Intestinal absorption of several .BETA.-lactam antibiotics. II. Absorption characteristics of amino-penicillins and amino-cephalosporins.

Abstract

To investigate the absorption characteristics of cephalexin, cephradine and amoxicillin, which are well absorbed from the gastrointestinal tract, the mechanisms of intestinal absorption of these antibiotics in rats were examined using the recirculating perfusion technique, the loop method and the everted gut sac technique. Cephradine was actively transported. Other antibiotics appeared to diffuse across the intestine down a concentration gradient. The accumulations of these drugs, in the intestinal tissue, especially cephalexin and cephradine, were particularly marked, and the accumulation of each of these 3 drugs was significantly inhibited at low temperature. These observations provide an experimental basis for the known rapid absorption of these antibiotics.