Patent ID: 9636308
Date: 2017-05-02
CPC Classifications: A61K

Claim:
1. A method of making sustained release microsphere formulation having a high buprenorphine drug load, comprising: providing a dispersed phase by mixing an encapsulating polymer, a primary solvent, a pharmaceutically effective amount of a salt form of buprenorphine having a solubility relative to the dispersed phase, and a co-solvent capable of increasing the solubility of the buprenorphine relative to the dispersed phase; wherein the ratio of the primary solvent to the co-solvent in the dispersed phase is 2:1 by weight, and wherein the primary solvent is dichloromethane and the co-solvent is benzyl alcohol; providing a continuous phase comprising an aqueous solution; mixing the dispersed phase with the continuous phase to form a microsphere formulation; and preparing a pharmaceutically acceptable microsphere suspension suitable to be delivered to a patient.