Controlled medicament ejection

A medicament ejector comprising:

• an ejection mechanism including at least one ejection chamber configured to contain a fluid-based solute medicament, and at least one ejection element, the ejection mechanism being configured to selectively effect controlled ejection of medicament from the at least one ejection chamber via activation of the at least one ejection element;
• a storage chamber configured to store the medicament, wherein the at least one ejection chamber is in continuous fluid communication with the storage chamber;
• and
• a controller configured to determine at least one indication of a characteristic of medicament in at least one of the ejection chamber and the storage chamber, and control ejection of medicament from the at least one ejection chamber based on the at least one determined indication, wherein the characteristic of the medicament is pressure of the medicament and wherein a current orientation of the ejection mechanism relative to a control orientation is determined from the at least one determined indication to control-ejection of medicament from the at least one ejection chamber based on the current orientation.