Aim To prepare triamcinolone-acetonide-acetate (T AA)-loaded solid lipid nanoparticles (SLN) carbomer gel with tripalmitin glycer ide (TPG), and investigate their characteristics and transdermal drug delivery. Methods SLN suspension was prepared by high-pressure homogeni zation technique, and then mixed with carbomer gel matrix to get SLN gel. The mo rphology, particle size with polydispersity index (PI) and zeta potential were e xamined by atomic force microscopy (AFM) and photon correlation spectroscopy (PC S). The entrapment efficiency, stability and in vitro drug release were also studied. The transdermal drug delivery through porcine ear skin was evaluated u sing modified Franz diffusion cells. Results The SLN had a sph erical shape with the average size of (95.5-186.2) nm, the zeta potential of ( -26.3- -15.7) mV and the entrapment efficiency of 67.4%-90.3% for di fferent TAA encapsulated compounds. TAA-SLN carbomer gel had good stability, the releas e profile in vitro fitted Higuchi equation. In comparison with conventional hydrogels, TAA-SLN carbomer gel resulted in higher drug permeation amount and d rug deposition within porcine ear skin after 24 h penetration experiment. Conclusion TAA-SLN carbomer gel is prepared with stable physicochem ical properties. The release profile and improved drug permeation into skin make it be a promising vehicle for transdermal drug delivery.