Entecavir Patent Evaluation, Method for Diastereomeric ImpuritiesEntecavir is an oral antiviral drug used in the treatment of hepatitis B infection. Entecavir is a guanosine nucleoside analogue with selective activity against hepatitis B virus (HBV), which inhibits reverse transcription, The initial patent on entecavir expired in South Africa in 2011 ZA 1991/07894. Current status available on: http://patentsearch.cipc.co.za/, which should have permitted lower-cost generic competitors to enter...