The present invention provides a simple and mild process for the preparation of nano- and/or microparticles, which particles contain one or more therapeutic agents dispersed in non-crystalline form in a matrix containing one or more polymers selected from cellulose ethers, cellulose esters, copolymers of methacrylic acid with one or more (meth) acrylic acid esters, copolymers of two or more (meth) acrylic acid esters and mixtures thereof, as well as pharmaceutical formulations containing the nano- and/or microparticles.
