Note 7 - Stockholders' Equity (Tables)

9 Months Ended

Mar. 31, 2019

Notes Tables

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

	Weighted Average, March 31, 2019		Range, March 31, 2019			Weighted Average, March 31, 2018		Range, March 31, 2018
Volatility		69%	58%	-	76%		74%	68%	-	75%
Dividend yield		-		-			-		-
Risk-free interest rate		2.71%	2.52%	-	2.78%		2.44%	1.75%	-	2.64%
Expected term (years)		3.8	1.9	to	4.3		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, 2018		6,827,225		$	1.11		3.8	$	-
Granted		350,000			0.68
Exercised		-			-
Forfeited		-			-
Expired		(70,625	)		1.26
Outstanding at March 31, 2019		7,106,600		$	1.09		3.3	$	57,050
Exercisable at March 31, 2019		7,106,600		$	1.09		3.3	$	57,050

Schedule of Nonvested Share Activity [Table Text Block]

	Options			Weighted Average Grant-Date Fair Value
Nonvested at July 1, 2018		-		$	-
Granted		350,000			0.35
Vested		(350,000	)		0.35
Nonvested at March 31, 2019		-		$	-

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

	Three months ended March 31, 2019		Three months ended March 31, 2018		Nine months ended March 31, 2019		Nine months ended March 31, 2018
General and administrative:
Fair value of stock bonuses expensed	$	-	$	1,500	$	-	$	8,723
Change in fair value from modification of option terms		-		-		211,185		243,761
Change in fair value from modification of warrant terms		-		7,091		118,233		163,956
Fair value of stock options expensed		5,250		682,485		97,375		782,135
Total	$	5,250	$	691,076	$	426,793	$	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		-		219		44,793		132,896
Fair value of stock options expensed		-		587,215		25,875		587,215
Total	$	-	$	587,434	$	81,783	$	841,104