Abstract
Purpose:
The purpose of this study was to test if experimental formulations of sulfadiazine-hyaluronic acid (Sulfa-HA) will cause any adverse ocular events or ocular irritancy in New Zealand white rabbits.
Methods:
The experimental design comprised of both short-term and long-term testing for Sulfa-HA. For short-term testing, a single New Zealand white rabbit was used for each formulation. A baseline examination was followed by single instillation of 0.1 mL Sulfa-HA formulations (1.14% 910 KDa and 2.5% 31 KDa) into the right conjunctival sac (OD). The left eye (OS) remains a control. To confirm the longer term ocular safety of the formulation, three New Zealand white rabbits each for Sulfa-HA (0.4% 910 KDa) and Sulfa-HA (0.4% 31 KDa) were tested. Following a baseline examination, 2-3 instillations per day of 0.1 mL were inserted into the OD conjunctival sac for 7 consecutive days. For both short and long-term testing, observation and ocular scoring were taken at 1, 4, 24, 48, 72 hours following the final instillation of the test formulation. Control and test eyes were observed and graded via slit-lamp according to modified Draize and Hackett-McDonald ocular scoring.
Results:
Short term results of Sulfa-HA showed some peri-limbal redness, however the control eye was either more red or equally as red the test eye. Long term results were also consistent with only very minor peri-limbal ocular redness from the Sulfa-HA test formulations, with average ocular scores of <0.25 OU. Overall, there were no signs of corneal swelling, abnormal ocular secretions, and corneal opacities, changes in the iris or abnormalities in the lens in both short and long-term testing with any of the formulations.
Conclusions:
Very low ocular irritancy was observed in both the short and long term ocular testing for HA-Sulfa formulations.
Keywords: 480 cornea: basic science •
486 cornea: tears/tear film/dry eye •
503 drug toxicity/drug effects