DOI: https://doi.org/10.55373/mjchem.v27i1.145

Keywords: Antioxidant; astaxanthin; medium-chain triglycerides oil; nanoemulgel; transdermal delivery

Abstract

Astaxanthin (AST), a lipophilic ketocarotenoid derived from seafood and microalgae, exhibits notable potential for skin health and ultraviolet (UV) protection. Its antioxidant properties effectively combat reactive oxygen species (ROS) within the skin layers. However, the oral bioavailability of AST is limited due to its lipophilic nature and poor water solubility. When applied topically, the antioxidant capabilities of AST can counteract oxidative stress and inflammation, contributing to its anti-ageing effects. Nevertheless, penetrating through the stratum corneum remains a challenge. To overcome this, nanoemulsion (NE) and nanoemulgel (NEG) have emerged as promising vehicles for enhancing AST delivery to the skin. This study characterised NE and NEG made from medium-chain triglyceride (MCT) oil and palm kernel oil (PKOlein) by particle size, polydispersity index (PDI), zeta potential, and pH. The mixed oil (MCT and PKOlein at a 1:1 ratio) NE had a smaller particle size (19.18 nm) and better stability (-27.14 mV zeta potential) than the MCT oil NE. However, the NEG formulations showed increased particle sizes, with MCT oil NEG exhibiting better stability (-11.47 mV) than the mixed oil variant. Solubility studies revealed that Tween 80-enhanced formulations significantly improved AST solubility, with phosphate buffer solution (PBS): Tween 80 (98:2) showing the highest solubility (13.255%). Meanwhile, histological studies demonstrated superior skin permeation for MCT oil formulations, attributed to shorter fatty acid chains, while mixed oil formulations exhibited better retention in the dermis layer. In conclusion, MCT oil offers better skin permeation, whereas mixed oil formulations provide sustained dermal retention, suggesting their potential for various topical applications. This research highlights the advantages of using MCT and mixed oil formulations to enhance the delivery and efficacy of active compounds in skincare products.