In a drug dosage form, the substance that contains the drug is called:

• A. Active ingredient
• B. Excipient
• C. Vehicle
• D. Solvent

Answer: (C)

In a drug dosage form, the substance that carries and presents the drug to the body is the vehicle. The vehicle acts as the medium in which the active ingredient is delivered, whether it’s a liquid base, an ointment base, a suspension medium, or a gel. The active ingredient is the drug itself—the component that provides the therapeutic effect. Excipients are inert additives used to aid manufacturing, stability, taste, texture, or appearance, but they are not the medium that carries the drug in the dosage form. The solvent is a type of vehicle used specifically for dissolving the drug in solution forms, but not all dosage forms are solutions; the broader term vehicle covers all carriers, including bases for semi-solid preparations. So the substance that contains the drug is the vehicle.