|
Stock options and warrants (Tables)
|
6 Months Ended |
|
Jun. 30, 2014
|
| Stock options and warrants [Abstract] |
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| Schedule of Recognized Stock-based Compensation |
| |
|
Three Months Ended
|
|
|
Six Months Ended
|
|
| |
|
2014
|
|
|
2013
|
|
|
2014
|
|
|
2013
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
Stock option to employees and directors
|
|
$ |
326,235 |
|
|
$ |
410,529 |
|
|
$ |
729,074 |
|
|
$ |
894,154 |
|
|
Stock options to consultants for APPY1 activities
|
|
|
157 |
|
|
|
597 |
|
|
|
339 |
|
|
|
1,193 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total stock-based compensation
|
|
$ |
326,392 |
|
|
$ |
411,126 |
|
|
$ |
729,413 |
|
|
$ |
895,347 |
|
|
| Schedule of the Income Statement Allocation of Stock-based Compensation |
| |
|
Three Months Ended
|
|
|
Six Months Ended
|
|
| |
|
2014
|
|
|
2013
|
|
|
2014
|
|
|
2013
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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Selling, general and administrative expenses
|
|
$ |
305,351 |
|
|
$ |
372,692 |
|
|
$ |
688,345 |
|
|
$ |
809,735 |
|
|
Research and development expenses
|
|
|
21,041 |
|
|
|
38,434 |
|
|
|
41,068 |
|
|
|
85,612 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total stock-based compensation
|
|
$ |
326,392 |
|
|
$ |
411,126 |
|
|
$ |
729,413 |
|
|
$ |
895,347 |
|
|
| Schedule of Fair Value Assumptions Used to Estimate Stock-based Compensation |
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|
2014
|
|
2013
|
|
| |
|
|
|
|
|
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Dividend yield
|
|
|
0 |
% |
|
|
0 |
% |
|
Expected price volatility
|
|
|
96-126
|
% |
|
|
127-128
|
% |
|
Risk free interest rate
|
|
|
1.52-1.70
|
% |
|
|
0.65-0.76
|
% |
|
Expected term
|
|
|
5 years |
|
|
5 years |
|
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| Summary of Stock Incentive Plan Activity |
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|
Shares
Underlying
Options
|
|
|
Weighted
Average
Exercise
Price
|
|
|
Weighted
Average
Remaining
Contractual
Term (Years)
|
|
|
Aggregate
Intrinsic
Value
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
Outstanding at January 1, 2014
|
|
|
1,218,265 |
|
|
$ |
8.70 |
|
|
|
|
|
|
|
|
Granted
|
|
|
652,100 |
|
|
|
2.28 |
|
|
|
|
|
|
|
|
Exercised
|
|
|
(39,079 |
) |
|
|
2.09 |
|
|
|
|
|
|
|
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Forfeited
|
|
|
(36,040 |
) |
|
|
32.29 |
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
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Outstanding at June 30, 2014
|
|
|
1,795,246 |
|
|
$ |
6.04 |
|
|
|
8.5 |
|
|
$ |
164,154 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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Exercisable at June 30, 2014
|
|
|
1,134,621 |
|
|
$ |
8.17 |
|
|
|
8.1 |
|
|
$ |
140,863 |
|
|
| Schedule of Nonvested Share Activity |
|
Nonvested Shares
|
|
Nonvested
Shares
Underlying
Options
|
|
|
Weighted
Average
Exercise
Price
|
|
|
Weighted
Average
Grant Date
Fair Value
|
|
| |
|
|
|
|
|
|
|
|
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Nonvested at January 1, 2014
|
|
|
200,446 |
|
|
$ |
2.95 |
|
|
$ |
2.48 |
|
|
Granted
|
|
|
652,100 |
|
|
|
2.28 |
|
|
|
1.91 |
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|
Vested
|
|
|
(187,356
|
) |
|
|
2.62 |
|
|
|
2.21 |
|
|
Forfeited
|
|
|
(4,565 |
) |
|
|
2.12 |
|
|
|
1.77 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
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Nonvested at June 30, 2014
|
|
|
660,625 |
|
|
$ |
2.38 |
|
|
$ |
1.99 |
|
|
| Schedule of Nonqualified Award Activity |
| |
|
Shares
Underlying
Options / Warrants
|
|
|
Weighted
Average
Exercise
Price
|
|
Weighted
Average
Remaining
Contractual
Term (Years)
|
|
|
Aggregate
Intrinsic
Value
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Outstanding at January 1, 2014
|
|
|
4,622,505 |
|
|
$ |
1.82 |
|
|
|
|
|
|
|
Granted
|
|
|
— |
|
|
|
— |
|
|
|
|
|
|
|
Exercised
|
|
|
(1,161,570 |
) |
|
|
1.36 |
|
|
|
|
|
|
|
Forfeited
|
|
|
(5,000 |
) |
|
|
30.00 |
|
|
|
|
|
|
| |
|
|
|
|
|
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|
|
|
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Outstanding at June 30, 2014
|
|
|
3,455,935 |
|
|
$ |
1.93 |
|
3.8 |
|
$ |
2,491,184 |
|
|