Fermentation formulation process

The basic process technology in vaccine production consists of fermentation for the production of antigen, purification of antigen, and formulation of the final vaccine. In bacterial fermentation, technology is weU estabHshed. For viral vaccines, ceU culture is the standard procedure. Different variations of ceU line and process system are in use. For most of the Hve viral vaccine and other subunit vaccines, production is by direct infection of a ceU substrate with the vims. 

Product Requirements. When an enzyme is recovered from fermentation broth, it is usually present in an aqueous solution or processed to a dried state. Both types of preparation have to be formulated to comply with requirements appropriate to their final appHcation. 

Upstream processing (fermentation) and downstream processing (purification and formulation) are physically separated, by being undertaken in separate buildings. Fermentation is generally undertaken in specially designed 42 000 1 stainless steel vessels. After recovery of the product from the cells, a number of chromatographic purification steps are undertaken, essentially within... 

The four antigens are produced in a fermentation process using the yeast Saccharomyces cerevisiae grown in chemically defined media. The purified antigens are formulated in aluminum-containing adjuvant in sterile liquid suspension. 

Citric acid separation from fermentation broth employs the full allotment of Sorbex beds in addition to the four basic Sorbex zones. The process utilizes a resin instead of a zeolite based adsorbent. The resin is a nonionic cross-linked polystyrene polyvinyl benzene formulation. Operating temperatures for this process are sufficient to overcome diffusion limitations with a corresponding operating pressure to maintain liquid-phase operation. The desorbent consists of water blended with acetone. Subsequent processing steps remove the desorbent from the desired extract product citric acid. 

Adding up the times of all steps, an industrial scale production takes roughly 3 weeks, of which 2 weeks are devoted to the fermentation and about 1 week is required for the downstream processing. Derivatization at positions 3 and 7 to yield an API is not included. Starting from 7-ACA, these processes may take 1 day each for the derivatization plus the time for purification, crystallization, and drying. The resulting bulk active cephalosporin can then be sterilized and formulated for marketing. 

Development of serum-free medium has great value for large-scale biopesticide production. The latest formulations are serum-free, such as SF900II (GIBCO /Invitrogen) and EX-CELL (JRH Biosciences). Cell culture medium supplementation using yeast extract (usually from alcoholic fermentation processes), milk, or soy protein concentrates, can also be an alternative to decrease cell culture medium costs (more details can be found in Chapter 5). 

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