Sustained release parenteral formulations of buprenorphine

An oil-in-water buprenorphine formulation including buprenorphine and a surfactant that emulsifies the buprenorphine in oil, wherein the drug release is controlled by varying the oil concentration and/or pH. A buprenorphine aqueous suspension formulation including a free base buprenorphine and a suspension stabilizer. A buprenorphine oil formulation including a buprenorphine salt suspended…