Pharmaceutical preparations and substances for the treatment of pain, neuropathic pain, cancer pain, perioperative pain, oncology, cancer symptoms, multiple sclerosis, spasticity, convulsions, seizures, epilepsy, paediatric epilepsy, intractable childhood epilepsy with generalized tonic-clonic seizures (ICE-GTC), generalized epilepsy with febrile seizures plus (GEFS+), dup 15, Doose syndrome, bladder dysfunction, inflammatory bowel disease, ulcerative colitis, Crohn's disease, Alzheimer's, Dr...