The aim of this work was to develop and evaluate solid lipid nanoparticles (SLN) containing all-transretinoic acid (ATRA) for topical delivery. SLN composed of coconut oil and curdlan improved the suspension instability
of ATRA in aqueous solution. The photodegradation of ATRA by light was reduced by incorporation in SLN. The loading efficiency of ATRA in SLN was higher than 95% (w/w). The amounts of ATRA released from SLN at 4 oC and at 37 oC were less than 15% and more than 60% (w/w) for 96 h, respectively. The ATRA-loaded SLN can be used as a potential carrier for topical delivery.