Preparation, optimization, and transcorneal permeability study of lutein-loaded solid lipid nanoparticles

Abstract

Abstract To improve the stability and corneal permeability of unstable poorly biocompatible lutein, lutein solid lipid nanoparticles (Lutein-SLNs) were prepared using ultrasonic assisted emulsion evaporation-low temperature curing method and optimized by response surface methodology (RSM). The properties of Lutein-SLNs were evaluated in terms of these encapsulation efficiency, particle size, zeta potential, transmission electron morphology (TEM), and corneal permeability in vitro. The stability and in vitro release behavior of the nanoparticles were also investigated. The optimal formulation was drug: glyceryl monostearate (GM): lecithin high potency (LHP): poloxamer-188 (P-188) = 1: 3.75: 1.78: 2.58 (w/w/w/w), which resulted in particle size, polydispersity index (PDI), encapsulation efficiency and zeta potential of 118.50 ± 1.02 nm, 0.136 ± 0.017, 94.43 ± 1.08 % and -25.84 ± 2.45 mV, respectively. Specifically, compared with free lutein, the stability of the Lutein-SLNs against heat, light and oxygen were improved by 4.42-fold, 3.41-fold and 3.21-fold, respectively. Finally, the in vitro release studies revealed that Lutein-SLNs had a good sustained release effect, and in permeation study the apparent permeability coefficient (Papp) of Lutein-SLNs was 1.52-fold greater than free lutein. Therefore, the method used in this study for preparing Lutein-SLNs was an efficient approach, and Lutein-SLNs could increase the transcorneal flux, improve the stability of lutein, and serve as an effective ophthalmic drug delivery system for lutein.