NCIt definition : A semi-solid composed of a soft, smooth mass with relatively thick consistency and
strong adhesiveness that becomes solid when dry.;
Alternative definition : CDISC: Substance intended for external application made of such materials and of such
consistency as to adhere to the skin and attach to a dressing; plasters are intended
to afford protection and support and/or to furnish an occlusion and macerating action
and to bring medication into close contact with the skin.;