Abstract: Raloxifene acid addition salts or solvates thereof, having improved dissolution properties in media comprising hydrochloric acid are described, compared with similar preparations based on raloxifene or raloxifene hydrochloride. The disclosed acid addition salts or solvates thereof show an improved bioavailability in media comprising hydrochloric acid, such as the gastric juice. The acid addition salts or solvates thereof are addition salts or solvates of raloxifene and a pharmaceutical acceptable acid selected among succinic acid, lactic acid, malonic acid or sulphuric acid. Further, crystalline forms of the raloxifene salts and solvates thereof are disclosed. The raloxifene acid addition salts and/or solvates thereof are useful for the preparation of pharmaceutical composition for oral administration capable of fast and reliable release of the active ingredients in the stomach of the patient, in particular for the treatment of cancer or osteoporosis, or for inhibiting cartilage degradation.