	US 11,744,803 B2
	PH-controlled pulsatile delivery system, methods for preparation and use thereof
Reinout Cornelus Andreas Schellekens, Groningen (NL); and Henderik Willem Frijlink, Eelde (NL)
Assigned to Stichting Groningen Centre for Drug Rese, Groningen (NL)
Appl. No. 11/989,112
Filed by Reinout Cornelus Andreas Schellekens, Groningen (NL); and Henderik Willem Frijlink, Eelde (NL)
PCT Filed Jul. 29, 2005, PCT No. PCT/NL2005/000559 § 371(c)(1), (2), (4) Date Mar. 2, 2009, PCT Pub. No. WO2007/013794, PCT Pub. Date Feb. 1, 2007.
Prior Publication US 2009/0181089 A1, Jul. 16, 2009
Int. Cl. A61K 9/48 (2006.01); A61K 9/28 (2006.01); A61K 31/00 (2006.01)

CPC A61K 9/4891 (2013.01) [A61K 9/286 (2013.01); A61K 9/2846 (2013.01); A61K 9/2866 (2013.01); A61K 31/00 (2013.01)]

20 Claims

1. A release system comprising:

a core comprising an active substance, and,

surrounding the core, a coating layer comprising a swellable agent embedded in pH-sensitive coating material,

wherein the swellable agent is embedded in a continuous matrix of the pH-sensitive coating material at a concentration below the percolation threshold of the swellable agent in the continuous matrix of the pH-sensitive coating material,

wherein the swellable agent, in its dry form, is able to take up at least five times its weight in water; and

wherein the embedded swellable agent is dispersed within the pH-sensitive coating material in the coating layer and is shielded from fluids by the pH-sensitive coating material.