Claims for Patent: 6,428,810

Summary for Patent: 6,428,810

Title:	Pharmaceutical formulation comprising omeprazole
Abstract:	An enteric coated oral pharmaceutical formulation comprising as active ingredient a compound selected from the group of omeprazole, an alkaline salt of omeprazole, one of the single enantiomers of omeprazole and an alkaline salt of one of the single enantiomers of omeprazole, wherein the formulation comprises a core material that comprises the active ingredient and optionally an alkaline reacting compound, the active ingredient is in admixture with a pharmaceutically acceptable excipient, such as for instance a binding agent, and on said core material a separating layer and an enteric coating layer. A hydroxypropyl cellulose (HPC) with a specific cloud point is used in the manufacture of the claimed pharmaceutical formulations. Furthermore, the application describes the processes for their preparation and the use of the claimed formulations in medicine.
Inventor(s):	Bergstrand; Pontus (Gothenburg, SE), Wang; Peter (Molndal, SE)
Assignee:	AstraZeneca AB (Sodertalje, SE)
Application Number:	09/485,218
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 6,428,810
Patent Claims:	1. An enteric coated oral pharmaceutical formulation comprising: (a) a core material which comprises an active ingredient selected from the group consisting of omeprazole, an alkaline salt of omeprazole, one of the single enantiomers of omeprazole and an alkaline salt of one of the single enantiomers of omeprazole; (b) a separating layer; and (c) an enteric coating layer, wherein the separating layer comprises a hydroxypropyl cellulose (HPC) with a cloud point of at least 38.degree. C., and wherein the light transmission at cloud point of a system comprising the HPC dissolved in a concentration of 1.0% (w/w) in a mixed solution of disodium hydrogen phosphate buffer 0.086 M and hydrochloric acid 0.1 M in the proportions 7:3 at a pH of 6.75-6.85 is 96%. 2. The formulation according to claim 1, wherein the HPC has a cloud point of at least 40.degree. C. 3. The formulation according to clam 1, wherein the HPC has a cloud point of at least 41.degree. C. 4. The formulation according to claim 1, wherein the enteric coating layer comprises a methacrylic acid copolymer. 5. The formulation according to claim 1, wherein the HPC has a low viscosity. 6. The formulation according to claim 1, wherein the active ingredient is omeprazole. 7. The formulation according to claim 1, wherein the active ingredient is a magnesium salt of omeprazole. 8. The formulation according to claim 1, wherein the active ingredient is a magnesium salt of the (-)-enantiomer of omeprazole. 9. The formulation according to claim 1, wherein the core material further comprises an alkaline reacting compound. 10. The formulation according to claim 1 or 9, wherein the core material further comprises a pharmaceutically acceptable excipient selected from the group consisting of binding agents, fillers, lubricants, disintegrating agents, surfactants and mixtures thereof. 11. A method for the treatment of gastrointestinal diseases in mammals comprising administering to a host in need thereof a therapeutically effective amount of the pharmaceutical formulation according to any one of claims 2-8 or 1. 12. A process for the manufacture of an enteric coated oral pharmaceutical formulation according to claim 1, comprising the steps: (a) forming the core material comprising the active ingredient; (b) applying the separating layer onto the core; and (c) applying the enteric coating layer onto the core coated with the separating layer. 13. The process according to claim 12, wherein an alkaline reacting compound is mixed with the active ingredient to form the core material. 14. The process according to claim 12 or 13, wherein a pharmaceutically acceptable excipient selected from the group consisting of binding agents, fillers, lubricants, disintegrating agents, surfactants and mixtures thereof is added to form the core material. 15. The process according to claim 12, wherein an alkaline reacting compound is mixed with the active ingredient and a binding agent to form the core material. 16. The process according to claim 12, wherein the HPC has a cloud point of at least 40.degree. C. 17. The process according to claim 12, wherein the HPC has a cloud point of at least 41.degree. C. 18. The process according to claim 12, wherein the enteric coating layer comprises a methacrylic acid copolymer. 19. The process according to claim 12, wherein the HPC has a low viscosity. 20. The process according to claim 12, wherein the active ingredient is omeprazole. 21. The process according to claim 12, wherein the active ingredient is a magnesium salt of omeprazole. 22. The process according to claim 12, wherein the active ingredient is a magnesium salt of the (-)-enantiomer of omeprazole.