A drug delivery device (1) is provided comprising a container (4), a first product (13A) and a second product (13B). The device (1) is configured to mix the first product (13A) and the second product (13B) with each other within the container (4) for forming a drug mixture (13A, 13B). The device (1) is further configured for dispensing the drug mixture (13A, 13B). The device (1) comprises a mixing member (20). The device (1) is switchable from a first state, in which the first product (13A) and the second product (13B) are separated, into a second state, in which the first product (13A) and the second product (13B) are mixed. The mixing member (20) is configured to exert a force onto the container (4) in order to move the container (4) to mix the first product (13A) and the second product (13B) with each other.Furthermore, a method for maintaining a predetermined property of a drug mixture (13A, 13B) to be dispensed from a drug delivery device (1) is provided.