Implantable drug delivery device

An implantable delivery device comprising at least a body, an inlet and an outlet and actuating means, wherein the actuating means comprise at least an actuator displacing a piston in a rotating cylinder forming at least one variable volume chamber, the volume of which is varied by rotation of said cylinder thereby pumping liquid such as a drug from a reservoir through said inlet and expelling said pumped liquid from said variable volume chamber through at least a first temporary chamber and said outlet by variation of said volume.