Triptolide-Loaded Solid Lipid Nanogel: Preparation and In-Vitro Evaluation

In order to topically deliver triptolide (TPL), we sought to develop and characterize solid lipid nano-particles based gel (SLNs-gel) before we investigated its inhibitory activity on HaCaT cells. Preparation of TPL-loaded SLNs (TPL-SLNs) was performed with a method involving melt-emulsion ultra-sonication and solidification at low temperature. The determined characteristics of TPL-SLNs were particle size (PS), encapsulation efficiency (EE), zeta potential (ZP), microscopic mor phology and release of TPL In-Vitro. After TPL-SLNs have been formulated into gel, we used the Franz diffusion cell method to evaluate the skin permeation and penetration characteristics of TPL-SLNs-gel on rat’s skin. Imaging results showed that particles of TPL-SLNs were homogeneous and well-dispersed. Meanwhile, the PS and ZP of TPL-SLNs were 89.21 ± 9.68 nm and −41.3 ± 6.23 mV, respectively, with EE being 89.3%. Also, we observed a significant improvement in pattern of In-Vitro TPL release from TPL-SLNs compared to free TPL. Furthermore, the cumulative penetration of TPL-SLNs-gel was higher (5.28 times) compared to free TPL. Besides, TPL-SLNs-gel demonstrated substantial higher cytostatic activity on HaCaT cells comparable to both free TPL and TPL-SLNs. Altogether, it is evident that a delivery system like SLNs-gel can potentially increase the transdermal bioavailability of TPL for effective inhibition of proliferous HaCaT cells