Which formulation provides gradual release of risperidone to achieve therapeutic levels?

• A. Immediate-release tablet
• B. Risperidone microspheres
• C. Effervescent tablet
• D. Sublingual tablet

Answer: (B)

Gradual release comes from a delivery system that slowly releases the drug over time rather than delivering it all at once. Risperidone encapsulated in microspheres uses a biodegradable matrix that gradually breaks down, steadily releasing risperidone and keeping therapeutic levels in the blood over an extended period. This long-acting approach reduces peaks and troughs and can improve adherence.

Immediate-release tablets release the drug quickly after ingestion, causing a rapid rise and then a fall in levels. An effervescent tablet and a sublingual tablet are also typically absorbed quickly and do not provide sustained release, so they don’t maintain steady therapeutic levels over time.