics of the purchased antibiotics, and the API content of each antibiotic was compared against the United States Pharmacopeia 43-National Formulary 38 (USP 43-NF 38) standards in absolute values and percentages. Results: Almost all samples produced in Indonesia (182/183, 99.5%, 95% CI 97.5% to 99.9%) were unbranded (123/183, 67.2%, 95% CI 60.2% to 73.7%) or branded generic (60/183, 32.8%, 95% CI 26.3% to 39.8%) and packaged in strips (165/183, 90.2%, 95% CI 85.2% to 93.8%). Around 12/183 (6.6%, 95% CI 3.6% to 10.8%) antibiotics were found to be OOS; these were mostly amoxicillin 125 mg dry syrup (6/12, 50%, 95% CI 24.3% to 75.7%) and ciprofloxacin 500 mg tablet (5/18, 27.8%, 95% CI 11.5% to 50.6%). Around 33% (4/12, 95% CI 12.5% to 61.2%) of amoxicillin 125 mg dry syrup samples had an API content above the label claim, the highest being 187%, whereas 16.7% (2/12, 95% CI 3.6% to 43.6%) were below the label claim, the lowest being 64%. About 27.8% (5/18, 95% CI 11.5% to 50.6%) of ciprofloxacin samples tested had an API content above the label claim; the highest was 120%. Conclusion: While the proportion of OOS antibiotics identified was relatively small, at a population level, it represents a significant proportion of sub-optimally treated infections.