An aqueous midazolam injection changes from approximately pH 3.5 in the ampoule to physiological pH after intravenous administration. Which molecular

Question

An aqueous midazolam injection changes from approximately pH 3.5 in the ampoule to physiological pH after intravenous administration. Which molecular sequence best explains both its formulation solubility and its rapid penetration into the central nervous system?

Accepted Answer

Protonation at acidic pH favours an open-ring, water-soluble form; deprotonation at physiological pH favours a closed-ring, lipid-soluble form

Answer

The ring remains open at both pH values; deprotonation alone increases lipid solubility at physiological pH

Answer

Protonation at acidic pH favours an open-ring, lipid-soluble form; deprotonation at physiological pH favours a closed-ring, water-soluble form

Answer

Protonation at acidic pH favours a closed-ring, water-soluble form; deprotonation at physiological pH favours an open-ring, lipid-soluble form

Answer

The ring remains closed at both pH values; reduced plasma protein binding increases water solubility at physiological pH

Midazolam Ring Opening — FRCA Primary MCQ

An aqueous midazolam injection changes from approximately pH 3.5 in the ampoule to physiological pH after intravenous administration. Which molecular sequence best explains both its formulation solubility and its rapid penetration into the central nervous system?