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

Abstract 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 °C for the study period and demonstrated a significant increase in curcumin permeation (∼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.