... bioavail-ability of an orally administered drug. 18 Drug AdministrationLüllmann, Color Atlas of Pharmacology © 2000 ThiemeAll rights reserved. Usage subject to terms and conditions of license. Drug Administration ... of drug is undesirable, or when ab-sorption is being slowed in order to pro-long the action of drugs that have ashort sojourn in the body.10 Drug AdministrationLüllmann, Color Atlas of Pharmacology ... membraneeasily. This is of major importance withrespect to the absorption, distribution,and elimination of drugs.20 Cellular Sites of ActionLüllmann, Color Atlas of Pharmacology © 2000 ThiemeAll...