The invention concerns a galenic system with prolonged/controlled release of the medicinal and/or nutritional active principle, for oral administration. The aim is to provide a system enabling to obtain with one single tolerable and acceptable dose of active principle, efficient therapeutic protection over 24 hours (increasing the bioabsorption time without affecting bioavailability). To achieve this, the invention provides a composition comprising two controlled release systems associated in series, namely: individualised coated particles (microcapsules) of active principle forming an internal phase, the coating comprising a film-forming polymer P1 (ethylcellulose), a nitrogenous polymer (polyvinylpyrrolidone), a softener (castor oil) and a lubricant (magnesium stearate), and an external phase of functional carriers: polyelectrolytic hydrophilic polymer: (alginate), neutral hydrophilic polymer (hydroxypropylmethylcellulose) and a gelling additive (calcium acetate), said composition spontaneously forming in the presence of water, a cohesive and stable composite macroscopic solid, wherein the external continuous phase is a gelled matrix including the active principle microcapsules. The invention is useful for delayed oral galenic formulation of metformin.