Canopy Growth Corporation's CEO is looking to assuage quality control fears less than a month after closing his company's takeover of Mettrum Health Corp.

Canopy CEO Bruce Linton said in an open letter released Thursday morning that steps are being taken "to enhance quality assurance practices and operational controls."

Canopy (WEED.TO), Canada's largest licensed medical cannabis producer, struck a $430-million all-stock takeover agreement with Mettrum in December, and the transaction subsequently closed at the end of January. The target company had announced a voluntary recall in November as a result of certain products being exposed to pesticides.

"The application of pest control products not registered for use on cannabis at Mettrum was inexcusable," Linton said in his open letter. "Mettrum has work to do to regain customer and physician confidence. I believe we have a team in place that is up to the challenge."