There are provided a solution for spray drying having a high transmittance and markedly reduced generation of undissolved matter； and a method for producing a solid dispersion by using the solution for spray drying so that clogging with the undissolved matter is reduced and dissolution is improved. More specifically, there is provided a solution for spray drying comprising hypromellose acetate succinate (HPMCAS) having a hydroxypropoxy molar substitution of 0.40 or more, a solvent, and a drug. There is also provided a method for producing a solid dispersion comprising the step of removing the solvent from the spray drying solution.
