Claims for Patent: 4,863,743

Summary for Patent: 4,863,743

Title:	Controlled release potassium chloride
Abstract:	A controlled release potassium chloride tablet is disclosed which is comprised of potassium chloride crystals having a mesh size of about 30 to about 50 mesh which are coated with a coating material comprised of ethylcellulose and hydroxypropylcellulose. The coated crystals form micro pellets which then can be compressed into tablets. The tablets disintegrate rapidly in an aqueous environment thus assuring a more uniform dissolution of the active component as compared with other types of controlled release potassium chloride dosage formulations. The distribution of the potassium chloride micro pellets over a wide surface area in the gastrointestinal mucosa aids in reducing the risk of gastrointestinal lesions. The formation of the coated micro pellets which disperse quickly upon contact with aqueous environment allow for the repeated chronic oral administration of a relatively large dose of potassium chloride (20 mEq).
Inventor(s):	Hsiao; Charles (Cooper City, FL), Chou; Chi T. (Monsey, NY)
Assignee:	Key Pharmaceuticals, Inc. (Kenilworth, NJ)
Application Number:	06/830,981
Patent Claims:	1. A pharmaceutical dosage unit in tablet form for oral administration of potassium chloride, comprising; a plurality of coated potassium chloride crystals, the amount of potassium chloride being in the range of about 64% to about 86.5% by weight based on the total weight of the dosage unit; a coating material for the individual potassium chloride crystals, the coating material comprising ethylcellulose in the amount in the range of about 9% to about 15% by weight based on the total weight of the coated crystals and at least one member selected from hydroxypropylcellulose and polyethylene glycol in an amount in the range of about 0.5% to about 3% by weight based on the total weight of the coated crystals and said ethylcellulose has a viscosity greater than 40 cp. 2. A pharmaceutical dosage unit as claimed in claim 1, wherein the tablet is further comprised of magnesium stearate in an amount in the range of about 0.5% to 2.0% by weight based on the total weight of the tablet. 3. A pharmaceutical dosage unit as claimed in claim 2, wherein the tablet is further comprised of a microcrystalline cellulose in an amount in the range of about 3 to 10% by weight based on the total weight of the tablet. 4. A pharmaceutical dosage unit as claimed in claim 3, further comprising cross-linked polyvinylpyrolidone in an amount in the range of about 0.5 to about 2.0% by weight based on the total weight of the tablet. 5. A pharmaceutical dosage unit as claimed in claim 1, wherein the potassium chloride is in the form of crystals which have a mesh size in the range of about 30 to about 50 mesh. 6. A pharmaceutical dosage unit as claimed in claim 5, wherein the potassium chloride crystals have a mesh size of about 40 mesh. 7. A pharmaceutical dosage unit as claimed in claim 1, wherein the ethylcellulose has a viscosity of from 85 to 110 cp. 8. A pharmaceutical dosage unit as claimed in claim 1, wherein the member selected from hydroxypropylcellulose and polyethylene glycol is hydroxypropylcellulose. 9. A pharmaceutical unit as claimed in claim 1, wherein the member selected from hydroxypropylcellulose and polyethylene glycol is polyethylene glycol. 10. A method of providing potassium to a subject in need of potassium, comprising administering to the subject a therapeutically useful amount of potassium chloride in a dosage unit according to claim 1. 11. The method of claim 10, wherein the dosage unit is disintegrated in water or on an aqueous food prior to administration. 12. The pharmaceutical dosage unit in tablet form of claim 2 comprising: 68-86.5% by weight of coated potassium chloride crystals; 0.5-3% by weight of magnesuim stearate; 3-15% by weight of microcrystalline cellulose; 0.5-2.0% by weight cross-linked polyvinyl pyrrolidone; wherein the individual potassium chloride crystals are coated with a material comprising ethyl cellulose in an amount in the range of about 9% to about 15% by weight based on the total weight of the coated crystals and at least one member selected from hydroxypropylcellulose and polyethlene glycol in an amount in the range of about 0.5% to about 3% by weight based on the total weight of the coated crystals.