Solid dispersion with improved solubility comprising tetrazole derivative as an active ingredient

An amorphous solid dispersion comprising a tetrazole compound of the formula (I) or a pharmaceutically acceptable salt thereof as an active ingredient:

• wherein,
• R1 is quinoline, isoquinoline, quinoxaline, pyridine, pyrazine, naphthalene, phenyl, thiophene, furan, 4-oxo-4H-chromene or cinnoline, which is unsubstituted or substituted by C1-C5alkyl, hydroxyl, C1-5alkoxy, halogen, trifluoromethyl, nitro or amino;
• R2 to R5 and R8 to R11 are each independently H, hydroxyl, halogen, nitro, C1-C5alkyl or C1-5alkoxy;
• R6 and R7 are each independently H, hydroxyl, halogen, nitro, C1-5alkylene or C1-5 alkoxy;
• and R6 and R7 may be connected to form a 4- to 8-membered ring;
• m and n are each independently integers ranging from 0 to 4;
• and
• X is CH2, O or S.