Freeze-drying process for ganciclovir for injection

The invention provides a freeze-drying process for ganciclovir for injection. The freeze-drying process comprises the following steps: sequentially carrying out pre-freezing, sublimation-drying and desorption drying on a ganciclovir injection liquid, and obtaining a ganciclovir freeze-dried powder injection, wherein the pre-freezing comprises the step of sequentially carrying out first pre-freezing, pressurizing and second pre-freezing on the ganciclovir injection liquid, wherein the first pre-freezing temperature is minus 3 DEG C to 3 DEG C; the pressurizing pressure is 0.1-0.2MPa; and the second pre-freezing temperature is minus 25 DEG C to minus 30 DEG C. The ganciclovir injection liquid is pre-frozen twice; a pressurizing operation is carried out between two pre-freezing procedures, so that the ganciclovir injection liquid is completely crystallized instantly; the residual moisture of the product in the desorption drying process is prevented; the solute transfer time in a liquid medicine is shortened; the upper structure and the lower structure are consistent; the freeze-drying time is greatly shortened; the plumpness of the product appearance is ensured; the tightness of the structure of a freeze-dried product is enhanced; the shrinkage phenomenon of the product is avoided; and the freeze-drying efficiency of the product is improved.