AstraZeneca has finalised plans to divest its Crohn's disease drug Entocort by selling US rights to the medicine to Perrigo for $380m. 

The move is part of an "externalisation" drive by the British drugmaker, which is selling non-core products to help it fill a short-term revenue gap caused by older products going off product, while investing in a pipeline of new medicines. 

Entocort had US sales of $89m in the first nine months of 2015. 

The deal, which is expected to complete by the end of 2015, follows AstraZeneca's sale of rights to Entocort outside the US in July to Tillotts Pharma, part of the Zeria Group. 

AstraZeneca said its earnings per share outlook for the year, which was upgraded at third-quarter results earlier this month, would not change as a result of the Perrigo transaction.