Flexible Pterostilbene Nanoliposomes for Enhanced Skin Delivery: Elasticity and Brightening Potential

This study aimed to develop a local drug delivery system using pterostilbene (PTS) flexible nanoliposomes (FNL) to overcome its limitations, such as poor water solubility and instability under light and oxygen. The research focused on optimizing deformability and transdermal delivery using dipotassium glycyrrhizinate and a single-chain surfactant as membrane softeners.

The encapsulation process and formulation of PTS FNL were systematically optimized through single-factor and orthogonal experiments. The physicochemical properties, stability, and transdermal performance of the optimized FNL were evaluated using dynamic light scattering, transmission electron microscopy (TEM), Turbiscan stability analysis, and in vitro/in vivo permeation studies.

The optimized PTS FNL exhibited high encapsulation efficiency (96.49 ± 0.7%), a particle size of (60.11 ± 0.54 nm), PDI (0.237), a zeta potential of (-10.16 ± 0.54 mV), and good stability at 4°C and 25°C for three months. TEM confirmed spherical morphology, while in vitro studies demonstrated superior skin retention and prolonged permeation compared to PTS nanoliposomes (NL) and GTCC solutions. In vivo tests on human volunteers revealed that 0.4% PTS FNL cream significantly improved skin elasticity and chromaticity over 28 days without adverse effects.

The enhanced deformability of PTS FNL contributed to its improved transdermal delivery, making it a promising candidate for cosmetic applications. The study highlights the effectiveness of membrane softeners in optimizing liposomal formulations, though long-term stability under varied conditions warrants further investigation.

The developed PTS FNL system significantly enhances skin permeation and stability, demonstrating great potential for cosmetic use in anti-aging and skin-brightening formulations. This approach provides a viable strategy for improving the delivery of poorly soluble active ingredients.