12. Penetration Enhancers, Solvents and the Skin
- Dennis Douroumis1 and
- Alfred Fahr2
Published Online: 4 FEB 2013
This edition first published 2013 © 2013 John Wiley & Sons, Ltd.
Drug Delivery Strategies for Poorly Water-Soluble Drugs
How to Cite
Hadgraft, J. and Lane, M. E. (2013) Penetration Enhancers, Solvents and the Skin, in Drug Delivery Strategies for Poorly Water-Soluble Drugs (eds D. Douroumis and A. Fahr), John Wiley & Sons Ltd, Oxford, UK. doi: 10.1002/9781118444726.ch12
School of Science, University of Greenwich, UK
Friedrich-Schiller University of Jena, Germany
- Published Online: 4 FEB 2013
- Published Print: 21 JAN 2013
Print ISBN: 9780470711972
Online ISBN: 9781118444726
- Hansen solubility parameter
There are very few excipients which have no effect on the barrier properties of the skin. Vehicle components will enter the stratum corneum and can have a number of interactions with the various components of the skin. In particular, they can interact with the structured skin lipids, they can change the environment of the lipids such that they enhance diffusion of the actives or they can influence the solubility of the actives. Few studies have examined how much of the excipients penetrate, more has been done to show their influence on permeation rates. In this chapter we will review the recent data that has indicated the way in which vehicles can influence concentration profiles of actives within the stratum corneum and how this may affect the subsequent active bioavailability. Although high concentrations of actives may be present in the stratum corneum, recent studies indicate that in certain circumstances, the active may be crystallized and therefore relatively poorly bioavailable. Sophisticated biophysical techniques are being developed to monitor the concentration profiles of both active and excipient within the skin. Future developments will also be discussed.