Transdermal absorption of L-dopa from hydrogel in rats.
To improve compliance in administration of l-dopa, transdermal absorption of the agent was investigated in rats in vitro employing two-chamber diffusion cells in which the excised rat abdominal skin was mounted, and in vivo using an alcoholic hydrogel containing l-menthol. The in vitro study revealed that in presence of l-menthol (2%, W/W), ethanol (20 and 40%, V/V) accelerated transdermal penetration of l-dopa with an increase of its percentages. The in vivo study showed that when the l-dopa-hydrogel containing 2% l-menthol and 40% ethanol was attached on the skin, plasma levels of l-dopa and norepinephrine increased with the time elapsed; the level of dopamine increased and reached a plateau thereafter; and the level of epinephrine was unchanged. These in vitro and in vivo findings indicated that the hydrogel formulation of l-dopa provides new direction in treating Parkinson's disease.
Sudo
J
J
Department of Clinical Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-02, Japan.
Iwase
H
H
Terui
J
J
Kakuno
K
K
Soyama
M
M
Takayama
K
K
Nagai
T
T
D000279:Administration, Cutaneous; D000818:Animals; D004298:Dopamine / Q000097:blood; D015259:Dopamine Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D004837:Epinephrine / Q000097:blood; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D007980:Levodopa / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D012869:Skin Absorption
D015259:Dopamine Agents; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007980:Levodopa; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine