| 摘要 |
The object of the present invention is a process which permits the increase of the bioavailability in the solid formulations of nifedipine and its derivatives. In consists in dissolving the active substance together with a polyethylene glycol, in a common solvent, then absorbing this solution on a micronized, inert excipient, soluble in the gastrointestinal juices, and finally, co-precipitating the active substance and the polyethylene glycol by evaporating the solvent. The very large surface of the excipient on which the solution is absorbed, and the presence of polyethylene glycol, which facilitate the homogeneous distribution of the solution on this surface, permit the active substance to precipitate and become very fine particles. The same results may be also obtained by blending homogeneously the micronized inert excipient with micronized nifedipine, and causing the mixture to be absorbed on a solution of polyethylene glycol, which by subsequent solvent evaporation, precipitates in fine particles that are homogeneously dispersed and in intimate contact with the active substance. Forms of solid dosage prepared with the mixture thus obtained, have shown a bioavailability higher than similar formulations already on the market. |
