Tube assembly (12), adapted for use in cooperation with a medical liquid supply device (10), comprising: - a supply tube (68) adapted to deliver a medical liquid or blood to a patient； - a vial inlet (24) for connecting vials (26) containing drugs to be delivered in the medical liquid or blood, the vial inlet (24) comprising a supply light (28), adapted to administer the drug (30) from vial (26) to supply tube (68), and a discharge light (32), adapted to provide a replacement liquid (34, 60) from a location (20, 64) within the set of tubes (12) to the interior of the vial (26) to replace the administered drug (30)； wherein the vial inlet (24) further comprises at least one one-way valve (70, 72) positioned along said discharge light (32) or said supply light (28)； characterized in that the vial inlet (24) further comprises means (56) to guarantee a secure connection of the vial (26), said means (56) being: - designed to guarantee a hermetic closure of the extracorporeal circuit (36) in the absence of any vial (26)； - arranged in such a way that the fluid connection can be opened only when a vial (26) is properly positioned at the vial inlet (24)； and - arranged such that the vial (26) can be withdrawn only when the fluid connection is closed.Conjunto de tubos (12), adaptado para su uso en cooperación con un dispositivo (10) de suministro de líquido médico, que comprende: - un tubo de suministro (68) adaptado para administrar un líquido médico o sangre a un paciente； - una entrada de vial (24) para la conexión de viales (26) que contienen fármacos que deben suministrarse en el líquido médico o la sangre, comprendiendo la entrada de vial (24) una luz de suministro (28), adaptada para administrar el fármaco (30) desde el vial (26) hasta el tubo de suministro (68), y una luz de descarga (32), adaptada para proporcionar un líquido de sustitución (34, 60) desde una ubicación (20, 64) dentro del conjunto de tubos (12) hasta el interior del vial (26) para sustituir el fárma
