Abstract: Any pharmaceutical preparation for oral administration with controlled release of active ingredient in the small bowel, on the basis of active ingredient carriers provided with at least one active ingredient which are provided with an inner layer to control the release of active ingredient and with a gastro-resistant coating layer disposed thereon, which is characterized in that the inner layer is formed from at least two diffusion layers whose permeability for the diffusing active ingredient decreases from the inside to the outside, and a method for the production thereof, are described.

Abstract: The invention relates to a process for the preparation of endo-nortropine using 8-benzyl-nortropan-3-one perchlorate, as well as the latter product. Endo-nortropine is the key product for the production of important azonia-spironortropanol esters, which are used as pharmaceuticals, particularly spasmolytics. There are three different synthesis methods for the preparation of said intermediate, which lead to different disadvantages. These problems are obviated by the present invention through the two-stage treatment of 8-benzyl-nortropan-3-one perchlorate with catalytically activated hydrogen, the starting product initially being prehydrogenated in aqueous suspension and at atmospheric pressure and ambient pressure with a palladium catalyst, at the end of the reaction the catalyst is recovered by filtration, the filtrate is passed over an anion exchanger and the now alkaline reacting solution is rendered turbulent at 1000 to 1500 r.p.m.