Effect of Squalane as a Carrier in O/W Nanoemulsions for Dermal Delivery of Vitamin E

High Resolution Image Download MS PowerPoint Slide Vitamin E, a potent antioxidant, is widely used in cosmetics to combat skin aging, but its lipophilic nature poses challenges for dermal delivery. Squalane, a biocompatible carrier, may enhance the stability and skin permeation of vitamin E in oil-in-water (O/W) nanoemulsions. O/W nanoemulsions containing vitamin E were formulated using high shear homogenization with varying coconut oil-to-squalane ratios (0:3, 1:2, 2:1, 3:0). Physicochemical properties (particle size, polydispersity index, ζ-potential, pH, conductivity) were characterized. In vitro release kinetics were assessed via dialysis, quantified by HPLC, and skin permeation was evaluated using Franz diffusion cells with porcine ear skin. Nanoemulsions exhibited hydrodynamic diameters of 107.67 ± 7.57 to 134.38 ± 3.15 nm, polydispersity indices of 0.21–0.24, and ζ-potentials of −37.4 ± 0.80 to −45.3 ± 0.90 mV, indicating high stability ( p < 0.05, ANOVA). The encapsulation efficiency for vitamin E was >99% across all formulations. These properties were maintained over 90 days of storage at 25 ± 1 °C in the dark, with no significant changes in diameter, PDI, or ζ-potential ( p > 0.05, ANOVA). Accelerated stability tests (centrifugation, thermal stress up to 80 °C) confirmed robustness, with minimal changes in key parameters. The V.E 0:3 formulation (pure squalane) showed the highest vitamin E release (0.341 h –1, Korsmeyer-Peppas model, R 2 = 0.993) and skin permeation (164.71 ± 10.06 μg cm –2 over 24 h, p < 0.05), significantly outperforming coconut oil-rich formulations (V.E 3:0:11.72 ± 12.41 μg cm –2 ). Steady-state flux (Jss) for V.E 0:3 was 35.1 ± 1.4 μg cm –2 h –1, compared to 0.1 ± 0.2 μg cm –2 h –1 for V.E 3:0 ( p < 0.05). Squalane-based O/W nanoemulsions significantly enhance the stability and dermal delivery of vitamin E, with the V.E 0:3 formulation demonstrating superior release kinetics and skin permeation. These findings support the potential of squalane-based nanoemulsions for effective topical delivery in cosmetic applications, warranting further in vivo studies to confirm efficacy and safety.