Effect of phenothiazines, disodium ethylenediaminetetraacetic acid and diethyl maleate on in vitro rat colonic transport of cefmetazole and inulin.

An in vitro rat colonic sac method developed in this study was found to be suitable for frequent collection of samples and determination of transport of compounds from serosal and mucosal medium, since the volume of both was large. Under no a treatment condition, both cefmetazole and inulin penetrated the intestinal mucosa via the paracellular route, but did so very poorly. Phenothiazines as well as disodium ethylenediaminetetraacetic acid increased the transport of cefmetazole and inulin, probably via the paracellular route, while diethyl maleate increased the transport of only cefmetazole, probably via the intracellular route. The effect of phenothiazines in increasing the clearance rate for both cefmetazole and inulin showed dependency on their initial concentrations in the mucosal medium with maximum action at a concentration of 30 microM for trifluoperazine, 20 microM for perphenazine, 75 microM for profenemine and 50 microM for propericiazine.