Abstract
Purpose :
Topically administered therapies remain a standard of care for many ocular diseases. Frequent administration, as well as achieving stable therapeutic levels through the night poses a central challenge for effective maintenance of ocular health. As a result, the need to develop treatments with improved effective durations has gained significant attention. The purpose of this study was to investigate if a limited solubility therapeutic agent like dexamethasone (DEXA) could be efficiently encapsulated in Silica Matrix and demonstrate controlled release with a single 30 µL eye drop for 24 hours.
Methods :
Two DEXA sustained release formulations, #09D and #12D) were tested. Dexamethasone was encapsulated in the Silica Matrix through sol-gel chemistry. New Zealand Rabbits were administered once with a single 30µL eyedrop in each eye. Tear samples were collected using a capillary up to 48 hours post dosing, and analyzed for DEXA by LC-MS/MS analysis from pooled left and right eye tear samples. In vitro DEXA and Si dissolutions were studied in sink condition and cumulative release as well as total dissolution and content was analyzed by spectrophotometry and HPLC. Intra ocular pressure (IOP) was monitored with Tonovet+ device.
Results :
DEXA was successfully encapsulated in both silica microparticle-silica hydrogel formulations. In vivo pharmacokinetic data demonstrated extended controlled release of DEXA in rabbit tear fluid for 24 hours. Treatment was well tolerated and no changes in IOP were detected.
Conclusions :
Efficient encapsulation of low solubility therapeutic agents like DEXA is possible by DelSiTechTM Silica Matrix technology ensuring extended release in-vivo for 24 hours.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.