Peer Review Report For: Quality of povidone-iodine and chlorhexidine-based oral care products in Nairobi, Kenya [version 1; peer review: 1 not approved]

Background: The oral cavity harbors many microbes that may cause diseases, including dental caries and periodontal diseases. Progressive inflammation from periodontal diseases may lead to gum detachment from the teeth. Povidone-iodine and chlorhexidine mouth rinses and gargles are broad-spectrum antimicrobial products that effectively manage dental caries and periodontal diseases and eliminate plaques. This study was conducted in Nairobi County, Kenya to establish the quality of povidone-iodine and chlorhexidine oral care products by determining the content of the active pharmaceutical ingredient and compliance with labeling requirements. Methods: A total of 34 samples (from 15 brands) of povidone-iodine and 15 samples (from nine brands) of chlorhexidine were collected from retail pharmacies using convenience sampling. All samples were subjected to labeling analysis, identity, and assay tests. Potentiometric titration was used to assay povidone-iodine in the samples, while chlorhexidine was assayed using high-performance liquid chromatography (HPLC) according to British Pharmacopeia 2017 specifications. Results: All samples complied with identification tests. Moreover, 47.1% of povidone-iodine and 66.7% of chlorhexidine products complied with pharmacopoeial assay specifications. Five povidone-iodine (14.7%) and four chlorhexidine (26.7%) samples had missing label information on the storage conditions and the address of the manufacturer. Conclusions: Strict adherence to current Good Manufacturing Practices (cGMP) by manufacturers of povidone-iodine and chlorhexidine mouthwashes/gargles is necessary to guarantee quality assured products in the market. Regular post-market surveillance and regulatory enforcement of standards are instrumental in minimizing the circulation of poor-quality products.