Alpha-Tocopherol Microcapsules Added with Moringa Oleifera Supercritical CO2 Extract As a Release System for Transdermal Applications

The design of the coacervate systems is proposed to ensure the bioavailability enhancement of cosmetic ingredients, attending to the demand for nourishing, anti-ageing, and, more recently, medical drug-like formulations [1]. Moringa oleifera L. leaf extract (Mo), obtained by supercritical fluid extraction with dioxide carbon (SFE-CO₂), was found to be a suitable candidate for cosmetic uses due to its rich α-tocopherol composition [2].

Built upon developing modelling microencapsulation by complex coacervation (MCC) using Arabic gum and gelatin adaptable to enclose numerous cosmetic ingredients, this study introduces the microencapsulation of Mo combined with α-tocopherol (Mo+α-toc) and α-tocopherol alone (α-toc). The aim is to explore their diffusion into synthetic membranes resembling human skin.

Methodology:

Physicochemical and imaging analyses were applied to the resulting products. Particle size and shape confirmed the morphology of the microcapsules, while the encapsulation efficiency (EE%), loading content (LC%), and solid content (SC%) measured the process viability.

The microcapsules and non-coacervated bioactives were also submitted to diffusion tests in a Franz cell device using synthetic Strat-M transdermal membranes to emulate human skin.

Results:

Imaging analyses depicted spherical delivery systems with a multinucleated morphology featuring bioactives within a porous structure covered by a dense polymeric shell. The average particle size was circa 60 μm. High encapsulation efficiency was confirmed, reaching 93.4±1.3% and 95.1±1.2% for Mo+α-toc and α-toc, respectively, with no significant differences. LC% was 10.0±1.3% and 10.3±1.2%, respectively, in which the load could reach no more than 14%, and SC% were determined within 8.3±0.1% and 8.4±0.5%.

Franz cell studies revealed faster diffusion of bioactive when incorporated in the microcapsules compared to non-coacervated bioactive, with receptor fluid and membrane showing significantly higher α-tocopherol content for microencapsulated forms.

References:

[1]Kessler, J. C., et al. (2023). Separations, 10(3), 210. https://www.mdpi.com/2297-8739/10/3/210

[2]Taofiq, O., et al. (2018). Industrial Crops and Products, 124, 44-52. https://doi.org/https://doi.org/10.1016/j.indcrop.2018.07.057