Claims for Patent: 7,919,116

Summary for Patent: 7,919,116

Title:	Controlled release metformin formulations
Abstract:	Sustained release pharmaceutical formulations comprising an antihyperglycemic drug or a pharmaceutically acceptable salt thereof are disclosed. The formulations provide therapeutic plasma levels of the antihyperglycemic drug to a human patient over a 24 hour period after administration.
Inventor(s):	Chen; Chih-Ming (Taipei, TW), Cheng; Xiu Xiu (Weston, FL), Jan; Steve (Coral Springs, FL), Chou; Joseph (Manassas, VA)
Assignee:	Andrx Labs, LLC (Davie, FL)
Application Number:	11/713,143
Patent Claims:	1. A method of treating a human diabetic patient with an oral solid sustained release tablet of metformin hydrochloride, comprising: administering the sustained release tablet to the human diabetic patient once a day under fed conditions, wherein the sustained release tablet comprises (i) metformin hydrochloride and (ii) a sustained release material, wherein the tablet does not employ an expanding polymer, the sustained release tablet provides therapeutic plasma levels of said metformin to the human patient over a 12 to 24 hour period after administration; and the sustained release tablet exhibits the following in vitro dissolution profile when tested in a USP Type 2 apparatus at 75 rpms in 900 ml of a pH 7.5 phosphate buffer and 37.degree. C.: 0-25% of the metformin is released after 2 hours; 10-45% of the metformin is released after 4 hours; 30-90% of the metformin is released after 8 hours; not less than 50% of the metformin is released after 12 hours; not less than 60% of the metformin is released after 16 hours and not less than 70% of the metformin is released after 20 hours. 2. The method as defined in claim 1 wherein the tablet exhibits the following in vitro dissolution profile when tested in a USP Type 2 apparatus at 75 rpms in 900 ml of a pH 7.5 phosphate buffer and 37.degree. C.: 0-15% of the metformin is released after 2 hours; 20-40% of the metformin is released after 4 hours; 45-90% of the metformin is released after 8 hours; not less than 60% of the metformin is released after 12 hours; not less than 70% of the metformin is released after 16 hours and not less than 80% of the metformin is released after 20 hours. 3. The method of claim 1 wherein the tablet is administered with or after a meal. 4. The method of claim 1 wherein the tablet is administered with or after evening meal. 5. The method of claim 1 wherein the tablet is an osmotic tablet with a homogeneous osmotic core.