Note 13 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	December 31, 2017			December 31, 2016
Deferred tax assets
Net operating loss carryforwards	$	5,310,628		$	7,547,296
Stock option compensation		2,141,973			2,720,186
Orphan Drug credits		2,537,039			1,218,069
Capitalized start-up costs and other		5,247,469			4,690,843
Valuation allowance		(15,237,109	)		(16,176,394	)
Net deferred tax asset		—
Deferred tax liabilities
Intangible assets		(2,223,678	)		(3,279,363	)
Net deferred tax liability		(2,223,678	)		(3,279,363	)

Summary of Operating Loss Carryforwards [Table Text Block]

Combined NOL Carryforwards:	December 31, 2017
Federal	$	20,629,817
State		20,640,700

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Rate reconciliation:	December 31, 2017			December 31, 2016
Federal tax benefit at statutory rate		(34.0	)%		(34.0	)%
State tax, net of Federal benefit		(16.3	)%		(2.3	)%
Change in fair value of warrant		(126.1	)%		—	%
Change in tax rate		205.5	%		—	%
Litigation settlement charge		—	%		4.6	%
Acquisition costs		—	%		2.8	%
Orphan drug credit		(36.0	)%		(4.4	)%
Change in valuation allowance		(38.8	)%		27.2	%
Stock compensation		1.2	%		4.2	%
Other		1.0	%		(0.1	)%
Total provision		(43.5	)%		(2.0	)%