Retardation of wound healing by silver sulfadiazine is reversed by Aloe vera and nystatin

Inhibition of wound contraction by topical anti microbial agents has been described. The purpose of this study was to further investigate that phenomenon and to explore the effect that other agents such as Aloe vera might have on this process. Full-thickness excised wounds were created on the dorsum of Sprague-Dawley rats under anaesthesia. The wounds were treated with topical agents three times daily for fourteen days, then observed until healed. Groups were: saline control, placebo (aqueous cream) control, silver sulphadiazine (SSD) cream 1%, SSD 0.5%, SSD 1% with Aloe vera, SSD 1% with nystatin, nystatin. Wound surface areas were measured each three days. Time to 50% and 90% healing was compared using ANOVA. Wound half-life and healing times were shortest in the SSD/Aloe vera and nystatin groups (P<0.05) and longest in the 1% SSD and saline control groups. The placebo group (aqueous cream) healed in a significantly shorter time (P<0.05) than the control (saline) group. Wound contraction was delayed by saline and SSD. Nystatin and Aloe vera, when added to SSD, reversed that effect. These data suggest that a dry wound (saline) heals slowly. Infection control without delay of wound healing is most appealing and clinical trials are planned.