Pharmaceutical formulations comprise a mono- or di-aminopyridine active agent for administration on a once- or twice-daily basis for use in the treatment of neurological diseases, in particular multiple sclerosis and Alzheimer's disease. The formulations, which are suitable for oral or percutaneous administration of the active agent, include the active agent in a carrier effective to permit release of the mono- or di-aminopyridine at a rate allowing controlled absorption thereof over, on the average, not less than a 12 hour period and at a rate sufficient to achieve therapeutically effective blood levels over a period of 12-24 hours following administration.
