Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Total Stock-based Compensation Expense from Stock Options, Restricted Stock and Warrants

The following table sets forth the total stock-based compensation expense resulting from stock options and warrants included in our Condensed Consolidated Statements of Operations:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019			2018
Research and development — employee	$	—	$	28,683	$	(2,672	)	$	89,105
General and administrative — employee		216,234		243,673		644,113			799,832
Total employee stock-based compensation	$	216,234	$	272,356	$	641,441		$	888,937
Research and development — non-employee	$	—	$	—	$	—		$	—
General and administrative — non-employee	$	—		19,517		—			60,384
Total non-employee stock-based compensation	$	—	$	19,517	$	—		$	60,384

Schedule of Share-based Payment Award, Fair Value of the Stock Options Granted, Assumptions

The fair value of the stock options was estimated using the Black-Scholes option-pricing model, based on the following assumptions:

	Nine Months Ended September 30, 2019		Nine Months Ended September 30, 2018
Risk-free interest rate		—		2.42	%
Expected volatility		—		91.6	%
Expected lives (years)		—		6
Expected dividend yield		—		0.00	%

Schedule of Share-based Compensation, Stock Options, Activity

Presented below is our stock option activity:

	Nine Months Ended September 30, 2019
	Number of Options (Employees)			Number of Options (Non-Employees)		Total Number of Options			Weighted-Average Exercise Price
Outstanding at January 1, 2019		2,190,835			365,000		2,555,835		$	10.69
Granted		—			—		—		$	—
Exercised, Forfeited or Expired		(181,837	)		—		(181,837	)	$	10.66
Outstanding at September 30, 2019		2,008,998			365,000		2,373,998		$	10.69
Options exercisable at September 30, 2019		1,857,291			365,000		2,222,291		$	11.29

Schedule of Outstanding Stock Options

The following table summarizes significant ranges of outstanding stock options under our plans at September 30, 2019:

Range of Exercise Prices		Total Number of Options		Weighted-Average Remaining Contractual Life (years)		Weighted-Average Exercise Price		Total Number of Options Exercisable		Weighted-Average Remaining Contractual Life (years)		Weighted-Average Exercise Price
$	0.77 - $5.00		1,123,449		7.84	$	2.13		971,743		7.81	$	2.16
$	5.01 – $11.00		165,834		3.19	$	10.98		165,834		3.19	$	10.98
$	11.01 – $15.00		623,193		5.54	$	13.89		623,193		5.54	$	13.89
$	15.01 – $98.28		461,523		3.96	$	27.09		461,523		3.96	$	27.09
			2,373,998		6.16	$	10.69		2,222,291		6.03	$	11.29