Nanoparticulate based ocular drug delivery technology: “Nanoemulsion a novel approach”

Abstract

Many ocular diseases or disorders require frequent administration of the drug. But poor ocular bioavailability of drugs (< 1%) from conventional ophthalmic formulations is a serious concern. The epithelial layers protect the eye and consequently limit the penetration of ocular drugs. In order to overcome the shortcomings of the standard form of ophthalmic dosage, much has been done to improve the absorption of pre-corneal drugs and to reduce the loss of pre-corneal drugs. Ophthalmic formulation based on Nanotechnology is one of the approaches to internal and external drug delivery. Nanotechnology systems with the right particle size can be made to ensure minimal irritation, adequate bioavailability, and tissue compatibility. Many of them have shown promising results in improving ocular availability. Nanoemulsions are the colloidal oil in water (o/w) or water in oil (w/o) nano-dispersions and homogenous systems, stabilized by surfactants and co-surfactants to reduce the interfacial tension. Typically, the droplet size is <150 nm. Due to the presence of very narrow size range of droplets, they appear as transparent, homogeneous and thermodynamically stable systems. They offer a high penetration rate into the deeper layers of tissue due to the nano-droplet size range.