Development and validation study for the chromatographic purification process for tetanus anatoxin on Sephacryl S-200...

The tetanus purified anatoxin is used in the preparation of multiple immunoprophylactics. WHO (World Health Organization) specifies that the tetanus anatoxin must exhibit a degree of purity greater than or equal to 1,000 Lf/mg protein nitrogen (PN). Today liquid chromatography is a well established technique for the purification of tetanus anatoxin and several different methods are used in production scale. On a small scale, we purified tetanus anatoxin on Sephacryl S-200 High Resolution (gel filtration) and we obtained a successful high-yield purification. On the basis of these results, by combining conventional tangential flow filtration (TFF) at 50,000 N.M.W.L. (Nominal Molecular Weight Limit) ultrafiltration membrane with gel filtration on Sephacryl S-200 High Resolution, we have been able to purify 14 lots of tetanus anatoxin using the Bioprocess System (Amersham Pharmacia Biotech) to a large scale operation. Using this method, 77,401,332 doses of tetanus toxoid were prepared in 14 consecutive lots, supporting the reproducibility and reliability of the method presented here.