# US 9,005,661 B2 · Osmotic pump controlled release tablet and preparation method thereof

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- Number: US 9,005,661 B2
- Document ID: US9005661B2
- Status: Granted
- Kind: B2
- Application number: 13/496,454
- Filed: 2010-04-29
- Published: 2012-07-05
- Granted: 2015-04-14
- Earliest claimed: 2009-09-15
- Assignees: Beijing Team Hospital Management Co., Ltd.
- Applicants: Qingwei Jiang; Weifeng Yi; Quanzhi Liu; Wenbin Yang; Junli Zheng
- Inventors: Qingwei Jiang; Weifeng Yi; Quanzhi Liu; Wenbin Yang; Junli Zheng
- Web page: https://patentgrep.com/patent/US9005661B2

## CPC

- A61K 9/0004: {Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas}
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)

## Abstract

An osmotic pump controlled release tablet and the preparation method thereof are disclosed. The osmotic pump controlled release tablet is composed of tablet core, semipermeable membrane and optional film coating. The material of said semipermeable membrane is composed of ethyl cellulose and povidone in the ratio of 1:1˜1:4 by weight. Said tablet core comprises drug containing layer and push layer. The osmotic pump controlled release tablet also characterizes in that; (1) the angle θ1 formed by the outer curved surface of the drug containing layer and the lateral surface is 120°-180°; and/or (2) the ratio of L1 to r is 0.27-1.0, wherein L1 is the vertical distance from the central vertex of the outer curved surface of the drug containing layer to the plane formed by the intersection line between the outer curved surface of the drug containing layer and the lateral surface, and r is the radius of the tablet core.

## Claims

### Claim 1

An oral osmotic pump controlled release tablet comprising ethyl cellulose and povidone as film forming materials of a semipermeable membrane, the osmotic pump controlled release tablet including a tablet core, a semipermeable membrane and an optional film coating layer, wherein the weight ratio of ethyl cellulose and povidone is 1:1 to 4:1; and wherein the tablet core comprises a drug-containing layer and a push layer, wherein:
(1) an angle θ1 formed by an outer curved surface of the drug-containing layer and a lateral surface of the drug-containing layer is 130°-180°, and an angle θ2 formed by an outer curved surface of the push layer and a lateral surface is 95°-120°, and
(2) a ratio of L1/r is 0.36-1.0, wherein L1 is a vertical distance from a central vertex of the outer curved surface of the drug containing layer to a plane formed by an intersection line between the outer curved surface of the drug containing layer and the lateral surface, and r is a radius of the tablet core, and a ratio L2/r is 0.04-0.27, wherein L2 is a vertical distance from a central vertex of the outer curved surface of the push layer to a plane formed by an intersection line between the outer curved surface of the push layer and the lateral surface, and r is a radius of the tablet core.

### Claim 2 (depends on 1)

A method for preparing the oral osmotic pump controlled release tablet of claim 1, wherein said method comprises coating the semipermeable membrane on the tablet core.

### Claim 3 (depends on 1)

The oral osmotic pump controlled release tablet according to claim 1, wherein the angle θ1 is 130° to 170°, and the ratio L1/r is 0.36-0.84.

### Claim 4 (depends on 1)

The oral osmotic pump controlled release tablet according to claim 1, wherein the angle θ1 is about 150°, and the ratio L1/r is about 0.58.

### Claim 5 (depends on 1)

The oral osmotic pump controlled release tablet according to claim 1, wherein the angle formed by the outer curved surface of the drug-containing layer and the lateral surface is about 150°, and the ratio L1/r is about 0.58.

### Claim 6 (depends on 1)

The oral osmotic pump controlled release tablet according to claim 1, wherein a pushing agent for the push layer is selected from the group consisting of methyl cellulose, hydroxypropyl cellulose, hypromellose, polyethylene, carbomer, sodium carboxymethyl starch, carboxymethyl cellulose or sodium salt thereof, cross-linked carboxymethyl cellulose sodium, and a combination thereof.