Sodium selenite pentahydrate is the basic ingredient for all selenium products from biosyn Arzneimittel GmbH. Since 2009, biosyn has been producing the active ingredient sodium selenite pentahydrate itself, thanks to a production process developed and patented in-house. Its purification and crystallization technologies allow the germ-free production of high-quality trace element compounds under clean room conditions. This means that the high quality requirements for the production of injectable liquid medicinal products in particular can be met. biosyn currently produces sodium selenite pentahydrate and anhydrous sodium selenite for oral and parenteral preparations. The company markets its selenium medicines worldwide under the brand name selenase®.