چكيده لاتين :
Infection is the primary source of mortality in bum patients. One of the main treatment
methods of bum wound infections is topical antimicrobial therapy, in which drugs have
to permeate a dead tissue called eschar. Unfortunately, most antimicrobial agents can not
permeate eschar in therapeutic levels. Surprisingly, permeation properties of this barrier and
effects of chemical or environmental conditions on it, including hydration level which is the
subject of the present investigation, is not thoroughly studied as yet.
Here, permeation of silver sulfadiazine (SSD), the most frequently used topical agent in
bum management, from itsי 0.6 mg/ml solution through human third-degree bum eschar was
studied 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 level
was 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 bum
eschar. Permeation of SSD through fully-hydrated tissue was about 20 times more than that of
semi-hydrated samples. Permeation of SSD through dry eschar was initially (up to 3 h) more
than those of semi- or fully hydrated tissues, but it ceased and reached a plateau at this time
point, while for the other systems continued and became more than that of the dry eschar at
later stages. The cumulative amount of drug permeated through the fully-hydrated tissue in
8 h was about 30 times more than that of the dry eschar.
Our results showed that hydration can clearly improve permeation of SSD and possibly
other drugs through third-degree bum eschar. A property which could easily change during
patient management, e.g., by covering, washing, or application of occlusive formulations.
