Gel-Based Materials for Ophthalmic Drug Delivery

Abstract

The most common route of administration of ophthalmic drugs is the topical route because it is convenient, non-invasive, and accessible to all patients. Unfortunately, drugs administered topically are not able to reach effective concentrations. Moreover, their bioavailability must be improved to decrease the frequency of administrations and their side effects, and to increase their therapeutic efficiency. For this purpose, in recent decades, particular attention has been given to the possibility of developing prolonged-release forms that are able to increase the precorneal residence time and decrease the loss of the drug due to tearing. Among these forms, gel-based materials have been studied as an ideal delivery system because they are an extremely versatile class with numerous prospective applications in ophthalmology. These materials are used in gel eye drops, in situ gelling formulations, intravitreal injections, and therapeutic contact lenses. This review is intended to describe gel-based materials and their main applications in ophthalmology.

Applications of Chitosan-Alginate-Based Nanoparticles—An Up-to-Date Review

“…Nonetheless, the eye is protected by several anatomic and physiological barriers (e.g., blinking, different membraneous layers, blood-retinal barrier, choroidal and conjunctival blood flow, lymphatic clearance, lacrimation) that limit the supply of drugs to affected tissues [71,[89][90][91]. Thus, developing nanocarriers for ocular delivery became necessary for improving drugs bioavailability, controlling drug release, decreasing the frequency of administrations, and increasing therapeutic efficiency [71,92,93].…”

Hybrid thermosensitive-mucoadhesive in situ forming gels for enhanced corneal wound healing effect of L-carnosine

“…In situ gels are suitable for simple and scalable preparation; they offer the convenience of being administered as free-flowing solution eye drops; and converted to gel on the ocular surface. The in-situ gels retain the drug at the elected superficial region and potentially reduce the frequency of administration (Cassano et al., 2021 ). In this respect, poloxamers have tissue penetration enhancing properties that could facilitate hydrophilic drugs like L-carnosine for accessing the corneal lipid barrier.…”

Urinary excretion patterns and potential risks of beta‐blocker ophthalmic drops in sports

“…Besides, the urinary carteolol level of subject C2 (48.9 ng/ml) was very close to the MRL. Previous studies indicated that the use of carbomer gels may increase the elimination half‐life of timolol 24,25 . The similarity of the two participants with urinary timolol levels exceeding the MRL, subjects T1 (349.2 ng/ml) and T3 (299.4 ng/ml), was the concurrent use of carbomer gels.…”