Note 12 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Net operating loss carryforwards	$ 5,875,074	$ 5,310,628
Stock option compensation	2,456,410	2,141,973
Orphan Drug credits	2,847,803	2,537,039
Capitalized start-up costs and other	7,349,092	5,247,468
Valuation allowance	(18,091,090)	(15,237,108)
Net deferred tax asset	437,289
Intangible assets	(2,223,678)	(2,223,678)
Net deferred tax liability	$ (1,786,389)	$ (2,223,678)