Peak-level collection times for different administration routes are: IV after 30 minutes, IM after 60 minutes, Oral after 1-2 hours.

• A. IV after 30 minutes; IM after 60 minutes; Oral after 1-2 hours
• B. IV after 1 hour; IM after 2 hours; Oral after 3-4 hours
• C. IV after 15 minutes; IM after 45 minutes; Oral after 30 minutes
• D. IV after 45 minutes; IM after 90 minutes; Oral after 2-3 hours

Answer: (A)

Peak plasma concentration varies with how a drug enters the body because absorption into the bloodstream controls how quickly the drug reaches its maximum level.

For intravenous administration, the drug is placed directly into the bloodstream, so the peak occurs at the end of the infusion. If the infusion lasts 30 minutes, the peak is expected around that 30-minute mark.

Intramuscular administration involves absorption from muscle tissue into the blood, which takes longer. A typical peak around 60 minutes reflects the time needed for the drug to be absorbed from the muscle into circulation.

Oral dosing goes through the GI tract, where absorption is slower and can be influenced by factors like food and formulation. A common peak time is about 1–2 hours after dosing.

Together, these times—IV at about 30 minutes, IM at about 60 minutes, and oral at about 1–2 hours—align with standard pharmacokinetic patterns for peak sampling in many drugs.