JPH07505707A - How to improve the elution rate of radioisotope generators - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Method of Improving the Elution Rate of a Radioisotope Generator The present invention provides a method for improving the elution rate of a radioisotope generator. a column containing a compatible support material, the column having an inlet and an outlet; The outlet is a tapped point where the eluate containing the daughter radioisotope is obtained via the eluate conduit. The inlet is connected to the tapping point, and the inlet is connected to the eluate tapping point. connected to a reservoir, and the reservoir is connected to the supply of air to the generator during its elution. elution rate of a radioisotope generator with an inlet for ld).

The radioisotope generator uses molybdenum, which produces daughter radioisotopes by radioactive decay. Daughter radioisotope such as technetium-99m from an adsorbed parent radioisotope such as 99 This is a device used to obtain a solution of radioactive isotopes. The daughter radioisotope solution is released Can be used for radiation diagnosis.

Typically, radioisotope generators have a relatively high adsorption force with respect to the parent radioisotope However, support materials with relatively low adsorption power for the daughter radioisotope, e.g. containing the parent radioactive isotope adsorbed onto an exchange medium or other medium such as alumina. including columns with To obtain the desired daughter radioisotope, the column is heated with a suitable solvent. Or eluted by washing with an eluent such as saline. As a result, The eluate containing the daughter radioisotope in the form of a dissolved salt can be used as a diagnostic agent, for example. It is useful for intravenous administration and can also be used for intravenous administration.

Contains a large amount of eluent to obtain large amounts of eluate from the generator in an easy and safe manner A reservoir is connected to the inlet side of the column, and a vial for the eluent is drained. It can be connected to the outlet side of the column at the tapping point of the generator. Ga The vacuum inside the vial draws the eluent from the reservoir through the column and into the vial. and thereby elute the daughter radioisotope from the column.

More particularly, the present invention provides that the column of the radioisotope generator is at least substantially alkaline. The parent isotope is molybdenum-99 and the daughter isotope is molybdenum-99. is technetium-99m and the eluent is saline, preferably saline. The present invention relates to a method for improving the elution rate of the above-mentioned radioisotope generator. like this The eluate produced by the Mo99-Tc99m generator can in particular be used directly as a diagnostic agent. can be administered intravenously to image organs or disease states where radioactivity has accumulated. (scanning).

However, eluates are generally used for selective radiolabeling of target organs or tissues. is not suitable. For this purpose, phosphonates, colloids, complexing ligands , peptides and biological macromolecules such as proteins etc. A marker substance with a specific property is required. Therefore, the Mo99-Tc99m generator The eluate is usually adapted for labeling the appropriate substance. In general, such signs The labeled label is very easy to operate, allowing users to easily perform the labeled test in the clinic or clinical laboratory. can be done. For this purpose, the user must mark the substance to be labeled with a so-called It can be freely processed in the form of a cold kit. The user obtains the The eluate can be easily obtained from a Mo99-Tc99m generator.

Column contains alumina as support material to which a small amount of hydrated manganese dioxide has been added It is common practice to use a Mo99-Tc99m generator for the above purpose. . Such a generator is disclosed, for example, in U.S. Pat. No. 3,970,583. . Hydrated manganese dioxide present on the support material usually has a favorable effect on the elution rate. i.e. by using such modified alumina as a carrier material, Generally, the elution rate is improved and fluctuations in the elution rate are avoided. However, this normal By using the carrier material used in the Mo99-Tc99m generator, the obtained The eluate used is especially used for the labeling of specific substances as defined above. It has been observed that it contains impurities which can cause problems in some cases. these markings The problem with low and/or variable labeling is expressed as a rate. these problems To avoid using unmodified alumina as a support material for columns in radioisotope generators, Some people also used .

Certainly this gives a positive effect on the labeled rate, but in reality the generator The improvement is not sufficient because the elution rate is not reproducible. As a result, radioactive isotope generation Instrument users continue to complain of unexplained fluctuating elution rates.

The purpose of the present invention is to eliminate these variations in elution rates as defined in the first paragraph. Avoiding and improving the elution rate of radioisotope generators giving eluates with even higher purity The purpose is to provide a method.

The purpose of this is that during generator elution, air is supplied to the eluent reservoir and air is This can be achieved by the present invention, which is characterized by having a low alcohol content. Wear. Surprisingly, alcohols like propatool or ethanol can It was found that the presence of even small amounts dramatically affects the elution rate. alcohol , especially property tools, may be used during generator assembly and are typically cleaned. Used in clinics or clinical laboratories for cleaning and sterilization. Therefore, radiation The air to which a sex isotope generator is exposed almost always contains trace amounts of alcohol. Of course. As mentioned above, when the generator is used, it should not be contaminated with this alcohol. The eluent air enters the eluent reservoir and thus the generator. Obviously, these trace amounts Alcohol is not sufficient to interfere with elution and result in low and/or variable elution rates. It's a minute. - From the above, this method is particularly applicable to Mo99-Tc99m generators, e.g. that is, the column contains a support material consisting at least substantially of alumina, and the parent isotope is molybdenum-99, and the daughter isotope is technetium-99m, which is molybdenum-99m. Applicable to radioisotope generators where the release agent is saline, preferably physiological saline. I understand. By using the method of the present invention, unmodified alumina can be during the entire elution period even when used as a carrier for Livdane-99. It was observed that a constant elution rate was guaranteed.

The alcohol content of the air supplied to the melt-abrasive reservoir depends on the frequency of generator use, Therefore, it is necessary to reduce the amount of air supplied per unit of time. Preferably , the alcohol content of the supplied air is such that the alcohol concentration in the eluent is 0.1 μl/ ml, preferably to such an extent that a value of 0.05 μI/ml is not reached. Is it necessary? This is demonstrated in the attached model example.

In practice, the alcohol content of the air supplied to the eluent reservoir can be controlled using suitable filtration means. can be easily reduced. A suitable filtering means for this purpose is a filter housing. The form of activated carbon granules contained within the holder or the activated carbon fill It is an activated carbon filter in the form of a Luther plate.

The present invention also provides for the alcohol content of the air supplied to the eluent reservoir during generator elution. as defined above, characterized in that it comprises suitable filtration means for reducing the amount of Regarding radioisotope generators. A suitable filtration means is an activated carbon filter as described above. Including Luther.

The filtration means preferably avoids internal leakage of alcohol-contaminated air during elution. is sealingly connected to the inlet of the eluent reservoir in order to

Typically, the eluent reservoir inlet is uniformly filled with a bacterial filter to keep the generator sterile. It is equipped with a tar. In a preferred embodiment, the filtration means used in the present invention Connect the release agent reservoir and the bacterial filter.

The invention will be explained in more detail using the following examples.

〔Example〕

[Example 1] Model experiment on elution rate with respect to propatool content of eluent Mo99-Tc99m generator with column packed with unmodified Ah03 and The same generator with a column packed with hydrated Mn0t-modified Altos was used. The effect of propatool in the eluent (0.9% NaCl aqueous solution) on the elution rate was The fruit was measured. The experiment was carried out by dissolving the propatool in a predetermined amount of eluent and then dissolving this “alcohol” This is done by using a “coal-contaminated” eluent to elute the generator. It was. The results of the first five elutions (Nnl-5) are shown in Table A below.

[Example 2] Introduced under the elution cover of the radioisotope generator at the elution rate Effects of property tools Place a 0.5 ml volume of PropaTool under the elution cover of the radioisotope generator, i.e. It was introduced near the inlet of the eluent reservoir. The Mo99-Tc99m generator used was It is equipped with a column packed with non-denatured Atto. After the second elution, another 0 ．． A 5 ml volume of PropaTool was introduced under the elution cover of the generator. Subsequent elution The results are shown in Table B below in relation to the presence and absence of an activated carbon filter.

A preferred embodiment of a filter holder that can be used is shown in a vertical cross-sectional view.

The holder shown in Figure 1 is adapted to accommodate activated carbon granules.

This holder includes a filter housing IO with a cover 11 firmly attached to its upper end. These parts are manufactured from synthetic materials. of the cover On the other side, the housing has a sealed connection with the inlet of the eluent reservoir of the radioisotope generator. have the means to do so. This connection means is a luer lock cone (luer 1 ock cone) 12, and is integrated with the holder housing. There is.

The cover can be removed from the housing and the holder can be filled with activated carbon granules. Ru. When used in a generator, the air supplied to the eluent reservoir is provided in the cover It enters the holder through the cavity 13, passes through the activated carbon granules, and then exits the housing through lumen 14 at the bottom of the housing. Holder is more centered Includes a skirting board (centring 5kirt) 15 and reinforcing ribs 16. figure The holder 20 shown in FIG. 2 is fixed within the boulder between its upper end 21 and lower end 22. Adapted to accommodate an activated carbon filter plate.

Continuation of front page (72) Inventor Kroon, Matthies Netherlands, ZG Peraten 1755, P-O Box 3, Westerduinveke 3, Mali Nkrot Medical B.V.

Claims (9)

[Claims] 1. a column containing a carrier material adapted to adsorb a parent isotope; The system has an inlet and an outlet, the outlet being an eluate conduit for the eluate containing the daughter radioisotope. The inlet is connected to the tap point where the fluid is obtained and the inlet is connected to the eluate storage via the eluate conduit. and a reservoir for supplying air to the generator during its elution. A method for improving the elution rate of a radioisotope generator having an inlet of During the elution of the chamber, air is supplied to the eluent reservoir and the air is supplied with a minimum amount of alcohol. A method characterized by comprising: 2. The radioisotope generator column comprises a support material consisting at least substantially of alumina. The parent isotope is molybdenum-99 and the daughter isotope is technetium-9. 9 m and the eluent is saline, preferably physiological saline. The method described in section. 3. During generator elution, air is supplied to the eluent reservoir, whose alcohol content is Alcohol concentration in the eluent is 0.1 μl/ml, preferably 0.05 μl/ml Claim 1 characterized in that it is reduced to such an extent that it does not reach the value of Or the method described in Section 2. 4. The alcohol content of the air supplied to the eluent reservoir is controlled using suitable filtration means. 4. A method as claimed in claim 3, characterized in that: 5. The alcohol content of the air supplied to the eluent reservoir is controlled using an activated carbon filter. 5. A method according to claim 4, characterized in that the method is reduced by using 6. a column containing a carrier material adapted to adsorb a parent isotope; The system has an inlet and an outlet, the outlet being an eluate conduit for the eluate containing the daughter radioisotope. The inlet is connected to the tap point where the fluid is obtained and the inlet is connected to the eluate storage via the eluate conduit. and a reservoir for supplying air to the generator during its elution. a radioisotope generator having an inlet for eluent storage during elution of the generator; including suitable filtration means to reduce the alcohol content of the air supplied to the storage container; A generator characterized by. 7. Claim 6, wherein the filtration means includes an activated carbon filter. generator. 8. Claims characterized in that the filtering means is sealingly connected to the inlet of the eluent reservoir. 7. The generator according to item 6 or 7. 9. The filtration means connects the eluent reservoir and the bacterial filter, i.e. the eluent 9. Generator according to claim 8, characterized in that it is sealingly connected to the inlet of the reservoir. .