Size and Vitamin E Release of Nanostructured Lipid Carriers with Different Liquid Lipids, Surfactants and Preparation Methods

Abstract

Solid lipid nanoparticles have excellent properties as delivery systems for dermal cosmetic and pharmaceutical formulations because they have good compatibility with the skin, protect the encapsulated substance from the medium, and control its release at the site of action. This work describes the preparation and characterization of nanostructured lipid carriers (NLC) containing vitamin E (NLC‐VE). The emulsion‐solidification technique was used to prepare the particles. Three non‐ionic surfactants (Tween 80, Cremophor RH40 and Pluronic F‐127) were used in two concentrations (5 and 10% (w/w)) and three liquid lipids (avocado oil, coconut oil and medium chain triglycerides (MCT)) were mixed with the solid lipid (stearic acid) to form the oil phase. Some processing variables (emulsification procedure, and time and energy during sonication) were modified to find the most suitable NLC in terms of particle size and release profile. Higher surfactant concentration produced more homogeneous nanoparticles with smaller diameter. The liquid lipid and its proportion in the oil phase also modified the characteristics of NLC‐VE. Time and sonication energy did not strongly affect the particle size (24–28 nm), with the exception of the highest time and amplitude, which produced particles with 14 nm. NLC‐VE prepared with stearic acid as solid lipid, 10% (w/w) Tween 80 as surfactant, and MCT as liquid lipid in a 1:3 mass proportion of solid lipid‐to‐liquid lipid, had a unimodal size distribution and the best vitamin E release (50% in 24 h). Results indicate that this system can be used to improve the delivery of vitamin E.