Abstract: A method and drug form are provided for increasing the oral absorption of .beta.-lactam antibiotics such as the penicillins, cephalosporins and related chemical species by the oral administration of said .beta.-lactam antibiotics in a suitable pharmaceutically accepted excipient to which has been added a hydroxy aryl or hydroxy aralkyl acid or salt, amide or ester thereof. The hydroxyaryl or hydroxyaralkyl acid or salt, amide or ester thereof is present in the drug form in quantities sufficient to be effective in enhancing the rate of oral absorption of the .beta.-lactam antibiotic.

Abstract: A method and drug form are provided for increasing the oral absorption of polar bioactive agents such as polypeptides by the oral administration of said polar bioactive agents in a suitable pharmaceutically accepted excipient to which has been added a hydroxyaromatic acid or salt as an adjuvant thereof. The adjuvant is present in the drug form in quantities sufficient to be effective in enhancing the rate of oral absorption of the polar bioactive agents.

Abstract: Novel, transient prodrug forms of the phenolic dihydroxy sympathomimetic amines have (i) the structural formula (I): ##STR1## wherein X is O, S or NR.sup.5 ; n is 1 or 2; R.sup.1 is the monodehydroxylated residue of a phenolic, nuclear dihydroxy natural sympathetic or sympathomimetic amine when n is 1, and the didehydroxylated residue of a phenolic, nuclear dihydroxy natural sympathetic or sympathomimetic amine when n is 2; R.sup.