Stock Option Plans and Warrants to Purchase Common Stock (Tables)

12 Months Ended

Dec. 31, 2019

Equity Incentive Plan [Member]

Summary of option and warrant activity

Shares available for grant at January 1, 2019	153,149
Increase in shares available for grant	1,000,000
Options granted	(596,740	)
Options forfeited	107,300
Shares available for grant at December 31, 2019	663,709

Share Based Compensation [Member]

Summary of option and warrant activity

Share-based compensation	2019		2018
Research and development	$	143,217	$	174,877
General and administrative		233,122		206,009
Total	$	376,339	$	380,886

Employee Stock Option [Member]

Summary of option and warrant activity

				Weighted Average
	Options			Options Exercise Price
Balance outstanding at December 31, 2017		785,655		$	7.15
Granted		370,420			1.14
Forfeited		(133,980	)		4.66
Balance outstanding at December 31, 2018		1,022,095		$	5.32
Granted		596,740			1.09
Forfeited		(111,863	)		3.27
Balance outstanding at December 31, 2019		1,506,972		$	3.77

Summary of weighted-average range of exercise prices for options and warrants outstanding and exercisable

Price Range	Weighted Average Remaining Contractual Life in Years	Outstanding Options		Exercisable Options
$0.71-$17.20	8.46		1,431,154		832,360
$20.00-$39.80	3.76		50,830		50,830
$41.00-$48.00	0.66		24,988		24,988
Total	8.17		1,506,972		908,178

Warrant [Member]

Summary of option and warrant activity

	Warrants			Weighted Average Exercise Price
Balance at December 31, 2017		2,577,238		$	4.38
Granted		3,738,155			2.20
Exercised		-			-
Expired		(11,750	)		1.64
Balance at December 31, 2018		6,303,643		$	3.09
Granted		-			-
Exercised		-			-
Expired		(110,932	)		14.80
Balance at December 31, 2019		6,192,711		$	2.88

Summary of weighted-average range of exercise prices for options and warrants outstanding and exercisable

Grant Date	Exercise Price	Remaining Contractual Life in Years	Outstanding Warrants		Exercisable Warrants
12/16/2016	$3.95	1.96		2,403,405		2,403,405
11/3/2017	$2.50	2.83		51,151		51,151
4/1/2018	$1.95	3.24		10,000		10,000
7/2/2018	$2.25	2.01		3,572,815		3,572,815
7/9/2018	$1.13	2.99		155,340		155,340
Total	$2.88	2.02		6,192,711		6,192,711