Home | My Site medicine manufacturers in usa, us pharmaceutical companies, top pharmaceutical companies in usa, leading pharmaceutical companies in usa, pharmaceutical companies usa, list of pharmaceutical companies in us, top us pharmaceutical companies, list of pharmaceutical companies in us, pharma companies usa, best pharmaceutical companies in usa, us pharmaceutical companies list, top 10 us pharmaceutical companies Welcome to Nivagen Pharmaceuticals. Nivagen is engaged in the development, acquisition and sales of generic prescription drugs and over the counter products for the North American market.