A method for making a modified release composition, comprising:selecting a desired active agent and polymer matrix for formulating into a modified release composition；assessing degradation effect on release of the active agent from the composition including plotting polymer molecular weight (Mwr) at onset of active agent release vs. active agent molecular weight (MwA)；predicting performance of multiple potential formulations for the composition based on the degradation assessment and average polymer matrix initial molecular weight (Mwo) to define a library of building blocks；determining the optimal ratio of the building blocks to satisfy a specified release profile； andmaking a modified release composition based on the optimal ratio determination.
