WHAT IS INTERFERON ALFA-2b?

DESCRIPTION OF INTERFERON ALFA-2b:

Interferon alfa-2b recombinant for injection has been classified as an alfa interferon and is a water soluble protein. It is obtained from the bacterial fermentation of the strain of Escherichia coli bearing a genetically engineered plasmid containing an Interferon alfa-2b gene from human leukocytes. The fermentation is carried out in a defined nutrient medium containing the antibiotic tetracycline hydrochloride at a concentration of 5-10mg/Liter. The presence of this antibiotic is not detectable in the final product. Molecular weight of Interferon alfa-2b is 19271 Daltons produced by recombinant DNA techniques. The specific activity of Interferon alfa-2b recombinant is approximately 2.6 * 108 IU/mg protein.

PHARMACOLOGY:

The interferons are a family of naturally occurring small proteins and glycoproteins with molecular weights of approximately 15000-2700 Daltons produced and secreted by cells in response to viral infections and to synthetic and biological inducers. Interferons exert their cellular activities by binding to specific membrane receptors on the cell surface. Once bound to the cell membrane, interferons initiate a complex sequence of intracellular events. In vitro studies demonstrated that these include the induction of certain enzymes, suppression of cell proliferation, immunomodulating activities, such as enhancement of the phagocytic activity of macrophages and augmentation of the specific cytotoxicity of lymphocytes for target cells and inhibition of virus replication in virus induced cells. The mean serum concentrations of Interferon alfa-2b following intramuscular and subcutaneous injections were comparable. The maximum serum concentrations obtained via these routes were approximately 18-116 IU/ml and occurred 3-12 hours after administration. The elimination of Interferon alfa-2b following both intramuscular and subcutaneous injections was approximately 2-3 hours. Serum concentrations were not detected by 16 hours after the injections. Urine concentrations of Interferon alfa-2b following a single dose (5 million IU/m2) were not detectable after any of the parenteral routes of administration. This result was expected since preliminary studies with isolated and perfused rabbit kidneys have shown that the kidney may be the main site of interferon catabolism.