In vitro, ex vivo, and in vivo studies of celecoxib topical platforms for antimicrobial activity and wound healing: a comparative assessment.

Background & rationale: Celecoxib (CXB), with its anti-inflammatory and recently discovered antibacterial activity, especially against sensitive and methicillin-resistant Staphylococcus aureus (MRSA), could be promising in treating local pain, superficial skin infections, wounds and infected wounds. The study aims to develop and compare commercially scalable topical formulations of CXB to explore their antimicrobial and wound-healing potential.

Methods: Carbopol gel, o/w cream, polyethylene glycol (PEG) ointment, and paraffin ointment were selected as the vehicles for the preparation of 3% CXB topical formulations. Appearance, pH, viscosity, spreadability, drug content, stability, in vitro release and permeation, and skin retention studies were performed. Further, antimicrobial assay, in vivo wound-healing and histopathology studies were carried out for each formulation.

Results: The formulations had an acceptable appearance, viscosity, spreadability, and drug content. The drug release at 6h was the highest from gel (2428.8ug/cm²), followed by PEG ointment (2230.1ug/cm²), cream (1897.8ug/cm²), and lastly, the paraffin ointment (1217.2ug/cm²). PEG ointment and gel showed the highest skin permeation, whereas cream and gel were better able to retain the drug in the skin. All the formulations exhibited appreciable zones of inhibition against sensitive and the resistant strains of Staphylococcus aureus. PEG ointment exerted a significantly greater (p < 0.001) wound-healing effect. Accelerated stability studies confirmed good physicochemical stability of the formulations.

Conclusion: PEG ointment, with its optimal drug release profile, skin permeation ability, and greater wound-healing action, can be considered as a promising topical delivery vehicle for CXB. CXB's antimicrobial potential could further aid in the prevention as well as treatment of wound infection.