Stabilization of interferons.

It is now obvious that there are a number of factors which can influence the stability of interferons. Since human fibroblast interferon is especially unstable both to heat and mechanical stress, the use of stabilizing conditions such as low pH or thioctic acid should facilitate purification and concentration of this interferon. Leukocyte interferon, on the other hand, seems to be more stable even when highly purified; however, losses in activity can occur in very dilute solutions containing low concentrations of protein. Inactivation during storage of interferons may be avoided by using freeze-dried preparations. In order to generate large quantities of purified, stable interferons for clinical use, there is a need to establish an armamentarium of different nontoxic techniques and approaches that will enable investigators to stabilize human interferons at each step in preparation, processing, concentration, purification, shipment and storage.