Note 11 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Asset Based Upon Expected Income Tax Rates	$ 23,167,000
Valuation Allowance Percentage	100.00%
Operating Loss Carryforwards	$ 42,395,000
Income Tax Expense (Benefit), Total	0	$ 0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 5,464,000	$ 5,500,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	(3.00%)	(3.00%)
State and Local Jurisdiction [Member] | Florida Department of Revenue [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 0	$ 399,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	5.50%	3.535%	4.458%
Orphan Drug Credit [Member]
Tax Credit Carryforward, Amount	$ 10,354,000