title: Long-lasting muscle relaxant activity of eperisone hydrochloride after percutaneous administration in rats.
abstract: Potency and duration of muscle relaxant activity of eperisone hydrochloride were examined after percutaneous administration in the intercollicular decerebrated rat rigidity model and compared to those of eperisone after intravenous injection. A continuous movement was loaded on the hindlimb of the rat model to maintain stable rigidity. The tonus of the hindlimb was recorded by EMG from the triceps surae and was quantified by using the public domain NIH Image program. Eperisone ointment administered percutaneously showed significant muscle relaxant activity at 8.4 cm2 (4.2 mg of eperisone)/rat. The effect was dose-dependent and lasted over 60 min. Intravenously injected eperisone showed significant activity at 1.25 mg/kg, but the decrease of tone was lost within 30 min after injection. Plasma eperisone levels were monitored in the same model, and they were well correlated to the dosage. These results suggest that percutaneously administered eperisone is absorbed efficiently and shows potent and long-lasting muscle relaxant activity.
authors.affiliation: Eisai Tsukuba Research Laboratories, Ibaraki, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsunaga
authors.forename: Y
authors.initials: Y
authors.lastname: Uemura
authors.forename: Y
authors.initials: Y
authors.lastname: Yonemoto
authors.forename: K
authors.initials: K
authors.lastname: Kanai
authors.forename: H
authors.initials: H
authors.lastname: Etoh
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Atsuta
authors.forename: Y
authors.initials: Y
authors.lastname: Nishizawa
authors.forename: Y
authors.initials: Y
authors.lastname: Yamanishi
mesh_terms: D000279:Administration, Cutaneous; D000704:Analysis of Variance; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003655:Decerebrate State; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004576:Electromyography; D006614:Hindlimb / Q000187:drug effects; D007091:Image Processing, Computer-Assisted; D007275:Injections, Intravenous; D008297:Male; D009125:Muscle Relaxants, Central / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D009126:Muscle Relaxation / Q000187:drug effects; D009127:Muscle Rigidity / Q000188:drug therapy*; D018482:Muscle, Skeletal / Q000187:drug effects*; D011427:Propiophenones / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D012015:Reference Standards; D014049:Tolperisone / Q000097:blood
chemical_list: D009125:Muscle Relaxants, Central; D011427:Propiophenones; C030848:eperisone; D014049:Tolperisone