Antimicrobial
therapy remains one of the most important methods of
wound management. Systemically administered antimicrobials may not achieve therapeutic levels in
wound and most agents cannot penetrate
burn eschar well enough when applied topically. Therefore, we tested the notion to increase permeability of eschar toward topical agents using
terpenes, a well-known class of skin permeation enhancers. Four
terpenes,
limonene (
hydrocarbon),
eucalyptol (
ether),
alpha-pinene oxide (
epoxide) and
geraniol (alcohol) were chosen and their effects on permeation of
silver sulphadiazine (
SSD), a widely used topical
antimicrobial agent, through human third-degree
burn eschar was evaluated using static diffusion cells. Results showed that
terpenes increased permeation flux of
SSD through eschar significantly (P<0.0001).
Limonene provided the highest flux enhancement ratio (9.0 times), followed by
geraniol,
eucalyptol and
alpha-pinene oxide with enhancement ratios of 5.5, 4.7 and 4.3 respectively. The effects of
terpenes on permeation lag-time, was less than 20%. Data analysis revealed that
terpenes increase permeation of
SSD mainly by increasing its partitioning into the eschar. The present results show that permeation of drugs through
burn eschar can be increased considerably by
terpenes and that
burn wound antimicrobial
therapy may be improved by
terpenes and possibly other penetration enhancers.