Abstract: Examples of containers for the production of a foamed sclerosant composition are provided. The containers include a container body comprising one or more sidewalls extending between a top and a bottom of the container body and a bottom surface, a foaming space being defined in an interior of the container body. The foaming space contains a sterile gas and a mixing element configured to be operatively coupled with a rotatable actuator without the actuator entering into the foaming space. The container includes a female coupling member for mating with a syringe, and a pressure equalizer for equalizing a pressure inside the foaming space with a pressure outside the foaming space. Systems and kits including such containers are also provided. Also disclosed are methods for the preparation of a sclerosant foam which may include a pressure release before extraction of the foam and/or a continued rotation of the actuator while the foam is being extracted.