Why should spiked dispensing devices not be used with vials of the Hospira UK Ltd paclitaxel 6 mg/ml concentrate for solution for infusion product?

During dilution of the Hospira UK Ltd paclitaxel 6 mg/ml concentrate for solution for infusion product, cytostatic dispensing needles or similar spiked devices should not be used because they can collapse the vial stopper, causing loss of the solution’s sterile integrity.