Cholinesterase inhibitor polymorph and application thereof

A process for preparing a crystal form of octahydroaminoacridine succinate, comprising:

• preparing a Crystal Form A of octahydroaminoacridine succinate by any one of:
• an anti-solvent addition test, an anti-anti-solvent addition test, gas-solid diffusion, slow volatilization, slow cooling, suspension stirring at room temperature, suspension stirring at 50° C., suspension stirring at 70° C., cyclical stirring at 50-5° C., gas-liquid diffusion, high polymer induced crystallization with volatilization, or high polymer induced crystallization with stirring and grinding, wherein said Crystal Form A is characterized by main characteristic X-ray powder diffraction peaks at the corresponding positions of 2θ values of 8.8°±0.2°, 16.4°±0.2°, 23.2°±0.2°;
• preparing a Crystal Form C of octahydroaminoacridine succinate by any one of:
• an anti-solvent addition test, an anti-anti-solvent addition test, slow cooling, suspension stirring at room temperature, suspension stirring at 50° C., suspension stirring at 70° C., cyclical stirring at 50-5° C., and gas-liquid diffusion, wherein said Crystal Form C is characterized by main characteristic X-ray powder diffraction peaks at the corresponding positions of 2θ values of 8.0°±0.2°, 24.1°±0.2°, 21.7°±0.2°;
• or
• preparing a Crystal Form F of octahydroaminoacridine succinate by any one of gas-solid diffusion or suspension stirring at room temperature, wherein said Crystal Form F is characterized by main characteristic X-ray powder diffraction peaks at the corresponding positions of 2θ values of 21.3°±0.2°, 7.1°±0.2°, 26.3°±0.2°.

A method of treating a disease caused by excessive activation of cholinesterase or a disease related to decreased choline function, comprising:

• administering an effective amount of a crystal form of octahydroaminoacridine succinate to a patient in need thereof, wherein said crystal form of octahydroaminoacridine succinate is one or more of:
• Crystal Form A of octahydroaminoacridine succinate, wherein said Crystal form A is characterized by main characteristic X-ray powder diffraction peaks at the corresponding positions of 2θ values of 8.8°±0.2°, 16.4°±0.2°, 23.2°±0.2°;
• Crystal Form C of octahydroaminoacridine succinate, wherein said Crystal Form C is characterized by main characteristic X-ray powder diffraction peaks at the corresponding positions of 2θ values of 8.0°±0.2°, 24.1°±0.2°, 21.7°±0.2°;
• Crystal Form F of octahydroaminoacridine succinate, wherein said Crystal Form F is characterized by main characteristic X-ray powder diffraction peaks at the corresponding positions of 2θ values of 21.3°±0.2°, 7.1°±0.2°, 26.3°±0.2°.