6. PATENT COSTS

We amortize intangible assets with definite lives on a straight-line basis over their estimated useful lives, ranging from 2 to 14 years, and review for impairment on a quarterly basis and when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable.

As of March 31, 2013, the Company's capitalized costs related to certain patent costs paid by Auxilium on behalf of the Company, which are reimbursable to Auxilium under the Auxilium Agreement. These patent costs are creditable against future royalty revenues. For each period presented below net patent costs consisted of:

	March 31,			December 31,
	2013			2012
Patents	$	472,375		$	472,375
Accumulated Amortization		(208,134	)		(192,053	)
	$	264,241		$	280,322

The amortization expense for patents for the three months ended March 31, 2013 was approximately $16,081. In the comparable period of 2012, the amortization expense for patents was approximately $12,945. The estimated aggregate amortization expense for each of the next five years is approximately as follows:

2013	$	48,000
2014		53,000
2015		25,000
2016		20,000
2017		20,000