Inventory

Inventory consists of the following at December 31, 2018 and 2017 (in thousands):



	December 31, 2018		December 31, 2017
Raw materials	$	4,961	$	3,852
Work in process	490		313
Finished goods	759		201
Total inventories	$	6,210	$	4,366

Inventory acquired prior to receipt of the marketing approval for TYMLOS, totaling approximately $1.6 million, was expensed as research and development expense as incurred. As of December 31, 2018, only $0.1 million of such costs had not yet been absorbed in goods sold to Customers. The Company began to capitalize the costs associated with the production of TYMLOS upon receipt of FDA approval on April 28, 2017.

Finished goods manufactured by the Company have a 36-month shelf life from date of manufacture.