Leading healthcare and pharmaceuticals firm GlaxoSmithKline (GSK) and Pfizer have announced plans to merge their respective consumer health businesses in a move that will see GSK separate to create two new global companies. GSK said it would have a majority controlling equity interest of 68% in the joint venture, which has combined sales of approximately £9.8 billion ($12.7 billion) and will bring brands such as Sensodyne, Voltaren and Panadol together with Advil, Centrum …