Tanshinone IIA and quercetin loaded nanoemulsion-thermogel composite system for enhanced acne management: In-vitro/ in-vivo evaluation

The combination of Tanshinone IIA (Tan IIA) and quercetin (QU) demonstrates therapeutic potential for acne treatment. However, their poor water solubility and limited epidermal permeation hinder their effective deposition and delivery within the skin. A novel composite system, referred to as TQ hydrogel, was developed to co-deliver Tan IIA and QU. This system integrated nanoemulsion and thermosensitive gels. The nanoemulsion formulation was optimized through pseudo-ternary phase diagram. The TQ hydrogel was prepared by incorporating a poloxamer-based matrix with the drug-loaded nanoemulsion. The morphology, in vitro drug release profiles, antioxidant capabilities, and antimicrobial efficiency of the TQ hydrogel were assessed. Furthermore, the in vivo anti-acne effects and underlying mechanisms of the TQ hydrogel were evaluated. The prepared nanoemulsion were spherical in shape with a mean particle size of 60 nm and zeta potential was about −8.12 mV. The TQ hydrogel exhibited temperature-triggered sol-gel transition at 30.4 °C. The cumulative release of QU and Tan IIA from TQ hydrogel was 88.69 % and 17.61 % for 24 h, respectively. TQ hydrogel displayed notable antioxidant activity and bactericidal properties. In vivo , TQ hydrogel significantly ameliorated the inflammatory microenvironment of acne tissues, suppressed the expression of androgen receptors (AR), and showed promising potential in reducing acne-induced scarring. TQ hydrogel, as a co-delivery carrier integrating nanoemulsion and thermosensitive gels, represented an ideal platform for acne treatment.