Novel Antiseptic Formulations for Skin and Soft Tissue Infections

Skin and soft tissue infections (SSTIs) often refer to acute conditions of inflammatory microbial occupation of the skin layers and underlying soft tissues. As one of the most frequent types of infections, SSTIs typically require medical intervention contributing to morbidity and mortality in both hospitalized patients and those in primary care. The present study aimed to formulate and characterize nanoemulsion as a carrier system to deliver triclosan and chlorhexidine digluconate (CHG) for the purpose of prevention and treatment of SSTIs, by targeting the layers within the skin. Four nanoemulsion formulations were developed successfully using an ultrasonication method. They were stable with a droplet size less than 115 nm along with polydispersity index from 0.15 to 0.41, the pH values in lightly acidic range (4.60-6.80) and the absolute zeta potential values higher than 20 mV. The degree of drug encapsulations ranged from around 77-85%. The result from in vitro permeation experiment exhibited that nanoemulsions made using eucalyptus oil transferred between 2.1 and 6.6 times greater amounts of triclosan through full thickness porcine skin than those formulated using olive oil or triclosan solution. They also lead to more drug being retained within the skin after 24 hours. These findings demonstrated that this nanoemulsion is a promising candidate for topical dermal delivery of a water-insoluble antiseptic agent to the skin. In contrast, although the skin permeation from CHG loaded nanoemulsions was lower than 2% CHG solution, eucalyptus oil nanoemulsion was more effective to withhold CHG in skin than olive oil nanoemulsion and solution, which may be advantageous for localized effect. Further investigations should be conducted to confirm the role of nanoemulsions in delivery of water-soluble antiseptics.