5. Inventory

Our inventory balance consists of the following:

	June 30, 2013		December 31, 2012
	(in thousands)
Raw materials	$	591	$	591
Work-in-process	10,819		7,884
Finished goods	133		278
	11,543		8,753
Inventories—current	133		278
Inventories—non-current	$	11,410	$	8,475

Inventories, stated at the lower of cost or market, consist of raw materials, work in process and finished goods. At June 30, 2013, $0.1 million of inventory was classified as current on the consolidated balance sheets as we expect this inventory to be consumed for commercial use within the next twelve months. At June 30, 2013, $11.4 million of inventory was classified as non-current on the consolidated balance sheets as we did not expect this inventory to be consumed for commercial use within the next twelve months. We obtain a number of inventory components from single source suppliers due to technology, availability, price, quality or other considerations. The loss of a single source supplier, the deterioration of its relationship with a single source supplier, or any unilateral violation of the contractual terms under which we are supplied components by a single source supplier could adversely affect our total revenues and gross margins.

The raw materials and work-in-process inventory is not subject to expiration and the shelf life for finished goods inventory is 24 or 36 months from the start of manufacturing of the finished goods. We evaluate for potential excess inventory by analyzing current and future product demand relative to the remaining product shelf life. We build demand forecasts by considering factors such as, but not limited to, overall market potential, market share, market acceptance and patient usage.