| Income Taxes (Details) - USD ($) | Dec. 31, 2019 | Dec. 31, 2018 | 
|---|---|---|
| Deferred tax assets: | ||
| Net operating losses carry forward | $ 31,688,387 | $ 34,531,577 | 
| Share-based compensation | 1,421,701 | 2,950,963 | 
| Research and development/orphan drug credits | 10,871,634 | 8,896,703 | 
| Intangibles | 5,942,126 | |
| Others | 13,172 | 15,285 | 
| Less: valuation allowance | (49,937,020) | (46,394,528) | 
| Deferred tax assets, net | 
| X | ||||||||||
| 
- Definition Amount of research and development/orphan drug credits. No definition available. 
 | 
| X | ||||||||||
| 
- References No definition available. 
 | 
| X | ||||||||||
| 
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from intangible assets including goodwill. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 |