Which one of the following groups is responsible for the duration of the local anesthetic action?
a) Intermediate chain
b) Lipophylic group
c) Ionizable group
d) All of the above
Intermediate chain.A lipophilic group (often an aromatic benzene ring) and a hydrophilic group (typically a tertiary amine) are separated by an intermediate chain with an ester or amide bond in local anaesthetics.