[Kinetics of liberation of the theophylline in semi-solid matrix based of Gelucire].

Dissolution of a tracer included in Gelucire is primarily governed by two physico-chemical nominative parameters of this auxiliary substance which are its melting point and its hydrophily-lypophily balance. As they are not dissociable and their interaction is very significant, the optimisation of a formulation containing a mix of Gelucire cannot be done with polynomial models. An indirect modelisation, as Simplex, is however possible.