Delayed release formulations and processes for making them

Abstract

Abstract There is disclosed a granular composition having particles of average particle size as determined by sieving in the range 70 to 500 microns, the said particles comprising up to 55% of active ingredient e.g. ferrous sulphate having primary particles the maximum dimension (A) of which as determined by microscopy is less than 50 microns and a particulate water soluble extender e.g. lactose having an average particle size (B) as determined by sieving in excess of 50 microns, the particles of active ingredient and water soluble extender being held in self-supporting spaced relationship by a water insoluble polymer film matrix e.g. of a polyacrylate polymer, providing the balance of the weight of the particle and being less than 50% by weight of the particle. The invention also extends to a blend convertible by pressure alone to a substantially continuous three-dimensional porous matrix substantially devoid of separate resin particles, of active ingredient/water soluble extender/resin particles, e.g. as above, in which the active ingredient comprises 45 to 60%, the water soluble extender comprises 35 to 45%, and the resin comprises 5 to 15% by weight and a water insoluble extending agent or filler for the matrix resin and a water soluble or insoluble tableting aid or lubricant, the active ingredient/water soluble extender/resin particles comprising 80 to 95%, the water insoluble extending agent or filler for the matrix resin comprising 5 to 15% and the lubricant 0.2 to 5% of the blend.

Inventors

• 👤 Anthony J. Trill

Bibliographic Details