Intangible Assets

12 Months Ended

Dec. 31, 2015

Intangible Assets

Intangible Assets

6. Intangible Assets

The Company purchased certain patents from Shire Laboratories, Inc. pursuant to a 2005 purchase agreement. These patents are being amortized over the weighted average life of the patents purchased in that transaction. Deferred legal fees have been incurred in connection with litigation related to patents for Oxtellar XR and Trokendi XR. The following sets forth the gross carrying amount and related accumulated amortization of these intangible assets, in thousands:

			December 31, 2015				December 31, 2014
	Weighted- Average Life		Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Purchased patents		10.0	$	2,292	$	2,292	$	2,292	$	2,067
Capitalized patent defense costs		9.5	$	994	$	18	$	—	$	—

Deferred legal fees will be capitalized as part of the patents upon successful outcome of the on-going litigation related to these patents, at which point amortization of those costs will begin. The Company reached an agreement to settle certain litigation related to Trokendi XR in October 2015, at which time the Company capitalized the costs associated with that litigation and began amortization.

The net book value of intangible assets was $1.0 million as of December 31, 2015 and was $0.2 million as of December 31, 2014. Amortization expense on intangible assets was approximately $243,000, $229,000, and $229,000 for the years ended December 31, 2015, 2014 and 2013, respectively.

There were no indicators of impairment identified at December 31, 2015 or December 31, 2014.