Which statement describes the pharmacokinetic differences between immediate-release and extended-release formulations?

• A. Immediate-release yields slower absorption and lower Cmax compared to extended-release.
• B. Immediate-release shows rapid absorption and higher Cmax and earlier Tmax; extended-release provides slower, more prolonged absorption, lower Cmax, longer Tmax, and often more predictable exposure.
• C. Immediate-release produces greater overall exposure than extended-release.
• D. Extended-release results in a higher Cmax and shorter Tmax than immediate-release.

Answer: (B)

How a formulation controls the rate of drug release and absorption is being tested here. Immediate-release products let the drug dissolve and be absorbed quickly, so plasma levels rise rapidly, reaching a higher peak (Cmax) earlier (shorter Tmax). Extended-release products release the drug more slowly, spreading absorption over a longer period, which lowers the peak concentration and lengthens the time to reach it (lower Cmax and longer Tmax). Because the same dose is given, the total exposure over time (AUC) is usually similar, but extended-release often provides a more predictable and steadier exposure within the dosing interval. This aligns with the described pattern: rapid absorption and higher Cmax with an earlier Tmax for immediate-release, versus slower, prolonged absorption, lower Cmax, longer Tmax, and often more predictable exposure for extended-release.