A system for transferring solutions from a first cartridge into a second cartridge comprises a cartridge holder, a plunger driver, and a cartridge connector. The cartridge connector carries a transfer needle and an exhaust needle. The cartridge holder positions the first cartridge against the cartridge connector so that the transfer needle penetrates the first cartridge septum. The second cartridge is removably inserted into another end of the cartridge connector so that both the transfer needle and the exhaust needle penetrate the second cartridge septum. The plunger driver is disposed to advance a plunger on the first cartridge to transfer solution from the first cartridge into the second cartridge thus displacing solution from the second cartridge through the exhaust needle. The cartridge connector includes a sealed interior waste chamber for receiving the solution from the second cartridge.