title: Rectal absorption of E-2078 (dynorphin analogue peptide) in rats.
abstract: The plasma levels in rats of a dynorphin analogue peptide (E-2078) after rectal administration have been studied. The bioavailabilities of E-2078 after rectal administration, subcutaneous injection, intramuscular injection, and oral administration were 21.6, 67.8, 67.1, 0.7%, respectively. The effect of dose, pH, osmolarity and viscosity on the rectal absorption of E-2078 were studied. A sigmoid relationship between the dose and the AUC was observed on rectal administration, while there was a linear relationship on intramuscular administration. The AUC was increased in acidic solution and highly viscous solution. The osmolarity did not affect the absorption of E-2078. In microscopic studies, E-2078 caused little or no damage to the rectal mucosa in rats.
authors.affiliation: Tsukuba Research Laboratories, Eisai Co., Ltd., Ibaraki, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Murahashi
authors.forename: A
authors.initials: A
authors.lastname: Kato
authors.forename: N
authors.initials: N
authors.lastname: Koyama
authors.forename: S
authors.initials: S
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Yuzuriha
authors.forename: Y
authors.initials: Y
authors.lastname: Miyake
mesh_terms: D000284:Administration, Oral; D000285:Administration, Rectal; D000595:Amino Acid Sequence; D000700:Analgesics / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D001682:Biological Availability; D004399:Dynorphins / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D007267:Injections; D007408:Intestinal Absorption; D008297:Male; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000008:administration & dosage / Q000493:pharmacokinetics*; D051381:Rats; D011919:Rats, Inbred Strains; D014783:Viscosity
chemical_list: D000700:Analgesics; D010446:Peptide Fragments; C061285:E 2078; D004399:Dynorphins