Oxymorphone, generally administered in the form of its hydrochloride salt, is a potent semi-synthetic opiate analgesic. Oxymorphone hydrochloride is indicated for the relief of moderate to severe pain and has been approved for use in the United States since 1959. Oxymorphone hydrochloride is also indicated as a pre-operative medication to alleviate apprehension, maintain anesthesia and as an obstetric analgesic. Additionally, oxymorphone hydrochloride may be used to alleviate pain in patients with dyspnea associated with acute left ventricular failure and pulmonary edema. It can be administered as an injectable solution, suppository, tablet or extended release tablet.
Some crystalline forms of oxymorphone hydrochloride are known. U.S. Pat. No. 8,563,571 describes oxymorphone hydrochloride crystalline Form A as a commercially produced form of oxymorphone hydrochloride. U.S. Pat. No. 8,563,571 also describes oxymorphone hydrochloride crystalline Form B. Other crystalline forms, including mixtures of forms, of oxymorphone hydrochloride are described in U.S. Pat. No. 7,851,482, U.S. Pat. No. 8,563,571 and WO 2012/163796.