Accrued expenses and other current liabilities (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Research and development costs	$ 2,784,448	$ 938,665
Payroll and employee-related costs	790,518	1,453,665
Professional fees	187,173	153,219
Consumer product-related costs	135,045	42,024
Total	$ 3,897,184	$ 2,587,573