Patent Number: 059441909
Section: description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A preferred embodiment of a radiopharmaceutical capsule safe according to the invention is shown in "exploded" or assembly form in FIG. 1. The radiopharmaceutical capsule safe includes a vial 10 in which a radiopharmaceutical capsule 12 is contained. As shown in greater detail in FIGS. 2A and 2B, the vial 10 is generally cylindrical and is made from plastic such as acrylic. A plurality of centering lands 14, e.g., four, protrude from the cylindrical inner wall 16 of the vial and extend longitudinally from the closed bottom end 17 of the vial substantially along the length of the vial. The centering lands 14 are evenly spaced circumferentially and center the radiopharmaceutical capsule 12 within the vial 10. The vial has two or more vial tabs 18 extending from the outer cylindrical surface 20 thereof. The vial tabs 18 preferably are evenly spaced circumferentially. The open upper end 22 of the vial has external threads 24. External threads 24 mate with internal threads 32 of vial cap 30 (FIGS. 3A and 3B). The vial cap is generally cylindrical and has a closed upper end 34 and an open lower end 36. It, too, is made from plastic or other radiotransmissive material such as acrylic. Like the vial 10, the vial cap 30 has two or more cap tabs 38 protruding from the cylindrical outer surface 40 thereof. The cap tabs 38 preferably are evenly spaced circumferentially. A neoprene gasket 42 is situated against the closed upper end 34 of the vial cap and ensures an airtight seal when the vial cap is screwed onto the vial 10, in an assembly procedure which will be described below. When closed, the vial is secured within a radiopaque safe which is comprised of a safe bottom 50 and a safe lid 70. As shown in greater detail in FIGS. 4A and 4E, the safe bottom 50 is a generally solid, cylindrical mass of lead (97% lead/3% antimony alloy) with a tapered or frustroconical lower portion 52. A boss 54 extends from the center of the upper surface 56 of the safe bottom. Vial-receiving cavity 58 is formed as a counterbore extending through the center of the boss 54 and approximately half-way through the axial length of the safe bottom. The counterbore configuration provides the vial-receiving cavity 58 with an annular shoulder 60. Two or more longitudinally extending semicircular grooves 62 are formed in the cylindrical surface 64 of the counterbore portion of the vial-receiving cavity 58. As shown in FIGS. 5A and 5B, the safe lid 70 is generally similarly shaped. Specifically, it is a generally solid, cylindrical mass of lead (97% lead/3% antimony alloy) with a tapered or frustroconical upper portion 72. Vial cap-receiving cavity 74 is formed as a counterbore which extends from the bottom surface 76 of the safe lid approximately half-way into the interior of the safe lid. The counterbore portion 78 of the vial cap-receiving cavity has a diameter and a depth that are substantially the same as the diameter and height, respectively, of the boss 54 extending from the upper surface 56 of the safe bottom. This permits the safe bottom and the safe lid to be positioned together with the boss extending into the counterbore portion 78 of the vial cap-receiving cavity 74 and with the surfaces 56 and 76 mating flush. The cylindrical surface 80 of the vial cap-receiving cavity 74 also has two or more longitudinally extending semicircular grooves 82 formed therein. The radiopharmaceutical capsule safe utilizes a lower and an upper lock ring 90 and 110, respectively (FIGS. 6A, 6B, 7A, and 7B). The lower and upper lock rings have generally similar construction. Both are formed from plastic such as acrylic and have two or more semicircular ridges 92, 112 extending longitudinally along their outer cylindrical surfaces 94, 114, respectively. The outer diameter of the lower lock ring is generally the same as the diameter of the counterbore portion of the vial-receiving cavity 58 in the safe bottom 50, and the inner diameter of the lower lock ring is substantially the same as the outer diameter of the vial 10. Similarly, the outer diameter of the upper lock ring is substantially the same as the diameter of the counterbore portion of the vial cap-receiving cavity 74 in the safe lid, and the inner diameter of the upper lock ring is substantially the same as the outer diameter of the vial cap 30. The lower lock ring 90 has a pair of diametrically opposed tab-receiving slots 96 which extend from the upper surface 97 of the ring toward the bottom of the ring. Tab-engaging slot extensions 98 extend circumferentially from the bottom of each of the tab-receiving slots 96 such that a cantilevered overhanging portion 100 is formed, with a slight undercut portion 102 indicated by the dashed lines in FIG. 6B. (One of the dashed lines of each pair represents the end wall 103 of each slot extension.) The configuration, which is shown in more detail in FIG. 6C, permits the tabs 18 extending from the outer surface of the vial 10 to slide down into the tab-receiving slots 96 and then to rotate counterclockwise as seen from above (i.e., to the right as shown in FIG. 6C) under the overhanging portion 100. Similarly, the upper lock ring 110 has diametrically opposed tab-receiving slots 116 extending from the bottom of the ring 118 substantially toward the top of the ring, and tab-engaging slot extensions 118 extending circumferentially a short distance from the tops of the tab-receiving slots 116. The tab-engaging slot extensions 118 have undercut portions 122, which are indicated by the dashed lines in FIG. 7B. (One of the dashed lines of each pair represents the end wall 123 of each slot extension.) Thus, the configuration of the upper lock ring is such that the tabs 38 extending from the outer surface of the vial cap slide up into the tab-receiving slots 116 and then can rotate clockwise (as seen from above) into the tab-engaging slot extensions 118. The radiopharmaceutical capsule safe is contained within an outer jar consisting of a jar bottom 130 made from plastic, such as polypropylene, and a mating jar lid 150, also made from plastic such as polypropylene. The jar bottom 130 is generally an open-topped cylindrical vessel with external threads at the open end thereof. The jar bottom has an annular rib 134 extending along the circumference of the jar bottom and located near the open end of the jar bottom. The jar lid 150 is similarly an open-bottomed cylindrical cap, with internal threads 152 that mate with the external threads 132 of the jar bottom 130. The radiopharmaceutical capsule safe of the invention is used as follows. When packaging the radiopharmaceutical capsule, the safe bottom 50 is inserted into the jar 130, as shown in FIG. 1. The safe bottom 50 is pressed past the annular rib 134 at the open end of the jar 130, and then the rib 134 snaps back to retain the safe bottom in the jar. The lower lock ring 90 is then press fit into the counterbore portion of the vial-receiving cavity 58, with the ridges 92 protruding from the locking ring fitting into the grooves 62 formed in the cylindrical surface 64 of the counterbore portion. An activated charcoal insert 13 is placed in the bottom of the vial bottom-receiving cavity to trap airborne iodine particles, and the vial 10 is inserted down into the vial bottom-receiving cavity 58 with the tabs 18 extending from the vial sliding down into the tab-receiving slots 96 in the lower lock ring 90. Similarly, the upper lock ring 110 is press fit into the counterbore portion of the cap-receiving cavity 74 in the safe lid, with the ridges 112 protruding from the upper lock ring fitting within the grooves 82 formed in the cylindrical wall surface of the cap-receiving cavity 74. It may be desirable to apply a small amount of adhesive to the outer surface of the upper lock ring to help secure it in place. The vial cap 30 is then inserted into the safe lid by sliding the tabs 38 extending therefrom along the tab-receiving slots 116 in the upper lock ring 110 and then rotating the vial cap such that the tabs 38 slide into the tab-engaging slot extensions 118. The radiopharmaceutical capsule 12 is then placed in the vial 10, and the safe lid/vial cap assembly is placed over the vial and rotated in a clockwise direction (as seen from above) to screw the vial cap 30 down onto the vial 10. (The lower portion 79 of the safe lid is the same diameter as the inside diameter of the rib 134 at the open end of the jar 130 such that the safe lid rests flush against the safe bottom.) Finally, the jar cap 150 is screwed onto the jar 130 to complete the package. When assaying of the radiopharmaceutical capsule is required, the plastic jar cap is unscrewed to expose the safe lid. The safe lid can be pulled straight off the vial cap if the tabs 38 are aligned with the tab-receiving slots 116 in the upper lock ring; otherwise, if the tabs 38 are positioned in the tab-engaging slot extensions 118, the safe lid is rotated clockwise a slight amount, until the tabs are felt to abut the opposite side-walls of the tab-receiving slots 116, and then the safe lid/upper lock ring assembly is lifted to expose the vial cap 30. At this point, because the vial cap 30 is made from plastic and is transmissive of radiation emitted by the radiopharmaceutical capsule, the capsule can be assayed without opening the vial itself. Because the radiopharmaceutical capsule typically is not dosed to a patient until some time later, the safe lid/upper lock ring assembly typically is then replaced over the vial cap 30. When it is ultimately desired to dose the radiopharmaceutical capsule to a patient, the safe lid is turned counterclockwise, as seen from above. As this is done, the tab-engaging slot extensions 118 in the upper lock ring will rotate into position over the tabs 38 extending from the vial cap 30, and then the vial 10 will be rotated such that the tabs 18 extending therefrom will rotate into position in the tab-engaging slot extensions 98 in the lower lock ring 90 (if they were not located there already). As the safe lid continues to be rotated, the vial cap 30 is unscrewed from the vial 10 and can be lifted away from the vial. Because the vial cap 30 is caused to rotate by means of the end walls 123 of the tab-receiving slot extensions 118 bearing against the tabs 38 as the safe lid is rotated counterclockwise, the tabs 38 will be positioned over the undercuts 122 as the vial cap 30 is lifted away from the vial 10. Thus, when the vial cap is disengaged from the vial and lifted away from it, the tabs will be retained in the undercuts 122 such that the vial cap is held securely in the safe lid. Similarly, because the vial is restrained from rotating (such that the vial cap can be unscrewed from it) by means of the tabs 18 extending therefrom butting up against the end walls 103 of the tab-engaging slot extensions 98 in the lower lock ring, the tabs 18 will be positioned under the undercuts 102 when the vial cap is removed from the vial. Thus, the radiopharmaceutical capsule can be poured out of the vial by turning the safe bottom over, but the vial will be retained in the safe bottom by means of the undercuts 102. It will be appreciated that the above-described embodiment is exemplary only and that modifications thereto will occur to those having skill in the art. For example, the upper and lower lock rings 110 and 90 may be foregone if appropriately shaped slots and slot extensions are formed in the counterbore portions of the cap-receiving and vial-receiving cavities, respectively. The tab/slot arrangement may even be reversed such that the tabs protrude from the walls of the vial bottom-receiving and vial cap-receiving cavities and the vial bottom and vial cap are grooved. Additionally, the number of ridges 92 and/or 112, and accordingly the number of positioning grooves 62 and/or 82, may be varied. The number of tabs 18 and/or 38 may be varied, as long as the number of tab-receiving and tab-engaging slots is varied accordingly. Other embodiments are deemed to be within the scope of the following claims.