Abstract:
An apparatus is used to dispense radiopharmaceuticals from a sealed source vial into capsules. The apparatus is particularly well suited for volatile radiopharmaceuticals such as radioiodine. This apparatus shields the operator from the radiopharmaceutical and also allows use of highly concentrated stock solutions.

Description:
FIELD OF THE INVENTION 
     In the field of nuclear medicine, radiopharmaceuticals are commonly prescribed for both diagnostic and therapeutic purposes. Most radiopharmaceuticals are dispensed into unit dose syringes under sterile conditions. Some radiopharmaceuticals, such as radioiodine (I-131 or I-123) are also dispensed in capsules so that they can be easily taken orally by the patient. The present invention is an apparatus and method to safely and accurately dispense liquid radiopharmaceuticals from a sealed vial into a capsule. 
     DESCRIPTION OF RELATED ART 
     Radiopharmaceuticals are commonly packaged in glass source vials sealed with a rubber septum and metal band. Radioiodine is often sold in source vials having a concentration of about 1,000 mCi/mL. In order to reduce radiation exposure during transportation and dispensing, these glass source vials are typically placed in a lead container which is referred in the industry as a pig. Radiopharmacies located across the country often keep several pigs on hand each containing a different radiopharmaceutical. When a prescription is received at a radiopharmacy, an aliquot of the radiopharmaceutical will be dispensed from the sealed glass source vial in the pig to a unit dose syringe or one or more capsules for administration to a patient. 
     In the past, some radiopharmaceuticals have been dispensed from a sealed source vial into capsules by hand using a syringe. Typically the dose is dispensed by hand into a single capsule. An operator grasps the lead pig housing a glass source vial containing a radiopharmaceutical in one hand and grasps a syringe with a needle in the other hand. The pig may have an opening or port above the rubber septum of the source vial. The operator inserts the needle through the port in the pig, punctures the rubber septum with the needle and withdraws an aliquot of the radiopharmaceutical into the syringe. The proximity of the hands to the radiopharmaceutical, especially in high concentrations, results in a rapid radiation exposure to the extremities of the operator. After transfer to the syringe, the activity level of the radiopharmaceutical in the syringe is measured using a dose calibrator. Corrections may be made for radioactive decay. An aliquot of the radiopharmaceutical is transferred from the syringe to one or more capsule bottoms filled with an excipient. A capsule top is placed on each capsule bottom and the completed capsules are placed in a transportation pig(s) for delivery to a hospital. At the medical facility, the capsules containing the radiopharmaceutical are orally administered to the patient for therapeutic or diagnostic purposes. 
     This manual prior art dispensing process is time consuming and subjects the operator to high extremity exposure rates from the radiopharmaceutical. There is a need for a better method and apparatus to dispense radiopharmaceuticals to reduce extremity exposure to occupational workers. 
     As an alternative to dispensing radioiodine by hand, some manufactures prefill capsules that are delivered to a medical facility or a radiopharmacy. These prefilled capsules are kept on hand until a need arises. This often requires use of larger and often multiple capsules to dispense the prescribed dose. It is common to require 2 or 3 prefilled capsules to deliver a single dose. Some patients do not tolerate multiple capsules or the increased amount of excipient caused by several capsules. So there is a dilemma. Prefilled capsules reduce extremity exposure but often require several capsules to deliver a dose. Manual filing of a single capsule with a stork solution having a high concentration (1,000 mCi/mL) results in extremity exposure to the radiopharmacist. There is a need for a method and apparatus that will allow dispensing into a single capsule and reduce extremity exposure to the radiopharmacist. 
     One attempt to solve the aforementioned difficulties is disclosed in International Application Number PCT/US02/32812, now publication number WO03/034444 entitled “Radiopharmaceutical Capsule Dispensing System” assigned to Mallinckrodt Inc., the assignee of the present invention. Unfortunately, the apparatus disclosed in the aforementioned publication was difficult to operate and sometimes resulted in more wasted product than anticipated. There is still a need for an apparatus and method that can prevent the escape of vapors from a source vial of a volatile radiopharmaceutical and provide safety and accuracy during the dispensing process. 
     SUMMARY OF THE INVENTION 
     The present invention is a method and apparatus for accurate dispensing of radiopharmaceuticals, including but not limited to highly volatile compounds such as radioiodine, from a sealed source vial into capsules which reduces extremity exposure to occupational workers and facilitates use of stock solutions with high concentrations. This capsule dispensing system is contained in a portable housing weighing less than 400 pounds. 
     The present invention allows dispensing of stock solutions of radioiodine having a concentration of 1,000 mCi/mL or more into a single capsule per dose. If properly used, this invention may reduce extremity exposure to a radiopharmacist by about 90% or more as compared to conventional manual filling techniques with a stock solution of 1,000 mCi/mL. 
     When a prescription for a radiopharmaceutical is received, a pump transfers a calculated volume of the radiopharmaceutical in accordance with this prescription from the sealed source vial into the capsule bottom. (The calculation accounts for a radioactive decay correction.) The capsule top is placed on the capsule bottom and the completed capsule is placed in a transportation pig. The top is screwed on the transportation pig and the completed capsule is ready for shipment to a medical facility for oral administration to a patient. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial perspective view of the elevation of the semi-automated custom capsule dispensing machine including an input device. 
         FIG. 2  is a perspective view of the semi-automated custom capsule dispensing machine with the door open showing the interior components and the interior of the housing. 
         FIG. 3  is an elevation view of the interior components of the semi-automated custom capsule dispensing machine with the pick-up needle assembly in the open position and a source vial of stock solution above the safe. 
         FIG. 4  is an elevation view of the semi-automated custom capsule dispensing machine with the exterior components in the start position. 
         FIG. 5  is an elevation view of the semi-automated custom capsule dispensing machine of  FIG. 4  with the pivot arm in the fill position and the toggle assembly in the lower position. 
         FIG. 6  is an elevation view of the semi-automated custom capsule dispensing machine of  FIG. 4  with the pivot arm in the fill position and the toggle assembly in the upper position. A dose of radiopharmaceutical is dispensed into the capsule bottom at this position. 
         FIG. 7  is an elevation view of the semi-automated custom capsule dispensing machine of  FIG. 4  with the pivot arm in the assemble position, and the toggle assembly in the lower position. 
         FIG. 8  is an elevation view of the semi-automated custom capsule dispensing machine of  FIG. 4  with the pivot arm in the assemble position, and the toggle assembly in the upper position. 
         FIG. 9  is an elevation view of the semi-automated custom capsule dispensing machine of  FIG. 8  with the assembly slide in the upper position. 
         FIG. 10  is an elevation view of the semi-automated custom capsule dispensing machine of  FIG. 8  showing the completed capsule being ejected from the machine. 
         FIG. 11  is a section view of the delivery needle assembly with the pivot arm and capsule bottom in the same position as shown in  FIG. 5 . 
         FIG. 12  is a section view of the delivery needle assembly with the pivot arm and the capsule bottom in the same position as shown in  FIG. 6 . 
         FIG. 13  is a section view of the delivery needle assembly with the push pin deflecting the delivery needle to cause a final drop of radiopharmaceutical to fall from the delivery needle into the capsule bottom. 
         FIG. 14  is an enlarged section view of the capsule bottom and capsule cap as positioned in the semi-automated custom capsule dispensing machine of  FIG. 7 . In this view the capsule stop is in the closed position as shown in  FIG. 19 , below. 
         FIG. 15  is an enlarged section view of the capsule bottom and capsule cap as positioned in the semi-automated custom capsule dispensing machine of  FIG. 8 . In this view the capsule stop is in the closed position as shown in  FIG. 19 , below. 
         FIG. 16  is an enlarged section view of the capsule bottom and capsule cap as positioned in the semi-automated custom capsule dispensing machine of  FIG. 9 . In this view, the capsule stop is in the closed position as shown in  FIG. 19 , below. 
         FIG. 17  is an enlarged section view of the completed capsule as positioned in the semi-automated custom capsule dispensing machine. In this view, the capsule stop is in the open position as shown in  FIG. 20 , below. 
         FIG. 18  is an enlarged section view of the completed capsule being ejected from the custom capsule dispensing machine of  FIG. 10 . In this view, the capsule stop is in the open position as shown in  FIG. 20 , below. 
         FIG. 19  is a top view of the capsule stop in the closed position as shown in  FIGS. 14-16 , above. 
         FIG. 20  is a top view of the capsule stop in the open position as shown in  FIGS. 17 and 18  above. 
         FIG. 21  is a top view of the capsule stop in the tool change out position allowing the upper capsule insert to be removed from the assembly system. 
         FIG. 22  is a section view along the line  22 - 22  of  FIG. 19  of portions of the assembly system  68 . In this view the slide arm is in the lower position. 
         FIG. 23  is a section view along the line  22 - 22  of  FIG. 19  except the slide arm is in the upper assemble position. 
         FIG. 24  is a section view along the line  24 - 24  of  FIG. 20 . In this view, the slide arm is in the upper eject position. 
         FIG. 25  is a partial view of the housing of the custom capsule dispensing machine with the top wall removed to show the z-shaped pathway of the conductors through the back wall of the housing. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 ,  2  and  25 , the semi-automated custom capsule dispensing system is generally identified by the numeral  30  and will hereinafter be referred to as the “Dispensing System  30 ”. The Dispensing System  30  includes an input device  32 . The input device can be any number of different devices including, but not limited to a key pad as shown, or a key board or touch screen not shown, or any number of other input devices well known to those skilled in the art. The input device may also include a display device  33 . The display device can be any number of different devices including, but not limited to a liquid crystal display as shown, or a monitor or plasma screen or any number of other display devices well known to those skilled in the art. Conductors run from the input device  32  through the housing  34  as better seen in  FIG. 23 . The conductors from the input device are connected to an actuator  85  that controls the pump  84 . Conductors run from the actuator through the housing  34  to a power source, not shown. Conventional 110 v, 60 Hz, power can be used to operate the Dispensing System  30 . 
     The Dispensing System  30  includes a housing  34  with a top wall  36 , bottom wall  38 , left side wall  40 , right side wall  42 , back wall  44  and front wall  46 , which in this case is a door. The door  46  is connected the left side wall  40  with hinges  48  and to the right side wall  42  with a latch  47 . A handle  50  is connected to the top wall  36 . The housing defines an outer surface  52  and an inner surface  54 . Shielding materials  56 , such as lead is located between the outer surface  52  and the inner surface  54 . The purpose of the shielding materials is to reduce the amount of radiation exposure to an operator from the radiopharmaceutical. Other shielding materials may also be suitable for this application. 
     The shielding materials define a chamber  58  inside the housing. Interior components of the Dispensing System  30  are located inside the chamber  58  of the housing. Exterior components of the Dispensing System  30  are located outside the housing. The exterior components include the toggle assembly, generally identified by the numeral  64 , the delivery needle assembly, generally identified by the numeral  66  and the assembly system, generally identified by the numeral  68 . The assembly system includes the slide subassembly  132  and the capsule stop subassembly  150 , better seen in subsequent figures. A shelf  67  is attached to the door  46  and is used to mount or partially secure the toggle assembly, the delivery needle assembly and the assembly system. A removable upper capsule insert  70  and a removable bottom capsule insert  72  are placed in the assembly system  68 . A capsule bottom  74  is placed in the removable capsule bottom insert and a capsule cap  76  is placed in the removable bottom capsule insert. (The capsule bottom, which contains a suitable excipient and the capsule cap, which does not contain excipient are better seen in  FIGS. 14-16 .) The purpose of the Dispensing System  30  is dispense a unit dose of a liquid radiopharmaceutical into the capsule bottom and to assemble the capsule bottom and capsule cap into a completed capsule  78  for administration to a patient, while reducing the radiation exposure to the operator. (The completed capsule is better seen in  FIGS. 17 and 18 .) 
     The interior components include an interior mounting plate  79 , a pick-up needle assembly  80 , a safe  82 , a pump  84 , which includes an actuator  85  and conductors  86 . A suitable pump is the model millGAT produced by Global FIA, Inc of Fox Island, Wash. although other pumps may also be suitable in this application. A suitable actuator  85  is the model CP-DSM produced by Valco Instruments Co., Inc. In  FIG. 2 , the door  46  is shown in the open position to better reveal the interior components and the chamber  58 . During operation of the Dispensing System  30 , the door  46  is open only when the radiopharmaceutical is being replenished as better seen in the next figure. During day to day operation of the Dispensing System, the door  46  is closed and the interior components are positioned inside the chamber  58  to reduce radiation exposure from the radiopharmaceutical to the operator. 
       FIG. 3  is an elevation view of the interior components of the Dispensing System with the pick-up needle assembly  80  in the clear position and a source vial  88  of radiopharmaceutical  90  above the safe  82 . The source vial  88  is shown in a position above the safe  82 . The source vial is in this position when it is inserted or removed from the safe. The source vial has a rubber septum  92  and a metal band  94 , which contain the radiopharmaceutical in the source vial. Containment is important with volatile radiopharmaceuticals like radioiodine. The present Dispensing System keeps the radiopharmaceutical sealed in the source vial, thus preventing radioactive fumes from escaping. This feature distinguishes the present invention from some prior art systems that required elaborate filtering systems to contain radioactive fumes from volatile radiopharmaceuticals. 
     The pick-up needle assembly  80  includes a pick-up needle  96 , a pick-up needle arm  98 , a sleeve  100 , a pick-up needle assembly guide rod and a pick-up needle assembly handle  104 . The pick-up needle assembly and the pick-up needle move from an clear position shown in  FIG. 3  to an inserted position shown in  FIG. 2 . The sleeve rides up and down the pick-up needle guide rod from the upper position the lower position. As the sleeve rides up and down, the arm and the needle are carried from the clear to the inserted position. While moving from the clear position to the inserted position, the pick-up needle  96  penetrates the rubber septum  92  and makes contact with the radiopharmaceutical in the bottom of the source vial  88 . In one embodiment, not shown, the pick-up needle has inlet holes on the side, not the end, like a conventional needle. Uptake of the radiopharmaceutical through a conventional needle could be obstructed by contact with the bottom of the source vial. 
     The pick-up needle assembly and the pick-up needle also move from a clear position shown in  FIG. 3  to an inserted position shown in  FIG. 2 . These positions enable the source vial of radiopharmaceutical to be inserted into the safe and be replaced as needed. In order to insert a source vial into the safe, the pick-up assembly and pick-up needle are moved to the upper clear position as shown in  FIG. 3 . The lid of the safe, not shown, is removed. A fresh source vial of radiopharmaceutical is inserted in the safe and the safe top is replaced on the safe. The operator grasps the finger  104  and rotates the sleeve  100 , the pick-up needle arm  98  and the pick-up needle from the clear to the engage position and from the upper to the lower position. While moving from the clear to the inserted position, the pick-up needle penetrates the rubber septum and comes into contact with the radiopharmaceutical in the source vial. The pick-up needle assembly and the pick-up needle are shown in the lower engaged position in  FIG. 2 . 
     To replace the source vial, the process is reversed. The pick-up needle assembly and the pick-up needle are moved from the lower to the upper position, withdrawing the needle from the rubber septum in the source vial. The pick-up needle assembly and the pick-up needle are then moved from the inserted to the clear position as shown in  FIG. 3 . The lid of the safe if taken off the safe and the old source vial is removed. A fresh source vial is put in the safe and the process is repeated. In many radiopharmacies, source vial replacement only occurs once per week. 
     A first conduit  106  connects the pick-up needle  96  with the pump  84 . A second conduit  108  connects the pump with the delivery needle  110  better seen in  FIGS. 11-13 . The radiopharmaceutical  90  flows from the source vial  88 , through the first conduit  106 , to the pump  84 , through the second conduit  108  to the delivery needle  110  and into the capsule bottom  74 , also better seen in  FIGS. 11-13 . 
       FIG. 4  is an elevation view of the Dispensing System  30  with the exterior components in the start position. The toggle assembly  64  includes a toggle frame  112 , a toggle arm  114 , a guide frame  116 , a spring stop  117 , a spring  118 , a connecting rod  120 , a pivot arm  122  and a pivot arm handle  124 . The spring  118  surrounds the rod  120  and is captured between the guide frame  116  and the spring stop  117 , mounted on the rod  120 . The removable bottom capsule insert  72 , is carried by the pivot arm  122 , the purpose of the toggle assembly is to move the bottom capsule insert and the pivot arm from a lower position shown in  FIG. 4  to the upper position shown in  FIG. 6 . This movement for the lower to the upper position and back is accomplished by actuation of the toggle arm  114  which is pivot mounted in the toggle frame  112 . Moving the toggle arm carries the connecting rod and the pivot arm from the lower to the upper position and back. The pivot arm handle  124  is grasped by the operator to move the pivot arm  122  from the start (6:00) position, to the dispense (9:00) position, and then to the assemble (3:00) position. 
     The pivot arm can be rotated by the pivot arm handle  124  from the start position shown in  FIG. 4  to the dispense position shown in  FIG. 5  to the assemble position shown in  FIG. 7 .  FIGS. 4-10  portray the operational sequence of the Dispensing System  30  for dispensing a dose  126  of radiopharmaceutical and assembly of a completed capsule  78 , best seen in  FIG. 18 . Each step of the sequence will be described below. 
     In  FIG. 4 , the pivot arm  122  (which is a component of the assembly system  68 ) is in the start or 6:00 position with the pivot arm handle pointing towards the operator. Because different sizes of capsules can be used, the Dispensing System has a set  128 , not shown, of removable upper capsule inserts and a set  130 , not shown, of removable bottom capsule inserts in different sizes to accommodate the different sizes of capsule. After reviewing the prescription for a unit dose, the operator decides on the size and number of capsule(s) needed and selects an appropriate upper capsule inset and an complementary sized bottom capsule insert from the sets  128  and  130 . For purposes of this example a medium sized capsule has been selected for assembly. The bottom capsule insert is placed in the pivot arm and the upper capsule insert in placed in the assembly system. A capsule bottom  74  is placed in the removable bottom capsule insert which is carried by the pivot arm, and a capsule cap  76  is placed in the removable upper capsule insert in the assembly system. The toggle assembly is in the lower position. For illustrative purposes, the claw  154  is shown separated from the removable upper capsule insert  70  in  FIGS. 4-6 ; however in actuality the claw  154  contacts the removable upper capsule insert  70  as better seen in  FIGS. 14-16 . The function to the claw and the upper capsule insert will be discussed in greater detail below. 
       FIG. 5  is an elevation view of the Dispensing System  30  of  FIG. 4  except the pivot arm in now the fill position (9:00) under the delivery needle assembly  66 . The toggle assembly in still in the lower position as shown in the preceding figure. The relative position of the capsule bottom and the delivery needle  110  are better seen in  FIG. 11 . The assembly system  68  includes a slide subassembly  132  and a capsule stop subassembly  150 . 
     The slide subassembly  132  includes a slide guide rod  134 , a slide handle  136 , a slide arm  138 , a slide assembly/ejection rod  140 , and a plurality of height assembly slide stops,  141 ,  142  and  143  rotateably mounted on a carousel  145 . A set  144 , not shown, of different sized removable slide stops allows the operator to select the appropriate size for the capsule being assembled. 
     The operator should rotate the carousel  145  to the proper location depending upon the capsule size to be used. Capsules come in various sizes including: 000, 00, 0, 1, 2, 3, 4, and 5. For smaller capsules (like a number 5), the tallest height assembly slide stop,  141  will be used. For medium sized capsules, the medium height assembly slide stop  142  will be used. (A medium sized capsule (number 3) is being assembled in this example.) For larger sized capsules (000), the small height assembly slide stop  143  will be used. The height assembly slide stop pins,  141 ,  142  and  143  prevent the slide subassembly  132  from being extended upward which could crush the capsule. The height assembly slide stops permit the user to repeatably and reliably assembly the capsule cap and the capsule bottom to the proper depth depending on the size of the capsule being used. 
     The capsule stop subassembly is also a part of the assembly system  68 . The capsule stop subassembly has three positions (tool change out, closed position and open position) better seen if  FIGS. 19-21 . In  FIGS. 4 and 21 , the capsule stop subassembly is in the tool change out position so an appropriately sized removable upper capsule inset can be placed in the tooling. In  FIG. 5  and  FIG. 19 , the capsule stop subassembly is in the closed position to hold the capsule cap  76  and the removable upper capsule insert in the tooling during assembly of the capsule. In  FIG. 10  and  FIG. 20 , the capsule stop subassembly is the open position to allow the completed capsule  78  to be ejected from the Dispensing System  30 . 
       FIG. 6  is an elevation view of the Dispensing System  30  of  FIG. 4  with the pivot arm  122  in the fill position underneath the delivery needle assembly  66 . The toggle arm has been actuated moving the toggle assembly  64  from the lower position of  FIG. 5  to the upper position as shown in  FIG. 6 . This moves the capsule bottom closer to the delivery needle  110 , as better seen in  FIG. 12 . The position of the assembly system  68 , the slide subassembly  132  and the capsule stop subassembly  150  have not changed from  FIG. 5  to  FIG. 6 . 
     The operator inputs into the input device  32 , shown in  FIG. 1 , the volume of liquid radiopharmaceutical to be dispensed. The desired volume to be dispensed from the source vial  88  onto the capsule excipient  146  in the capsule bottom  74  is calculated based upon the quantity of activity requested by the physician&#39;s prescription order and the radioiodine source strength at the time the capsule is made. The operator actuates the input device  32  to dispense the dose and signals are sent from the input device  32  to the actuator  85 , shown in  FIGS. 2 and 3 . The pump  84  then pumps the dose of liquid radiopharmaceutical from the source vial  88  through the delivery needle into the excipient in the capsule bottom held in the removable bottom capsule insert which is carried by the pivot arm. 
     A droplet of liquid radiopharmaceutical will sometimes hang on the tip  111  of the delivery needle  110  after the pump has been actuated to dispense the dose of radiopharmaceutical. To ensure that the lingering droplet of liquid radiopharmaceutical falls in the capsule bottom a push pin  148  is positioned in the delivery needle assembly  66  to deflect the delivery needle  110  causing the lingering droplet to move into the capsule bottom, as shown in greater detail in  FIGS. 11-13 . After the pump has dispensed the dose, the push pin is pressed inward (one to several times) in order to deflect the needle so that it touches the capsule wall as shown in  FIG. 13 . This motion is needed in order to remove the last droplet from the delivery needle  110 . Thereafter, the toggle arm  114  of the toggle assembly  64  is moved to the lower position as previously shown in  FIG. 4 , lowering the pivot arm  122 . The operator then grasps the pivot arm finger and moves the pivot arm to the assemble (3:00) position as shown in  FIG. 7 . 
       FIG. 7  is an elevation view of the Dispensing System  30  of  FIG. 4  with the pivot arm  122  in the assemble or 3:00 position, and the toggle assembly  64  in the lower position. The capsule stop subassembly  150  is in the closed position. The capsule stop subassembly  150 , better seen in section in  FIGS. 22-24 , includes a capsule stop subassembly handle  152 , a claw  154 , a u-shaped recess  156  in the claw, a slide stop rod  162 , a position pin  160 , a position pin spring  161 , an upper bushing  164 , a lower bushing  166 , and a sleeve  168 . The capsule stop subassembly handle is rotatably mounted on the slide rod  135 . The capsule stop subassembly handle  152  and the claw  154  are integrally connected and move in tandem. 
     The capsule stop subassembly handle  152  and the claw can be moved by the operator to three different positions better seen in  FIGS. 19-21 . The first position, as shown in  FIGS. 7 and 19  is referred to as the closed position and is also shown in  FIGS. 14-16 . In the closed position, the claw  154  contacts the capsule cap and holds it in place during the assembly process. The second position of the capsule stop subassembly handle  152  and the integral claw is referred to as the open position and is the position shown in  FIG. 10  and  FIGS. 17-18 . In the open position, the u-shaped recess  156  in the claw  154  is clear of the capsule cap and the completed capsule may be ejected from the assembly system. The third position of the capsule stop subassembly handle  152  and the integral claw is referred to as the tool change out position, better seen in  FIG. 21 . In the tool change out position, the operator can remove and replace the removable upper capsule insert to accommodate capsule caps of different sizes. This is also the position where the operator inserts the capsule cap into the removable upper capsule insert. Before moving to the next step, the operator moves the toggle arm  114  to the upper position as shown in the next figure. 
       FIG. 8  is an elevation view of the Dispensing System  30  of  FIG. 4  with the pivot arm in the assemble (3:00) position, and the toggle assembly  64  in the upper position. The capsule stop subassembly handle  152  and the integral claw are in the closed position as shown in  FIG. 19  to hold the capsule cap in the removable upper capsule insert during the assembly process which will be described in the following figures. 
       FIG. 9  is an elevation view of the Dispensing System  30  of  FIG. 8  with the assembly slide  136  in the upper position. The assembly/eject rod is moved upward as the assembly slide  136  is moved upward to complete the assembly of the capsule cap and the capsule bottom as better seen in section view in  FIG. 16 . A removable height assembly stop  142  engages the slide stop rod  162  to prevent crushing of the capsule cap and the capsule bottom. The height of the removable height assembly stop is selected to complement the size of the capsule for a particular dose. Several other removable height assembly stops of different heights,  141  and  143  are positioned on a rotating carousel  145 , to facilitate reconfiguration of the Dispensing System  30 , when different sized capsules are required. The Dispensing System comes with a set  144 , not shown of removable height stops to facilitate production of capsules of different sizes. After the completed capsule  78  has been assembled, the slide assembly is returned to the lower position. 
       FIG. 10  is an elevation view of the Dispensing System  30  of  FIG. 8 . In order to eject the completed capsule  78 , the capsule stop subassembly handle  152  and the integral claw must be moved to the open position, better seen in  FIG. 20 . In the open position, the u-shaped recess of the claw is positioned above the completed capsule. Then, the slide assembly is moved to the upper position as shown in  FIG. 10  to eject the completed capsule  78  through the u-shaped recess of the claw. A section view of the ejection of the completed capsule is shown in  FIG. 18 . 
       FIGS. 11-13  are section views of the delivery needle assembly  66  including the cowling assembly  170  which includes the upper portion of the cowling  172  and the lower portion  174  which sit on the shelf  67 . In order to reduce exposure to operator, certain parts of the Delivery System  30  can be formed of tungsten instead of lead. Tungsten has better shielding properties than lead. The following components can be fabricated from tungsten: the upper portion of the cowling  172 , the lower portion of the cowling  174 , the source vial safe,  82  and the source vial lid, the push pin  148 , the pivot arm  122 , the removable upper capsule insert  70 , the removable lower capsule insert  72  and the jig  186 . 
       FIG. 11  shows the pivot arm  122 , the removable lower capsule insert  72  and the capsule bottom  74  below the delivery needle assembly  66  in the same position as  FIG. 5 . In  FIG. 11  and  FIG. 5 , the toggle assembly  64  is in the lower position.  FIG. 12  shows the toggle assembly  64  in the upper position as seen in  FIG. 6 . The radiopharmaceutical is dispensed into the capsule bottom  74  in  FIG. 12 .  FIG. 13  shows the toggle assembly  64  in the upper position as seen in  FIG. 6 . In  FIG. 13 , the push pin  148  is pushed inward to deflect the delivery needle  110  into contact with the capsule bottom, as shown. The contact with the capsule bottom causes the last droplet of radiopharmaceutical to move into the capsule bottom, thus completing the dispensing of the radiopharmaceutical. 
       FIGS. 14-18  are section views of the assembly and ejection process of the capsule.  FIG. 14  is a section view of the components shown in  FIG. 5 . The capsule cap  76  is positioned above the capsule bottom  74  and the toggle assembly  64  is in the lower position.  FIG. 15  is a section view of the components shown in  FIG. 6 . The toggle assembly  64  has been shifted to the upper position.  FIG. 16  is a section view of the components shown in  FIG. 9 . The assembly/eject rod  140  has been raised to assemble the capsule cap and the capsule bottom.  FIG. 16  is a section view of the claw and adjustable hold down pin in the open position.  FIG. 17  is a section view of the components shown in  FIG. 10 . In this view, the completed capsule  78  is ejected from the Dispensing System  30 . 
       FIGS. 19-21  are plan views of the capsule stop subassembly  150  including the claw  154  and the capsule stop subassembly handle  152 . In  FIG. 19 , the capsule stop subassembly is in the closed position holding the capsule cap in the removable upper capsule insert as better seen in section view in  FIG. 14 . In  FIG. 20 , the capsule stop subassembly is in the open position allowing the completed capsule to be ejected from the Dispensing System as better seen in section view in  FIG. 18 . In  FIG. 21 , the capsule stop subassembly is in the tool change out position allowing the removable upper capsule insert to be removed from the jig so another insert of a different size can be placed in the jig. 
       FIG. 22  is a section view along the line  22 - 22  of  FIG. 19  of the assembly system  68 . The assembly system includes the slide subassembly and the capsule stop subassembly  150 . The capsule stop subassembly is best seen in plan view in  FIGS. 19-21 . The slide subassembly is better seen in  FIGS. 22-24  as the subassembly moves through the various assembly steps. In  FIG. 22 , the slide arm  138  is in the lower position as shown in  FIG. 7 . The assembly/eject rod  140 , better seen in  FIG. 15  is likewise in the lower position. In  FIG. 23 , the slide arm is in the assemble position as better seen in  FIG. 9 . The assembly/ejection rod  140 , better seen in  FIG. 16  is also in the upper assemble position. In  FIG. 24 , the slide arm  138  is in the eject position as shown in  FIG. 10 . The assembly/eject rod  140 , better seen in  FIG. 18  is also in the eject position. 
     In  FIG. 22 , a screw  158  connects slide handle  136  to slide rod  135  which converts to slide arm  138 . An upper bushing  164  and a lower bushing  166  are pressed fit into a sleeve  168 . The sleeve is pressed to fit in a bore in the handle  152 . 
     A position pin spring  160  is held in place in the handle  152  by a spring retainer  190 . The spring retainer threadibly engages the capsule stop subassembly handle  152 . The spring  161  surrounds a portion of the position pin  160 . A spring stop  192  is mounted on the position pin  160 . The spring  161  is captured between the spring retainer  190  and the spring stop  192 . This arrangement gives the position pin  160  the ability to engage and disengage recesses in the shelf  67  as the capsule stop assembly handle  152  moves from the position of  FIG. 19 , to the other positions shown in  FIGS. 20 and 21 . 
       FIG. 23  is a section view along the line  22 - 22  of  FIG. 19 . The slide handle  136  and the slide arm  138  are in the upper assemble position as shown in  FIG. 9 . The assembly/eject rod  140  is in the upper assemble position as best seen in  FIG. 16 . 
       FIG. 24  is a section view along the line  24 - 24  of  FIG. 20 . In this view, the slide handle  136  and the slide arm  138  are in the upper eject position as shown in  FIG. 10 . The assembly/eject rod  140  is likewise in the upper eject position as best seen in  FIG. 18 . 
       FIG. 25  is a perspective of the pathway of the conductors  86  through the housing  34 . In order shield operators, a z-shaped pathway  87  is formed in the shielding materials  56  and the back wall  36 . The conductors  86  are placed in this z-shaped pathway.