Betaine–salicylic acid cocrystal for enhanced skincare and acne treatment

Salicylic acid (SA) is a natural lipophilic active ingredient commonly used in cosmetics and skin disease treatments, offering benefits such as exfoliation, anti-inflammation effects, antibacterial properties, oil control, and acne alleviation. However, its poor water solubility, low bioavailability, and potential side effects, such as allergies, irritation, and dryness, hinder its widespread application. In this study, we prepared a betaine–salicylic acid (BeSA) cocrystal and systematically characterized its crystal structure, biological activity, and clinical efficacy. The results showed that BeSA has significantly lower irritancy and cytotoxicity than SA, but exhibits excellent anti-inflammatory and antioxidant properties as well as high moisturizing and anti-acne efficacy, making it a potential alternative to SA. Further, quantum chemical calculations and molecular docking simulations were conducted to investigate the intrinsic mechanisms underlying the excellent bioactivity of BeSA cocrystals. This study introduces an innovative solution for safer and more effective skincare formulations based on SA and offers theoretical guidance regarding material engineering and further material optimization, which has crucial implications for both industry and academia.