Lamination or coextrusion of
the active layer to a structural mono or multilayer film
(S) can solve the packaging design. Fig. 2 shows a diagram
of the most complex solution, which includes a structural
and a protective layer. The use of mathematical models
based on numerical approximations such as finite difference
methods can provide predictions of the release behaviour
of this kind of complex structure, since no analytical
solutions to Fick’s laws are available.