NCIt definition : A solid composed of an impermeable occlusive backing and a formulation matrix in which
the active and/or inert ingredient(s) are dissolved or dispersed; possibly includes
an adhesive layer.;
Alternative definition : CDISC: A drug delivery system that often contains an adhesive backing that is usually
applied to an external site on the body. Its ingredients either passively diffuse
from, or are actively transported from, some portion of the patch. Depending upon
the patch, the ingredients are either delivered to the outer surface of the body or
into the body. A patch is sometimes synonymous with the terms Extended Release Film
and System.;