All-trans retinoic acid-loaded lipid nanoparticles as a transdermal drug delivery carrier

The objective of this study was to investigate the effects of drug amounts (0.1%, 0.2% and 0.3% w/w), amounts of the oil (10%, 15% and 20% w/w of lipid matrix) and types of the oil (soybean oil (S), medium chain triglycerides (M), oleic acids (O) and linoleic acids (L)) in lipid matrix of all-trans retinoic acid (ATRA)-loaded nanostructured lipid carriers (NLCs) for transdermal drug delivery. The ATRA-loaded solid lipid nanoparticles (SLNs) were formulated with 30% w/w cetyl palmitate. All lipid nanoparticles had average sizes between 130 and 241 nm and had negative zeta potentials. The drug loading of all formulations was higher than 95%. The release of drug from all lipid nanoparticles followed zero-order kinetics. The amount of drug released from all the NLCs and SLNs was significantly greater than the drug released from the ATRA suspension. The ATRA flux of the SLNs was higher than the NLCs. The flux of the NLCs containing oleic acid was significantly higher than the other types of oils. The chemical stability at 4 °C, the percentage of ATRA remaining in all the lipid nanoparticles tested was higher than 80%. It can be concluded that both the SLNs and NLCs are promising dermal drug delivery systems for ATRA.