Note 10 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

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

	2020			2019
Deferred tax assets:
Net operating loss carryforward	$	14,737,240		$	15,328,336
Research and development tax credit carryforward		1,189,110			1,122,536
Stock-based compensation expense		4,870			1,877,284
Accrued salaries and directors' fees		72,721			450,503
Depreciation		-			8,571
Total deferred tax assets		16,003,941			18,787,230
Deferred tax liabilities
Depreciation		28,274			-
Net deferred tax assets		15,975,667			18,787,230
Valuation allowance		(15,975,667	)		(18,787,230	)
Net deferred tax asset after reduction for valuation allowance	$	-0-		$	-0-

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

	2020			2019
U.S. federal statutory rate applied to pretax loss	$	(621,194	)	$	(497,833	)
Permanent differences		65			278
Research and development credits		(66,574	)		(47,053	)
Change in valuation allowance, net of expired items and other adjustments		687,703			544,308
Reported income tax expense	$	-0-		$	-0-