Other

Toshio Okabe

Misao Miyamoto

Toshihisa Oda

Toyohiko Bunrin

Tetsuyuki Nishiyama

An amorphous solid dispersion of efonidipine hydrochloride having a high intestinal absorbability can be formed by subjecting a mixture containing efonidipine hydrochloride of the formula (I), hydroxypropylmethylcellulose acetate succinate and optionally a thermostabilizer to a step A of heat treatment at from 85 to 140&deg; C. or mechanochemical treatment at from 0 to 140&deg; 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 vapor-containing gas; or treating the above-mentioned mixture with a hot steam at from 100 to 140&deg; 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. Formula (I):

Growing community of inventors

Saitama-ken, Japan

Toshio Okabe