US3801818A - Radioactive generator with permeable closure - Google Patents

Abstract

A radioactive generator has silicone or neoprene closures to vent the gases released during the generation of radioactive eluate. The generator comprises a hollow, generally cylindrical body in which a column of radioactive material is contained, and the ends of which are closed by silicone or neoprene stoppers fabricated from material such as methylvinylpolysiloxane or polychloroprene. The generator can be subjected to sterilizing procedures such as autoclaving and retain its sterile condition, while at the same time gases generated internally may be vented through the closures.

Description

United States Patent. 1

Hulit et al.

[451 Apr. 2, 1974 RADIOACTIVE GENERATOR WITH PERMEABLE CLOSURE 75] Inventors: Harry]. l-lulit, Amboy; Thomas V. Czaplinski, Brunswick, both of NJ.

[73] Assignee: E. R. Squibb & Sons, Inc.,

Princeton, NJ.

221 Filed: Oct. 24, 1972 21 Appl. No.: 300,092

[52] U.S.Cl ..'.....250/496,128/1.l s11 Int.Cl. ..G2lh 5/00 [58] Field of Search 250/106. R, 106 T; 23/267 A, 259; 128/1.1, 1.2

[5 6] References Cited UNITED STATES PATENTS 3,156,532 11/1964 Doel'ing 250/106 T 3,133,196 5/1964 Rochlin 136/89 3,369,121 2/1968 Bruno et al. 250/108 R Primary Examiner-Harold A. Dixon Attorney, Agent, or Firm-Lawrence S. Levinson; Merle J. Smith; John J. Archer [5 7] ABSTRACT A radioactive generator has silicone or neoprene closures to vent the gases released during the generation of radioactive eluate. The generator comprises a hollow, generally cylindrical body in which a column of radioactive material is contained, and the ends of which are closed by silicone or neoprene stoppers fabricated from material such as methylvinylpolysiloxane or polychloroprene. The generator can be subjected to sterilizing procedures such as autoclaving and retain its sterile condition, while at the same time gases generated internally may be vented through the closures.

6 Claims, 2 Drawing Figures RADIOACTIVE GENERATOR WITH PERMEABLE CLOSURE BACKGROUND OF THE INVENTION The present invention relates to-a generator for the production of radioactive eluate,-and more specifically a generator having silicone or neoprene closures to permit the venting of gases internally generated.

The use of radioactive isotopes for the diagnosis and treatment of various medical problems is well-known. Generators such as that described in U. S. Pat. No. 3,369,121, Feb. 13, 1968, are widely used in the production of radioactive eluate. These generators are utilized since certain radioactive isotopes have a very short half-life and, consequently, it is necessary for the physician to prepare such isotopes as, and where, they are to be used.

An example of such an isotope is the 99m isotope technetium which is used for the localization of brain tumors. This isotope has a half-life of six hours and is obtained as the daughter product of molybdenum M It is separated in the form of the pertechnetateion from M0 absorbed on an alumina column, by elution with dilute hydrochloric acid or saline. At various times during autoclaving, gases may be internally generated. These gases reduce the isotope yield of the generator and, in any event, must be removed for the obtainment of eluate.

Previously, the generators were closed by pierceable rubber stoppers through which a hypodermic needle was inserted to vent the gases. This is a very timeconsuming and tedious operation, and since the materials are always undergoing fairly rapid degeneration, the yield of a particular generator can be reduced. The present invention utilizes silicone or neoprene closures which are pervious to the generated gases. At the same time the silicone or neoprene closures may be subjected to any popular sterilizing technique such as autoclaving and resist the inflow of any bacteria. In sum mary, the silicone or neoprene stoppers are gas pervious yet maintain generator stability.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a radioactive eluate generator which maintains sterility at all times.

Another object of the present invention is the provipolychloroprene. The stoppers are pierceable so as to admit solution for the production of the radioactive isotope. The stoppers, however, are sufficiently pervious to vent any and all gases internally generated. Furthermore, the stoppers may be subjected to any preferred sterilizing technique, such as autoclaving, and will effectively maintain sterile conditions at all times.

The above and other objects of the present invention will be apparent as the description continues and when read in conjunction with the annexed drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cross sectioned view of a preferred embodiment.

FIG. 2 is a perspective view of an individual closure.

DETAILED DESCRIPTION The present invention is associated with a radioactive material generator similar to that shown and described in U. S. Pat. No. 3,369,121. Briefly, the radioactive material generator comprises a column 10 fabricated from a plastic or similar type material. The column 10 has a shell 12 and is surrounded by a plurality of integral fins 14.

The column 10 is closed by stoppers 16, 18, which are pervious to the passage of gas therethrough and may be made from silicone or neoprene, of which more will be described at a subsequent point. Included in column 10 is the curvilinear partition 20 which basically separates it into two parts, the upper part 22 and the lower part 24. The partition 20 can be integral with the shell 12 or suitably attached thereto, and it tapers from section 22 toward section 24 providing a rather restricted opening 26 at the bottom thereof. The exact dimensions of the partition are unimportant, however, it has been found that it should extend a slight distance below the top of a breather tube 28 which punctures closure 18, which breather tube permits the interior of section 24 to communicate with the atmosphere. To assure sterility, the breather tube is fitted with a suitable filter material 30 which prevents the flow of bacteria to the interior of the shell 12.

Positioned at the upper end of the partition 20 is a disc 32, which must be perforated, and on which rests a filter pad 34. At the top of filter 34 is a granulated radioactive alumina 36, and optionally, a cation exchange resin such as Dowex-SO x8 to prevent the passage of the alumina through the column during elution. The granulated alumina 36 may be retained in place by use of a perforated disc 38 which is held in place by a retaining ring 40.

In preparing a radioactive solution, eluent is emitted from the eluent container 42 into section 22 via the hypodermic needle 44 which pierces closure 16. The hypodermic needle 46 withdraws the radioactive solution that has been prepared in section 22 and passed to section 24.

As shown in FIG. 2 the closures 16, 18 are in the nature of circular plugs with a central depression 50 and a circular flange 52. The closures are c'lose-fittedly received within compatible openings in the top and bottom of column 10 and are maintained in place by the cover members 54, 56 which are preferably fabricated from ductile metals and which are crimped thereabout; the covers 54, 56 engage the shoulders 54a, 56a permanently maintaining the closures l6, 18 in their respective positions in the column.

During the sterilization of the generators, particularly during autoclaving, a substantial quantity of gases are generated in the sections 22, 24. In the past, a hypodermic needle has been inserted into top closure 16 to vent these gases. This has proved to be a rather inconvenient manner of venting the gases as well as consuming an unusual amount of time. The use of silicone, neoprene or like material, as compared to the prior use of rubber, produces a number of advantages. Silicone or neoprene is sufficiently porous to permit the escape of internally generated gases without the use of hypodermic needles, in that, the gases merely pass through the closure body. In addition, the silicone or neoprene is easily pierced by hypodermic needles and is essentially completely selfsealing The particular silicone chosen is preferably one of the organopolysiloxanes, notably methylvinylpolysiloxane, one of the Dow Corning Silastic brand. These closures are useful over a wider temperature range than any other rubber-like material, for instance, they retain their physical properties in a low and high temperature range of lF to 500F and therefore can be autoclaved. The particular neoprene chosen is preferably polychloroprene manufactured by the Tompkins Rubber Co.

The yield of radioactive solution of any given generator is strikingly increased by the use of the silicone or neoprene closures. The radioactive materials involved, have relatively short half-lives and any time wasted venting gases results in an under utilization of the generator. The stoppers, therefore, not only permit the simple venting of the trapped gases and elimination of additional hypodermic needles, but they effectively increase the yield of a given generator.

Many changes may be made in the details of the instant invention without departing from the spirit and scope of the appended claims, which changes are intended to be embraced therewithin.

What is claimed is:

1. In a generator containing a column of sterile elutable radioactive material to be utilized for diagnosis and treatment for medical conditions, said generator of the type which comprises a hollow body closed at its top and bottom by pierceable autoclavable closures and having positioned therein and spaced from the bottom thereof a source of elutable, short-lived radioactive material, whereby a sterile eluate ready for utilization is delivered from the body, the improvement which comprises said autoclavable closures being fabricated from material which is pierceable, and gas pervious permitting the venting directly through said closures of gases formed in the generator, said closures being sufficiently dense to prevent the passage of fluid directly therethrough as well as preventing the inflow of bacteria therethrough.

2. The generator of claim 1 wherein the closures are made from silicone.

3. The generator of claim 1 wherein the closures are permanently affixed to said body to seal said body.

4. The generator of claim 3 wherein the closures are fabricated from methylvinylpolysiloxane.

5. The generator of claim 1 wherein the closures are made from neoprene.

6. The generator of claim 5 wherein the pierceable closures are fabricated from polychloroprene.

[UNITED STA'IES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,801,818 Dated April 2, 1974 Invencofls) Harry J. Hglit and Thomg v. Czeplinski It is certified that error appears in the above-identified patent andfnat said Letters Patent are hereby corrected as h balm" Urider "Inventors: "Amboy" should be 'South Amboy'- 'and "Brunswick" should be -North Brunswick--.

Column 1 line 19, --ofshould be inserted before "teohnetiom" Column I line" 22, delete the. hyphen fol lowing "pertech netat e" Signed and sealed this 30t day of July 1971,.

( EAL) Attest:

0N JR. c. MARSHALL DANN MCCOY M GIBS Commissioner of Patents Attestin'g Officer x

Claims (6)

1. In a generator containing a column of sterile elutable radioactive material to be utilized for diagnosis and treatment for medical conditions, said generator of the type which comprises a hollow body closed at its top and bottom by pierceable autoclavable closures and having positioned therein and spaced from the bottom thereof a source of elutable, shortlived radioactive material, whereby a sterile eluate ready for utilization is delivered from the body, the improvement which comprises said autoclavable closures being fabricated from material which is pierceable, and gas pervious permitting the venting directly through said closures of gases formed in the generator, said closures being sufficiently dense to prevent the passage of fluid directly therethrough as well as preventing the inflow of bacteria therethrough.

2. The generator of claim 1 wherein the closures are made from silicone.

3. The generator of claim 1 wherein the closures are permanently affixed to said body to seal said body.

4. The generator of claim 3 wherein the closures are fabricated from methylvinylpolysiloxane.

5. The generator of claim 1 wherein the closures are made from neoprene.

6. The generator of claim 5 wherein the pierceable closures are fabricated from polychloroprene.

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