Pharmaceutical giant AstraZeneca said the European Medicines Agency had accepted the marketing authorisation application for its constipation tablet Naloxegol.The investigational drug is aimed at relieving constipation caused by pain-killing opioid medicines. It was developed using technology from American biopharmaceutical company Nektar Therapeutics. Under the terms of their licensing agreement, the green light from European regulators means AstraZeneca must now make a $25m milestone payment to Nektar.TB