PROCESS FOR PRODUCING EFONIDIPINE HYDROCHLORIDE PREPARATIONS

摘要

The present invention can form an amorphous solid dispersion of efonidipine hydrochloride having a high intestinal absorbability which can be formed by subjecting a mixture containing efonidipine hydrochloride of formula (I), hydroxypropylmethylcellulose acetate succinate and optionally a thermostabilizer to a step A of heat treatment at from 85 to 140 ~C or mechanochemical treatment at from 0 to 140 ~C, and then to a step B of dipping treatment into a water-containing solution, impregnation treatment with a water-containing solution or contacting treatment with a water vaporcontaining gas; or treating the above-mentioned mixture with a hot steam at from 100 to 140 ~C and a high pressure. Further, in the above-mentioned step A, the mixture is subjected to high frequency heating, making it possible to give a solid dispersion of efonidipine hydrochloride having a high intestinal absorbability without using the step B. This process is quite advantageous in the production in that the use of an organic solvent is not required.