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

Abstract

Background: Chloramphenicol capsules are widely used in low- and middle-income settings, yet product quality can vary across brands, with implications for therapeutic effectiveness and antimicrobial resistance. Evidence from Freetown, Sierra Leone, has been limited.Objectives: To evaluate key pharmaceutical quality attributes, uniformity of dosage units, dissolution, and assay of chloramphenicol capsule brands marketed in Freetown and benchmark performance against compendial specifications.Methods: An experimental, laboratory-based study was conducted at the National Pharmaceutical Quality Control Laboratory, Pharmacy Board of Sierra Leone. Nine brands (coded C1-C9) were purchased from registered outlets (January 2025). Tests followed pharmacopoeial procedures: (i) Uniformity of dosage units by mass variation with Acceptance Value (AV) criteria (USP <905>: pass at Stage-1 if AV≤15; Stage-2 if AV≤ 25); (ii) Dissolution using Apparatus I (basket), 100 rpm, 900 mL 0.1 M HCl at 37 °C, 45-min sampling, UV-Vis at 278 nm; working target ≥ 80% dissolved; (iii) Assay by UV-Visible spectrophotometry at 278 nm, expressed as percent label claim; working acceptance 95-105%. All tests were performed in triplicate per brand where applicable.Results: Uniformity of dosage units: 6 brands (66.7%) passed at Stage-1; three brands (C1, C5, C8) failed Stage-1 (AV>15) but passed Stage-2 (all AV≤25), yielding compliant overall.Dissolution: 5 brands (55.6%) met the ≥80% release target at 45 min (C1, C3, C5, C7, C8). Four brands (C2, C4, C6, C9) failed, with mean% dissolved of 39.6%, 6.9%, 45.3%, and 41.4%, respectively. Assay: 6 brands (66.7%) were within 95-105% label claim (C1, C2, C4, C6, C7, C9). Three brands were below spec: C3 (93.87%), C5 (81.57%), C8 (81.11%). Across all brands, mean assay values ranged from 81.11% to 103.53%.Conclusions: Substantial inter-brand variability was observed. While all brands ultimately complied with dose uniformity (after Stage-2 where needed), nearly half failed dissolution and one-third failed assay, indicating a meaningful risk of inconsistent clinical performance. Strengthened manufacturing controls, risk-based post-market surveillance, and routine compendial testing are warranted to ensure safe, effective, and reliable chloramphenicol capsule products in this market.