Patent ID: 9393211
Filing Date: 2016-07-19
CPC Classification: A61K

Claim Text:
1. A method of making a sustained release microsphere formulation having a high buprenorphine drug load, the method comprising the steps of: providing a dispersed phase by mixing an encapsulating polymer, a primary solvent, a pharmaceutically effective amount of buprenorphine free base having a solubility relative to the dispersed phase, and a co-solvent capable of increasing the solubility of the buprenorphine free base relative to the dispersed phase; wherein the ratio of the primary solvent to the co-solvent in the dispersed phase is 2:1 by volume, 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 micro sphere formulation; wherein the microsphere formulation prepared in the presence of the 2:1 volume ratio of dichloromethane to benzyl alcohol in the dispersed phase has at least a two-fold increase in the release rate of buprenorphine free base compared to a release rate of the microsphere formulation prepared without the addition of benzyl alcohol in the dispersed phase.