Lipid nanoparticles (SLN, NLC): Overcoming the anatomical and physiological barriers of the eye - Part II - Ocular drug-loaded lipid nanoparticles.

In the recent decades, various controlled delivery systems have been introduced with the aim to improve solubility, stability and bioavailability of poorly absorbed drugs. Among all, lipid nanoparticles gather interesting properties as drug or gene delivery carriers. These systems, composed either of solid lipids (SLN) or of solid and liquid lipids (NLC) stabilized with surfactants, combine the advantages of other colloidal particles such as polymeric nanoparticles, fat emulsions and liposomes avoiding their main disadvantages. Lipid nanoparticles represent an interesting approach for eye drug delivery as they can improve the corneal absorption of drugs enhancing their bioavailability. The Generally Recognized as Safe status of formulation excipients, the scaling-up facilities and the possibility of sterilization, make them suitable for industrial production. In this review, the latest findings, potential applications, and challenges related to the use of lipid nanoparticles for ocular drug delivery are comprehensively discussed.