vivek pingle

I am facing a problem. I am trying to manufacture drainage cleaning materials. For that one of the chemicals used is Sodium hydroxide. But it absorbs moisture the moment it comes in contact with air. It absorbs moisture when i am trying to pack ii in the 50gm pouches. Can some one help me as to how to prevent this. How to prevent sodium hydroxide from absorbing moisture. I need help over this very urgently as all my raw materials are getting wasted due to this.