[A device for the drug-capsule administration into the rat stomach and its pharmacological application (author's...

To assess the absorption of drugs given in capsule form to rats, the method of administration was studied using gastric-cannulated rats. The body weight of these rats remained the same as even when given casein hydrolysate and vitamins in addition to the usual chow diet. Indomethacin (IM) capsule (2 mg/capsule) was given and the plasma concentration and anti-inflammatory action of IM were studied. The maximum plasma concentration was seen at 2 hr after administration of one capsule. The carrageenin-induced edema of rat hind paw was inhibited with the ingestion of only one capsule. In addition, the time course of the plasma concentration of IM correlated with that of the inhibitory effect of carrageenin-induced edema. In the case of administration of a barium sulfate capsule to the cannulated rats, the transfer of the barium sulfate was clearly observed on the X-rays. Our findings suggest that this approach to the estimation of drugs is feasible, at least in experimental animals.