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A Novel Method to Eliminate Preservatives in Eye Drops
Diana Stanton1, Christopher Batich2,3, Gregory Schultz4
11 Department of Chemical Engineering, University of Florida , Gainesville, Florida.
Summary
Preservative-free eye drops may soon be a reality. Immobilized poly diallyldimethylammonium chloride (p-DADMAC) effectively eliminates bacteria and does not negatively impact common eye drop active ingredients, making it a promising preservative alternative.
Area of Science:
- Ophthalmology
- Materials Science
- Microbiology
Background:
- Multidose eye drops require preservatives to maintain sterility.
- Preservatives can cause adverse side effects in ophthalmic applications.
- A novel FDA-cleared gauze dressing utilizes immobilized poly diallyldimethylammonium chloride (p-DADMAC) as an antimicrobial agent with minimal release.
Purpose of the Study:
- To evaluate p-DADMAC-treated gauze as a preservative replacement in multidose eye drop bottles.
- To assess the antimicrobial efficacy of p-DADMAC against bacterial contamination.
- To determine potential interactions between p-DADMAC and common ophthalmic active ingredients (AIs).
Main Methods:
- Inoculation of eye drop bottles with Staphylococcus aureus to test p-DADMAC's microbicidal efficacy.
- High-performance liquid chromatography (HPLC) to analyze the impact of p-DADMAC on timolol and dorzolamide concentrations.
- Assessment of moxifloxacin (Vigamox®) microbicidal activity after exposure to p-DADMAC gauze.
Main Results:
- p-DADMAC-treated gauze effectively eliminated Staphylococcus aureus in all tested samples.
- Timolol and dorzolamide concentrations increased post-exposure, but this effect was mitigated when the p-DADMAC material was presoaked.
- The microbicidal activity of moxifloxacin remained unaffected by p-DADMAC gauze exposure.
Conclusions:
- Immobilized p-DADMAC demonstrates significant microbicidal efficacy.
- p-DADMAC shows minimal detrimental interaction with ophthalmic active ingredients.
- p-DADMAC-treated materials are a viable candidate for replacing traditional preservatives in eye drops.
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