Stability, Bio-functional Nanoemulsion Derived from Thai Herbal for Enhanced Topical Efficacy

The objective of this study was to develop and evaluate a stable nanoemulsion for the treatment of dermatitis using the traditional Thai recipe of Khun Nithets Sukkij, consisting of turmeric, cannabidiol (CBD), and cottonseed oil. Using the cold process cream method, two emulsifiers, Viscolam and Aquamax, were compared using four formulations (Dev#1-Dev#4). The study employed several evaluation methods including accelerated stability testing (Freeze-Thaw cycles), analysis of nanoparticles with a Zeta sizer, chemical integrity with Fourier transform infrared (FTIR) spectroscopy, antimicrobial activity with the agar well diffusion method, antioxidant capacity with the DPPH assay, and in vitro safety with the MTT assay. The experiment resulted in the successful stabilization of a nanoemulsion with an optimal particle size of 162.67 nm, which was highly colloidally stable, as indicated by a zeta potential of -72 to -96 mV. The formulations showed good antimicrobial activity, with maximum inhibition zones against Staphylococcus aureus (16.30 ± 2.73 mm) and Candida albicans (19.17 ± 0.55 mm), but no inhibitory activity against Escherichia coli . The research found that the formulated nanoemulsion, namely, formulation Dev#2, is safe (cell viability>80%), stable, and cost-effective topical formulation that effectively integrates traditional Thai herbal knowledge with modern dermatological applications.