Why must the Wockhardt UK Ltd flucloxacillin 250 mg powder for solution for injection or infusion product not be mixed with an aminoglycoside in the same syringe, container or giving set?

The Wockhardt UK Ltd product, flucloxacillin 250 mg powder for solution for injection or infusion, must not be mixed with an aminoglycoside in the same syringe, container or giving set because precipitation may occur.