Note 7 - Stockholders' Equity (Tables)

12 Months Ended

Jun. 30, 2019

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Weighted Average, June 30, 2019	Range, June 30, 2019			Weighted Average, June 30, 2018	Range, June 30, 2018
Volatility	68%	58%	-	76%	74%	68%	-	75%
Dividend yield	-		-		-		-
Risk-free interest rate	2.34%	1.92%	-	2.78%	2.44%	1.75%	-	2.64%
Expected term (years)	4.1	1.9	to	4.6	5	3	-	6

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life		Aggregate Intrinsic Value
Outstanding at July 1, 2017		4,545,097		$	1.42		2.9	$	176,575
Granted		2,647,500			0.76
Exercised		-			-
Forfeited		-			-
Expired		(365,312	)		2.35
Outstanding at June 30, 2018		6,827,225		$	1.11		3.8	$	-
Granted		655,000			0.74
Exercised		-			-
Forfeited		-			-
Expired		(70,625	)		1.26
Outstanding at June 30, 2019		7,411,600		$	1.08		3.1	$	20,375
Exercisable at June 30, 2019		7,411,600		$	1.08		3.1	$	20,375

Schedule of Nonvested Share Activity [Table Text Block]

	Options			Weighted Average Grant-Date Fair Value
Nonvested at July 1, 2018		-		$	-
Granted		655,000			0.36
Vested		(655,000	)		0.36
Nonvested at June 30, 2019		-		$	-

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year ended June 30, 2019		Year ended June 30, 2018
General and administrative:
Fair value of stock bonuses expensed	$	-	$	8,723
Change in fair value from modification of option terms		211,185		243,761
Change in fair value from modification of warrant terms		118,233		163,956
Fair value of stock options expensed		206,525		782,135
Total	$	535,943	$	1,198,575
Research and development:
Fair value of stock bonus expensed	$	-	$	15,098
Change in fair value from modification of option terms		11,115		105,895
Change in fair value from modification of warrant terms		44,793		132,896
Fair value of stock options expensed		29,575		587,215
Total	$	85,483	$	841,104