Enhancing absorption of drugs from gastrointestinal tract using acylcarnitines

A method of enhancing the rate of gastrointestinal absorption of an orally or rectally administered poorly absorbed drug selected from the group consisting of .beta.-lactam antibiotics, aminoglycoside antibiotics, antiviral agents, amino acids, smooth muscle relaxants and polypeptides, said method comprising the steps of preparing a dosage form capable of being orally or rectally absorbed, said dosage form comprising a therapeutically effective dosage amount of said drug and an absorption enhancing effective amount of an acylcarnitine agent of the formula:

• ##STR2## wherein R is saturated acyl(C.sub.2 -C.sub.20), acyl(C.sub.2 -C.sub.20) with 1 to 6 double bonds, hydroxyacyl(C.sub.2 -C.sub.20) with 1 to 3 hydroxy groups, ketoacyl(C.sub.4 -C.sub.20), unsaturated hydroxyacyl(C.sub.5 -C.sub.20) or carbalkoxyacyl(C.sub.5 -C.sub.20) and X is a pharmaceutically acceptable counterion.