title: Absorption characteristics of model compounds with different molecular weights from the serosal caecal surface in rats.
abstract: The purpose of this study was to clarify the absorption characteristics of drugs across the serosal caecal surface membrane, occupying a large absorption area in the peritoneal cavity in rats. Absorption of phenolsulfonphthalein (PSP) and fluorescein isothiocyanate dextrans (FDs) as model drugs after application to the rat serosal caecal surface was investigated using a cylindrical diffusion cell. PSP was absorbed from the rat serosal caecal surface, followed by appearance in the plasma and bile. The time course of the remaining PSP amount in the diffusion cell obeyed first-order kinetics, and the rate constant, Ka, was calculated to be 8.01 x 10(-3) min(-1). No significant difference was seen in the absorption ratio of PSP, which was approximately 90% in 6 h for three doses (0.3, 0.5 and 1 mg), suggesting linear absorption. Moreover, the absorption ratios of FDs from the rat serosal caecal surface at 3 h decreased with an increase in the molecular weight (24.7% for FD4, 12.8% for FD-10 and 3.4% for FD-40).
authors.affiliation: School of Pharmaceutical Sciences, Nagasaki University, Japan. koyo-n@net.nagasaki-u.ac.jp
authors.forename: Koyo
authors.initials: K
authors.lastname: Nishida
authors.forename: Seiichi
authors.initials: S
authors.lastname: Nose
authors.forename: Akiko
authors.initials: A
authors.lastname: Kuma
authors.forename: Takahiro
authors.initials: T
authors.lastname: Mukai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kawakami
authors.forename: Mikiro
authors.initials: M
authors.lastname: Nakashima
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sasaki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sakaeda
authors.forename: Junzo
authors.initials: J
authors.lastname: Nakamura
mesh_terms: D000042:Absorption; D000818:Animals; D002432:Cecum / Q000187:drug effects*; D003911:Dextrans / Q000493:pharmacokinetics*; D004058:Diffusion; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D007202:Indicators and Reagents / Q000493:pharmacokinetics*; D007700:Kinetics; D008297:Male; D008970:Molecular Weight; D010637:Phenolsulfonphthalein / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003911:Dextrans; D007202:Indicators and Reagents; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate; D010637:Phenolsulfonphthalein