Patent ID: 9532991
Date: 2017-01-03
CPC Classifications: A61K,A61P

Claim:
1. Microspheres for sustained release of an active agent comprising: an active agent selected from the group consisting of risperidone, 9-hydroxy risperidone, and a salt thereof; and a polymer blend consisting of a first uncapped poly(lactide-co-glycolide) having a first carboxyl terminal group and a second uncapped poly(lactide-co-glycolide) having a second carboxyl terminal group; wherein the first uncapped poly(lactide-co-glycolide) has a molecular weight from 55,000 to 85,000 and a molar ratio of lactide to glycolide in a range from 65:35 to 90:10; wherein the second uncapped poly(lactide-co-glycolide) has a molecular weight from 15,000 to 35,000 and a molar ratio of lactide to glycolide in a range from 50:50 to 75:25; wherein a weight ratio of the first uncapped poly(lactide-co-glycolide) to the second uncapped poly(lactide-co-glycolide) is in a range from 50:50 to 95:5; and wherein the active agent is encapsulated in the polymer blend and the active agent is in an amount of from 10% to 60% based on a total weight of the microspheres.