Alternative definition : EDQM-HC: Flexible single-dose preparation intended to be applied to the unbroken skin
to obtain a systemic delivery over an extended period of time. Transdermal patches
consist of a backing sheet supporting a reservoir or a matrix containing the active
substance(s) and on the top a pressure-sensitive adhesive, which assures the adhesion
of the preparation to the skin. The backing sheet is impermeable to the active substance(s)
and normally impermeable to water. In reservoir systems the active substance may be
dissolved or dispersed in a semi-solid basis or in a solid polymer matrix, which is
separated from the skin by a rate-controlling membrane. The pressure-sensitive adhesive
may, in this case, be applied to some or all parts of the membrane, or only around
the border of the membrane and the backing sheet. Matrix systems contain the active
substance in a solid or semi-solid matrix, the properties of which control the diffusion
pattern to the skin. The matrix system may also be a solution or dispersion of the
active substance in the pressure-sensitive adhesive. The releasing surface of the
patch is covered by a protective liner to be removed before applying the patch to
the skin.;
Currated CISMeF NLP mapping