Studies on the promoting effects of carboxylic acid derivatives on the rectal absorption of beta-lactam antibiotics in rats
Nishimura, K.; Nozaki, Y.; Yoshimi, A.; Nakamura, S.; Kitagawa, M.; Kakeya, N.; Kitao, K.
Chemical and Pharmaceutical Bulletin 33(1): 282-291
ISSN/ISBN: 0009-2363 PMID: 4006019 DOI: 10.1248/cpb.33.282
The promoting effects of sodium salts of N-acyl-L-phenylalanines, p-substituted benzoic acids, saturated straight-chain fatty acids, saturated straight-chain .alpha.-bromofatty acids and N-acyl-N-methylglycines on the rectal absorption of sodium ampicillin (ABPC Na) were investigated in rats. The absorption-promoting effect of each carboxylic acid sodium salt was parabolically correlated with its lipo-hydrophilic character (log P). The optimal log P value (log Po) of carboxylic acids exerting the maximum rectal absorption-promoting effect was in the range of 4.2.sbd.4.8. Among these carboxylic acids, sodium caprate was selected for examination of its rectal absorption-promoting action on 4 penicillins (ampicillin, sulbenicillin, piperacillin and mezlocillin) and 8 cephalosporins (cephacetrile, ceftizoxime, cephalothin, cefazolin, cefmetazole, cefotiam, cefoperazone and cefpiramide). The extents of rectal absorption of the .beta.-lactam antibiotics coadministered with sodium caprate correlated well with the permeability of the drugs to cellulose membrane.