[[Image:Donkey paddock 2.JPG|thumb|right|200px|<small><center>Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary]</center></small>]]
Most drugs are transported in the aqueous phase of blood plasma. To
Most drugs are transported in the aqueous phase of blood plasma. To
have an effect, a drug must reach cell membrane receptors or enter cells.
have an effect, a drug must reach cell membrane receptors or enter cells.