Curcumin-loaded Nanostructured Lipid Carriers for ocular drug delivery: Design optimization and characterization

The current study sought to formulate, optimize, and evaluate curcumin-loaded Nanostructured Lipid Carriers (NLCs) for their in vitro and ex vivo characteristics. NLCs, prepared using hot-melt emulsification and ultrasonication techniques, were optimized using a Central Composite Design (CCD) and evaluated for their in vitro physicochemical characteristics. Their stability over a 3 month period and transcorneal permeation across excised rabbit corneas (ex vivo) were assessed for the optimized NLCs. The optimized NLC, with a particle size of 66.8 +/- 2 nm, polydispersity index of 0.17 +/- 0.05, entrapment efficiency of 96 +/- 1.6%, and drug loading of 3.1 +/- 0.05% w/w, was chosen using CCD. The optimized NLCs showed optimum ex vivo stability at 4 degrees C for the study period and demonstrated a significant increase in curcumin permeation (similar to 2.5-fold) across the rabbit cornea in comparison to the control. Overall, these studies indicated the successful development of NLCs using the design of experiment approach; the formulation enhanced curcumin permeation across excised corneas and did not show any harmful side effects.