A peroral sandwich model tablet with timed release, containing proxyphylline and nitroglycerin, was developed. One layer of the tablet constituted the rapidly disintegrating and dissolving initial phase; the other, the depot phase, was in the form of an insoluble, indigestible skeleton. Amount of drugs in the tablet and their liberation rate constants were based on pharmacokinetic calculations. Upon chewing and masticating a depot tablet, the retard action usually is lost due to an increase of the surface. This problem would not be serious with proxyphylline, which is relatively nontoxic, but could be dangerous or fatal in the case of nitroglycerin. To obtain safety with this product, proxyphylline of the depot phase was incorporated into the pores of an indigestible plastic skeleton of the matrix, and nitroglycerin was dissolved in the plastic particles of the matrix. In vitro and in vivo experiments proved the loss of depot action for both drugs upon mastication of the tablet, yet the nitroglycerin release was slow enough not to cause unwanted side effects.