Tablet which is intended for the administration by the oral route of at least one active principle and which is capable of guaranteeing a dual release mechanism for the said active principle, the first being conditioned by the time and the second being conditioned by the pH, in which the said active principle is present therein in the form of a microparticulate system, the microparticles of which have a core formed in all or part of the said active principle and coated with at least one layer which conditions the said release profile of said active principle and which is formed of a material composed of at least: - from 30% to 50% by weight, with respect to the total weight of the said coating, of at least one polymer A which is insoluble in the gastrointestinal fluids and which is chosen from ethylcellulose, cellulose acetate butyrate, cellulose acetate, ammonio (meth)acrylate copolymers of type "A" or of type "B", esters of poly(meth)acrylic acids, and their blends; - from 30% to 60% by weight, with respect to the total weight of the said coating, of at least one polymer B which has a pH value for dissolution within the pH range from 5 to 7 and which is chosen from: ∘ copolymer(s) of methacrylic acid and of methylmethacrylate, ∘ copolymer(s) of methacrylic acid and of ethyl acrylate, ∘ cellulose derivatives, such as cellulose acetate phthalate, cellulose acetate succinate, cellulose acetate trimellitate, hydroxypropylmethylcellulose phthalate or hydroxypropylmethylcellulose acetate succinate, ∘ shellac, ∘ polyvinyl acetate phthalate, and ∘ their blends, and the said coating layer of the microparticles being composed of a single layer formed of the said material; the said microparticles being dispersed within the tablet, the said microparticles being capable of releasing the said active principle according to a three-phase modified release profile characterized by: - in contact with an environment, the pH of which is at a lower value than that of the pH for dissolution of the polymer B, a delayed and prolonged release profile with a given latency time of between 0.5 and 12 hours, in particular between 0.5 and 8 hours, indeed even between 1 and 5 hours, and according to a time for half release t 1/2 of between 0.75 and 24 hours, in particular between 0.75 and 12 hours, indeed even between 0.75 and 8 hours, especially between 1 and 5 hours, at the end of which time half of the active principle present is released; - in contact with an environment, the pH of which is at a higher value than that of the pH for dissolution of the polymer B, a release of the active principle without a latency time and with a t 1/2 of between 0.1 and 2 hours; it being possible for the kinetics or release of the active principle to be determined by in vitro dissolution test carried out in a USP type II paddle device with a rotational speed of the paddles of 75 rpm, by UV spectrometry, on the one hand in a 0.1N HCl medium and, on the other hand, in a 0.05M potassium phosphate medium at pH 6.8. - from 30% to 50% by weight, with respect to the total weight of the said coating, of at least one polymer A which is insoluble in the gastrointestinal fluids and which is chosen from ethylcellulose, cellulose acetate butyrate, cellulose acetate, ammonio (meth)acrylate copolymers of type "A" or of type "B", esters of poly(meth)acrylic acids, and their blends; - from 30% to 60% by weight, with respect to the total weight of the said coating, of at least one polymer B which has a pH value for dissolution within the pH range from 5 to 7 and which is chosen from: ∘ copolymer(s) of methacrylic acid and of methylmethacrylate, ∘ copolymer(s) of methacrylic acid and of ethyl acrylate, ∘ cellulose derivatives, such as cellulose acetate phthalate, cellulose acetate succinate, cellulose acetate trimellitate, hydroxypropylmethylcellulose phthalate or hydroxypropylmethylcellulose acetate succinate, ∘ shellac, ∘ polyvinyl acetate phthalate, and ∘ their blends, and ∘ copolymer(s) of methacrylic acid and of methylmethacrylate, ∘ copolymer(s) of methacrylic acid and of ethyl acrylate, ∘ cellulose derivatives, such as cellulose acetate phthalate, cellulose acetate succinate, cellulose acetate trimellitate, hydroxypropylmethylcellulose phthalate or hydroxypropylmethylcellulose acetate succinate, ∘ shellac, ∘ polyvinyl acetate phthalate, and ∘ their blends, and - in contact with an environment, the pH of which is at a lower value than that of the pH for dissolution of the polymer B, a delayed and prolonged release profile with a given latency time of between 0.5 and 12 hours, in particular between 0.5 and 8 hours, indeed even between 1 and 5 hours, and according to a time for half release t 1/2 of between 0.75 and 24 hours, in particular between 0.75 and 12 hours, indeed even between 0.75 and 8 hours, especially between 1 and 5 hours, at the end of which time half of the active principle present is released; - in contact with an environment, the pH of which is at a higher value than that of the pH for dissolution of the polymer B, a release of the active principle without a latency time and with a t 1/2 of between 0.1 and 2 hours;