Stockholders' equity (Tables)

12 Months Ended

Dec. 31, 2019

Equity [Abstract]

Schedule of Grant Date Fair Value of Warrant, Valuation Assumptions

The grant date fair value of the warrants issued in connection with the Pharmakon Senior Secured Notes was estimated at the time of grant using the Black-Scholes option-pricing model using the following weighted average assumptions:

Risk free interest rate	1.67		%
Expected term (in years)	3
Expected volatility	65.10		%
Annual dividend yield	0.00		%
Fair value of common stock	$	6.72

Schedule of Warrants

As of December 31, 2019, the Company had the following warrants outstanding to purchase shares of Common Stock:

Number of Shares	Exercise Price Per Share	Expiration Date
1,866,831	$8.16	November 1, 2020
810,357	$6.72	September 12, 2022