Antimicrobial efficacy of multi-purpose contact lens disinfectant solutions following evaporation

作者：Kilyington Simon^*; Powell Charles H; Lam Anthony; Lonnen James

来源：Contact Lens and Anterior Eye, 2011, 34(4): 183-187.

DOI：10.1016/j.clae.2011.02.010

• Multi-purpose solutions
• Fusarium
• Candida
• Acanthamoeba
• Disinfection
• Evaporation
• Alexidine
• Le Chatelier's principle

Purpose: Non-compliance is a significant factor in contact lens related microbial keratitis and includes solution reuse and failure to recap the lens storage case resulting in evaporation effects. To address this, impact of partial evaporation on the antimicrobial efficacy of multipurpose contact lens care solutions was investigated.
Methods: Solutions were evaporated under a stream of air to 2x and 4x concentration and challenged with Fusarium solani (ATCC 36031), Candida albicans (ATCC 10231) and Acanthamoeba castellanii (ATCC 50370). The level of organism kill at 6 h was compared to the non-evaporated product.
Results: ReNu with MoistureLoc (R) (RML) lost 90-100% of biocidal activity against C. albicans on evaporation, 75-99% for F. solani and 29-33% with A. castellanii at 2x or 4x concentration, respectively. OPTI-FREE (R) RepleniSH (R) lost 72-90% efficacy against C. albicans and F. solani, and 61% at 2x and 10% at 4 x concentration with A. castellanii. ReNu (R) MultiPlus, AQuify (R) Multi-Purpose and Biotrue (TM) showed only loss in efficacy with C. albicans at 4x concentration giving 79%, 34.5% and 48% reduction, respectively. No loss in biocidal activity on evaporation was obtained with Complete (R) Revitalens for all organisms.
Conclusion: Partial evaporation can affect biocidal efficacy of multi-purpose solutions and may have been a significant factor in an outbreak of Fusarium keratitis cases associated with RML. Evaporation results in increased binding of cationic disinfectants to counter-ions in the formulation, reducing ability to attach and rupture anionic microbial cell walls. Interaction may also occur between the biocidal ingredient and other components, such as surfactants, resulting in sequestration of activity through micelle formation.

• 出版日期2011-8