Abstract
Purpose:
One of the leading causes for blindness among the elderly is glaucoma. Among leading standards of care for glaucoma treatment are prostaglandin eye-drops, administered once daily. However, treatment is confounded by lack of patient compliance, inefficient placement of drops and losses of ~90% of the dosage to drainage by the tear duct. We present feasibility data of a novel, preservative-free, self-administered, Travoprost-containing sustained release, nanoengineered product that can be placed in the conjunctival cul de sac by the patient, every 30 days.
Methods:
Appropriately-sized drug-containing nanoengineered matrices were prepared using a combination of proprietary process conditions and blends of PLG/ hydrophilic polymers. Formulations varied in composition, end groups and amount and type of amphiphilic co-excipient. Travoprost-containing matrices were analyzed as followes: content (µg/mg device) by HPLC, integrity of encapsulated drug (HPLC), microstructure (SEM), in-vitro release studies at 37°C, pH 7.4 using a flow-through system and rate of hydration model developed in-house.
Results:
Travoprost-containing dry nano-matrices contained 39-100 µg of intact drug per device, with >90% encapsulation efficiency. Ester-end group PLGA combined with hydrophilic polymers provided a flexible, biodegradable matrix. SEM of the matrices showed a fine nanostructure, with interconnecting pores, suitable for rapid water uptake into a flexible hydrogel, post-placement. The prototypes released Travoprost in-vitro at 37°C at a rate of 0.8-3.5 µg per day, at 65% released in 2 weeks. The nanomatrix remained flexible and hydrated throughout the study, with its hydrated flexural modulus similiar to that of ocular conjunctiva. The nanomatrix was assessed for the rate of water update and its hydration into a hydrogel. By visual assessment, the dry, flexible nanomatrix absorbed water in approximately 30 seconds to become a tissue-conforming, adherent hydrogel.
Conclusions:
The data demonstrates the the feasibility of a non-invasive, preservative-free, self-administered Travaprost-containing 30-Day sustained release, biodegradable dosage form. This novel product addresses a vital clinical need and has the potential to transform drug administration for both ocular surface disorders and intraocular diseases. The sterile product is placed in the conjunctival cul de sac with an applicator.