Important to remember about pilocarpine?

Important to remember about pilocarpine?

• A. It is unstable due to its lactone structure (ester hydrolysis and epimerization)
• B. It is highly stable against hydrolysis
• C. It is a nicotinic receptor antagonist
• D. It does not interact with muscarinic receptors

Answer: (A)

Pilocarpine contains a lactone ring, which makes it prone to hydrolysis and possible epimerization. In water and at varying pH, the lactone can open, breaking the ring to give a hydrolyzed product, and stereochemical changes at the chiral center can alter activity. This instability is a key thing to remember because it affects formulation, storage, and potency. Pilocarpine is a muscarinic receptor agonist, so it certainly does interact with muscarinic receptors, not act as a nicotinic antagonist or be entirely noninteractive. Thus the statement that it is unstable due to its lactone structure (ester hydrolysis and epimerization) best captures the important point.

Pilocarpine contains a lactone ring, which makes it prone to hydrolysis and possible epimerization. In water and at varying pH, the lactone can open, breaking the ring to give a hydrolyzed product, and stereochemical changes at the chiral center can alter activity. This instability is a key thing to remember because it affects formulation, storage, and potency. Pilocarpine is a muscarinic receptor agonist, so it certainly does interact with muscarinic receptors, not act as a nicotinic antagonist or be entirely noninteractive. Thus the statement that it is unstable due to its lactone structure (ester hydrolysis and epimerization) best captures the important point.