Development and Optimization of <i>Kunzea ericoides</i> Nanoemulgel Using a Quality by Design Approach for Transdermal Anti-Inflammatory Therapy

This study investigates the Quality by Design-driven development and optimization of a nanoemulgel incorporating Kunzea ericoides oil for transdermal therapy. Nanoemulgels enhance percutaneous drug delivery, sustain release profiles, and improve bioavailability. A Central Composite Design was employed to optimize critical formulation parameters, with ANOVA confirming a statistically significant impact on particle size and drug release kinetics (p &amp;lt; 0.05). The optimized formulation exhibited a particle size of 112.38 nm, a polydispersity index of 0.203, and a zeta potential of -29.0 mV, ensuring colloidal stability. In vitro drug release followed the Higuchi model (R² = 0.989, kH = 4.776), indicating diffusion-controlled kinetics, while the Korsmeyer-Peppas model (n = 0.88) suggested an anomalous transport mechanism. Antibacterial studies determined minimum inhibitory concentrations of 250 µg/mL for Staphylococcus aureus and 500 µg/mL for Escherichia coli, indicating greater susceptibility in S. aureus. In vivo anti-inflammatory evaluation using a carrageenan-induced paw edema model demonstrated a statistically significant reduction in inflammation (p = 0.005 at 60 min), with near-complete resolution by 240 min. These findings underscore the potential of Kunzea ericoides nanoemulgel as a promising transdermal therapeutic, integrating controlled drug release with potent anti-inflammatory and antibacterial properties for dermatological and inflammatory conditions.