Abstract
Purpose:
The safety and tolerability of a proprietary, cross-linked, biodegradable hyaluronic acid (CMHA)-based polymer being developed as a dry eye and corneal repair therapy was evaluated in a 28-day rabbit study.
Methods:
Male and Female New Zealand white rabbit eyes were dosed via bilateral topical dosing six times per day using two concentrations (0.4% and 0.75%) of the CMHA (SentrX, UT) for 28 days. A subset of animals was observed for an additional 14 days after the final dose of the test article. Slit-lamp biomicroscopy and indirect ophthalmoscopy were performed at baseline and at Days 7, 14, 21, 28, 35 and 42. The examinations utilized the McDonald-Shadduck scoring system and were performed by a board certified veterinary ophthalmologist. Representative photographs were taken at various exam time points. IOP was performed at baseline, immediately prior to dosing, and prior to termination. Complete blood count, clinical chemistry, and coagulation factor testing was performed for all animals in the study prior to dosing and prior to necropsy. Urine was collected at the time of necropsy for urinalysis. Blood was collected at baseline (pre-dose) and at 28 days prior to termination for clinical chemistry. Eye globes were enucleated and adnexa collected from each animal and preserved for histopathology analysis. Gross necropsy was conducted and main organs collected and stored for future histopathology analysis.
Results:
The compound was safe and well tolerated. Animals exhibited a lack of clinical anomalies, with the exception of some mild conjunctival congestion in a minimal number of animals. No effect on the IOP was observed during the course of the study. In addition, clinical pathology values were within normal ranges.
Conclusions:
Variations of this novel CMHA polymer have previously been shown to be efficacious in promoting ocular wound healing and to act as a potential ocular drug delivery vehicle for small and large molecules. This study establishes the ocular tolerability and safety of one version of the polymer.