Transport of Drugs across Membranes

Conference paper


In contrast to many compounds of physiological significance the penetration of drugs through membranes is, in general, passive, by diffusion or filtration. Most drugs are weak organic acids or bases, which in the unionized state are lipid soluble, but are hydrophilic when dissociated. In the undis-sociated state they can penetrate lipid membranes but not when present as ions. Hydrophilic compounds penetrate membranes only when pores are present or, when transported actively by special mechanisms. The permeation of drugs depends, accordingly, on their lipid solubility, pKa and pH on the one hand and on the nature of the membrane on the other. When pH gradients exist across a lipid membrane, bases will concentrate on the more acid side and acids on the more alkaline side, i.e. in that space in which a larger proportion of the substance is dissociated and trapped as nonpenetrating ion (Schanker 1962). This type of diffusion has been called “non-ionic diffusion” by Milne et al. (1958).


Gastric Juice Physiological Significance Ionic Diffusion Anic Acid Lipid Solubility 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Höber, R., and H. Höber, 1937: J. Cell. Comp. Physiol. 10, 401.CrossRefGoogle Scholar
  2. Kurz, H., 1961: Biochem. Pharmacol. 8, 20.CrossRefGoogle Scholar
  3. Kurz, H. and H. Trunk, 1965: Naunyn-Schmiedebergs Arch. exper. Path. Pharmak. 251, 106.CrossRefGoogle Scholar
  4. Levine, R. R., and E. W. Pelikan, 1964: Ann. Rev. Pharmacol. 4, 69.CrossRefGoogle Scholar
  5. Milne, M. D., B. H. Scribner, and M. A. Crawford, 1958: Amer. J. Med. 24, 709.PubMedCrossRefGoogle Scholar
  6. Schanker, L. S., 1962: Pharmacol. Rev. 14, 501.PubMedGoogle Scholar
  7. Sperber, I., 1959: Pharmacol. Rev. 11, 109.PubMedGoogle Scholar
  8. Travell, J., 1960: Ann. N. Y. Acad. Sci. 90, 13.PubMedCrossRefGoogle Scholar
  9. Vogt, W., 1965: Naunyn-Schmiedebergs Arch. exper. Path. Pharmak. 250, 210.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag/Wien 1967

Authors and Affiliations

  • W. Vogt
    • 1
  1. 1.Department of PharmacologyMax-Planck-Institut für experimentelle MedizinGöttingenGerman Federal Republic

Personalised recommendations