1,4-ジヒドロピリジン系カルシウム拮抗薬と乳糖の相互作用

抄録

In the series of 1,4-dihydropyridine-type compounds, manidipine dihydrochloride and benidipine hydrochloride are potent and long-acting calcium antagonists with similar physicochemical properties. Interaction between these drugs and lactose monohydrate, which is widely used as a diluent in the preparations, was observed when the thermal analysis of their physical mixture at a molar ratio of 1:1 was carried out. On the differential thermogram, a new endothermal peak before the melting of manidipine or benidipine was observed, and at this time, weight loss was also observed. This suggests that, during thermal analysis, a portion of the water molecule in lactose monohydrate migrates to drug molecules to form their hydrates. This kind of phenomenon could not be observed in the case of physically mixing these drugs with lactose anhydrate. Moreover, it was found that the degree of conversion to the hydrate form was independent of the degree of crystallinity.