Disclosed is a pharmaceutical formulation comprising an active agent in solid dispersion with a matrix polymer, wherein the active agent is 4-[3-(4-cyclopropanecarbonyl-piperazine-1-carbonyl)-4-fluoro-benzyl]-2H-phthalazin-1-one or a salt or solvate thereof, and the matrix polymer exhibits low hygroscopicity and high softening temperature and wherein the matrix polymer is selected from: copovidone, hydroxypropyl methylcellulose phthalate (HPMCP), hydroxypropyl methylcellulose acetate succinate (HPMCAS), 2-hydroxypropyl-,6-cyclodextrin (HPBCD), hydroxypropyl methylcellulose (Hypromellose, HPMC), polymethacrylates, hydroxypropyl cellulose (HPC), and cellulose acetate phthalate (CAP). Also disclosed is the use of the formulation in the manufacture of a medicament for treating cancer. Further disclosed is a method of producing a solid amorphous dispersion of 4-[3-(4-cyclopropanecarbonyl-piperazine-1-carbonyl)-4-fluoro-benzyl]-2H-phthalazin-1-one comprising: (i) mixing a suitable amount of 4-[3-(4-cyclopropanecarbonyl-piperazine-1-carbonyl)-4-fluoro-benzyl]-2H-phthalazin-1-one or a pharmaceutically acceptable salt or solvate thereof with a desired amount of at least one matrix polymer, wherein the matrix polymer exhibits low hygroscopicity and high softening temperature and wherein the matrix polymer is selected from: copovidone, hydroxypropyl methylcellulose phthalate (HPMCP), hydroxypropyl methylcellulose acetate succinate (HPMCAS), 2-hydroxypropyl -,B-cyclodextrin (HPBCD), hydroxypropyl methylcellulose (Hypromellose, HPMC), polymethacrylates, hydroxypropyl cellulose (HPC), and cellulose acetate phthalate (CAP) (ii) increasing the temperature of the mixture to produce a melt and (iii) extruding the melt to produce a solid product.
