This research protocol "Comparative pharmacokinetics and pharmacodynamics of peginterferon Bacterial Intravenous Protein 48 kilodaltons (BIP48) and 40 kilodaltons (40kDa) in healthy volunteers." This is a Phase I clinical trial which will compare pharmacokinetic and pharmacodynamic parameters, and safety of two products: peginterferon alfa-2a (PEGASYS ®) and BIP48. It will be a double-blind, randomized crossover with a rest period (wash-out) of 4 weeks. The study population will be 32 healthy male volunteers to whom will be administered a single dose of 180 microgram of each product, subcutaneously. The study will have a total duration of 14 days in each treatment step. The serum concentration of PEG-interferon for both products, measured by enzyme immunoassay (EIA) and by antiviral activity of PEG-interferon, is the main variable.For this purpose 15 samples of each volunteers will be needed. Clinical and laboratory variables, useful as pharmacodynamics parameters Beta-2 microglobulin (β2M) - 2'5'oligoadenylate synthetase - oligoadenylate synthetase (OAS)- and neopterin) and safety evaluation, will be measured.

Double-blind study, ie, the volunteers and the study team will not be aware of the product administered. As the presentations of the two products are different, only the professional who will administer the injections will not be blinded, and will not have contact with volunteers or members of the study team after applying the medication.

Inclusion Criteria:

• No history of chronic diseases;
• Preserved oral health;
• No history of acute illness in the last 30 days;
• Absence of significant clinical symptoms and signs on physical examination;
• laboratory tests within normal limits;
• imaging tests within normal limits;
• Seronegative tests for HIV and B and C Hepatitis; Signing the consent form;
• Male;
• Age between 18 and 35 years;
• Body mass index between 19 and 26 (weight in kg / height in meters squared).

Exclusion Criteria:

• Patients with hypersensitivity to Interferon alpha, Escherichia coli-derived products, polyethylene glycol (macrogol), or any constituent salts of these preparations.
• Individuals treated with some type of interferon at any time, prior to the present research.
• History of chronic diseases such as autoimmune diseases, liver failure, decompensated cirrhosis, heart disease, renal failure, diabetes mellitus, thyroid diseases, hemoglobinopathies, cytopenias, history of psychiatric disease, retinopathy, optic neuritis.
• History of acute viral disease in the last 30 days;
• Current use of medications that alter immunity: corticosteroids, immunosuppressants;
• History of known allergy to drugs, including interferon or to any component of the product (at the discretion of the investigator);
• Having undergone surgery during the 6 months prior to study entry; Had donated blood three months prior to study entry;
• History of alcoholism or current use of alcohol;
• Use of other illicit drugs in the past 6 months;
• Participation in a clinical study with previous therapeutic intervention in the year prior to inclusion.