United States Patent:  6,013,281

Assignee:  Astra Aktiebolag (Sodertalje, SE)

Filed:  March 8, 1996

A new oral pharmaceutical dosage form comprising a core material that contains a proton pump inhibitor, one or more alkaline reacting compounds and optionally pharmaceutical excipients having a water soluble separating layer and an enteric coating layer. The core material as such is alkaline reacting and the separating layer between the alkaline reacting core material and the enteric coating layer is formed in situ as a water soluble salt between the alkaline reacting compound(s) and the enteric coating polymer. The invention also describes a new efficient process for the manufacture of such a dosage form comprising two functionally different layers in one manufacturing step, and its use in medicine.

SUMMARY OF THE INVENTION

According to one aspect of the invention a new pharmaceutical dosage form is provided in the form of an enteric coated tablet. Alternatively, individually enteric coated units are prepared and filled into a capsule, a sachet or included in a tableted multiple unit dosage form.

The present invention is characterized by the presence of a separating layer between an alkaline reacting core material comprising a pharmaceutically active acid labile substance and an enteric coating layer, wherein the separating layer comprises a water soluble salt of an enteric coating polymer.

According to a second aspect the present invention provides a process for the manufacture of two functionally different layers in one manufacturing step. By such a process a separating layer comprising a water soluble salt of an enteric coating polymer is obtained, as well as the enteric coating layer itself.

Thus, the present invention simplifies the preparation of enteric coated articles comprising a separating layer between a core material and an enteric coating layer by providing a new process for the manufacture of such dosage forms. According to said process the separating layer is formed by an in situ reaction between the enteric coating polymer and the alkaline core material comprising the pharmaceutically active substance.

Claim 1 of 21 Claims

1. A process for preparing an oral pharmaceutical formulation comprising the steps of:

forming a core material comprising a proton pump inhibitor and at least one alkaline reacting compound, wherein the concentration of the alkaline reacting compound is about 0.1 mmol/g dry ingredients in the alkaline containing part of the core material, and

applying an enteric coating polymer layer so as to surround the core material thereby forming in situ a separating layer as a water soluble salt product between the alkaline compound and the enteric coating polymer.

____________________________________________
If you want to learn more about this patent, please go directly to the U.S. Patent and Trademark Office Web site to access the full patent.