CONTROLLED RELEASE MULTIPLE LAYER COATINGS

摘要

A process for making controlled release pharmaceutical formulations is provided, which comprises supplying a plurality of solutions with syringe pumps for fluid bed coating, coating a substrate with a pH dependent soluble polymer solution, coating the polymer coated substrate with at least one layer of a solution of a therapeutically active substance and at least one layer of a second polymer solution, and alternating the layers so that the number, order, and volume of the layers controls the release of the therapeutically active substance. In alternate embodiments, the consecutively applied layers may contain coating materials, active ingredients or a mixture of coating materials and active ingredients; the layers can be applied in varying order. Also provided is a system for applying the coatings, wherein the syringe pumps are controlled by a computer in accordance with predetermined instructions.