An actuating device having integrated plunger is configured to be removably mounted to an automatic mixing device for a syringe. The actuating device includes lower and upper housings, a trigger member, a lockout ring, a mixing biasing member, a delivery plunger, a plunger biasing member, and a mixing plunger. The mixing plunger is releasably engaged with the trigger member in an initially locked state and engageable with at least one seal of the mixing device. The trigger member is operable to initiate decompression of the mixing biasing member and engagement of the mixing plunger with the at least one seal of the mixing device. The delivery plunger may also be activated to expand from a first, collapsed configuration to a second, expanded configuration by actuation of the trigger member.
