Oseltamivir (has known by its brand name 'Tamiflu') is a prodrug, requiring ester hydrolysis for conversion to the active form, Oseltamivir carboxylate. Oseltamivir was the first orally active neuraminidase inhibitor commercially developed by US based Gilead Sciences and is currently marketed by F. Hoffmann-La Roche (Roche). Oseltamivir is an antiviral drug which works by blocking the function of the viral neuraminidase protein. US FDA approved Oseltamivir for prophylaxis of uncomplicated influenza A and B. Currently, Oseltamivir is the only first line defense drug available for the treatment of Swine Flu.