Sustained-release theophylline tablet

• US 6,426,091 B1
• Filed: 03/21/2000
• Issued: 07/30/2002
• Est. Priority Date: 09/30/1997
• Status: Expired due to Fees

• Current Assignee: Kowa Pharmaceutical Co., Ltd. /Old/ (KOWA Company Limited)
• Original Assignee: Kowa Pharmaceutical Co., Ltd. /Old/ (KOWA Company Limited)
• Inventors: Sunohara, Masaaki, Kamakura, Minoru, Okumura, Mutsuo
• Primary Examiner(s): Page, Thurman K.
• Assistant Examiner(s): Bennett, Rachel M.
• Application Number:
  US09/509,322
• Time in Patent Office: 861 Days
• Field of Search: 424/464, 424/465, 424/490, 424/494, 424/495, 424/497, 424/486, 424/487
• US Class Current: 424/468
• CPC Class Codes: A61K 31/522 having oxo groups directly attached to the heterocyclic ring, e.g. hypoxanthine, guanine, acyclovir
• CPC Class Codes: A61K 9/2081 with microcapsules or coated microparticles according to A61K9/50
• CPC Class Codes: A61K 9/5026 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• CPC Class Codes: A61K 9/5047 Cellulose ethers containing no ester groups, e.g. hydroxypropyl methylcellulose
• CPC Class Codes: A61P 11/06 Antiasthmatics

Abstract

A theophylline sustained release tablet obtained by coating core granules composed mainly of theophylline with a layer of a coating film composed of a hydrophobic material and a plastic excipient and optionally containing an enteric polymer material to form coated granules and then by compressing the coated granules together with a disintegrating excipient.

Claims

1. A theophylline sustained release tablet comprising (i) core granules having a theophylline content of 98% or more, (ii) at least one coating film layer composed of a hydrophobic material, and a plastic excipient to form coated granules and (iii) a disintegrating excipient, and coated granules and said disintegrating excipient being compression molded to form the theophylline sustained release tablet, wherein the sustained release action is obtained by the tablet disintegrating into the coated granules that are dispersed immediately and the theophylline is gradually dissolved from the dispersed coated granules.

2. A theophylline sustained release tablet as claimed in claim 1, wherein the coated granules are obtained by coating core granules mainly composed of theophylline coated with at least one layer coating film composed of a hydrophobic material, an enteric polymer material and a plastic excipient.

3. A theophylline sustained release tablet as claimed in claim 1 or 2, wherein the core granules mainly composed of theophylline have a high hardness, a particle size of 50 to 1700 μ

m.

4. A theophylline sustained release tablet as claimed in claim 1 or 2, wherein the coated granules are coated with two layers.

5. A theophylline sustained release tablet as claimed in claim 1 or 2, wherein the coated granules are a mixture of at least two coated granules having different coating compositions or coating amounts.

6. A theophylline sustained release tablet as claimed in claim 1 or 2, wherein the hydrophobic material in the coating is a water insoluble polymer material.

7. A theophylline sustained release tablet as claimed in claim 1 or 2, wherein the plastic excipient in the coating is triethyl citrate, glyceryl fatty acid ester, cetanol, hardened castor oil, hardened rapeseed oil, or carnauba wax.

8. A theophylline sustained release tablet as claimed in claim 2, wherein the enteric polymer material in the coating is a methacrylic acid copolymer or hydroxypropylmethylcellulose phthalate.

9. A theophylline sustained release tablet as claimed in claim 1 or 2, wherein the amount of the coating in the coated granules is 5 to 50 parts by weight based upon 100 parts by weight of the core granules.

10. A theophylline sustained release tablet as claimed in claim 1 or 2, wherein the amount of the disintegrating excipient is 5 to 15 parts by weight based upon 100 parts by weight of the theophylline.

12. A theophylline sustained release tablet as claimed in claim 6, wherein the water insoluble polymer material is selected from the group consisting of ethylcellulose, ethyl acrylate-methyl methacrylate copolymers, and amino alkyl-methacrylate polymers.

11. A theophylline sustained release tablet comprising (i) core granules having a theophylline content of 98% or more, (ii) 5 to 50 parts by weight, based upon 100 parts by weight of the core granules, of at least one coating film layer composed of a hydrophobic material and a plastic excipient to form coated granules, and (iii) 1 to 25 parts by weight, based upon parts by weight of theophylline of a disintegrating excipient, and coated granules and said disintegrating excipient being compression molded to form the theophylline sustained release tablet, wherein the the sustained release action is obtained by the tablet disintegrating into the coated granules that are dispersed immediately and the theophylline is gradually dissolved from the dispersed coated granules.

13. A theophylline sustained release tablet as claimed in claim 11, wherein the coated granules are obtained by coating core granules mainly composed of theophylline coated with at least one layer coating film composed of a hydrophobic material, an enteric polymer material, and a plastic excipient.