Compared with other prior art schemes, the new process for refining the high-purity cephalosporin bulk drug cefodizime sodium has the advantages of simple operation, high yield and high product purity. The product prepared by the new process has the following advantages: the particle size of cefodizime sodium is uniform, the fluidity is good, and the packaging is easy; the solvent residue is low, the ethanol residue is below 0.3%, and the solvent residue is reduced by 90.0%. Concrete process steps are:
(1) Dissolve sodium isooctanoate in ethanol solution first, add a small amount of hydrochloric acid until the pH of the solution is 6.0 to 6.5, and add sodium isooctanoate to the ethanol solution;
(2) At room temperature, sequentially mix ethanol, cefodizime acid, benzophenone hydrazone, sodium metabisulfite, and triethylamine, and stir until the cefodizime acid dissolves into the cefodizime acid solution.
Use activated carbon for injection to decolorize the cefodizime acid solution at 0-30°C.
(3) Decolorize the cefodizime acid solution in step 2, then mix the decolorized cefodizime acid solution with the ethanol solution of sodium isooctanoate in step 1, stir, add a small amount of hydrochloric acid until the pH of the solution is 6.5～ 7.0, to the ethanol solution of cefodizime sodium crystals;
(4) The cefodizime sodium crystals are purified in a sterile-grade filter washing and drying machine using an ethanol solvent. Wash the filter cake with absolute ethanol for 15 to 20 minutes, then filter with suction, then wash the filter cake with acetone for 15 to 20 minutes, and filter with suction to get to the wet material of cefodizime sodium;
(5) Dry the cefodizime sodium wet material by using a sterile filter washing and drying machine.
Vacuum drying in a three-in-one drier for 1 hour, followed by hot water drying at 50-53° C. for 6-8 hours, to obtain a finished product of cefodizime sodium with a moisture content within 3.5%.