The invention relates to a solid form intended for the oral administration of at least one active agent and capable of ensuring a dual mechanism for the release of said active agent, whereby the first release is conditioned by time and the second release is conditioned by pH. The invention is characterised in that the active agent is present in the form of a microparticulate system, the microparticulates of which include a core which is made up entirely or partly of said active agent and coated with at least one layer which conditions the release profile of the active agent and which is formed by a material containing at least: (i) 25% to 75% by weight, relative to the total weight of the coating, of at least a polymer A that is insoluble in the gastrointestinal fluids, (ii) 25% to 75% by weight, relative to the total weight of the coating, of at least a polymer B that has a solubilisation pH value in the pH range of from 5 to 7, and (iii) 0 to 25% by weight, relative to the total weight of the coating, of at least one plasticiser, said polymers A and B being present in a polymer(s) B/polymer(s) A weight ratio that is at least equal to 0.25. The invention also relates to a method for preparing this solid form and the corresponding microparticulates.
