Patent ID: 6294200
Filing Date: 2001-09-25
Classification: A61K

Abstract:
A tablet for pharmaceutical use suitable to release the active substances in subsequent and predetermined times, comprising a three layered core covered by a partial coating layer, said core having the following structure:an upper layer consisting of active substance and suitable excipients to allow a fast release of the active substance when the tablet comes into contact with an aqueous medium;an intermediate layer whose composition comprises polymeric material suitable to form a barrier able to determine a time interval between the release of the active substance contained in the upper layer and the active substance contained in the lower layer,a lower layer comprising one or more active substances and having the same or a different composition as the upper layer, said lower layer allowing the controlled release of said active substances;and wherein said partial coating layer consists of granulated polymeric substances, adjuvant substances and plasticizing agents applied by compression on the whole lateral surface and on the lower base of said three layered core thus forming an impermeable barrier which resists dissolution for a predetermined period of time while allowing for the release of the active substance both from the upper layer and from the lower layer, said polymeric substances being selected from hydroxypropylmethylcellulose having viscosity between 4,000 and 100,000 cP when measured at 20.degree. C. in a 2% aqueous solution.