Comprehensive analysis of salicylic acid-derivatized alginate: Synthesis, characterization, and anti-acne potential.

Salicylic acid (SA) is commonly utilized in the early treatment of acne due to its therapeutic efficacy. However, its clinical performance is hindered by limited aqueous solubility, stability and potential for irritation. This study addresses these challenges through deriving SA with alginate (SA-g-Alg) based on a complementary advantages strategy, designed to retain the bioactivity of SA while mitigating its drawbacks. A comprehensive investigation into the structure, physiochemical properties and anti-acne bioactivities of SA-g-Alg was conducted. The results demonstrate that SA-g-Alg achieved a 30-fold higher aqueous stability compared to free SA, along with enhanced moisturizing capacity and reduced cytotoxicity and skin irritation. These enhancements were attributed to the multi-hydroxy and inherent high biocompatibility of alginate. It is noteworthy that SA-g-Alg, with a grafting degree of 24.9 %, exhibited a synergistic effect, as evidenced by its superior lipid regulating ability, comparable antibacterial efficacy and prolonged anti-inflammatory bioavtivity compared to equivalent salicylic acid group in free SA. Moreover, in vivo studies employing a rabbit ear acne model show that a 2 % SA-g-Alg formulation was as effective as a clinical established 2 % SA ointment in therapeutic management of acne. In conclusion, this study underscores the enhanced physiochemical and anti-acne properties of SA-g-Alg, highlighting its potential as a promising therapeutic agent for the treatment of mild to moderate acne.