Post‑market quality evaluation of chloramphenicol eye drops marketed in Freetown, Sierra Leone

Abstract

Background: Substandard and falsified (SF) ophthalmic antibiotics undermine patient safety and antimicrobial stewardship in low‑resource settings. For chloramphenicol eye drops, critical quality attributes appearance/clarity, extractable volume, pH, identification and assay directly influence safety and therapeutic performance.Objective: To evaluate the pharmaceutical quality of chloramphenicol eye drops marketed in Freetown, Sierra Leone, against British Pharmacopoeia (BP) specifications.Methods: Nine brands (C1-C9) were sampled from registered outlets across the Western Area and tested at the National Pharmaceutical Quality Control Laboratory. Visual inspection assessed appearance/clarity. Extractable volume was measured using a graduated cylinder versus a labelled 10 mL claim. pH was assessed with indicator paper (target BP range 7.0-7.5). Identification employed UV-Visible spectrophotometry (λmax ≈ 278 nm), and assay used UV-Vis quantification with A (1%, 1 cm) absorptivity at 278 nm; BP acceptance for potency was 90-110%.Results: Origins: China 44.4%, India 33.3%, not indicated 22.2%. Extractable volume: 4 brands matched 10 mL; 5 exceeded (11-13 mL). pH: 7 within BP (7.0-7.5); 2 below spec (pH 6.0). Clarity: 8 clear and particle‑free; 1 showed yellowish discoloration with particulates. Assay: all 9 within 90-110% (range 94.9-108.0%).Conclusion: Most products met BP potency specifications but deviations in pH, extractable volume and clarity indicate quality control gaps. Findings support strengthened post‑marketing surveillance, complete labelling for traceability and improved manufacturing controls (buffering, container‑closure).