A formulation is provided that includes a volume of an aqueous multivalent physiological ion solution compatible with cerebrospinal fluid containing at least one divalent cation of magnesium or calcium, and at least one anion of carbonate or phosphate, and having a pH between 6.5 and 8.0. A zwitterionic therapeutic agent other than baclofen is dissolved the solution to achieve higher concentration or ease of solution and/or storage relative to therapeutic saline solutions of the same agent. A process of delivering a zwitterionic therapeutic agent into a subject is provided that includes dissolving a therapeutic amount of the zwitterionic therapeutic agent in a volume of artificial cerebrospinal fluid to form a stable formulation. The solution is then administered to the subject using an intrathecal pump.