n. the intake of small droplets of fluid by a cell by cytoplasmic engulfment. It occurs in many white blood cells and in certain kidney and liver cells. Compare phagocytosis.
Drugs are usually administered distant to their site of action in the body; they must then pass across cell membranes to reach their site of action. For example, drugs given by mouth must pass across the gut membrane to enter the bloodstream and then pass through the endothelium of vessel walls to reach the site of action in the tissues. This process is called absorption and may depend on lipid di?usion, aqueous di?usion, active transport, or pinocytosis – a process in which a cell takes in small droplets of ?uid by cytoplasmic engulfment.... drug absorption
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