Recent Progress of Solid Lipid Nanoparticles and Nanostructured Lipid Carriers as Ocular Drug Delivery Platforms

Sufficient ocular bioavailability is often considered a challenge by the researchers, due to the complex structure of the eye and its protective physiological mechanisms. In addition, the low viscosity of the eye drops and the resulting short ocular residence time further contribute to the observed low drug concentration at the target site. Therefore, various drug delivery platforms are being developed to enhance ocular bioavailability, provide controlled and sustained drug release, reduce the number of applications, and maximize therapy outcomes. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) exhibit all these benefits, in addition to being biocompatible, biodegradable, and susceptible to sterilization and scale-up. Furthermore, their successive surface modification contributes to prolonged ocular residence time (by adding cationic compounds), enhanced penetration, and improved performance. The review highlights the salient characteristics of SLNs and NLCs concerning ocular drug delivery, and updates the research progress in this area.

Automated summary

The challenge faced by researchers in achieving sufficient ocular bioavailability is due to the complex structure of the eye and its protective physiological mechanisms. Low viscosity eye drops and short ocular residence time contribute to low drug concentration at the target site. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are being developed as drug delivery platforms to overcome these challenges and enhance ocular bioavailability. They are biocompatible, biodegradable, and can be sterilized and scaled-up. Surface modifications can prolong ocular residence time, enhance penetration, and improve performance.