The invention is related to an apparatus comprising a valve body comprising at least two inlet channels and at least one outlet channel and forming a central cavity connecting the at least two inlet channels and the at least one outlet channel, wherein the central cavity encloses a blocking assembly arranged for closing each of the at least two inlet channels by default and for opening an inlet channel when fluid pressure is applied from that inlet channel; wherein each of the at least two inlet channels is configured for fluid communication with a respective reservoir of at least two reservoirs. The invention is further related to a medical device for delivering at least two drug agents from at least two separate reservoirs comprising an apparatus of the aforementioned kind.