Abstract
Purpose :
To evaluate the antiseptic activity of MDV-0911 I/D by means of time-killing and lag of regrowth assays.
Methods :
In vitro assays were performed on MDV-0911 I/D (eye drops formulation based on 0.66% povidone iodine), on its vehicle (negative control) and on the vehicle containing well-known antibiotic, antimycotic and antiviral drugs (positive controls). Antibacterial and antifungal efficacies were tested through the time-kill and lag of regrowth assays on 10 bacterial and 5 fungal strains. Killing rate evaluation was conducted over a time-period from 10s to 12h. Lag of bacterial regrowth was evaluated after a contact time of 2 and 60 min, followed by a neutralization-dilution step and viable counting. Bacterial and fungal counting were performed at time 0 and at regular interval times of 2 hours, up to 8 hours. Antiviral activity was tested by the time-kill and growth curve kinetics assays on 6 viral strains. Killing rate was evaluated over a time period from 5s to 12h by means of reduction factors (log) between the logarithmic titre of the virus control and the logarithmic titre of the test organisms. Growth curve kinetics were evaluated after a contact time of 2 and 60 min followed by a neutralization-dilution step and cell viability assay. Viral titre was performed at constant interval times from 3 hours up to 24 hours.
Results :
MDV-0911 I/D showed an immediate and complete inhibitory effect at the earliest time-point examined with at least 99.9% reduction (corresponding to ≥3 Log10 and ≥5 Log10 reduction in bacterial and fungal colony numbers respectively, compared to the negative control; ≥3 Log10 reduction in virus titre compared to initial inoculum) at each time point. In the lag of regrowth assay, MDV-0911 I/D induced a rapid (as early as 2 min of contact time), immediate (at the T0), complete (≥99.999%) and sustained (greater than 8 hours) suppression of microbial regrowth in all tested pathogens. Moreover, MDV-0911 I/D induced much superior growth inhibition at all time-points examined vs vehicle and vs positive control. Likewise, its inhibitory effects, evaluated through the growth-curve kinetics assay, were much more pronounced.
Conclusions :
MDV-0911 I/D has a strong antiseptic activity against all of the 10 bacterial, 5 fungal, and 6 viral strains tested in this study, stronger than vehicle, antibiotics, antivirals and antimycotics tested in the study.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.