Patent ID: 6117451
Filing Date: 2000-09-12
Classification: A61K,Y10S

Abstract:
A metformin HCl formulation in the form of a tableting powder, capable of being directly compressed into a tablet, which comprises:(a) 70 to 79% by weight on a dry weight basis of metformin HCl having a particle size range of about 400 to 600 microns and a density range of 0.75 to 0.90 g/ml;(b) 10 to 20% by weight on a dry weight basis of a pharmaceutically acceptable hydroxypropyl methylcellulose having a number average molecular weight of 80,000 to 90,000, a particle size range of about 400 to 600 microns and a density range of 0.25 to 0.70 g/ml as a diluent and binder;(c) 0.1 to 15% by weight on a dry weight basis of a pharmaceutically acceptable hydroxypropyl cellulose having a number average molecular weight of 800,000 to 1,200,000 and a particle size range of about 177 to 590 microns as a diluent and binder;(d) 5 to 15% by weight on a dry weight basis of a pharmaceutically acceptable polymerized povidone having a number average molecular weight of 300,000 to 1,000,000 as a binder capable of bonding the other ingredients in this composition under direct pressure into tablet form;(e) 1 to 10% by weight on a dry weight basis of a pharmaceutically acceptable dibasic calcium phosphate in the form of spherically granulated particles having a particle size range of 400 to 450 microns, an angle of repose of 28 to 35 degrees, and a density range of 0.35 to 0.60 g/ml to improve flow and compression characteristics of the tableting powder;(f) 1 to 10% by weight on a dry weight basis of microcrystalline cellulose, having a density range of 0.2 to 0.45 g/ml, which is compressible into a tablet;(g) 0.1 to 2% by weight on a dry weight basis of colloidal silicon dioxide, having a density range of 0.029 to 0.040 g/ml as a glidant to improve flow characteristics of the tableting powder; and(h) 0.1 to 2% by weight on a dry weight basis of a pharmaceutically acceptable solid lubricant having a particle size of about 450 to 550 microns and a density of 1.00 to 1.80 g/ml to facilitate compression and ejection of tablets from a die cavity used in the tableting process.