To quantify the repeatability and accuracy of ejected volume we conducted experiments where a fraction of the total ampoule volume was ejected and collected in vials containing dry cotton wool. The specified volume of drug ejected was varied in the range 50–200 μL and the ejected drug volume was determined from the difference between the post- and pre-injection weight of the vial. Ejections of 50 μL were conducted in groups of four per ampoule-reload. Ejections of 100 μL were conducted in pairs per ampoule reload. Ejections of 150 and 200 μL were each conducted from a fully loaded ampoule.