A lipid Based Carrier for Ocular Delivery of Difluprednate

Abstract

Ocular drug delivery is one of the outmost interesting and motivating administration way that confronts the pharmaceutical scientists. The systemic and topical routes are engaged for ophthalmic drug delivery, though both have significant restrictions. Intravitreal drug administration is an invasive route often used with the aim to reach the site of action; however it may be associated with numerous disorders such as endophthalmitis, vitreous hemorrhage and retinal detachment particularly when applied recurrently. Therefore this technique should not be employed except for special therapeutic indications. For the systemic route, penetration of the drugs into the tissues of the eye is extremely limited because, like the brain, the eye is protected by highly restrictive blood-ocular barriers. These barriers have two parts: blood-aqueous barrier (BAB) and blood-retinal barrier (BRB). The BAB, located in the anterior eye segment, is composed of endothelial cells in the uvea restricting the passage of water-soluble drugs from the blood circulation to the aqueous humor, while the BRB is positioned in the posterior chamber and composed of retinal pigment epithelium and the retinal capillaries, hindering the entrance of drug present in blood to the retina. This necessitates high drug concentration in the plasma to be able to reach its site of action increasing the incidence of side effects. Preparation of lipid nanocapsules (LNC) is one of the approaches to formulate drugs that are poorly water-soluble which can be dissolved in the oil core. LNC were prepared by a solvent-free phase inversion method that allows the preparation of very small nanocapsules by thermal manipulation of oil/water emulsified system.