Textbooks

Laurence L. Brunton; Randa Hilal-Dandan; Björn C. Knollmann


... At therapeutic doses, several modifying factors are significant. Compounds containing a quaternary ammonium group do not penetrate cell membranes readily; hence, anti-ChE agents in this category are absorbed poorly from the GI tract or across the skin and are excluded from the CNS by the blood...