| 摘要 |
Described is a delayed and timed release multiparticulate pharmaceutical composition which liberates the active material after 4-8 hours, gives controlled release of all active material over the next 8-20 hours, and is free from organic acids. The composition is in the form of spheroids having a neutral spherical support with a first coating in which particles of the active material are uniformly distributed, and a second coating. The first coating comprises a water soluble polymer and a water-insoluble polymer. The second coating comprises two pH independent polymers having different degrees of permeability with respect to gastric and intestinal environments, and optionally a pH dependent polymer, a plasticizer, and a filler uniformly distributed in the coating. In the first coating, the weight ratio of water soluble to water insoluble polymers is preferably 0.1-0.9, preferably 0.45-0.55. In the second coating the weight ratio of less permeable polymer to more permeable is 97/3 to 80/20. Suitable fillers include talc, colloidal silica, magnesium stearate and/or glyceryl monostearate. Also described is a method for the preparation of the composition.
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