Cleaning of a fluid path system for hyperpolarization of a pharmaceutical product

The present disclosure relates to a method for cleaning a reusable fluid path system for hyperpolarization of a pharmaceutical product, said reusable fluid path system being continuously at least partly contained by a polarizer; the method comprising the steps of a) providing the polarizer with an inlet tube having a first inlet tube end for fluid contact with a fluid vessel and a second inlet tube end configured for fluid contact with a vial, for holding the pharmaceutical product during hyperpolarization; b) providing the polarizer with an outlet tube having a first outlet tube end configured for receiving the vial and a second outlet tube end for connecting to a receiving vessel; c) sealing the second inlet tube end with the first outlet tube end; d) fluidly connecting a medium vessel to the first inlet tube end; e) fluidly connecting a collector vessel to the second outlet tube end; f) cleaning the reusable fluid path system by transferring a cleaning medium from the medium vessel into the reusable fluid path system; g) ejecting the cleaning medium from the reusable fluid path system into a collector vessel; and h) drying the reusable fluid path system.