GlaxoSmithKline (GSK), the UK based healthcare multinational, is to buy out its stake in its consumer healthcare venture with Novartis at a cost of $13 billion. The joint venture, which includes the toothpaste brand Sensodyne and painkiller brand Panadol, as well as Nicotinell stop smoking aids, was formed in 2015 as part of Novartis’ portfolio transformation, which comprised a three-part inter-conditional transaction with GSK, including the combination of the Novartis …