# US 4,859,461 A · Coatable ion exchange resins

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- Number: US 4,859,461 A
- Document ID: US4859461A
- Status: Granted
- Kind: A
- Application number: 07/046,378
- Filed: 1987-05-04
- Granted: 1989-08-22
- Earliest claimed: 1986-07-30
- Assignees: Fisons Limited
- Inventors: San-Laung Chow; Yegnaswami Raghunathan
- Web page: https://patentgrep.com/patent/US4859461A

## CPC

- A61K 9/5047: {Cellulose ethers containing no ester groups, e.g. hydroxypropyl methylcellulose}
- A61K 9/1623: {Sugars or sugar alcohols, e.g. lactose; Derivatives thereof; Homeopathic globules}
- A61K 9/1635: {obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates}
- A61K 9/1652: {Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin (homeopathic globules A61K9/1623)}
- A61K 47/585: {Ion exchange resins, e.g. polystyrene sulfonic acid resin}
- 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

Sulfonic acid cationic exchange resin particles which have been treated to improve their coatability with up to about 20% by weight of a compound selected from hydroxypropylmethyl cellulose, hydroxypropyl cellulose, hydroxypropyl sorbitol, sorbitol, and polyvinylpyrrolidone.

## Claims

### Claim 1

A process for enhancing the coatability of sulfonic acid cationic exchange resin particles which comprises contacting said particles with an aqueous solution containing from at least about 3% to about 20% by weight of an impregnating agent, based on the combined weight of the impregnating agent and the particles, said agent being selected from the group consisting of hydroxypropylmethyl cellulose, hydroxypropyl cellulose, sorbitol, hydroxypropyl sorbitol, and polyvinylpyrrolidone, and thereafter individually coating said particles with a waterpermeable diffusion barrier.

### Claim 2 (depends on 1)

The process of claim 1 wherein the impregnating agent is hydroxypropylmethyl cellulose.

### Claim 3 (depends on 1)

The process of claim 1 wherein the impregnating agent is hydroxypropyl cellulose.

### Claim 4 (depends on 1)

The process of claim 1 wherein the impregnating agent is sorbitol.

### Claim 5 (depends on 1)

The process of claim 1 wherein the impregnating agent is hydroxypropyl sorbitol.

### Claim 6 (depends on 1)

The process of claim 1 wherein the impregnating agent is polyvinylpyrrolidone.