The invention discloses a freeze-
drying process of
thymalfasin for injection. The freeze-
drying process is characterized by including the first step of pre-freezing, the second step of primary sublimation
drying and the third step of secondary sublimation drying. In the second step of primary sublimation drying, seven-stage step temperature rise is adopted, wherein a, a
coolant is heated to -10 DEG C+ / -1 DEG C, and heat preservation is conducted for 1-1.5 h; when the vacuum degree reaches 15 Pa+ / -3 Pa, automatic pulsed gas infiltration is conducted, and when the vacuum degree reaches 25 Pa+ / -5 Pa, gas infiltration is stopped; b, the
coolant is heated to -5 DEG C+ / -1 DEG C, heat preservation is conducted for 1-1.5 h, and gas infiltration is conducted till the vacuum degree reaches 25 Pa+ / -5 Pa; c, the
coolant is heated to 0 DEG C+ / -1 DEG C, heat preservation is conducted, and gas infiltration is conducted till the vacuum degree reaches 25 Pa+ / -5 Pa; d, the coolant is heated to 5 DEG C+ / -1 DEG C, heat preservation is conducted, and gas infiltration is conducted till the vacuum degree reaches 25 Pa+ / -5 Pa; e, the coolant is heated to 10 DEG C+ / -1 DEG C, heat preservation is conducted, and gas infiltration is conducted till the vacuum degree reaches 25 Pa+ / -5 Pa; f, the coolant is heated to 15 DEG C+ / -1 DEG C, heat preservation is conducted, and gas infiltration is conducted till the vacuum degree reaches 25 Pa+ / -5 Pa; g, the coolant is heated to 25 DEG C+ / -1 DEG C, heat preservation is conducted, and gas infiltration is conducted till the vacuum degree reaches 33 Pa+ / -3 Pa. By means of the freeze-drying process, it can be ensured that the
moisture content and
impurity limit of the finished product meet the requirements of National
Drug Standards, and the time of the whole freeze-drying process can be shortened.