Microbial contamination of medicines, medical devices, cosmetics, child and personal care products: a comprehensive review of secondary contamination risks in home-use settings

While various compliance with Good Manufacturing Practice and regulations ensures the safety and quality of manufactured products across the supply chain, the transition from controlled environment to home use represents a lurking hazard for microbial contamination, particularly among vulnerable populations. This comprehensive review examines the nature, extent, and clinical significance of microbial contamination in home-use medicines, medical devices, cosmetics, and personal care products, identifying common patterns and prevention strategies across product categories. Literature searches of PubMed, Web of Science, and Google Scholar identified studies examining secondary contamination of consumer-use products applied to skin and mucous membranes. Five categories were analyzed: medicines (eye drops, nasal irrigation devices), medical devices (nebulizers, breast pumps), infant care equipment (feeding bottles, pacifiers), cosmetics (mascara, lipsticks, eyeliners), and personal care products (contact lens cases, toothbrushes). Results showed that contamination rates ranged from 2 to 100% across products despite quality control and stringent regulation oversights. The predominant microbial contaminants were Pseudomonas aeruginosa , Enterobacter spp., Staphylococcus aureus , fungi, and molds. Biofilm formation was ubiquitous across nebulizers, contact lens cases, and feeding equipment, despite reported compliance with manufacturer instructions. Vulnerable individuals, including immunocompromised individuals, neonates, and elderly persons, are exposed to serious risk, including keratitis, respiratory exacerbations, and neonatal sepsis. These findings indicate that post-marketing contamination represents a critical regulatory gap between manufacturing controls and home-use. Addressing this hazard requires integrated strategies, including innovative product designs, antimicrobial surface technologies, standardized evidence-based hygiene protocols, post-market surveillance systems, and targeted public health interventions, accounting for socioeconomic barriers and health literacy disparities.