Nature of business and basis of presentation (Details)	Feb. 10, 2023	May 16, 2022 USD ($) $ / shares shares	Jun. 30, 2023 USD ($) $ / shares	Dec. 31, 2022 USD ($) $ / shares	Jun. 30, 2022 USD ($)
Common stock, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001
Reverse stock split ratio	0.05
Cash balance | $			$ 27,685,131	$ 28,786,647	$ 39,062,415
Atrin Pharmaceuticals, Inc
Cash balance | $		$ 2,489,745
Common Stock | Atrin Pharmaceuticals, Inc
Issuance of stock upon acquisition of Atrin (in shares). | shares		55,869
Common stock, par value (in dollars per share) | $ / shares		$ 0.001
Number of shares to purchase under option | shares		163,757
Series A Convertible Preferred Stock | Atrin Pharmaceuticals, Inc
Issuance of stock upon acquisition of Atrin (in shares). | shares		2,949,630
Conversion value | $		$ 68,800,000
Preferred stock conversion ratio		10