Absorption Characteristics of Model Drugs from the Gastric Serosal Surface in Rats

Abstract

The in-vivo absorption characteristics of phenol red were studied after application to the rat gastric serosal surface, using a cylindrical glass cell. There was no significant difference between absorption ratios of 0.3, 1 and 3 mg phenol red in 6 h, suggesting linear absorption from the gastric serosal surface. When phenol red and bovine serum albumin were applied, drug absorption decreased with increasing protein concentration, indicating that protein binding is an important factor controlling drug absorption from the gastric serosal surface. These findings may be useful in the development of novel administration routes for drug delivery to the stomach.