A Bioactive Oleogel Incorporating Chamomile Hydroglyceric Extract: Physicochemical Characterization, Occlusive...

Oleogels have emerged as promising anhydrous semisolid systems for dermato-cosmetic and pharmaceutical applications owing to their improved physicochemical stability, enhanced occlusive properties, reduced dependence on preservatives, and ability to incorporate and deliver both lipophilic and dispersed hydrophilic bioactive compounds. The present study aimed to develop and comprehensively characterize a multifunctional lipid-based oleogel incorporating a Matricaria chamomilla hydroglyceric extract together with sea buckthorn oil and sweet almond oil as natural sources of antioxidant and skin-protective phytoconstituents for potential topical applications. The formulation was prepared by the melt method and comprehensively characterized for its physicochemical, functional, and biological properties. The chamomile extract exhibited a high phenolic content and pronounced antioxidant activity, while HPLC-DAD analysis confirmed the presence of characteristic phenolic acids and flavonoids. The developed oleogel showed good physicochemical stability under accelerated storage conditions, appropriate pH for topical application, favorable spreadability, pseudoplastic flow behavior with a Casson yield stress of 0.19 Pa, and a homogeneous microstructure with a mean droplet size of 5.4 ± 1.1 μm. The formulation also demonstrated pronounced occlusive properties (67.9 ± 0.3% and 56.4 ± 0.2% after 24 and 48 h, respectively), preserved the antioxidant activity of the incorporated phytoconstituents, and provided controlled biphasic release of phenolic compounds, reaching 64.9 ± 5.9% after 24 h in Franz diffusion studies. Furthermore, no cytotoxic effects were observed on HaCaT keratinocytes, confirming the good in vitro biocompatibility of the formulation. Overall, the developed oleogel successfully combined physicochemical stability, preserved antioxidant functionality, controlled phenolic release, pronounced occlusive properties, and biocompatibility, highlighting the potential of anhydrous oleogel systems as multifunctional topical delivery platforms for plant-derived bioactive compounds.