Patent ID: 8399475

Claim:
A crystalline form of naltrexone hydrochloride hydrate selected from the group consisting of: (a) Form II having an x-ray diffraction pattern having characteristic peaks expressed in degrees 2θ (±0.2°) at 8.0, 10.8, 11.7, 12.9, 15.9, 17.1, 18.5, 20.8, 23.5, and 26.4; (b) Form VIII having an x-ray diffraction pattern having characteristic peaks expressed in degrees 2θ (±0.2°) at 11.4, 11.8, 13.1, 13.5, 15.9, 19.6, 22.6, 23.1, 24.5, and 25.8; and (c) Form XI having an x-ray diffraction pattern having characteristic peaks expressed in degrees 2θ (±0.2°) at 8.3, 11.5, 11.9, 16.5, 17.2, 21.9, 23.8, and 27.3.