Presidential Greeting - American Society for Laser Medicine and ...

CAN A FRACTIONAL LASER ASSIST TRANSDERMAL ABSORPTION OF LIDOCAINE IN AN IN VIVO ANIMAL
MODEL?
Georgette Ori, Spencer Brown, Jeffrey Kenkel, UT Southwestern Medical Center, Dallas, TX
Background and objectives: It is thought that the pretreatment of skin with a laser enhances transdermal delivery
of drugs. Several studies have looked at the effects ex vivo. The aim of this study is to demonstrate in vivo firstly
that laser can enhance transdermal penetration of a drug and secondly that this can be manipulated by altering the
laser settings. Study Design, Methods/Materials: 3 pigs were included in this IACUC approved study. On day
0, a 400cm 2 area on the abdomen was marked and 5g of LMX4 (Ferndale laboratories) was applied under
occlusion. Blood was drawn at time 0, 60, 90, 120, 180 and 240 minutes and biopsies taken for histology. On day
7, the Er:YAG laser (2490nm, Profile, Sciton) was used at 500µm, 250µm and 50µm ablative depth, 22% density to
pretreat a 400cm 2 area on the abdomen. 5g of LMX4 was applied immediately with occlusion for 60 mins, and then
removed. Blood was drawn at time 0, 60, 90, 120, 180 and 240 minutes. The serum was extracted and analyzed
for lidocaine levels and its metabolite monoethyglycinide (MEGX). Results: Serum levels of lidocaine and MEGX
were undetectable in untreated skin. Following laser treatment levels of both lidocaine and MEGX were
detectable. Peak levels of lidocaine were significantly higher (p=0.02) at 250µm (0.59mg/L), compared to 500µm
(0.29mg/L) and 50 µm (0.31mg/L). Peak levels of MEGX were significantly higher (p