Controlled release tacrine drug delivery systems and methods for preparing same

摘要

The present invention pertains to controlled release tacrine drug delivery systems comprising an immediate release composition and a sustained release composition wherein (1) the immediate release composition comprises in percentages by weight of the immediate release composition: (A) immediate release pellets comprising: (a) nonpareil seeds in an amount from about 25% to about 75%; (b) tacrine in an amount from about 10% to about 80%; and (c) a binding agent in an amount from about 1% to about 10%; and (B) a sealing layer over the immediate release pellets comprising: (a) a sealing agent in an amount up to about 6%, and (b) a first plasticizing agent in an amount up to about 5%; and (2) the sustained release composition comprises in percentages by weight of the sustained release composition; (A) the immediate release composition; and (B) a sustaining layer over the immediate release composition comprising; (a) a water-insoluble polymer in an amount from about 40% to about 90%; (b) a water-soluble polymer in an amount up to about 10%; and (c) a second plasticizing agent in an amount up to about 10%; wherein the sustaining layer and the immediate release composition are present in the sustained release composition in a ratio by weight from about 1:9 to about 4:6, respectively, and the immediate release composition and the sustained release composition are present in the drug delivery system in a ratio by weight from about 0.01:1 to about 1:1, respectively.