Recent Advances in the Excipients Used for Modified Ocular Drug Delivery

Abstract

In ocular drug delivery, maintaining an efficient concentration of the drug in the target area for a sufficient period of time is a challenging task. There is a pressing need for the development of effective strategies for drug delivery to the eye using recent advances in material sciences and novel approaches to drug delivery. This review summarizes the important aspects of ocular drug delivery and the factors affecting drug absorption in the eye including encapsulating excipients (chitosan, hyaluronic acid, poloxamer, PLGA, PVCL-PVA-PEG, cetalkonium chloride, and gelatin) for modified drug delivery.

Characterization and Evaluation of Rapamycin-Loaded Nano-Micelle Ophthalmic Solution

“…However, the lipophilic and hydrophobic properties of RAPA and the existence of the blood–ocular barrier and corneal barrier greatly limit its clinical application in ophthalmology [ 40 ]. Encapsulation of the hydrophobic drugs into nanoparticles has proven to be an effective strategy for improvement of their solubility, stability, and bioavailability [ 41 , 42 ]. Here, we successfully developed an ophthalmic delivery system for RAPA using PVCL-PVA-PEG, with high encapsulation efficiency, good solubility and stability, and satisfactory bioavailability.…”

Overview of processed excipients in ocular drug delivery: Opportunities so far and bottlenecks

“…Mucins comprise no fewer than 20 anionic O-glycosyl proteins, making up the membrane gel layer that protects the eye surface. Mucins create a glycocalyx layer on the conjunctival and ocular surfaces [ 136 ]. Excipients that provide adherence to this mucous membrane have a long ocular residence duration [ 137 ].…”

“… Byproducts of acidic degradation [ 167 ] Poly(lactic acid) (PLA) Increase viscosity Easy to process, synthesized from natural sources The slow rate of degradation [ 168 ] Poly(orthoester) (POE) Increase viscosity surface erosion degradation not extensively researched for medication delivery applications [ 168 ] Poly(methacrylates) and derivatives (PMMA) Increase viscosity a well-known ocular polymer that is affordable Non-biodegradable [ 122 ] Poly(acrylic acid) PAA Increase viscosity mucoadhesive, highly easily soluble in water breakdown into acidic byproducts [ 126 ] Gelatin Increase viscosity Gelling, emulsifying, plus foaming appearances fairly accessible Inexpensive Not antigenic like collagen Groups may be chemically changed Not for long-tenure drug conveyance arrangements. The low percentage of dilapidation [ 132 ] Collagen Increase viscosity Biocompatible, biodegradable, bioactive, and has a long antiquity of practice in medicine Perils of immunogenicity, varying quality, and animal source issues [ 136 ] Dextran Increase viscosity High biocompatibility It is hard to functionalize. [ 133 ] Chitosan Mucoadhesive Biodegradable Biocompatible Antioxidant that is nontoxic and a...…”