Patent ID: 6221399
Filing Date: 2001-04-24
Classification: A61K

Abstract:
A method of making a solid interpolymer complex for use as a controlled release matrix for a controlled release product for oral administration, from a first polymer and one or more second complementary polymers capable of complexing with the first polymer to form the interpolymer complex, wherein one of the first polymer or the second complementary polymer is a synthetic polymer, which method includes the steps of:(1) dissolving the first polymer in a solvent;(2) dissolving the second complementary polymer in a solvent therefor, the solvent for said second polymer being the same as that used for step (1) or different;(3) the solvent in at least one of step (1) or (2) functioning as a complexation inhibitor or adding a complexation inhibitor to the solution of step (1) or the solution of step (2), so that a complexation inhibitor is present to prevent the interpolymer complex from precipitating from solution prior to step (6);(4) mixing together the solutions of steps (1) and (2);(5) if necessary, adjusting the pH of the mixture of step (4) to insure the desired complexation when solvent is removed while avoiding precipitation of the complex; and(6) spraying the resulting solution into a vessel to remove solvent, including any complexation inhibitor added thereto, to enable the polymers to complex and thereby produce solid particles of said complex.