ABSTRACT
The antimicrobial activity of MiraFlow, an extra-strength cleaner containing 20% isopropyl alcohol, was evaluated using various microorganisms including Acanthamoeba. Other leading cleaners, disinfecting solutions and heat were evaluated for comparison. MiraFlow had greater antimicrobial activity than the other cleaning solutions against all five test microorganisms. When evaluated against Acanthamoeba castellanii, MiraFlow was significantly better than disinfecting solutions containing 3% hydrogen peroxide, with D-values of less than 12 seconds and 1 hour, respectively. Thermal disinfection of Acanthamoeba cysts occurred rapidly at temperatures above 60 degrees C. The data suggest that either thermal disinfection or cleaning lenses for 20 seconds with MiraFlow followed by disinfection in an amoebacidal solution such as 3% hydrogen peroxide, should inactivate Acanthamoeba cysts found as chance contaminants on lenses.
Subject(s)
Anti-Infective Agents , Contact Lenses , Disinfection , Sterilization , 1-Propanol/pharmacology , Hot Temperature , Hydrogen Peroxide , Ophthalmic Solutions , Polyethylene Glycols/pharmacology , Polypropylenes/pharmacology , Surface-Active Agents/pharmacologyABSTRACT
This study was designed to assess the microbiological risk associated with using unpreserved saline buffered with either borate or phosphate salts. The results indicate that borate buffer has measurable antimicrobial activity and can control some microbiological contamination. However, phosphate-buffered saline can become easily contaminated and usually promotes growth or maintains viability of adventitious contaminants.
Subject(s)
Bacteria/drug effects , Boric Acids/pharmacology , Phosphates/pharmacology , Sodium Chloride/pharmacology , Animals , Aspergillus/drug effects , Aspergillus/growth & development , Bacteria/growth & development , Buffers/pharmacology , Candida albicans/drug effects , Candida albicans/growth & development , Escherichia coli/drug effects , Escherichia coli/growth & development , Isotonic Solutions , Pseudomonas/drug effects , Pseudomonas/growth & development , Serratia marcescens/drug effects , Serratia marcescens/growth & developmentABSTRACT
A comparison of seven hydrogen peroxide systems for disinfection of contact lenses is presented. Each system differs by the manner in which the remaining peroxide is neutralized after disinfection. These differences are reflected in the total time required by each system, the resulting pH, unreacted peroxide and residual products. The flexibility and potential risks of each system are also discussed.
Subject(s)
Contact Lenses, Extended-Wear , Contact Lenses, Hydrophilic , Disinfectants , Disinfection/methods , Hydrogen Peroxide , Sterilization/methods , Chemical Phenomena , Chemistry , HumansABSTRACT
A minimal salts medium adjusted to physiological pH and osmolality was buffered with either 0.3% phosphate or 1.2% borate and evaluated for antimicrobial activity. The borate-buffered medium, either with or without a carbon source, exhibited significant antimicrobial activity against 15 Pseudomonas strains, 12 strains of enteric bacteria, and 7 strains of staphylococci. The borate-buffered system appears suitable for use as a generic vehicle for ophthalmic pharmaceutical agents.
Subject(s)
Anti-Bacterial Agents , Borates/pharmacology , Buffers , Culture Media , Enterobacteriaceae/drug effects , Pseudomonas/drug effects , Solutions , Staphylococcus/drug effects , Time FactorsABSTRACT
Several chemical disinfecting solutions for soft contact lenses were evaluated according to the tests suggested by FDA in the May 1983 revision of the Microbiological Guidelines. It was experimentally determined that cleaning and rinsing lenses remove 3.5 to 3.9 logs of microorganisms. Furthermore, it was determined that only 3% hydrogen peroxide had a rapid enough disinfection rate to meet the safety factor requirement within four hours as suggested in the "D-value test.' when contaminated lenses were cleaned, rinsed, and disinfected with commercially available solutions, all failed to disinfect the lenses within the minimum time specified on the label. These results were used to recommend significant changes in the Microbiological Guidelines. These changes include (1) limiting the rechallenge requirement during preservative effectiveness testing to only disinfecting solutions, (2) using the death rate kinetic profile of any approved chemical disinfecting solution as a basis for comparison of a new chemical disinfecting solution, and (3) using the results of the multi-item test for any approved chemical disinfecting solution as a basis for comparison of a new, proposed chemical disinfecting solution.
Subject(s)
Contact Lenses, Hydrophilic/standards , Disinfectants/standards , Microbiological Techniques , Humans , Hydrogen Peroxide , SolutionsABSTRACT
The effect of EDTA (ethylenediaminetetraacetate), steroids, and preservatives on the antimicrobial activity of 10% sodium sulfacetamide solutions was evaluated in this study by kill rate and minimum inhibitory concentration (MIC) using five representative microorganisms. The results indicate that thimerosal-preserved sulfacetamide solutions containing EDTA are more effective against Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus epidermidis, and Candida albicans than similar paraben-preserved solutions. Furthermore, the addition of EDTA improves the kill rate, but not the MIC, for the Pseudomonas, Serratia, and Candida species regardless of the preservative. The combination of a steroid with sulfacetamide does not affect its antimicrobial activity.
