Effect of Hydration on Barrier Performance of Third-Degree Burn Eschar

Infection is the primary source of mortality in bum patients. one of the main treatmentmethods of bum wound infections is topical antimicrobial therapy, in which drugs haveto permeate a dead tissue called eschar. unfortunately, most antimicrobial agents can notpermeate eschar in therapeutic levels. surprisingly, permeation properties of this barrier andeffects of chemical or environmental conditions on it, including hydration level which is thesubject of the present investigation, is not thoroughly studied as yet.here, permeation of silver sulfadiazine (ssd), the most frequently used topical agent inbum management, from its' 0.6 mg/ml solution through human third-degree bum eschar wasstudied in vitro at different hydration levels of fully-hydrated, semi-hydrated and dry eschar.the experiments were performed at 32°c, using franz-type diffution cells. hydration levelwas adjusted by controlling the contact condition of eschar tissue with an aqueous medium.results showed that hydration can severely affect permeation of ssd through the bumeschar. permeation of ssd through fully-hydrated tissue was about 20 times more than that ofsemi-hydrated samples. permeation of ssd through dry eschar was initially (up to 3 h) morethan those of semi- or fully hydrated tissues, but it ceased and reached a plateau at this timepoint, while for the other systems continued and became more than that of the dry eschar atlater stages. the cumulative amount of drug permeated through the fully-hydrated tissue in8 h was about 30 times more than that of the dry eschar.our results showed that hydration can clearly improve permeation of ssd and possiblyother drugs through third-degree bum eschar. a property which could easily change duringpatient management, e.g., by covering, washing, or application of occlusive formulations.