Development and clinical evaluation of a supramolecular acid-enzyme complex for skin exfoliation, sebum control, and pore refinement

Enzyme fragility remains a major challenge in research and applications. Free enzymes are highly unstable, inactivated by heat, acid, alkali, or organic solvents, and often lose activity even under optimal storage conditions. Limiting their use in cosmetics. Few commercial products combine acids and enzymes effectively. To investigate the physicochemical properties, in vitro exfoliation efficacy, and effects on facial skin parameters of a supramolecular acid-enzyme complex (SAE) composed of mandelic acid (MAN), betaine (BET), and composite enzymes (CE; papain and bromelain), thereby establishing a theoretical foundation for cosmetic applications. The supramolecular structure was characterized using Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (¹H-NMR) spectroscopy. Dissolution experiments were conducted to compare the solubility of SAE and CE in aqueous solutions. Enzymatic activity assays evaluated the stabilizing effect of supramolecular deep eutectic technology on enzymes. In vitro exfoliation tests assessed acid-enzyme synergy in keratin removal. A 4-week clinical trial evaluated the efficacy of a 2% SAE essence aqueous solution on facial skin parameters. Dissolution experiments confirmed that supramolecular deep eutectic technology significantly improved enzyme solubility. Enzymatic activity tests demonstrated that this technology effectively preserved protease activity, substantially enhancing its practical applicability. Furthermore, in vitro exfoliation efficacy tests revealed that this technology strengthened the synergistic interaction between acids and enzymes, and exhibited superior stratum corneum-removing capability of the SAE. In clinical evaluations of efficacy, after 7 days of using the essence containing SAE, the formulation significantly enhanced cheek gloss (+8.08%), while reducing comedones volume(-16.25%). after 28 days, significantly enhanced cheek hydration (+25.0%, SCH), gloss (+15.93%), and smoothness (−7.78% SEsm), while reducing TEWL (−6.86%), sebum (−15.54%), roughness (+16.24% SEr), and pore metrics (volume: −39.98%; count: −30.64%), and decreased comedones (Blackheads: −70.33%; Whiteheads: −52.42%; all p <0.05). The supramolecular acid-enzyme complex demonstrates enhanced stability, improved solubility, and superior exfoliation efficacy compared to free enzymes. Clinical results further confirm its multifunctional benefits including enhancing skin hydration, sebum regulation, barrier repair, pore refinement, and comedolytic effects. This study provides both theoretical and practical foundations for developing stable acid-enzyme combinations in dermatological applications.