PRODUCT INFORMATION
WARNING
Alpha interferons, including INTRON® A, cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory eva luations. Patients with persistently severe or worsening signs or symptoms of these conditions should be withdrawn from therapy. In many but not all cases these disorders resolve after stopping INTRON A therapy. See WARNINGS and ADVERSE REACTIONS.

DESCRIPTION
INTRON® A (Interferon alfa-2b) for intramuscular, subcutaneous, intralesional, or intravenous Injection is a purified sterile recombinant interferon product.

INTRON A recombinant for Injection has been classified as an alpha interferon and is a water-soluble protein with a molecular weight of 19,271 daltons produced by recombinant DNA techniques. It is obtained from the bacterial fermentation of a 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 to 10 mg/L; the presence of this antibiotic is not detectable in the final product. The specific activity of interferon alfa-2b, recombinant is approximately 2.6 × 108 IU/mg protein as measured by the HPLC assay.

Powder for Injection Vial Strength Million IU  mL Diluent Final Concentration after Reconstitution million IU/mL* mg INTRON A† per vial Route of Administration
*
Each mL also contains 20 mg glycine, 2.3 mg sodium phosphate dibasic, 0.55 mg sodium phosphate monobasic, and 1.0 mg human albumin.
†
Based on the specific activity of approximately 2.6 × 108 IU/mg protein, as measured by HPLC assay. 
10  1 10 0.038 IM, SC, IV, IL
18 1 18 0.069 IM, SC, IV
50 1 50 0.192 IM, SC, IV

Prior to administration, the INTRON A Powder for Injection is to be reconstituted with the provided Diluent for INTRON A (Sterile Water for Injection USP) (see DOSAGE AND ADMINISTRATION). INTRON A Powder for Injection is a white to cream-colored powder.

Solution Vials for Injection Vial Strength Concentration* mg INTRON A† per vial Route of Administration
*
Each mL contains 7.5 mg sodium chloride, 1.8 mg sodium phosphate dibasic, 1.3 mg sodium phosphate monobasic, 0.1 mg edetate disodium, 0.1 mg polysorbate 80, and 1.5 mg m-cresol as a preservative.
†
Based on the specific activity of approximately 2.6 × 108 IU/mg protein as measured by HPLC assay.
‡
This is a multidose vial which contains a total of 22.8 million IU of interferon alfa-2b, recombinant per 3.8 mL in order to provide the delivery of six 0.5-mL doses, each containing 3 million IU of INTRON A (for a label strength of 18 million IU).
§
This is a multidose vial which contains a total of 32.0 million IU of interferon alfa-2b, recombinant per 3.2 mL in order to provide the delivery of five 0.5-mL doses, each containing 5 million IU of INTRON A (for a label strength of 25 million IU). 
18‡ MIU multidose 3 million IU/0.5 mL 0.088 IM, SC
25§ MIU multidose 5 million IU/0.5 mL 0.123 IM, SC, IL
Solution in Multidose Pens for Injection Pen Strength Concentration* Million IU/1.5ml INTRON A Dose Delivered
(6 doses, 0.2 mL each) mg INTRON A† per 1.5 mL Route of Administration
*