Fabrication and Characterization of Azadirachta indica oil Induced Nanoemulgel Using 33 Central Composite Design (CCD): Assessment of Antibacterial Activity

Background: In this study, neem oil's therapeutic potential against bacterial inflammations is explored through nanoemulsion technology. Despite its historical significance in traditional medicine, neem oil formulations face challenges such as limited stability and poor solubility. Nanoemulsions offer a promising solution by enhancing neem oil's efficacy, stability, and patient acceptability. Utilizing Response Surface Methodology (RSM), specifically Central Composite Design (CCD), enables systematic optimization of nanoemulsion formulations, enhancing their therapeutic potential. Materials and Methods: In this research, the Central Composite Design was instrumental in fine-tuning parameters like the concentration of surfactant (A), speed of homogenization (B), and running time of homogenization (C). These variables were explored across three different levels. Particle size, serving as the dependent variable, was assessed as the response to variations in these independent factors. Mathematical equations and response surface plots were used to understand the relation between the factors influencing the outcome and the resulting dependent variable. Results: The optimized CCD model has a particle size of 97.9 nm, a zeta potential of -21.0 mV, and a PDI value of 0.512. Carbopol 934 was utilized in formulating the nanoemulgel. The observed responses closely resembled the anticipated outcomes from the optimized process. Morphological analysis and in vitro release studies were employed to characterize the prepared nanoemulgel formulation. Conclusion: The Response Surface Methodology facilitates the formulation of neem oil emulsion with the smallest droplet size possible. Furthermore, the nanoemulgel exhibited significant antibacterial activity against Staphylococcus aureus (S. aureus).