8. Inventory

Inventory as of June 30, 2016 and December 31, 2015 consisted of the following:

(in thousands)	June 30, 2016		December 31, 2015
Raw materials	$	4,231	$	900
Work in process		6,659		2,743
Finished goods		1,431		74
Total inventory	$	12,321	$	3,717

Inventory acquired prior to receipt of marketing approval of ONIVYDE was expensed as research and development expense as incurred. The Company began to capitalize the costs associated with the production of ONIVYDE upon receipt of approval from the U.S. Food and Drug Administration on October 22, 2015.