The present invention relates to a solid form, intended for the administration by oral route of at least one active ingredient and capable of guaranteeing a double release mechanism of said active ingredient, the first being determined by time and the second being determined by the pH, characterized in that said active ingredient is present there in the form of a microparticle system the microparticles of which possess a core formed wholly or partly by said active ingredient and coated with at least one layer determining said release profile of said active ingredient and formed by a material composed at least (i) 25 to 75% by weight relative to the total weight of said coating of at least one polymer A which is insoluble in the gastro-intestinal fluids, (ii) 25 to 75% by weight relative to the total weight of said coating of at least one polymer B possessing a solubilization pH value comprised within the pH range from 5 to 7, and (iii) 0 to 25% by weight relative to the total weight of said coating of at least one plasticizer, said polymers A and B being present in a polymer(s) B/polymer(s) A weight ratio at least equal to 0.25 It moreover relates to a method for the preparation of this solid form and of the corresponding microparticles.
