An Innovative Topical Drug Formulation for Wound Healing and Infection Treatment: In vitro and in vivo Investigations of a Povidone-Iodine Liposome Hydrogel

BACKGROUND: In topical wound treatment, the combination of anti-infectious therapy and a healing-promoting moisturization has not been accomplished yet. OBJECTIVE: Evaluation of a new topical drug consisting of a povidone-iodine (PVP-I) liposome hydrogel allowing for both antiseptic and moist treatment. METHODS: Pharmaceutical formulation of a complex of PVP-I (3%) and phosphatidylcholine in a hydrogel. In vitro, interaction of the complex with relevant micro-organisms was analysed by electron microscopy. Antimicrobial activity was investigated using Staphylococcus aureus in a suspension test. Tissue toxicity was examined by an explantation test in a rodent model. A randomized clinical study on efficacy and tolerability in wound healing was carried out on 35 patients with mesh grafts in parallel groups (PVP-I liposome hydrogel vs. Bactigras) for proof of concept in humans. RESULTS: A direct interaction of the PVP-I liposomes with micro-organisms by attachment to the cell surface was documented. A significantly better microbicidal activity and tissue tolerability of the PVP-I liposome hydrogel compared to conventional PVP-I formulations was shown. The results of the clinical study, especially measurements of neo-epithelization per time and transplant loss, demonstrate significant differences in favour of the PVP-I liposome hydrogel. CONCLUSION: The novel PVP-I liposome hydrogel combines microbicidal and wound healing activities resulting in enhanced epithelization.