Method for preparing long acting progestational hormone injection embedded agent and use

The present invention introduces the preparation process of injection microballoon with PLGA, PLA or other biodegradable polymer as skeleton material and the progestational hormone, gestrinone, as model medicine, and through solvent evaporation. The microballoon may be injected to subcutaneous part or muscle for delayed releasing for over 15 days. The microballoon skeleton material inside body degrades gradually into small molecular matter excreted to outside the body. The gestrinone microballoon injection may be administrated conveniently and is superior to conventional tablet form, which is orally taken frequently to result in damage to liver and kidney and other negative reaction. Rat experiment shows that the preparation of the present invention may be used in treating endometriosis, etc.