A novel method for the preparation of a highly densified and at least partly, preferably fully or almost fully hydrated ceramic for use in the preparation of a pharmaceutical composition notably for controlled-release of one or more therapeutically, prophylactically and/or diagnostically active substance. The method involves a concomitant step of hydrating and densifying a bioresorbable and hydratable ceramic such as calcium sulphate. The invention also relates to compositions comprising such a highly densified ceramic. The pharmaceutical composition is useful for targeted and controlled local prolonged release of active substances, e.g. anti-cancer agents, whereby the spectrum and severity of side effects are minimized due to an optimized local concentration-time profile.