Purchased Patents

3 Months Ended

Mar. 31, 2013

Purchased Patents

Purchased Patents

7. Purchased Patents

In connection with a purchase agreement with Shire Laboratories, Inc., the Company acquired certain patents in 2005. The following sets forth the gross carrying amount and related accumulated amortization of the patents, in thousands:

		March 31, 2013				December 31, 2012
		(unaudited)
	Weighted-	Gross Carrying		Accumulated		Gross Carrying		Accumulated
	Average Life	Amount		Amortization		Amount		Amortization
Purchased patents	10.0	$	2,292	$	1,666	$	2,292	$	1,609

Amortization expense for the three months ended March 31, 2013 and 2012 was approximately $57,000 each period. The estimated annual aggregate amortization expense through December 31, 2015 is $229,000.

There were no indicators of impairment identified at March 31, 2013 or December 31, 2012.