Topically Delivered Minocycline Penetrates a Full-Thickness Burn Eschar and Reduces Tissue Bacterial Counts.

Abstract

Injuries to the skin are often complicated by invasive infections. Standard treatment with intravenous antibiotics has limited tissue penetration and sometimes, major systemic toxicity. Traditional topical delivery of antimicrobials also has limited effectiveness and duration of action. We demonstrate the use of a new Platform Wound Device (PWD) for delivery of topical, ultrahigh concentrations of minocycline as well as lidocaine onto the burn eschar and on the surface of excisional wounds in a total of 56 burn wounds and 24 excisional wounds in a porcine model. Wounds were created on day 0, debrided on day 3, and pigs were killed on day 7. After 3 days of PWD with minocycline treatment, bacterial count was 5.44 log CFU/g in dorsal wound tissue inoculated with methicillin-resistant Staphylococcus aureus, less than that after treatment with silver sulfadiazine cream (7.64 log CFU/g). Pain was also relieved or eliminated in burn wounds and full-thickness excisional wounds when lidocaine was delivered by the PWD. The results demonstrate that ultrahigh concentrations of antibiotics can be delivered effectively by the PWD, and will accelerate wound bed preparation.