“…A conceivable reduction of the number of relapses may, hFwever, be achieved by giving the psychotropic drug as a preparation with prolonged effect, e. g. an esterified drug dissolved in oil and administered by intramuscular injection (Bethell et al (1966), Crompton (1967). Convenient for such a preparation are solely drugs with a high therapeutic effect per milligram, as only a limited amount of the drug citn be given by each injection.…”