| 摘要 |
<p>The invention concerns a microparticulate system for delayed and controlled release of active principles whereof the in vivo absorption window is essentially limited to the high parts of the gastrointestinal tract, said system being designed for oral administration. The invention aims at providing a system for reliably releasing active principles through a double time-dependent and pH-dependent mechanism. Therefor, the invention proposes a multiple microcapsule galenic oral formulation designed so as to guarantee its therapeutic efficacy, and wherein the release of active principles is controlled by a double release-triggering mechanism: time-triggering and pH-triggering. Said system consists of microcapsules (200 to 600 νm) comprising a core of active principles coated with a coating film (not more than 40 wt. %) including a hydrophilic polymer A (Eudradigit®L) and a hydrophobic compound B (vegetable wax with melting point between 40 to 90°C), B/A ranging between 0.2 and 1.5. Said microcapsules have a dissolving behaviour in vitro such that at constant pH 1.4, a latent period ranging between 1 and 5 hours is observed followed by a release of active principles and such that the shift from pH 1.4 to of pH 6.8 results in a release of active principles without latent time in vitro.</p> |
