7 Dexedrine slow release 'spansules' containing 10 mg of the active ingredient dexamphetamine. Contained within a plastic case manufactured by Menley and James. Smith Kline and French introduced Dexedrine, to treat psychiatric patients, and suffering from depression, fatigue, listlessness and narcolepsy. Launched in 1952, it was the first medicine to be supplied in a sustained-release capsule known as a Spansule. Patients could take one capsule, and the drug would be slowly released 8 to 10 hours.