@article{oai:nagasaki-u.repo.nii.ac.jp:00023368,
 author = {Nishida, Koyo and Sato, Norihito and Nakakoga, Yuki and Mukai, Takahiro and Sasaki, Hitoshi and Nakamura, Junzo},
 issue = {10},
 journal = {Journal of Pharmacy and Pharmacology},
 month = {Oct},
 note = {We examined the importance of application volume and area in the absorption of phenol red as a model drug from the rat liver surface, for pharmaceutical formulation concerning administration form. When 1 mg of phenol red was applied to the rat liver surface in-vivo using a cylindrical glass cell (i.d. 9 mm) in three volumes (0.1, 0.2 or 0.334 mL), the shape of the plasma concentration pattern differed greatly, particularly the maximum concentration.   These patterns were well fitted by a two-compartment model with first-order absorption, and the obtained absorption rate constant Ka decreased inversely according to the application volume.   The absorption ratio and biliary recovery of phenol red at 6 h was increased with glass cell area (i.d. 6, 9 or 14 mm; area 0.28, 0.64 or 1.54 cm2).   Furthermore, the permeability coefficient Papp derived from Ka did not depend on application area, indicating no difference in absorption characteristics of liver surface.   This also implies transport of a drug by a passive diffusion from the liver surface. After intraperitoneal administration to the rat liver surface for clinical application, increase in application volume resulted in the delayed disappearance of phenol red from plasma.   However, the difference was not as marked as that using a glass cell.   The assumption that the effective area relating to the absorption changed with the application volume enabled us to estimate Papp. Consequently, we speculate absorbability can be estimated precisely by considering application volume and area., Journal of Pharmacy and Pharmacology, 49 (10), 976-980, 1997},
 pages = {976--980},
 title = {Effect of application volume and area on the absorption of phenol red as a model drug from the liver surface in rats},
 volume = {49},
 year = {1997}
}