Accrued Expenses and other payables (Schedule of Accrued Expenses) (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Accrued Liabilities, Current [Abstract]
Accrued clinical trial and other expenses	$ 1,226,998	$ 1,504,240
Compensation and related benefits	88,518	542,434
Deferred rent	18,051	27,457
Patent fees	30,000	40,000
Other expenses	82,300	162,300
Accrued expenses	$ 1,445,867	$ 2,276,431