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2020 OMIG Abstract

In vitro Antiviral Activity of Lumify® and Besivance®, Two Benzalkonium Chloride Preserved Eye Drops, Against Severe Acute Respiratory Syndrome-related Coronavirus 2 (SARS-CoV-2)

Kimberly A. Millard, MS, Patrick J. McCormick, PhD
Bausch + Lomb, A Division of Bausch Health Companies, Rochester, NY

Purpose: Benzalkonium chloride (BAK) is a quaternary ammonium compound commonly used as a preservative in ophthalmic topical solutions. The activity of BAK against SARS-CoV-2 (COVID-19 virus) is not well understood. We evaluated the in vitro antiviral activity of brimonidine tartrate ophthalmic solution, 0.025% (Lumify®) and besifloxacin ophthalmic suspension 0.6% (Besivance®), each containing 0.01% BAK, against SARS-CoV-2 using a Vero E6 host-cell system.

Methods: SARS-CoV-2 (strain USA-WA1/2020) cultures were prepared by suspending in Minimal Essential Medium (MEM) with 5% heat inactivated Fetal Bovine Serum (FBS). Time kill testing of SARS-CoV-2 was conducted by multiple dosing of each test formulation at contact times representative of those recommended in the Instructions for Use of each product. All tests were conducted in triplicate and in accordance with ASTM E1052-20, suspension time-kill test for virus, standard practices. Briefly, the initial SARS-CoV-2 suspension was diluted 1:10 with the test formulations for a final concentration of 1x 103.5 – 1 x 104.5 infective units/mL. Following the required contact time, test solutions were neutralized with 10 mL MEM with 10% Newborn Calf Serum, serially diluted, and inoculated onto the Vero E6 host-cell system. Appropriate controls and test samples were incubated with the Vero cells at 36°C ± 2°C, and after four to nine days the presence of residual viable virus was scored. Viral titers, expressed as 50% tissue culture infective dose per mL (TCID50/mL), were calculated using the Spearman-Karber computation, and log10 reductions were determined.

Results: Log10 reductions for brimonidine tartrate 0.025% were >1.80, >2.14, and >2.02 at 8-hour, 24-hour, and 72-hour contact times, respectively; while log10 reductions for besifloxacin were >1.95 at the 24-hour and >2.56 at the 72-hour contact times. These results indicate complete inactivation of SARS-CoV-2 at all contact times.

Conclusion: BAK-preserved brimonidine and besifloxacin eye drops demonstrated in vitro antiviral activity against the SARS-CoV-2. The clinical relevance of these in vitro findings is not known.

Disclosure: E



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