San Diego-based Ligand Pharmaceuticals said Wednesday afternoon that it has acquired CyDex Pharmaceuticals, a Kansas-based drug reformulation firm. Ligand said it will pay $31.2M in upfront cash, $4.3M at the one year anniversary of closing, and unspecified earn out based on revenue share. CyDex had 2010 revenues of $16.3M. Ligand said CyDex will operate as a wholly owned subsidiary of the firm.