The invention discloses a preparation method of a
cetrorelix freeze-dried pharmaceutical composition. The preparation method comprises the following steps: preparing
mannitol and a
cetrorelix acetate solution; controlling the temperature of the solution at 0-15 DEG C; filtering; and sub-packaging into a container, and freeze-
drying. The pH value of the
mannitol and
cetrorelix acetate solution is 3.1-5.6. The sterilization filtering mode of low-temperature
filtration solves the defects of difficult
filtration and content loss under room-temperature
filtration, and the increase of the pH value of the intermediate liquid
medicine indicates that the dosage of
acetic acid is reduced, so that the pressed
powder can be obviously prevented from being pumped up under the sublimation effect, the pressed
powder is prevented from being far away from the bottom of a
bottle, and the product is unqualified; meanwhile, content loss before and after freeze-
drying due to the fact that excessive
acetic acid takes away active ingredients in the sublimation process is avoided. Finally, under the current freeze-
drying process condition, the product quality is remarkably improved, the product yield is remarkably improved, the batch-to-batch difference is remarkably reduced, and commercialized production of high-quality products is facilitated.