| Deferred tax assets | December 31, 2016 | |||||
| Net operating loss carryforwards | $ | 7,547,296 | ||||
| Stock option compensation | 2,720,186 | |||||
| Orphan Drug credits | 1,218,069 | |||||
| Capitalized start-up costs and other | 4,690,843 | |||||
| Valuation allowance | (16,176,394 | ) | ||||
| Net deferred tax asset | $ | — | ||||
| Deferred tax liabilities | ||||||
| Intangible assets | (3,279,363 | ) | ||||
| Net deferred tax liability | $ | (3,279,363 | ) | |||
| Valuation allowance at beginning of year | $ | — | ||
| Changes recorded to income tax provision | 5,017,047 | |||
| Changes recorded in purchase accounting | 11,159,347 | |||
| Valuation allowance at end of year | $ | 16,176,394 |
| Combined NOL Carryforwards: | December 31, 2016 | |||||
| Federal | $ | 19,842,612 | ||||
| State | $ | 20,222,492 | ||||
Rate reconciliation: | December 31, 2016 | |||
| Federal tax benefit at statutory rate | (34.0 | ) % | ||
| State tax, net of Federal benefit | (2.3 | ) | ||
| Litigation settlement charge | 4.6 | |||
| Acquisition costs | 2.8 | |||
| Orphan drug credit | (4.4 | ) | ||
| Change in valuation allowance | 27.2 | |||
| Stock compensation | 4.2 | |||
| Other | (0.1 | ) | ||
| Total provision | (2.0 | ) % | ||