Claims for Patent: 5,690,960

Summary for Patent: 5,690,960

Title:	Pharmaceutical formulation of omeprazole
Abstract:	A new oral pharmaceutical formulation containing a novel physical form of a magnesium salt of omeprazole, a method for the manufacture of such a formulation, and the use of such a formulation in medicine.
Inventor(s):	Bengtsson; Inga Siv (Goteborg, SE), Lovgren; Kurt Ingmar (Molnlycke, SE)
Assignee:	Astra Aktiebolag (Sodertalje, SE)
Application Number:	08/313,036
Patent Claims:	1. A stable oral formulation comprising: a core containing a magnesium salt of omeprazole said salt having more than 70% crystallinity as determined by x-ray powder diffraction; a subcoating layer; and an enteric coating layer, whereby the thickness of the enteric coating layer does not effect the release of omeprazole into solution at the pH predominantly present in the small intestine. 2. A formulation according to claim 1, wherein the formulation is a tablet formulation. 3. A formulation according to claim 1, wherein the formulation is a pellet formulation. 4. A formulation according to claim 1, wherein the enteric coating comprising an enteric coating material, optionally containing one or more pharmaceutically acceptable plasticizers, dispersants, colorants and pigments. 5. A formulation according to claim 4, wherein the enteric coating comprises water-based polymer solutions or dispersions of acrylates, hydroxypropyl methylcellulose acetate succinate, hydroxypropyl methylcellulose phthalate, polyvinyl acetate phthalate, cellulose acetate trimellitate and/or cellulose acetate phthalate. 6. A formulation according to claim 1, wherein the enteric coating constitutes from 1.0% by weight of the weight of the core material. 7. A formulation according to claim 6, wherein the enteric coating constitutes at least 3.0% by weight of the weight of the core material. 8. A formulation according to claim 1 wherein the subcoating layer(s) comprise polymeric, filmforming compounds or tablet excipients which are soluble or insoluble but disintegrating in water, and optionally containing pH-buffering, alkaline compounds. 9. A formulation according to claim 1 wherein the produced enteric coated formulation contains an overcoat, optionally comprising one or more pharmaceutically acceptable plasticizers, dispersants, colorants and pigments. 10. A process for the manufacture of a formulation of a pharmaceutical composition for the oral administration of magnesium omeprazole comprising the steps of: (a) forming a core material containing magnesium omeprazole salt said salt having at least 70% crystallinity as determined by x-ray powder diffraction; (b) applying in the presence of water at least one subcoating layer onto the core; (c) further applying in the pittance of water at least one enteric coating layer onto the subcoated core; and drying the prepared formulation. 11. A process according to claim 10, wherein the subcoating layer(s) is applied on the core material by a drycoating process. 12. The oral formulation according to claim 8 or 1 wherein the core is coated with more than one subcoating layer. 13. The oral formulation according to any one of the claim 1, 4-7 or 9 wherein the enteric coating comprises more than one layer. 14. The oral formulation according to claim 1 wherein the crystalline magnesium omeprazole has a mean mass particle size diameter of less than 30 .mu.m. 15. The oral formulation according to claim 1 wherein the crystalline magnesium omeprazole has a hygroscopicity of less than 2% by weight. 16. The formulation according to claim 1, wherein the core material is in the form of pellets, granules or tablets. 17. A method for inhibiting gastric acid secretion in mammals and man by administering to a host in need thereof a therapeutically effective dose of an enteric coated formulation according to any of claims 1 to 9. 18. A method for the treatment of gastric acid related diseases in mammals and man by administering to a host in need thereof a therapeutically effective dose of an enteric coated formulation according to any of claims 1 to 9. 19. The formulation according to claim 1, wherein the core further comprises an alkaline reacting compound. 20. The process according to claim 10, wherein the core material further comprises an alkaline reacting compound. 21. A pharmaceutical composition produced in accordance with the process of claim 10. 22. An improved oral pharmaceutical composition containing a core of omeprazole salt with a subcoating and an enteric coating wherein the improvement comprises magnesium omeprazole salt having more than 70% crystallinity as determined by x-ray powder diffraction.