AUREOMYCIN ABSORPTION AND DISTRIBUTION IN THE GASTRO-INTESTINAL TRACT OF THE DOG

¹ Lederle Laboratories Division, American Cyanamid Company, Pearl River, New York

1. Four hours after oral administration, the recovery of unabsorbed aureomycin from the dog gastro-intestinal tract was linearly related to the dose over the range 5 to 25 mgm. per kgm. Higher dose levels were not investigated. The total 4-hour recovery was 58.6 per cent of the dose administered.

2. In view of the lack of data regarding what proportion of the difference between the dose administered and the amount recovered represents absorbed aureomycin, this regression line is suggestive but insufficient evidence to indicate the absence of a maximal rate of aureomycin absorption from the dog gastrointestinal tract during a 4-hour period.

3. Two and four hours after oral administration of 25 mgm. per kgm., aureomycin is fairly evenly distributed throughout the gastro-intestinal tract of the dog. After six hours, practically no aureomycin was detected in the stomach, very little in the small intestine, and was concentrated in the large intestine to the extent of approximately 58 per cent of the dose administered. A similar distribution pattern was observed four hours after doses of 5 and 10 mgm. per kgm.

4. Aureomycin is absorbed from the stomach, small intestine, and the large intestine of the dog.

5. The 48-hour recovery of aureomycin from the feces of dogs given 5, 10, and 25 mgm. per kgm. ranged from approximately 2 to 58 per cent of the total dose administered. Nearly all the aureomycin was excreted during the first 24 hours.