Formulation Optimization on Semi-Solid NLC Dispersions Containing Antioxidant Herbal Oils: A Novel Approach for Cosmeceuticals

Abstract

Skin aging prevention is increasingly important in cosmetics. Topical application of antioxidants protects the skin against reactive oxygen species (ROS) generated as a result of continuous exposure to UV radiation. Herbal oils offer significant anti-aging potential due to their antioxidant content. Lipid nanoparticles (i.e., SLN and NLC) have been comprehensively evaluated for dermal drug delivery and cosmetic applications since they offer enhanced skin hydration and improved percutaneous penetration. The latest approach for dermal application is the usage of semi-solid lipid nanoparticle dispersions, which offer unique advantages. Semi-solid SLN/NLC dispersions have a suitable consistency for dermal application and can be prepared by a one-step production method without additional excipients. Furthermore, they preserve the colloidal particle size in spite of their semi-solid consistency. Development of novel cosmeceutical semi-solid NLC dispersions containing valuable herbal oils such as pomegranate seed, argan, grape seed, and coconut oils was aimed at in this study. Formulation optimization was performed using a modeling program based on response surface methodology (RSM). Optimum semi-solid NLC formulation (Opt-NLC) was prepared using Compritol 888ATO and argan oil at amounts of 0.8403 and 0.5457 g, respectively. The particle size of the Opt-NLC formulation was found to be 188.6 ± 3.58 nm, which falls within the targeted size range. PDI was also reduced and a more uniform particle size was obtained by optimization. Rheological and mechanical characterization results revealed that Opt-NLC has suitable properties in terms of product performance and consumer compliance. As a result, formulation optimization of semi-solid NLC dispersions containing antioxidant herbal oils was successfully performed using RSM methodology.