Stock-Based Compensation

3 Months Ended

Mar. 31, 2018

Stock-Based Compensation [Abstract]

Stock-Based Compensation

(11)   Stock-Based Compensation

Stock-Based Compensation Expense

The table below shows total stock-based compensation expense for the three months ended March 31, 2018 and 2017, and the classification of these expenses:

	Three Months Ended March 31,
	2018		2017
Costs of product sales	$	6,435	$	2,937
Costs of contract services		2,923		817
Research and development		13,461		8,609
Selling, general and administrative		50,542		49,201
	$	73,361	$	61,564

Stock Option Plans Activity

Additional information with respect to stock option activity during the three months ended March 31, 2018 under our Stock Option Plans is as follows:

				Weighted-
		Weighted-		Average
	Shares	Average		Remaining		Aggregate
	Under	Exercise		Contractual		Intrinsic
	Option	Price		Life		Value
Outstanding at December 31, 2017	3,295,502	$	1.16		6.3 years	$	1,383,525
Granted	15,000	$	1.34				-
Exercised	-	$	-				-
Forfeited	(9,698)	$	0.79				5,535
Outstanding at March 31, 2018	3,300,804	$	1.16		6.1 years	$	1,148,005
Exercisable at March 31, 2018	2,362,740	$	1.32		5.0 years	$	669,417
Vested and expected to vest at March 31, 2018	2,880,952	$	1.23		5.8 years	$	893,612

As of March 31, 2018, there was $355,517 of total unrecognized compensation cost related to stock options granted under our Stock Option Plans.  The unrecognized compensation cost is expected to be recognized over a weighted-average period of twenty months.  The total fair value of stock options that vested during the three months ended March 31, 2018 and 2017 was $0, respectively.

Stock Bonus Plan Activity

Activity with respect to non-vested shares under the Stock Bonus Plan as of March 31, 2018 and 2017 and changes during the three months ended March 31, 2018 and 2017 are presented below:

	Three Months Ended March 31,
	2018			2017
		Weighted-Average			Weighted-Average
	Shares Under	GrantDate		Shares Under	Grant Date
	Contract	Fair Value		Contract	Fair Value
Unvested at beginning of period	57,760	$	0.68	102,048	$	0.84
Granted	-	$	-	-	$	-
Vested	-	$	-	-	$	-
Forfeited	-	$	-	-	$	-
Unvested at end of period	57,760	$	0.68	102,048	$	0.84

As of March 31, 2018, there was $24,446 of total unrecognized compensation cost related to common stock granted under our Stock Bonus Plan.  The unrecognized compensation cost at March 31, 2018 is expected to be recognized over a weighted-average period of fifteen months.

Employee Stock Purchase Plan Activity

During the three months ended March 31, 2018 and 2017, we issued 18,138 and 3,823 shares of common stock, respectively, under the Employee Stock Purchase Plan.  Cash received by us upon the purchase of shares under the Employee Stock Purchase Plan for the three months ended March 31, 2018 and 2017 was $17,957 and $1,950, respectively. As of March 31, 2018, 16,756 options had been purchased under this plan but the employee(s) had not exercised their right to acquire the common stock under the terms of the Employee Stock Purchase Plan.