Novel Microemulsion Containing Benzocaine and Fusidic Acid Simultaneously: Formulation, Characterization, and In...

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Wound Healing Technologies

Background:

• Low water solubility of active pharmaceutical ingredients often limits their efficacy in topical formulations.
• Microemulsions offer enhanced drug permeation and localization due to small droplet sizes and high surface areas.
• Combining antibacterial and anesthetic agents in a single formulation can improve wound management.

Purpose of the Study:

• To formulate and characterize a novel microemulsion containing fusidic acid (FA) and benzocaine (BNZ) for wound healing.
• To evaluate the in vitro drug release, ex vivo drug permeation, and in vitro wound healing activity of the developed microemulsion.
• To compare the performance of the microemulsion against conventional formulations like Fucidin cream and an oily benzocaine solution.

Main Methods:

• Microemulsion formulation preparation and characterization (viscosity, droplet size, zeta potential).
• In vitro release studies for both FA and BNZ from the microemulsion and control formulations.
• Ex vivo skin permeation and accumulation studies.
• In vitro wound healing assays to assess the biological activity.

Main Results:

• The developed microemulsion exhibited a stable structure with a zeta potential of -3.014 ± 1.265 mV and a droplet size of 19.388 ± 0.480 nm.
• Fusidic acid release from the microemulsion was significantly higher than from Fucidin cream (p < 0.001), while benzocaine release was comparable to the oily solution (p > 0.05).
• The microemulsion showed lower ex vivo permeation but higher drug accumulation for both FA and BNZ compared to controls, and demonstrated dose-dependent in vitro wound healing activity.

Conclusions:

• The FA- and BNZ-loaded microemulsion is a promising single-formulation strategy for wound healing, particularly for poorly water-soluble drugs.
• The formulation enhances the release of fusidic acid and achieves higher drug accumulation at the wound site.
• The developed microemulsion presents a novel approach to improve the efficacy of combined antibacterial and anesthetic therapies in wound management.