CS269441B1 - Filter for the preparation of biologically active substances labeled with iodine radionuclides - Google Patents

Abstract

The solution relates to a filter for the preparation of biologically active substances labeled with iodine radionuclides. The essence of the solution is that the porous material of the filter contains an adsorbed derivative of 1, 3, 4, 6 tetrachloro-3'-z, 6'-diphenylglycoluril, the porous material is filter paper, the filter may contain another layer of porous material with adsorbed silver chloride or sodium gyrosulfite, the next layer may be filter paper and the last layer a membrane filter with a pore size of 0.22 to 0.4/um.

Description

The invention relates to a filter for the preparation of biologically active substances labeled with iodine radionuclides. The filter can be used for labeling all preparations in which the iodination agent itself is elemental iodine.

Several different methods of labeling biologically active substances with iodine radionuclides are described in the professional literature.

In the case where the molecule of the substance contains an iodine atom, the labeling is carried out by an exchange reaction and radioactive sodium iodide by long-term heating of the solutions of the reaction mixtures to higher temperatures (333 - 373 K). For example, Zeltman, AM and Kahn, M., J. Am. Chern. Soc. 76. 1554 (1954) label iodotyrosines in this way in an aqueous solution at 62 °C, Nakamura, Ϊ. et al., J. Nucl. Med., 28, 1112 (1977), Anghileri, LJ, Int. J. Appli-RAd. Isotopes 1£, 328 (1963), Burgee, A. et al., Endocrinology 21» 1189 (1963), Recese, M. et al., J. Labelled Comp. Radiopharm. 15. 555 (1978), Pabel, M. C, et al., Int. J. Appl. Rad. Isotopes 25. 421 (1974), Toth, G., Radiochem. Radioanal. Letters 30. 297 (1977) and Taunog et al., J. Biol. Chem. 194. 655 (1952) label iodothyronine in this way in an aceate buffer of pH 5.3 with the possible addition of elemental iodine, and Hallaba, E. et al., J. Nucl. Med., 15. 270 (1974) label tyrosine in this way in an ethanolic solution at 338 K. Similarly, Hallaba, E. et al., Isotopenpraxis 2, 194 (1966), Henry R. et al., CEA Report 1784 (1960), Serafini, AN et al., J. Nuol. Med. 16, 629 (1975), Wheeler, 0. H. et al., Int. J. Appl. RAd. Isotopes 21, 110 (1970), Desai, CN et al., Int. J. Appl. RAd. Isotopes 19. 153 (1968), Suner, AA et al., Radiomech. Aota 12, 119 (1969) and Hupf, Ξ. B. et al·, J· Nucl. Med. 12, 525 (1978) in acetate buffer at pH 5 to 7 indicates Bengal red and Kopička K. et al., Czechoslovak Author's certificate No. 249288 in aqueous solution under catalysis by Cu ⁴ salts indicates monoiodobromosulfophthalein.

For substances that do not contain iodine in their molecule, labeling is carried out using radioactive iodine by adding various oxidizing agents to the solution of the reaction mixture. Of the inorganic agents, Abdel-Wahad, M. P. et al., Isetopenpraxis 2» 166 (1973) use potassium iodate and Charamza 0., Isotopenpraxis 2, 298 (1966) use hydrogen peroxide. The reaction takes place for various compounds for a period of 40 minutes to 10 hours. Very often, chloramine T is added to the solution of the reaction mixture as an oxidizing agent according to the now classic model Greenwood, Hunter: Nature ... 194, 495 (1962) as described, for example, by Hallaba, E. et al., Int. J. Appl. Radiat. Isotopes 22, 46 (1971), Krohn K. A. et al., Int. J. Appl. Radiat. Isotopes 25. 315 (1974) and Coleman R. E. et al. J. Lab. Clin. Med. 83. 977 (1974). The reaction takes place within a few minutes, its yield varies between 30 and 80%. Another frequently used oxidizing agent is lactoperoxidase as reported by Me Ilhiney J. et al., Endocrinology 21· 1259 (1974), Thorell J. I. et al., Biochem. Biophys. Aota 251. 363 (1971) and Marchalonis J. J., Biochem. J. 113. 299 (1969). The reaction is usually completed within 30 minutes and the yield varies between 30 and 90%. A very frequently used oxidizing agent is also iodide monochloride, the use of which is described in the papers of Peabody R. A. et al., J. Nucl. Med. 15, 195 (1974), Reif A. E., J. Nucl. Med. 2, 148 (1968) and Haxhe J. J. et al., Clin. Chin Aota 8, 302 (1963). The reaction is completed within 10 to 60 minutes with a yield in the range of 50 to 80%. For the iodination of proteins, labeling with 1, 3, 4, is described in the papers of Fraker P. J. et al., Biophys. Res. Commun. 80, 859 (1978) and Woods W. G., J. Clin. Chem. Clin. Biochem., 12, 1051 (1981). 6 - tetrachloroO-3cK , 6 -dlphenylglycolurilu (Iodogen), According to the described method, iodogen, which is practically insoluble in aqueous solution, is applied as a thin filter to the surface of a glass vessel, in which, after adding a reaction mixture consisting of a protein and radioactive iodide, the labeling takes place. The disadvantage of this method is the difficulty of reproducible application of the iodogen film related to the selection of suitable iodogen solvents, the complicated application technique and the stability of the prepared vessels and thus the associated relatively low and variable yields of the labeled product. A variation of this method is reported by Richardson A. P. et al., Nuol. Med. Commun., χ, 355 (1988), who introduce iodogen into the reaction mixture in the form of a suspension. Although in this case the yields are significantly higher,

CS 269 441 B1 The main disadvantage is that acetone is used as a solvent for iodogen and iodogen must be removed from the product and the product must be cleaned especially carefully if it is to be used for human use.

The main of these disadvantages is eliminated by the method according to the invention, in which the porous material of the filter, through which the labeling by filtration is carried out, contains an adsorbed derivative of 1, 3, 4, 6 tetrachloro-3cA, 6 <4 - diphenylglyoluril, the filter may contain another layer of porous material with adsorbed silver chloride or sodium pyrosulfite, the next layer may be filter paper and the last layer a membrane filter with a pore size of 0.22-04 / μm.

The main advantages of the method according to the invention include the simplicity of preparing the filter, the ease of its production on a large scale, the extraordinary simplicity and speed of labeling of biologically active substances prepared with its help, the high yield of the labeled substance, the increase in the stability of the preparations, the possibility of obtaining a sterile product directly and the possibility of performing labeling even on a microscale. Another advantage of the method according to the invention is the possibility of performing all operations of preparing radioactive biologically active substances, i.e. both labeling and removal, if necessary, of unreacted iodide and sterilization of the product in a single operation, if the individual filters mentioned are used simultaneously in the form of a composite filter.

Example 1

A strip of chromatography paper is dipped in 10 ml of chloroform solution of iodogen (2 mg/ml). Watmamm 3 MK. After drying and shaping into a suitable shape, it is ready for use.

Example 2

A strip of Watmann 4 chromatography paper is soaked in 10 ml of a suitable silver nitrate solution (0.5 M). After drying in the dark, this paper is soaked in 0.5 M hydrochloric acid. This is followed by several washings with distilled water until neutral. After drying and shaping into a suitable shape, the filter is ready for use.

Example 3 A strip of Watmann 4 chromatography paper is soaked in 10 ml of an aqueous solution of silver nitrate (0.01 M). After drying in the dark, this paper is soaked in a 0.01 M sodium metabisulfite solution. After thorough washing with distilled water, drying and shaping to a suitable shape, the filter is ready for use.

Example 4

We assemble a composite filter consisting of the filter prepared according to Example 1, an intermediate layer of Watmann 4 chromatography paper without further modifications, and the filter prepared according to Example 2.

Example 5

We assemble a composite filter consisting of the filter prepared according to Example 1, the filter prepared according to Example 3 and a membrane filter with a pore size of 0.4 µm. The individual openings are interspersed with openings made of chrome, Watmann 4 paper without further modifications.

Claims (8)

SUBJECT OF THE INVENTION 1. A filter for the preparation of biologically active substances labeled with iodine radionuclides, characterized in that the porous material of the filter contains an adsorbed derivative of 1, 3, 4, 6 tetrachloro-3, 6 c< - diphenyl glycoluril. 2. The filter according to item 1, characterized in that 3. Filter according to item 1, characterized in that it has adsorbed silver oxide. 4· The filter according to item 3· characterized in that it is made of paper. The porous material is filter paper. contains another layer of porous material the porous material of the next layer is the filter 5. The filter according to item 1, characterized in that it contains an additional layer of porous material with adsorbed silver pyrosulfite. 6. The filter according to item 5, characterized in that the porous material of the next layer is filter paper. 7. The filter according to items 3 or 5, characterized in that it comprises an additional layer formed by a membrane filter with a pore size of 0.22-0.4 µm. 8. Filter according to points 3 or 5 or 7, characterized in that it contains additional intermediate layers free of active substances.