The In Vitro Evaluation of Povidone-Iodine Against Multiple Ocular Adenoviral Types

Abstract

Abstract

Purpose:

Povidone-iodine (P-I) is being touted as a topical antiviral treatment for eye infections caused by adenovirus (Ad). This study evaluated the in vitro antiviral activity of the several P-I concentrations previously used in clinical studies against multiple ocular Ad types commonly associated with eye infections.

Methods:

The antiviral activity of four concentrations of P-I was compared to vehicle for seven types of Ad after incubating the P-I with Ad at 33°C for various lengths of time. Following incubation and neutralization of the P-I with sodium thiosulfate, viral titers were determined for each Ad type and time point.

Results:

Virucidal (99.9%, ≥3-Log₁₀) reductions in titers were produced for 5%, 2%, and 0.4% P-I at 1 min for types Ad5 and Ad7a. Similar reductions were produced at 5 min for types Ad3, Ad4, and Ad8. For type Ad19/64, virucidal reductions took 60 min for 5% P-I and 15 min for 2% and 0.4%. For type Ad37, 60 min (5%), 15 min (2%), and 5 min (0.4%) were required to produce virucidal reductions. There were no virucidal reductions in titers produced by 0.001% P-I.

Conclusions:

P-I produced greater than 3-Log₁₀ reductions of titers at 1–5 min for most of the ocular types tested (types Ad3, Ad4, Ad5, Ad7a, and Ad8). However, it took longer (15–60 min) for these reductions to be produced for types Ad19/64 and Ad37. The antiviral activity of P-I may be Ad type dependent.