Pharmaceutical composition of kappa opioid receptor agonist, preparation method therefor, and use thereof

A pharmaceutical composition of a kappa opioid receptor agonist, the pharmaceutical composition comprising a compound represented by formula (I), or a stereoisomer thereof, or a metabolite thereof or a pharmaceutically acceptable salt thereof, optionally an osmotic pressure regulator, and a pH adjusting agent and water for injection;

• wherein the compound represented by formula (I) is:
• wherein:
• R1, R2, and R3 are independently selected from the group consisting of H, CN, Cl, F, unsubstituted C1-C8alkyl, substituted C1-C8alkyl, unsubstituted C3-C10 cycloalkyl, and substituted C3-C10 cycloalkyl;
• R4 is selected from H, unsubstituted C1-C8alkyl, substituted C1-C8alkyl, unsubstituted C3-C10 cycloalkyl, and substituted C3-C10 cycloalkyl;
• R5 and R6 are independently selected from H, unsubstituted C1-C8alkyl, substituted C1-C8 alkyl, unsubstituted C3-C10 cycloalkyl, substituted C3-C10 cycloalkyl, unsubstituted aryl, substituted aryl, unsubstituted heterocyclyl, and substituted heterocyclyl;
• R7 is selected from H, unsubstituted C1-C8alkyl, substituted C1-C8alkyl, unsubstituted C3-C10 cycloalkyl, and substituted C3-C10 cycloalkyl;
• R8 and R9 are independently selected from H, unsubstituted C1-C8 alkyl, substituted C1-C8 alkyl, unsubstituted C3-C10 cycloalkyl, O-substituted C1-C8 alkyl, O-unsubstituted C1-C8 alkyl, CH3O(CH2CH2)nCH2CH2—, and HO(CH2CH2)nCH2CH2—;
• R10 is
• R11 is OR12 or NR13R14;
• R12 is selected from H, unsubstituted C1-C24 alkyl, substituted C1-C24 alkyl, O-substituted C1-C24 alkyl, O-unsubstituted C1-C24 alkyl, CH3O(CH2CH2)nCH2CH2—, and HO(CH2CH2)nCH2CH2—;
• R13 and R14 are independently selected from H, unsubstituted C1-C24 alkyl, substituted C1-C24 alkyl, 0-substituted C1-C24 alkyl, 0-unsubstituted C1-C24 alkyl, CH3O(CH2CH2)nCH2CH2—, and HO(CH2CH2)nCH2CH2—;
• and
• n is an integer from 0 to 100;
• the pH adjusting agent is hydrochloric acid;
• and pH of the pharmaceutical composition is 3.0-5.0.