The present invention provides solid dispersions or solid dispersionpharmaceutical preparations containing a water-soluble polymericsubstance(s) and a phenylalanine compound of the formula (1) orpharmaceutically acceptable salts thereof, wherein A represents the formula(2) and the like, B represent an alkoxy group and the like, E represents ahydrogen atom and the like, D represents a substituted phenyl group andthe like, T, U and V represent a carbonyl group and the like, Arm representsa benzene ring and the like, R1 represents an alkyl group and the like, R2,R3, and R4 may be the same or different from one another and eachrepresent a hydrogen atom, a substituted amino group and the like, and Jand J' represent a hydrogen atom and the like； production methods thereof,and solubilized pharmaceutical preparations containing a solubilizer(s) andthe compound (I) or pharmaceutically acceptable salts thereof. Accordingto the solid dispersion pharmaceutical preparations or solubilizedpharmaceutical preparations, though they contain the phenylalaninecompound of the formula (1) that is a poorly-soluble drug as an activeingredient, the pharmaceutical preparations having high solubility and oralabsorbability can be obtained.(see formula 1)(see formula 2)
