Transfer port system

Abstract: A transfer port system to allow material to transfer between two dockable sterile environments. Two doors provide access to the sterile environments. A peripheral flange frames one of the doors while another peripheral flange forms the opening to the other sterile environment. Doors connect to one another, when the sterile environments are docked. and then move as a unit into the one sterile environment in order to allow the material transfer. Outer and inner gaskets seal the sterile environments and with the peripheral flanges form an interface between the sterile environments during material transfer. The portions of the gaskets and peripheral flanges that were exposed to the unsterile ambient prior to docking are actively heated in order to maintain sterility during the time when the sterile environments are docked and prior to the time that the doors are moved to the open position. The doors can be connected to one another prior to their opening by vacuum. The vacuum has an added benefit of drawing contaminants from between the doors.

Description: This invention relates to a transfer port system to allow material transfer between two sterile environments in which the two sterile environments dock with one another during the material transfer. More particularly, the invention relates to such a transfer port system in which doors provided for access to the two sterile environments are sealed by gaskets. Even more particularly, the invention relates to a transfer port system in which gasket surfaces are heated to maintain sterile conditions during the material transfer between the sterile environments. The use of sterile manufacturing environments has become increasing more important in many industrial processes. The electronic and pharmaceutical industries have a particularly low tolerance for inorganic and organic contaminants. An example of processing that must be conducted in aseptic conditions concerns the preparation of medicants, solutions, and suspensions within the pharmaceutical industry by freeze drying. In accordance with such production, the product is loaded into vials under sterile conditions and is then transported in an transporter isolator to a freeze dryer. The transporter isolator is a sterile vehicle for the transport of vials and docks at the end of its journey with the freeze dryer for the transfer of vials onto the shelves of the freeze dryer. After the docking of the transporter isolator and the freeze drier and the transfer of the vials, the product is freeze dried and the vials are stoppered within the freeze drier. Between freeze drying operations, the freeze dryer can be sterilized with steam, hydrogen peroxide vapour solutions and the like so that its sterility is maintained. During the transfer of vials into the freeze dryer from the transporter isolator, a sterile interface must be maintained between the transporter isolator and the freezer dryer chamber. The same problem exists in any transfer port system in which material transfer is to be accomplished between two sterile environments. The difficulty in the maintenance of the sterile interface is that components of the transfer port system have been exposed to unsterile ambient conditions prior to linkage or docking of the two sterile environments. This problem is compounded by imperfections in the mating of components of the transfer port system. In order to maintain sterility at the interface, heat is applied to the components that have been exposed to the unsterile environment. Such sterilisation is not without problems due to the thermal mass of the components of the transfer port system and the attendant required heating time to attain an assurance of a sterile condition. It is known from EP-A-0730907 that a transfer port system between two sterile environments can be provided including door frames, door connection means, part opening means and heating means for sterilizing the peripheral juncture between the frames. The invention provides a transfer port system that is designed such that its components can be rapidly heated in order to maintain the necessary sterile interface between sterile environments during material transfer. Additionally, the transfer port system is designed to accommodate slight misalignments between its components. The invention provides a transfer port system to allow material transfer between two sterile environments. The two sterile environments have a docked position, adjacent to one another, to allow the material transfer, and an undocked position, separated from one another. A door means is provided for the transfer port system in order to access the two sterile environments. The door means includes first and second doors having a closed position closing the two sterile environments and an open position with the first and second doors connected to one another and situated within one of the two sterile environments. In the open position of the two doors, material transfer is allowed between the two sterile environments. First and second peripheral flanges are connected to the first door and the other of the two sterile environments, respectively, and are positioned to initially contact one another when the two separate sterile environments are in the docked position. The first and second peripheral flanges have matched abutting surfaces aligned with and in contact with one another during the initial contact of the first and second peripheral flanges. Additionally, lateral sealing surfaces are connected to the matched abutting surfaces and are shaped to form two opposed, outer and inner peripheral grooves when the matched abutting surfaces are in contact. Outer and inner gaskets are provided with sealing portions configured to seat within the outer and inner grooves and to seal against the lateral surfaces of the first and second peripheral flanges during the initial contact thereof. The outer gasket is connected to the one of the two sterile environments and the inner gasket is connected to the second door. As a result, when the first and second doors are in the closed position, the two separable environments are sealed by the outer and inner gaskets at the first and second peripheral flanges, respectively. When the two sterile environments are in the docked position, with the first and second doors in the open position, the outer gasket peripherally seals both of the two sterile environments at the second peripheral flange and the inner gasket peripherally seals the first and second doors at the first peripheral flange. A heating means is provided for heating the first and second peripheral flanges during their initial contact. Such heating sterilises the lateral sealing surfaces, the matched abutting surfaces and the sealing portions of the outer and inner gaskets. A connection means is provided for connecting the first and second doors to one another when the sterile environments are in the docked position. This allows movement of the first and second doors into the open position as a unit. When the two sterile environments are in the undocked position, part of the sealing portions of the outer and inner gasket are exposed to unsterile conditions. Additionally, the matched abutting surfaces are also exposed. In order to assure the sterile transfer of material, all of these foregoing exposed surfaces are heated to sterile temperatures during the initial contact of the first and second peripheral flanges. Since the sealing surfaces of the gaskets are in fact captured between the two peripheral flanges, light misalignments can be tolerated between the peripheral flanges and gaskets. Moreover, since the sealing is effected between gasket and peripheral flange, the peripheral flanges can be connected to the environments and doors in an insulated manner to reduce the thermal mass of the system that must be heated to sterile temperatures. For a better understanding of the invention, reference will now be made, by way of exemplification only, to the accompanying drawings, in which: Figure 1 is a sectional view of a transfer port mechanism of the invention in the undocked position; Figure 2 is a fragmentary, sectional view of a transfer port system of the invention shown in the docked position during initial contact of the first and second peripheral flanges; Figure 3 is a sectional view taken along line 3-3 of Figure 2; Figure 4 is a fragmentary sectional view of the transfer port system of in Figures 1 and 2 applied to a freeze dryer and transporter isolator with the doors shown in the open position; Figure 5 is an enlarged fragmentary view of Figure 3; Figure 6 is a cross-sectional view of a gasket in accordance with the invention; and Figure 7 is a sectional view taken along lines 7-7 of Figure 4. With reference to Figures 1 to 4, a transfer port system 1 in accordance with the invention is illustrated to transfer material between sterile environments 2 and 3 which are respectively, a freeze drier and a transporter isolator. Vials 4 constitute the sterile material to be transferred between the two environments. The sterile environments 2 and 3 from an undocked position (Figure 1) are moved to a docked position, adjacent to one another (Figure 2). Although not illustrated, the sterile environment 3 (the transporter isolator) would be provided with a carriage adapted to ride in tracks leading up to sterile environment 2 (the freeze drier.) First and second doors 10 and 12 provide access to the sterile environments 2 and 3. When the sterile environments 2 and 3 are in the docked position, the first and second doors 10 and 12 connect to one another and then, as a unit, pivot into the sterile environment 2 to allow material to be transferred between the two sterile environments 2 and 3 (Figure 4). The transporter isolator is an elongated container. In order to allow the sterile environment 3 of the transporter isolator to interface with other sterile environments positioned opposite and 180 degrees from the sterile environment 2, although not illustrated, provision can be made to enable the rotation of the complete transporter isolator together with its door 12. The first door 10 is connected to crank-like arms 16 and 18 by pivots 13 and 14. The crank-like arms 16 and 18 are in turn connected to a stub shaft 20 which is hollow to permit a vacuum drawn through the axle and vacuum lines 22 and 24. It is the vacuum that connects the first and second doors 10 and 12 to one another. The second door 12 is secured in the closed position by two latch members 26 and 28 that engage with latch arms 30 and 32. The latch arms 30 and 32 are connected to an axle 34 which rotates in a counterclockwise direction to free the second door 12 from the sterile environment 3. The vacuum, drawn through the vacuum lines 22 and 24 and when the sterile environments are in the docked position, connect the first and second doors 10 and 12 to one another. Counterclockwise rotation of the axle 34 opens latching members holding the second door 12 in place and rotation of the stub shaft 20 rotates the crank-like members 16 and 18 in the counterclockwise direction and in turn rotating the assemblage of the first and second doors 10 and 12 in the open direction. When the first and second doors 10 and 12 are in the open position, material transfer is allowed between the sterile environments 2 and 3. With additional reference to Figure 5, first and second peripheral flanges 36 and 38 are respectively connected to the periphery of the first door 10 and the periphery defining the opening to the sterile environment 3. The first and second peripheral flanges 36 and 38 (when viewed in plan) approximate a frame-like rectangle having rounded corners. The first peripheral flange 36 is connected to the first door 10 by means of studs 40 and 42 provided about the periphery of the first peripheral flange 36. The first peripheral flange 36 is insulated from the first door 10 via an insulation pad 44. The second peripheral flange 38 is identical to the first peripheral flange 36 and is connected to a wall 46 defining the sterile environment 3. The second peripheral flange 38 is mounted on an insulation pad 47. The provision of studs 48 and 50, which are provided about the periphery of the second peripheral flange 38, securely connect second peripheral flange 38 to wall 46. Each of the insulation pad 44 and insulation pad 47 in a plan view have a rectangular ring-like configuration with rounded corners to match the first and second peripheral flanges 36 and 38. The first and second peripheral flanges 36 and 38 have a transverse cross-section in the shape of an equilateral trapezoid. The shorter parallel side of this form defines an abutting surface 52 of the first peripheral flange 36 which matches a matched abutting surface 54 of the second peripheral flange 38. Lateral sealing surfaces 56 and 58 connect to the abutting surface 52 and lateral sealing surfaces 60 and 62 connect to the abutting surface 54. When the abutting surfaces 52 and 54 are in contact, which initially occurs during docking of the sterile environments 2 and 3, outer and inner peripheral grooves 64 and 66 are formed. Outer and inner gaskets 68 and 70 have sealing portions that seat within the outer and inner peripheral grooves 64 and 66 and thus, seal against the lateral sealing surfaces 56, 58, 60 and 62 of the first and second peripheral flanges 36 and 38. During this initial contact, surfaces of the first and second peripheral flanges 36 and 38 and the outer and inner gaskets 68 and 70 that were previously exposed to unsterile conditions are sterilised in place to allow the first and second doors 10 and 12 to open. Each of the outer and inner gaskets 68 and 70 has connected head and base portions 72 and 74. The head portions 72 are of triangular cross-section and the base portions 74 are of rectangular cross-section. The sealing portions of the outer and inner gaskets 68 and 70 are formed by the head portions 72 of outer and the inner gaskets 68 and 70. With additional reference to Figure 6, each of the head portions 72 is given a slight concavity as indicted by radius R so that the head portions 72 of the outer and inner gaskets 68 and 70 can be compressed between the first and second peripheral flanges 36 and 38 in case of slight misalignment thereof during docking of the two sterile environments 2 and 3. By way of example, each of the head portions 72 can be approximately 6 mm. in height, about 17.5 mm. in width and be provided with a radius R of about 25 mm. Each of the first and second peripheral flanges can have a base of about 33 mm. in width with the lateral sealing surfaces 56, 68 and 60, 62 sloping toward the matched abutting surfaces 52 and 54, respectively, at about a 45 degree angle and a height of about 15 mm. The outer and inner gaskets 68 and 70 could be provided with ribs situated at the three apexes of the triangular cross-section of the head portions 72. Base portions 74 are of rectangular configuration to form flat strip-like sections that are used to anchor the outer and inner gaskets 68 and 70 to a sealing flange 94 (discussed below) and the second door 12. To this end, the base portions 74 are held between clasp members 76 and 78 which are in turn connected to the sealing flange 94 and the second door 12 by sets of studs 80. Each of the clasp members 76 and 78 is of rectangular ring-like configuration with rounded corners to confirm to the outer and inner gaskets 68 and 70. The gasket described above is made of silicon rubber having a maximum rated temperature of about 315° C and a hardness of Shore A 50. Other materials are possible. When the sterile environments 2 and 3 are in the undocked position, the sterile environment 2 is sealed between the first peripheral flange 36 and the head portion 72 of the outer gasket 68. This leaves an exposed surface of the gasket 68 that is subjected to the ambient, unsterile environment as well as the matched abutting surface 52 and the lateral sealing surface 56 of the first peripheral flange 36. At such time, the sterile environment 3 is sealed between the head portion 72 of the inner gasket 70 and the second peripheral flange 38. Thus, the head portion 72, the matched abutting surface 54, and the lateral sealing surface 60 are also exposed to the ambient, unsterile environment. With specific reference to Figure 5, when a vacuum is drawn during initial contact of the first and second peripheral flanges 36 and 38, the first and second doors 10 and 12 as a unit are swung into the open position to lie within the sterile environment 2. Thus, if the previously exposed surfaces were not sterilised upon such initial contact, there would be no assurance that the two sterile environments 2 and 3 were not contaminated. Therefore, provision is made to heat the first and second peripheral flanges 36 and 38 and the outer and inner gaskets 68 and 70 to a sufficiently high temperature that sterile conditions are assured upon the opening of the first and second doors 10 and 12. With additional reference to Figure 7, cartridge-like or sheathed electrical heating elements 82 and 84 are provided to heat the first and second peripheral flanges 36 and 38 and therefore the outer and inner gaskets 68 and 70. Current is continuously supplied to electrical heating elements so that the foregoing assemblage between loading operations is maintained at about 140°. Prior to loading the current is increased to attain a sterilising temperature of about 220° C. During an initial period of about 30 seconds, when the sterile environments are first docked, but prior to opening of the first and second doors 10 and 12. the heating is continued. When the first and second peripheral flanges 36 and 38 first come together a vacuum is drawn between the first and second doors 10 and 12. In addition to its connection function, the vacuum acts to draw potential contaminants from between the first and second doors 10 and 12 and out of the system. At the conclusion of the initial period, the second door 12 is unlatched as described above and the first and second doors 10 and 12 as a unit swing or pivot into the sterile environment 2. In the illustrated embodiment each of the heating elements 82 and 84 have a power output of about 4 KW. Each heating element 82, 84 can be formed from two sections, for example, the illustrated sections 82a and 82b of the heating element 82, to permit thermal expansion. The first and second peripheral flanges 36 and 38 are insulated in their mounting by the pads 44 and 47. Backing pieces 86 and 88 of stainless steel may be provided to position the heating elements 82 and 84 against the first and second peripheral flanges 36 and 38. Due to the insulated mounting of the heating elements 82 and 84 the power output thereof goes directly to sterilising the previously unsterilised surfaces rather than also heating other components of the transfer port system 1. The pad 44 additionally serves as a vacuum seal when the first and second doors 10 and 12 are connected by vacuum. The first and second doors are formed by sheet material to lower the thermal mass of each of the first and second doors 10 and 12. The insulation and such door construction permits the requisite temperature to be attained rapidly. Such sheet metal construction adds flexibility to the first and second doors 10 and 12 to enhance the ability of docking even with slight imperfections in flatness of the outer and inner gaskets 68 and 70 and/or the matched abutting surfaces 52 and 54. The separation of the sterile environments 2 and 3 is the reverse of the operation described above and throughout the time sterile environments 2 and 3 are docked sterile temperatures are maintained. The sterile environment 3 being a freeze drier can be steam sterilised to allow changing types or batches of medicants and the like. To this end, a frame 90 is connected to a wall 92 of the freeze drier vestibule (the illustrated portion of the sterile environment 2) to allow movement of a steam or slot door (not illustrated). The frame 90 has a slot-like flange 92 (within which the steam or slot door slides) that is connected to a sealing flange 94. The sealing flange 94 is in turn connected to the frame 90. The elements are held in place by studs of which a stud 96 is illustrated. An interior gasket 98 is interposed between the sealing flange 94 and the frame 90 to seal the sterile environment 2. Exterior gaskets 100 and 102 seal the steam door which vertically slides (down prior to steam sterilisation and up thereafter) within slots of the slot-like flange 92 in a guillotine-like manner.

Claims: A transfer port system (1) to allow material transfer between two sterile environments, the two sterile environments (2,3) having a docked position, adjacent to one another, with their portals in alignment to allow the material transfer and an undocked position, separated from one another, the transfer port system comprising: door means (10,12) for providing access to the two sterile environments and including first (10) and second (12) doors having a closed position closing the two sterile environments (2,3) and an open position with the first and second doors (10,12) connected to one another and situated within one of the two sterile environments (2,3), thereby to allow the material transfer between the two sterile environments; first and second peripheral flanges (36,38) connected to the first door (10) and the other (3) of the two sterile environments, respectively, and positioned initially to contact one another when the two sterile environments are in the docked position; an outer gasket (68) connected to the one of the two sterile environments (2,3) and an inner gasket (70) connected to the second door (12) so that when the first and second doors (10,12) are in the closed position, the two separable environments (2,3) are sealed by the outer and inner gaskets (68,70) at the first and second peripheral flanges (36,38), respectively, and when the two sterile environments (2,3) are in the docked position, with the first and second doors (10,12) in the open position, the outer gasket (68) peripherally seals both of the two sterile environments (2,3) at the second peripheral flange (38) and the inner gasket (70) peripherally seals the first and second doors (10,12) at the first peripheral flange; heating means (82,84) for heating the first and second flanges (36,38) during their initial contact; connection means (16,18) for connecting the first (10) and second (12) doors to one another when the two sterile environments (23) are in the docked position, thereby to allow movement of the first and second doors into the open position characterized in that the first and second peripheral flanges (36,38) have matched abutting surfaces (52,54) aligned with and in contact with one another during the initial contact of the first and second peripheral flanges (36,38) and lateral surfaces (60,62) are connected to the matched abutting surfaces (52,54) and shaped to form two opposed, outer and inner peripheral grooves (64,66) when the matched abutting surfaces are in contact; and in that the outer and inner gaskets (68,70) having sealing portions configured to seat within the outer and inner grooves (64,66) and to seal against the lateral sealing surfaces (60,62) of the first and second peripheral flanges (36,38) during the initial contact thereof and in that the heating means (82,84) able to sterilize the lateral sealing and matched abutting surfaces and the sealing portion of the out and inner gaskets. A transfer port system (1) according to Claim 1 further comprising thermal insulation (44,47) configured to thermally insulate the first and second peripheral flanges (36,38) from the first door (16) and the other of the two sterile environments (2,3). A transfer port system (1) according to Claim 1 or Claim 2 in which: each of the first and second flanges (36,38) has a transverse cross-section in the form of an equilateral trapezoid having parallel base and apex sides and lateral sides outwardly sloping from the apex side to the base sides, the apex side defining the matched abutting surfaces (52,54) and the lateral sides defining the lateral sealing surfaces (60,62) ; and each of the first and second gaskets (68,70) has connected head and base portions (72,74) of respectively triangular and rectangular transverse-cross-sections; and the sealing portions of the outer and inner gaskets are formed by the head portions (72) of the outer and inner gaskets. A transfer port system (1) according to Claim 3 in which the head portion (72) has concave side portions to seat within the grooves. The transfer port system (1) according to Claim 3 in which the outer and inner gaskets (68,70) are connected to the one of said two environments (2,3) and the second door (12), respectively, by being clamped between peripheral clasping members (76,78) at their the base portions. A transfer port system (1) according to any preceding claim in which the heating means (82,84) comprises electrical heating elements located within the first and second peripheral flanges (36,38). A transfer port system (1) according to any preceding claim in which: each of said first and second doors (10,12) is formed by sheet-like material; and the connection means includes means for forming a vacuum between the first and second doors. A transfer port system (1) according to any one of Claims 3 to 7 in which the head portion (72) has concave side portions to seat within the grooves. A transfer port system (1) according to Claim 8, in which the heating means (82,84) comprises electrical heating elements located within the first and second peripheral flanges (36,38). A transfer port system (1) according to any preceding claim in which the outer and inner gaskets (68,70) are connected to said one of the two environments (2,3) and the second door (12), respectively, by being clamped between peripheral clamping members (76,78) at their the base portions. A transfer port system (1) according to any preceding claim in which: each of the first and second doors (10,12) is formed by sheet-like material; and the connection means includes means for forming a vacuum between the first and second doors.

Inventors: BAXTER ANDREW R, KENDALL JOHN S, WHITMAN CHARLES R, BAXTER, ANDREW R., KENDALL, JOHN S., WHITMAN, CHARLES R.
Applicants: BOC GROUP INC, THE BOC GROUP, INC.
Application year: 1997
Main classification: B01L1
IPC codes: F24F13, H01L21, B65G49, B01L1