Phospholipid structured microemulsion as effective carrier system with potential in methicillin sensitive Staphylococcus aureus (MSSA) involved burn wound infection

Burn wounds are foremost site for bacterial colonization and multiplication. Staphylococcus aureus is one of the most predominant pathogen found in burn wounds. Fusidic acid (FA) is widely employed in the treatment of complicated skin infections caused by Staphylococcus aureus. Hence, the aim of this study was to investigate the usefulness and efficacy of topical FA (2% w/w) loaded biocompatible microemulsion-based-system (FA-ME) in eradicating MSSA bacterial infections which otherwise was less effective when dealt with conventional formulations. For construction of pseudoternary phase diagram, ratio of oil (IPM):water:S-mix is 20:30:50% w/w and proportion of Smix (Phospholipid: Tween 80 (T80):Ethanol) is in the ratio of 1:2:1, respectively. The hypothesis relates here to the role of phospholipids as part of the nano-scale structure of microemulsion systems to overcome the hurdles of drug delivery. The prepared FA-ME system was evaluated for its therapeutic efficacy and carrier-specific characteristics such as globule size, % transmittance, transmission electron microscopy, drug content and stability. Selected microemulsion system was incorporated into gel form and evaluated for texture analysis, drug permeation in 24 h and treatment of burn wounds. Burn wound infection was established with MSSA ATCC 25923 in BALB/c mice and the process of wound healing as well as bacterial loading in the wound was estimated. The developed nanosized FA-ME system demonstrated improved wound healing, better spreadability and enhanced therapeutic efficacy due to the changes in the behavior of the drug molecules by way of carrier-characteristics.