Elan Corporation and Emisphere Technologies have announced the successful completion of two phase one clinical trials for its oral formulation of heparin. Heparin, an anticoagulant and an antithrombotic compound, is prescribed for a variety of cardiovascular complaints. Elan has also announced it will exercise all of its warrants representing 250,000 shares of Emisphere ordinary stock. This will bring its stake in Emisphere up to 8.6 per cent.