Absorption is defined as:

Absorption is defined as:

• A. How the drug is eliminated from the body.
• B. How the drug is distributed among the organs after it is absorbed into the bloodstream.
• C. How the active part of a drug is metabolized into a more water-soluble compound that can be readily excreted by the kidneys.
• D. How the drug passes from its site of administration into the bloodstream.

Answer: (D)

Absorption is the process by which a drug crosses from its site of administration into the bloodstream. This initial step determines how much of the dose becomes available systemically (bioavailability). For example, an oral tablet must dissolve and pass through the intestinal lining to reach the blood. After absorption, the drug is distributed to tissues (distribution), may be metabolized into more water-soluble forms for excretion (metabolism), and is eventually eliminated from the body (excretion). The other descriptions refer to later steps in the body's handling of the drug, not entry into the bloodstream.

Absorption is the process by which a drug crosses from its site of administration into the bloodstream. This initial step determines how much of the dose becomes available systemically (bioavailability). For example, an oral tablet must dissolve and pass through the intestinal lining to reach the blood. After absorption, the drug is distributed to tissues (distribution), may be metabolized into more water-soluble forms for excretion (metabolism), and is eventually eliminated from the body (excretion). The other descriptions refer to later steps in the body's handling of the drug, not entry into the bloodstream.