Abstract:
Nanoemulsions facilitate efficient drug delivery through the skin, overcoming the limitations of traditional topical formulations. However, their poor stability, low viscosity, and rapid drug release restrict their application in topical delivery. Nanoemulsions with enhanced stability, modified rheology, and increased viscosity, such as shear-thinning behavior, are well-accepted by patients due to their dosage integrity, controlled drug release properties, and ease of application. For oil-in-water emulsions, these challenges can be addressed by optimizing nanoemulsion formulation and modifying the rheological behavior of the continuous phase with biopolymers without significantly impacting the emulsion properties. Therefore, in this study, olive oil nanoemulsion was formulated and modified with xanthan gum and gum acacia to explore as a potential controlled topical delivery vehicle. Oil-in-water nanoemulsion formulated with the optimized composition of olive oil, tween 80, and water was used as the drug carrier and further modified with natural polysaccharides. The effect of gum on nanoemulsion different physiochemical characteristics, stability, rheology, drug release, and encapsulation efficiency were investigated. Results showed that the developed nanoemulsion behaved as low viscosity Newtonian fluid and released 100% drug within 6 h. Modification with xanthan and gum acacia had significantly improved formulation viscosity, drug encapsulation efficiency (> 85%), and controlled drug release by up to 40% with a release pattern following Korsmeyer–Peppas model. Additionally, xanthan gum modified formulation exhibited shear thinning rheology by forming an extended network in the continuous phase, whereas gum acacia modified formulation behaved as Newtonian fluid at high shear rate (> 200 s-1). Furthermore, xanthan gum modified formulations had improved zeta potential, stability, monodispersity, and hemocompatibility and showed high antibacterial activity against S. aureus than gum acacia modified formulations. These results indicate the higher potential of xanthan gum modified formulation as a topical delivery vehicle. In addition, the skin irritation test confirmed the safety of the developed formulations for topical use. Finally, an in vivo skin penetration test was conducted to assess the distribution and penetration of ciprofloxacin in various layers of the skin. The study found that the highest concentration of the drug was present in the stratum corneum, with drug concentration decreasing in the deeper layers of the skin.