The present invention relates to a granule comprising a solid core on which is supported an active ingredient, said active ingredient being selected from gamma-hydroxybutric acid or one of its pharmaceutically acceptable salts, said granule further comprising, supported on said solid core, one or more compounds which may generate gas evolvement, one or more diluents, said granule being in that it is coated with a membrane, and in that the solid core represents from 15% to 50% by weight based on the total weight of the granule.本發明係有關於一種包括固體核心其上支載有活性成分之顆粒，該活性成分係選自於γ-羥基丁酸或其醫藥上可接受之鹽類中之一，該顆粒進一步包括支載於該固體核心上的可產生氣體釋放之一或多個化合物、一或多個稀釋劑，該顆粒係為以膜包衣，及以該顆粒之總重為基準，該固體核心係占15重量%至50重量%。
