Nanostructured Materials for Ocular delivery: Nanodesign for Enhanced bioadhesion, Transepithelial Permeability and Sustained Delivery

Abstract

Effective drug delivery to the eye is an ongoing challenge due to poor patient compliance coupled with numerous physiological barriers. Eye drops for the front of the eye and ocular injections for the back of the eye are the most prevalent delivery methods, both of which require relatively frequent administration and are burdensome to the patient. Novel drug delivery techniques stand to drastically improve safety, efficacy and patient compliance for ocular therapeutics. Remarkable advances in nanofabrication technologies make the application of nanostructured materials to ocular drug delivery possible. This article focuses on the use of nanostructured materials with nanoporosity or nanotopography for ocular delivery. Specifically, we discuss nanotopography for enhanced bioadhesion and permeation and nanoporous materials for controlled release drug delivery. As examples, application of polymeric nanostructures for greater transepithelial permeability, nanostructured microparticles for enhanced preocular retention time and nanoporous membranes for tuning drug release profile are covered.

Ocular delivery of proteins and peptides: Challenges and novel formulation approaches

“…Yuan and group for the first time demonstrated the sustained release and enhanced corneal permeability of doxycycline-loaded PVA nanowafer over 24 hours in mice. The same group reported the efficacy of such PVA fabricated nanowafer loaded with axitinib for treating CNV in a murine ocular burn model [196, 197]. This smart platform integrating nanofabrication as well as drug delivery technologies has been able to establish itself further by demonstrating sustained delivery of dexamethasone and cysteamine for effective treatment of dry eye disease and corneal cystinosis respectively [198–200].…”

Ultra-small micelles based on polyoxyl 15 hydroxystearate for ocular delivery of myricetin: optimization, in vitro, and in vivo evaluation

“…Many sources of materials, ranging widely from synthetic to natural origins, can be applied as the nanocarrier of micelle eyedrops. However, most of these materials are not authorized pharmaceutical excipients, and the ocular biocompatibility of these materials has been the subject of debate (Kim et al., 2015). Micelle eyedrops fabricated with more biodegradable and biocompatible materials, especially authorized materials, are still desired to address issues of ocular irritation and toxicity.…”

Emerging Novel Nanopharmaceuticals for Drug Delivery

“…Sustained release and increased corneal permeability of nanowafer delivered doxycycline were compared with topical eye drops, increasing corneal residence time from a few minutes to up to 24 h in mice. These results demonstrate the immense scope for utilizing nanoporous materials to surmount the limitations of ocular drug delivery [62].…”