Enhanced chlorhexidine skin penetration with eucalyptus oil

Chlorhexidine was applied to the surface of donor skin and its penetration and retention under different conditions was evaluated. Skin penetration studies were performed on full-thickness donor human skin using a Franz diffusion cell system. Skin was exposed to 2% (w/v) CHG in various concentrations of eucalyptus oil (EO) and 70% (v/v) isopropyl alcohol (IPA). The concentration of CHG (μg/mg of skin) was determined to a skin depth of 1500 μm by high performance liquid chromatography (HPLC).The 2% (w/v) CHG penetration into the lower layers of skin was significantly enhanced in the presence of EO. Ten percent (v/v) EO in combination with 2% (w/v) CHG in 70% (v/v) IPA significantly increased the amount of CHG which penetrated into the skin within 2 min.The delivery of CHG into the epidermis and dermis can be enhanced by combination with EO, which in turn may improve biocide contact with additional microorganisms present in the skin, thereby enhancing antisepsis.Chlorhexidine (CHG) is a broad spectrum antimicrobial agent widely used for skin antisepsis prior to invasive procedures. However, the efficacy of CHG is reduced in the presence of organic matter and at low pH [1]. Furthermore, CHG, as with other antiseptic preparations exhibits restricted penetration through the skin; our previous studies demonstrate that CHG from aqueous and alcoholic [70% (v/v) isopropyl alcohol (IPA)] solutions poorly penetrate the full thickness skin to the deeper skin layers [2,3]. This limits its efficacy against microorganisms residing in the lower layers of the epidermis and dermis, including hair follicles and sebaceous glands [2-6]. These persisting microorganisms, which include coagulase negative staphylococci, anaerobic bacteria such as Propionibacterium spp., and yeast Candida spp., may subsequently cause infection when the protective skin barrier is breached during surgical procedures [7-10]. These microorganisms may also contaminate invasive medical devices such as intravascula