Enhanced skin penetration of 10-hydroxy-2-decenoic acid via anionic polymer formulations and skin hydration modulationOA

Background:The skin barrier function is primarily determined by the stratum corneum(SC),which restricts the penetration of active compounds.Royal jelly(RJ)contains 10-hydroxy-2-decenoic acid(10H2DA),an unsaturated fatty acid with potential cosmetic and therapeutic benefits.However,its penetration through the skin is limited.Objective:This study aimed to develop cosmetic formulations incorporating various polymers to enhance the skin penetration of 10H2DA and to explore the relationship between skin condition and 10H2DA penetration.Materials and methods:Formulations containing anionic cross-linked polymers,specifically acrylates/C10-30 alkyl acrylate crosspolymer and carboxyvinyl polymers,were compared with RJ extracts without excipients.Franz diffusion cells with Strat-M membranes and ex vivo human skin models were used.Liquid chromatography-tandem mass spectrometry was used to analyze 10H2DA permeation,and desorption electrospray ionization(DESI)imaging mass spectrometry(IMS)was used to confirm penetration depth.Clinical evaluations were performed using tape stripping in healthy participants to assess the relationship between skin hydration and 10H2DA penetration.Results:The formulation with anionic cross-linked polymers increased 10H2DA permeation by more than tenfold compared with the control.DESI-IMS confirmed 10H2DA penetration into the epidermis beyond the SC.A strong positive correlation was observed between skin hydration and 10H2DA penetration in the clinical tapestripping study.Conclusion:These findings suggest that both the formulation strategy and condition of the skin critically influence the dermal penetration of low-molecular-weight amphiphilic compounds such as 10H2DA.This approach may serve as an effective strategy for enhancing transdermal drug delivery in cosmetic and therapeutic applications.