Solid lipid nanoparticles loaded thermoresponsive pluronic–xanthan gum hydrogel as a transdermal delivery system

The aim of this study was to develop and investigate thermoresponsive hydrogel incorporating curcumin (Cur) for application as a transdermal delivery system. Cur was encapsulated within solid lipid nanoparticles via ultrasonic homogenization, and these were introduced into a thermoresponsive hydrogel composed of pluronic F68 (PF68) and F127 (PF127). The hydrogel composed of PF68 and PF127 in 10:90 ratio transformed from sol to gel at 29.3 °C close to skin temperature. The skin adhesiveness and adhesive strength of the hydrogel with 0.2% (w/w) of XG was 1.64 and 1.24 times higher than those of the hydrogel without XG, respectively. The physiochemical characteristics of prepared formulations were investigated via observation of particle size, polydispersity index, transmission electron microscopy, and scanning electron microscopy. Moreover, Fourier transform infrared spectroscopy analysis was performed at physiological temperature, which revealed lower hydrogen bonding intensity at gel phase than at sol phase. The cumulative amount of Cur that penetrated significantly increased compared with the Cur ethanol solution.