REACTIONS OF RADIOACTIVE COMPOUNDS FACILITATED BY A SOLID PHASE

Abstract

The current invention provides a method for performing chemical reactions of radioactive compounds, and a device, system and method for improved heating for chemical reactions.

Claims

1. A method for performing a chemical reaction of a radioactive compound comprised in a mixture, wherein said method comprises the following steps: (a) contacting said mixture with a solid phase, followed by (b) heating said mixture to a temperature selected in the range from 30° C. up to 150° C., wherein steps (a) and (b) do not involve contacting said solid phase with an alkaline solution, wherein said chemical reaction does not result in the formation of a new bond on a radionuclide comprised in said radioactive compound, wherein said radioactive compound does not comprise fluorine-18.

2. The method according to claim 1, wherein (a) contacting said mixture with said solid phase results in the attachment of said radioactive compound to said solid phase, and wherein said method further comprises the step of: (c) detaching said radioactive compound from said solid phase by contacting said solid phase with an eluent, wherein said eluent is selected from the group consisting of aqueous solutions, organic solvents, or mixtures thereof, optionally wherein said organic solvent is ethanol or a mixture of water and ethanol.

3. The method according to claim 2, wherein said chemical reaction comprises an acid hydrolysis of said radioactive compound, wherein said acid hydrolysis occurs during said heating, optionally wherein said acid hydrolysis comprises the use of an acid selected from the group consisting of phosphoric acid, hydrochloric acid, sulfuric acid, trifluoroacetic acid, and aqueous mixtures thereof, optionally wherein said acid is 80 wt % phosphoric acid.

4. The method according to claim 3, wherein said acid hydrolysis comprises a removal of a protecting group from said radioactive compound, optionally wherein said removal results in a deprotected radioactive compound, optionally wherein said protecting group is selected from the group consisting of tert-butylcarbamate (t-Boc or Boc), tert-buylester (OtBu), Benzylester (BzO), benzylidene, tetrahydropyranyl ether (THP), acetal, trityl (Trt), and methoxymethyl ether (MOM).

5. The method according to claim 1, wherein said temperature is selected in the range from 30° C. up to 70° C., and the duration of said heating is selected in the range from 1 minute up to 15 minutes, optionally wherein said temperature is selected in the range from 30° C. up to 55° C. and the duration of said heating is selected in the range from 1 minute up to 10 minutes.

6. The method according to claim 4, wherein said method comprises the following step: (d) attaching a biological moiety to the deprotected radioactive compound, wherein said attaching results in a radiolabeled biological moiety, optionally wherein said biological moiety is a polymer of amino acids.

7. The method according to claim 6, wherein said biological moiety is an antibody or a fragment thereof, optionally wherein said antibody or fragment thereof is a diagnostic and/or a therapeutic compound targeted against an antigen expressed in a cell, optionally in a tumor cell, optionally wherein said antigen is HER2.

8. The method according to claim 7, wherein said antibody or fragment thereof is a heavy chain variable domain derived from a heavy chain antibody (V.sub.HH), or a fragment thereof, optionally wherein said heavy chain antibody (V.sub.HH) has at least 80% amino acid identity with SEQ ID NO: 7 or SEQ ID NO: 8.

9. The method according to claim 1, wherein said radioactive compound comprises a radionuclide selected from the group consisting of α-emitters and β-emitters, optionally selected from the group consisting of hydrogen-3, astatine-211, carbon-11, carbon-14, bromine-76, iodine-123, iodine-124, iodine-125, iodine-131, phosphorus-32, and sulfur-35.

10. The method according to claim 1, wherein said radioactive compound is N-succinimidyl-4-(1,2-bis(tert-butoxycarbonyl)guanidino)methyl-3-[(131)I]iodobenzoate (Boc.sub.2-[.sup.131I]SGMIB).

11. The method according to claim 10, wherein N-succinimidyl-4-(1,2-bis(tert-butoxycarbonyl)guanidino)methyl-3-[(131)I]iodobenzoate (Boc.sub.2-[.sup.131I]SGMIB) is converted to N-succinimidyl-4-guanidinomethyl-3[(131)I]iodobenzoate ([.sup.131I]SGMIB) with a yield of at least 30% during heating, as determined by quantitative HPLC, wherein the duration of said heating is from 1 minute to 10 minutes, optionally from 1 minute up to 5 minutes.

12. A device (1) for receiving and heating a chemical reaction vessel (3) comprising a mixture, said device (1) comprising a heating means (5) and an opening (2) configured for receiving said chemical reaction vessel (3), said heating means (5) at least partially surrounding said opening; wherein said heating means (5) comprises: an insulator polymer (9), a resistive conductor (8) embedded in said insulator polymer; wherein said device (1) is configured for, when said chemical reaction vessel (3) comprising said mixture is present in said opening (2), heating the mixture present in said chemical reaction vessel according to a predetermined temperature requirement by powering said heating means (5), optionally wherein said device (1) is a tubular sleeve and said opening is a lumen surrounded by said device (1).

13. Device (1) according to claim 12, wherein said insulator polymer (9) is a silicone or a polyimide, optionally wherein the melting temperature of said insulator polymer (9) is higher than 150° C.

14. Device (1) according to claim 12, wherein said resistive conductor (8) is an etched foil heating element or a wire wound heating element.

15. Device (1) according to claim 12, wherein said heating means (5) is a flexible sheet, optionally wherein said flexible sheet: has a rectangular shape; has a thickness from 0.5 mm up to 1.5 mm and/or comprises a reinforcement layer covering one side of said flexible sheet, optionally wherein said reinforcement layer consists of glass and/or fiber glass.

16. Device (1) according to claim 12, wherein said device comprises a metal sleeve (4) placed between the heating means and the opening and surrounding the opening, optionally wherein said metal is copper.

17. Device (1) according to claim 12, wherein said device (1) comprises a control unit, wherein said control unit is configured to maintain said predetermined temperature requirement relating to a temperature of said mixture being in a predetermined subrange comprised in a range from 30° C. to 150° C. by controlling the power supplied to said heating means, optionally wherein the device further comprises a temperature sensor, wherein said controlling is based on measurement by said temperature sensor.

18. A system (10) for performing a chemical reaction in a mixture, comprising: a device (1) claim 12; a chemical reaction vessel (3) placed within the opening (2) of device (1), said chemical reaction vessel (3) comprising a chamber (30), an inlet (31), and a solid phase suitable for acting as a facilitator in said chemical reaction; wherein said system (10) is configured for, when said mixture is inserted in the chamber (30) through said inlet (31), heating said mixture present in said chemical reaction vessel (3) according to a predetermined temperature requirement by powering said heating means (5), thereby allowing said chemical reaction to take place within said chamber (30).

19. System (10) according to claim 18, wherein said chemical reaction vessel (3) further comprises an outlet (32), optionally wherein said chemical reaction vessel is an SPE cartridge.

20. A method according to claim 1, wherein said solid phase used in step (a) is a silica, optionally selected from the group consisting of Sep-Pak tC18, Step-Pak C18, Oasis HLB, Oasis MCX, Oasis MAX, Sephadex LH-20, and combinations thereof.

Description

LEGEND TO THE FIGURES

[0300] FIG. 1—Overview of the synthesis of [.sup.131I-SGMIB.

[0301] FIG. 2—Schematic description of the tC18 Sep-Pak cartridge deprotection procedure.

[0302] FIG. 3—Evolution of the yield of the fully deprotected product as a function of the heating temperature, wherein said heating is for 20 minutes.

[0303] FIG. 4—Evolution of the yield of the fully deprotected product as a function of the heating temperature, wherein said heating is for 5 minutes.

[0304] FIG. 5—Example of the cassette used for the automation of heated deprotection of Boc.sub.2-protected [*I]I-SGMIB.

[0305] FIG. 6—Different views of an example embodiment of a device and system according to the invention. FIG. 1a shows a first cut away view. FIG. 1b shows a perspective view. FIG. 1c shows a second cut away view.

[0306] FIG. 7—Example embodiments of a heating element comprised in a system according to the invention. FIG. 2a shows an example of a heat pad comprising a wire wound heating element. FIG. 2b shows an example of a heat pad comprising an etched foil heating element.

[0307] FIG. 8—The simulated effect of power the heating means comprised in an example embodiment of a device according to the invention (SolidWorks). FIG. 3a shows a thermal distribution of said device. FIG. 3b show the temperature of said device as a function of time of powering said heating means.

[0308] FIG. 9—The simulated effect of power the heating means comprised in an example embodiment of a system according to the invention (SolidWorks). FIG. 4a shows a thermal distribution of said system. FIG. 4b show the temperature of said system as a function of time of powering said heating means.

REFERENCES

[0309] [1] MOSDZIANOWSKI, C., et al. Epimerization study on [18F] FDG produced by an alkaline hydrolysis on solid support under stringent conditions. Applied radiation and isotopes, 2002, 56.6: 871-875. [0310] [2] U.S. Pat. No. 8,476,063B2 [0311] [3] US20020183660A1 [0312] [4] U.S. Pat. No. 9,408,257B2 [0313] [5] KR101320762B1

EXAMPLES

[0314] The following examples are offered for illustrative purposes only, and are not intended to limit the scope of the present invention in any way.

Example 1: Manual Reactions

Manual Process Description

[0315] The set of experiments described herein aimed at reproducing the preliminary results obtained for the “cold” synthesis of the SGMIB linker using a heated cartridge during the deprotection step (=cold experiments conducted by ORA). Following this first proof-of-concept, a series of manual “hot” syntheses using a heated cartridge were conducted (=radioactive experiments conducted by Camel-IDS), which are described in detail below.

[0316] The examples detailed below describe the performance of the novel method on the deprotection of Boc.sub.2-N-succinimidyl-4-guanidinomethyl-3-[(*)I]iodobenzoate ([*I]SGMIB-Boc.sub.2), a radiohalogenation agent used for radiolabeling of targeting compounds. [*I]SGMIB is obtained via the synthesis procedure described in FIG. 1. A detailed description of tC18 Sep-Pak cartridge deprotection procedure us depicted in FIG. 2.

[0317] With the presented set of experiments, the potency of deprotection via a method according to the invention a heated cartridge is evaluated at different reaction temperatures and will be evaluated in function of reaction times and the type of acid (and its concentration) used.

[0318] In process measurement of deprotection potency and quality of the radioactive compounds are assessed by gradient RP-HPLC analyses. Identical chromatographic conditions are used to assess the fully automated procedure.

[0319] Materials and Methods

[0320] All reagents (N-chlorosuccinimide (NCS), tin-precursor (SGMTB-Boc.sub.2), sodium iodide (Na.sup.127I), phosphoric acid 85% (H.sub.3PO.sub.4), acetic acid (HOAc)) and solvents (acetonitrile (ACN), ethanol (EtOH)) were obtained commercially from Merk-Sigma and used without further purification. For deprotection, Sep-Pak C18 Plus Short/Light Cartridge were obtained commercially from Waters.

[0321] Na[.sup.131I]I was obtained commercially from GE Healthcare in 0.05 M NaOH solution with a volumic activity of 800 μCi/μL (29.6 MBq/μL). UV/Radio-HPLC analyses were performed on a Shimadzu LC-20AT Liquid chromatography system equipped with a C-18 column (X-Select, CSH, C18, 3.5μ, 100×4.6 mm) with the flow rate set at 1.50 mL/min with the following gradient: t=0: 90% A, 10% B; t=15 min: 100% B; with A=H.sub.2O with 0.05% TFA and B=ACN with 0.05% TFA.

General Experimental Protocol

[0322] a) Na.sup.131 preparation

[0323] To a 10 mL vial: [0324] 1. Adding 20 μL of H.sub.2O (WFI) [0325] 2. Adding desired amount of cold iodine (Na.sup.127I) [0326] 3. Adding 5 μL of 10×diluted PBS solution [0327] 4. Adding desired activity of radioactive iodine (Na.sup.131I) [0328] .fwdarw.evaporation at 45° C. until complete drying

[0329] b) Labeling Step

[0330] To the dry Na.sup.131I (10 mL vial): [0331] 1. Adding desired oxidizing reagent solution (NCS) [0332] 2. Adding desired tin precursor solution (SGMTB-Boc.sub.2) [0333] .fwdarw.Labeling time: 5 min/23° C. [0334] 3. QC HPLC: 10 μL of labeled solution in 90 μL of H.sub.2O+0.05% TFA (vinj: 100 μL) [0335] c) Concentration and deprotection steps (SGMIB-Boc.sub.2)

[0336] To the Labeled solution (10 mL vial): [0337] 1. Dilution with desired volume of H.sub.2O (WFI) [0338] 2. Loading diluted labeled solution on desired tC18 cartridge [0339] 3. Rinsing tC18 cartridge with desired volume of H.sub.2O (WFI) [0340] 4. Drying tC18 cartridge with air [0341] 5. Adding desired volume of phosphoric acid 85% (H.sub.3PO.sub.4) in tC18 cartridge [0342] 6. Adding tC18 cartridge to a water bath after being closed with two stoppers [0343] .fwdarw.Deprotection time: 20 min/desired T° C.

[0344] d) Elution Final Product Step (SGMIB)

[0345] To the tC18 cartridge (Sep-Pak): [0346] 7. Washing with desired volume of H.sub.2O (WFI) [0347] 8. Drying with air [0348] 9. Eluting final product (.sup.131I-SGMIB) with desired volume of EtOH/H.sub.2O (70/30)+1% HOAc [0349] 10. QC HPLC: 10 μL of eluted solution in 90 μL of H.sub.2O+0.05% TFA (v.sub.inj: 100 μL)

Experimental Conditions (Manual)+Results Tables

[0350] As mentioned above, with the presented set of experiments, the potency of deprotection using a heated cartridge is evaluated at different reaction temperatures, ranging from 23° C. up to 75° C. The corresponding results (Deprotection yields) can be found in the table depicted below. The relevant RP-HPLC chromatograms are described part 3.

[0351] The first results indicate that for a deprotection time of 20 min within a temperature range of 23° C.-75° C., deprotection reaction yield measures >75%. Within a 32° C.-75° C. range, the deprotection yield increases >92%, while it measures >99% between 40° C.-75° C.

[0352] For a deprotection time of 5 min and a temperature range of 23° C.-55° C., deprotection reaction yield measures >30%. Within a 40° C.-75° C. range, the yield increases >73%, while it measures >99% between 55° C.-75° C.

[0353] Importantly, efficient heated cartridge deprotection was confirmed for [*I]SGMIB that was radioiodinated in a reaction mixture consisting of either EtOH/HOAc or ACN/HOAc. These experiments indicated that the observed deprotection efficiency was independent of the constitution of the radioiodination reaction mixture (which takes place before deprotection).

[0354] Table 1 describes the set-up of the experiments, whereas Table 2 lists the results obtained for each of these experiments.

[0355] In addition, RP-HPLC results indicate that when the deprotection reaction takes place at 75° C., an impurity to [*I]SGMIB is observed, ranging from 3-12%. Deprotection reactions at 40° C. do not give rise to this impurity (<1%).

TABLE-US-00001 TABLE 1 (part 1): Set-up of the manual experiments Step Exp 1 2 3 4 5 6 7 8 Date 2020 2020 2020 2020 2020 2020 2020 2020 Mar. 16 Mar. 18 Mar. 19 Apr. 16 Apr. 17 Apr. 16 Apr. 17 Apr. 17 Drying Radio. .sup.131| .sup.131| .sup.131| step isotope Na.sup.127| 100 1 Ci 1 Ci 5 Ci 5 Ci (eq) mCi Drying 10 min 10 min 10 min time Drying 45° C. 45° C. 45° C. T° C. Lab. Oxidant 1.8 mg in 600 μL 3.75 mg in 1.25 mL 3.75 mg in step (NCS) EtOH/HOAc (99/1) EtOH/HOAC 1.25 mL ACN/HOAC (87.5/12.5) (87.5/12.5) Tin 0.48 mg in 600 μL 1.5 mg in 1.25 mL 1.5 mg in 1.25 precursor EtOH/HOAc (99/1) EtOH/HOAC mL ACN/HOAC (87.5/12.5) (87.5/12.5) End 1.2 mL 2.5 mL 2.5 mL volume Lab. time 20 min 5 min 5 min Lab. T° C. 23° C. 23° C. 23° C. Conc. + H.sub.2O 4 mL 6 mL 8 mL 6 mL 8 mL dep. (dilution) steps tC18 Short Light Short Short Sep-Pak type H.sub.2O  5 mL 5 mL 5 mL (rinsing) H.sub.3PO.sub.4  2 mL 2 mL 2 mL 85% Dep. 20 min 20 min 20 min time Dep. T° C. 75° C. 40° C. 32° C. 23° C. 40° C. 32° C. Elution H.sub.2O 8 mL 10 mL 10 mL 15 mL 15 mL step (rinsing) Eluent EtOH/H.sub.2O (70/30) + 1% EtOH/H.sub.2O (70/30) + EtOH/H.sub.2O HOAc 1% HOAC (70/30) + 1% HOAc Elution Straight Straight Reverse Straight Straight mode Eluent 3.5 mL 1.5 mL 1.0 mL 2.0 mL 2.0 mL volume

TABLE-US-00002 TABLE 1 (part 2): Set-up of the manual experiments Exp 9 10 11 12 13 14 Date Step Apr. 22, 2020 Apr. 21, 2020 Apr. 21, 2020 Apr. 21, 2020 Apr. 22, 2020 Apr. 22, 2020 Drying Radio. .sup.131I .sup.131I Step isotope Na.sup.127I (eq) 5 Ci 5 Ci Drying time 10 min 10 min Drying T ° C. 45 ° C. 45 ° C. Lab. Oxidant 3.75 mg in 1.25 mL EtOH/HOAc (87.5/12.5) 3.75 mg in step (NCS) 1.25 mL ACN/HOAc (87.5/12.5) Tin precursor  1.5 mg in 1.25 mL EtOH/HOAc (87.5/12.5) 1.5 mg in 1.25 mL ACN/HOAc (87.5/12.5) End volume 2.5 mL 2.5 mL Lab. time 5 min 5 min Lab. T ° C. 23 ° C. 23 ° C. Conc. + H.sub.2O 8 mL 8 mL dep. (dilution) steps tC18 Short Short Sep-Pak type H.sub.2O 5 mL 5 mL (rinsing) H.sub.3PO.sub.4 2 mL 2 mL 85% Dep. time 5 min 5 min Dep. T ° C. 23° C. 55° C. 45° C. 50° C. 55° C. Elution H.sub.2O 15 mL 15 mL step (rinsing) Eluent EtOH/H.sub.2O (70/30) + 1% HOAc EtOH/H2O (70/30) + 1% HOAc Elution Straight Straight mode Eluent 2.0 mL 2.0 mL volume

TABLE-US-00003 TABLE 2 (part 1): Results of the manual experiments Exp 1 2 3 4 5 6 7 8 Starting Activity 80.6 83.2 79.6 48.1 44.2 49.0 43.6 30.1 (MBq) Collected 70 71 67.4 41.8 38.9 42.2 38.7 27.5 activity (MBq) Deprotection >99 >99 >99 >99 92 75 >99 92 yield (%) SGMIB yield 87 96 95 99 92 75 99 92 (purity (%)) SGMIB (MBq) 60.9 68.2 64.0 41.4 35.8 31.7 38.3 25.3 Overall yield (%) 76 82 80 86 81 65 88 84 Collected 3.4 1.4 0.8 2.2 2.1 2.1 2.1 2.2 volume (mL)

TABLE-US-00004 TABLE 2 (part 2): Results of the manual experiments Exp 9 10 11 12 13 14 Starting Activity 24.0 29.2 29.1 29.2 23.6 23.9 (MBq) Collected 21.2 26.9 26.4 26.7 21.7 21.5 activity (MBq) Deprotection 30 73 91 96 >99 >99 yield (%) SGMIB yield 30 73 91 96 99 99 (purity (%)) SGMIB (MBq) 6.4 19.6 24.0 25.6 21.5 21.3 Overall yield (%) 27 67 83 88 91 90 Collected 2.1 2.0 2.1 2.1 2.2 2.1 volume (mL)

[0356] The evolution of deprotection yield according to heating (for 20 min) can be seen in FIG. 3. The evolution of deprotection yield according to heating (for 20 min) can be seen in FIG. 4.

[0357] A few reaction parameters are identified to influence the deprotection yield.

[0358] Parameter 1. Temperature: [0359] Time Deprotection: 20 min

[0360] Within a temperature range of 23° C.-75° C., deprotection reaction yield measures >75%

[0361] Within a temperature range of 32° C.-75° C., deprotection reaction yield measures >92%

[0362] Within a temperature range of 40° C.-75° C., deprotection reaction yield measures >99% [0363] Time Deprotection: 5 min

[0364] Within a temperature range of 23° C.-55° C., deprotection reaction yield measures >30%

[0365] Within a temperature range of 40° C.-75° C., deprotection reaction yield measures >73%

[0366] Within a temperature range of 55° C.-75° C., deprotection reaction yield measures >99%

[0367] Side products to (.sup.131I)SGMIB:

[0368] Deprotection reaction at 75° C. during 20 min: side products to (.sup.131I)SGMIB range 3-12% Deprotection reaction at 30-40° C. during 20 min: side products to (.sup.131I)SGMIB<1%

Example 2: Automated Reactions

[0369] The described experimental examples were obtained through a full automated procedure with an integrated cartridge heater using an ORA Neptis synthesizer. The experiments aimed at replicating the results obtained via manual syntheses.

[0370] The assessment of the efficacy of deprotection at different temperatures and reaction times have been performed by carrying-out HPLC analyses of the resulting product using identical chromatographic conditions compared to the manual syntheses.

[0371] The examples detailed below describe the performance of the novel method on the deprotection of Boc.sub.2-N-succinimidyl 4-guanidinomethyl-3-[(*)I]iodobenzoate ([*I]I-SGMIB-Boc.sub.2), a radiohalogenation agent used for radiolabeling of targeting compounds.

Materials and Methods

[0372] The manual synthesis was translated into a sequence that allows for use on the ORA Neptis synthesizer. This particular synthesizer for radiopharmaceuticals uses a disposable referred to as a “cassette”, prepared prior to each experiment, and allows reproducing the manual synthesis in an automated fashion by performing a predefined sequence of “steps”. Designing a suitable cassette and a sequence of steps allows for a reproducible radiochemical synthesis. The cassette layout used for the experimental examples is detailed below can be found in FIG. 5.

[0373] The cassette consists in an ensemble of single-used manifolds comprising 3-way valves, on which are placed various consumables such as, non-exhaustively, vials filled with reagents, solid-phase extraction (SPE) or anion-exchange cartridges or syringes. Each step consists of an ensemble of setpoints (among those, for example, the position of a valve, the position of a syringe, the pressure and flow rate of nitrogen to be applied, the temperature of an oven or the actuation of the vacuum pump) that is applied for a pre-defined amount of time.

[0374] The following paragraph describes the full “template” sequence. The specific parameters that are varied between experimental examples are further detailed in Table 3. The results of the different experimental examples are described in Table 5.

[0375] Full automated sequence describing the different steps: [0376] A. A solution containing the radioactive isotope is placed in the reactor (position 13) prior to radio-synthesis. [0377] B. The solution is dried using a nitrogen flow and by heating the reactor. [0378] C. Next, the precursor and the oxidant (position 15) are transferred into the reactor. [0379] D. The radiolabeling reaction occurs in the reactor. [0380] E. The reaction mixture is diluted with water (position 12) using the 10 mL syringe (position 7), and the resulting diluted solution is then loaded on the tC18 cartridge (position 8). The eluate resulting from loading the tC18 cartridge is sent to the waste. [0381] F. The reactor and the tC18 cartridge are rinsed with water (position 12) using the 10 mL syringe (position 7). [0382] G. The acid (position 6) is loaded on the tC18 cartridge using the 10 mL syringe (position 7). Once the tC18 cartridge has been saturated with acid, the valve in position 9 is closed, ensuring that the acid remains on the tC18 cartridge during deprotection. [0383] H. The cartridge is heated for a pre-defined amount of time to allow for deprotection on the tC18 cartridge. [0384] I. The tC18 cartridge is rinsed with water (position 12) using the 10 mL syringe (position 7), which forces the remaining acid and eluate to be sent to the waste. [0385] J. The eluent for collection (position 10) is loaded on the tC18 cartridge using the 10 mL syringe (position 7). The eluate is collected in the collection vial (position 5).

TABLE-US-00005 TABLE 3 Materials used in the automated experiments Experiment EXAMPLE 1 EXAMPLE 2 EXAMPLE 3 Date 09 Apr 2020 15 Apr 2020 16 Apr 2020 Drying Radioactive .sup.131I isotope Drying time 20 min Drying 70° C. temperature Labeling Precursor [00001] 1.5 mg in 1.25 mL of EtOH/AcOH 88/12 Oxidant N-Chlorosuccinimide (NCS) 3.75 mg in 1.25 mL of EtOH/AcOH 88/12 Labeling time 20 min Trapping Dilution volume 5.5 mL on tC18 type tC18 plus Short (WAT036810) tC18 Acid used H.sub.3PO.sub.4 (85% wt %) and Volume of acid 2.5 mL deprotection used Deprotection 20 min time Deprotection 75° C. 60° C. temperature Elution Rinsing volume 15 mL Eluent EtOH/water 70/30 with 1% AcOH composition Eluent volume 2.5 mL 2 mL

[0386] The full automated sequence described above allows for subsequent elution of pure [*I]I-SGMIB, constituted in EtOH/water 70/30 with 1% AcOH, into a conjugation vial that contains an appropriate amount of targeting compound in a conjugation buffer. After conjugation, [*I]I-SGMIB-labelled targeting compound is purified using a cartridge and eluted into formulation buffer ready for end-use. This part of the process is currently being translated into the synthesis sequence. An example of the cassette used for the automation of heated deprotection of Boc.sub.2-protected [*I]ISGMIB can be found in FIG. 5.

Chromatographic Conditions

[0387] UV/Radio-HPLC analyses were performed on a Shimadzu LC-20AT Liquid chromatography system equipped with a C-18 column (X-Select, CSH, C18, 3.5μ, 100×4.6 mm) with the flow rate set at 1.50 mL/min with the following gradient: t=0: 90% A, 10% B; t=15 min: 100% B; with A=H.sub.2O with 0.05% TFA and B=ACN with 0.0 5% TFA.

[0388] Detailed HPLC features: [0389] HPLC: Shimadzu LC-20AT—Prominence Liquid Chromatography [0390] Gradient and solvent [0391] UV Detector: Shimadzu SPD-20A—Prominence UV/VIS Detector [0392] Dual detection: 220 nm/254 nm [0393] Radio Detector: Elysia RAYTEST Sockel 3″ GABI Nova 1.0 [0394] RA-detection: 5 μL loop [0395] HPLC column: X-Select, CSH, C18, 3.5μ, 100×4.6 mm [0396] Rheodyne injector: 100 μL PEEK-loop [0397] Software: GINA X station Gabi Nova 31038

[0398] Each sample wass injected into an identical solvent mixture to the initial HPLC run conditions

H.sub.2O/ACN+0.05% TFA(90/10)

[0399] Reagents/cold references products: UV chromatograms (220-254 nm)

TABLE-US-00006 TABLE 4 Elution times Labeling step Deprotection step SGMTB-Boc.sub.2 12.7 min [*I]]I-SGMIB- 6.6-11.5 min N-chlorosuccinimide 1.5 min Boc.sub.2 (NCS) [*I]I-SGMIB 4.4 min Acetic acid (HOAc) 1.0 min [*I]I-SGMIB-Boc.sub.2 6.6-11.5 min

Results

[0400] The experimental results are displayed in Table 5.

TABLE-US-00007 TABLE 5 Experimental results for the automated reactions Experiment EXAMPLE 1 EXAMPLE 2 EXAMPLE 3 Starting activity 61.0 MBq 33.4 MBq 28.2 MBq Activity collected 45.8 MBq 24.1 MBq 24.3 MBq at the end of the synthesis Collected activity 75.08% 72.16% 86.17% Deprotection   >99%   >99%   >99% efficacy [*I]I-SGMIB yield   94%   94%   97% (purity) Overall yield  70.6%  67.8%  83.6% Collected volume 2.30 mL 1.74 mL 1.57 mL after elution

[0401] These first results indicate that the deprotection reaction yield measures >99%, after reactions at both 75 and 60° C., and after only 20 minutes of incubation.

[0402] With this new invention, efficient heated cartridge deprotection was also confirmed for [*I]SGMIB that was radioiodinated in a reaction mixture consisting of either EtOH/HOAc or ACN/HOAc. These experiments indicated that the observed deprotection efficiency was independent of the constitution of the radioiodination reaction mixture (which takes place before deprotection). In addition, RP-HPLC results indicate that when the deprotection reaction takes place at 75° C., an impurity to [*I]SGMIB is observed, ranging from 3-12%. Deprotection reactions at 40° C. do not give rise to this impurity (<1%).

[0403] These findings are exceptional and contrast with the historical method for deprotection (where only about 30% corresponds to deprotected [*I]I-SGMIB after radioiodination in EtOH/HOAc. In addition, the level of impurities was much higher in the latter case, ranging about 25% in contrast to below 1% in the case of a method according to the invention.

Example 3: Example Device According to the Invention

[0404] FIG. 6 shows different views of an example embodiment of a device 1 and system 10 according to the invention. FIG. 6a shows a first cut away view. FIG. 6b shows a perspective view. FIG. 6c shows a second cut away view.

[0405] The device 1 is adapted for receiving and heating a chemical reaction vessel 3 comprising a mixture (not shown). As illustrated in FIG. 6, the system 10 comprises the device 1 and the chemical reaction vessel 3 that are mutually adapted in diameter and length such that the device 1 surrounds the chemical reaction vessel 3 in such a way that heat generated within a heating means 5 comprised in the device 1 may be carried over to the chemical reaction vessel 3. To this end, the device 1 comprises an opening 2 configured for receiving said reaction vessel 3, and the heating means 5 at least partially surrounding said opening. In embodiments as shown in the Figure, the chemical reaction vessel 3 is a cartridge. In embodiments, the cartridge is an SPE cartridge. The chemical reaction vessel 3 comprises a reactor chamber 30, an inlet 31, a housing 33, and an outlet 32.

[0406] The heating means 5, which may, e.g., be according to embodiments of the heating means according to Example 2 and FIG. 7, comprises an insulator polymer 9 and a resistive conductor 8 embedded in said insulator polymer 9.

[0407] The device 1 is configured for, when a chemical reaction vessel 3 comprising a mixture is present in said opening 2, heating the mixture present in said chemical reaction vessel according to a predetermined temperature requirement by powering said heating means 5. The device 1 comprises a metal sleeve 4 placed between the chemical reaction vessel 3 and the heating means 5 and surrounding the chemical reaction vessel. In embodiments, the metal is copper.

[0408] The use of a copper metal sleeve is illustrated in FIGS. 8 and 9 which show the simulated effect of power the heating means.

[0409] The heating means 5 comprises an adhesive layer for attaching said heating means 5 to the metal sleeve 4. This has the advantage of easier mounting of the device and/or improved structural integrity of the device and/or improved thermal conductivity for heat propagating from the heating means to the metal sleeve. The device 1 furthermore comprises a cover 6. The cover 6 conveniently keeps the device together. In embodiments according to this example, it comprises one or more holes 60 for the power supply to the heating pad 3.

[0410] In embodiments, the device 1 comprises a control unit and a temperature sensor, wherein said control unit is configured to maintain said predetermined temperature requirement relating to a temperature of said mixture being in a predetermined subrange comprised in a range from 30° C. to 150° C., preferably from 30° C. to 80° C., more preferably from 30° C. to 50° C., by controlling the power supplied to said heating means 5 based on measurement by said temperature sensor. In preferred embodiment, said predetermined temperature requirement relates to reaching a stable temperature quickly and after a short equilibration time, preferably without any overshoot.

[0411] In embodiments as illustrated by FIG. 6, the device 1 is a tubular sleeve and the opening 2 is a lumen surrounded and defined by said device. In embodiments, the heating means has a maximum dimension from 10 mm up to 200 mm, preferably from 20 mm up to 100 mm. Thereby, the length and/or resistance value and/or maximum power of the resistive conductor is adapted to the dimensions and/or requirements of the chemical reaction vessel chosen for use with the device and/or in function of the predetermined temperature requirement.

[0412] The chemical reaction vessel 3 further comprises a solid phase (not shown) suitable for acting as a facilitator in the chemical reaction. In embodiments, the chemical reaction vessel 3 comprises a metal, and/or a metal alloy and/or glass and/or fiber glass and/or an organic polymer. In preferred embodiments according to this example, the chemical reaction vessel 3 consists of one or more organic polymers. In embodiments the solid phase is a silica, preferably one or more of Sep-Pak tC18, Step-Pak C18, Oasis HLB, Oasis MCX, Oasis MAX and Sephadex LH-20. In preferred embodiments according to this example, the solid phase is Sep-Pak tC18.

[0413] In embodiments, a mixture is introduced via said inlet 31 for letting a chemical reaction facilitated by a solid phase take place within said reaction chamber 30 by electrically powering the heating means 5, after which the mixture may be extracted via the outlet 32. In embodiments, the mixture comprises a radioactive compound, wherein said chemical reaction is a chemical reaction of the radioactive compound facilitated by a solid phase.

[0414] The predetermined temperature requirement may relate to requiring a target temperature of 50° C. in the chemical reaction vessel for a duration of three minutes while starting from an initial temperature that is, e.g., 30° C. or 40° C. or 50° C. or 60° C. or 70° C. The predetermined temperature requirement furthermore specifies the maximum time for the transition from 60° C. to 50° C. is three minutes requirement that the overshoot remains below 1° C.

[0415] In this example, the temperature requirement is met by means of a control unit being a programmable logical controller (PLC) comprising a 24 V power supply. Since the power of the heating means is low in this example, heat is supplied directly by the controller. Temperature is measured by means of a temperature sensor comprising a thermocouple board of the PLC. The control unit is configured such that temperature is controlled according to a PID control. This relates to specific parameters configured to avoid temperature overshoot.

Example 4: Example Heating Means According to the Invention

[0416] FIG. 7 shows example embodiments of a heat pad 5 as heating element according to the invention. FIG. 7a shows first embodiments of a heat pad comprising a wire wound heating element. FIG. 7b shows second embodiments of a heat pad comprising an etched foil heating element. Both embodiments may, e.g., be combined with Example 1 as being the heating means or one of the heating means of the devices 1 of Example 1.

[0417] Both embodiments relate to a heat pad 5 comprising an insulator polymer 9 and a resistive conductor 8. Hereby, the first embodiments provide a resistive conductor 8 comprising a wire wound heating element, whereas the second embodiments provide a resistive conductor 8 comprising an etched foil resistive conductor. In third embodiments (not shown) according to the invention, the resistive conductor 8 comprises both one or more wire wound heating elements and one or more etched foil resistive conductors. In embodiments, the resistive conductor has an insulation resistance of more than 100 kΩ, preferably more than 1 MΩ, preferably at least 10 MΩ. In embodiments, the power rating is from 0.1 W up to 10 W, preferably from 0.5 up to 4 W, more preferably about 1 W or 1.25 W or 1.50 W or 1.75 W or 2 W.

[0418] In embodiments, the insulator polymer 9 comprises silicone and/or polyimide. The insulator polymer 9 of the second embodiments of FIG. 7b may be different from that of the first embodiments of FIG. 7a but may also be the same. In embodiments the insulator polymer 9 comprises both silicone and polyimide. The insulator polymer 9 preferably consists of a silicone or a polyimide. In embodiments, the melting temperature of the insulator polymer is higher than 150° C., preferably higher than 200° C.

[0419] In example embodiments, the heat pad 5 is a flexible sheet having a rectangular shape. The thickness of the flexible sheet is from 0.5 mm up to 1.5 mm, in examples it is from 0.5 mm up to 1.0 mm. In example embodiments, the thickness is 0.7 mm. The flexible sheet comprises a reinforcement layer covering one side of said flexible sheet. The reinforcement layer preferably consists of glass and/or fiber glass.

[0420] In example embodiments, the heat pad comprises an adhesive layer for attaching the heat pad to further portions of the device. For the device of Example 1, this may be the metal sleeve 4 or a cover 6 surrounding the heating means.

[0421] FIG. 7a illustrates embodiments of the heat pad 5 comprising an insulator polymer 9 and a wire wound heating element 8. Such element 8 may for instance be created by spiraling fine resistance wires around a fiberglass cord, followed by laying out the element 8 in a predetermined pattern over the insulator polymer 9. However, other ways of creating such elements as known to the skilled person may be considered. In example embodiments, the pattern relates to one or more spirals extending over portions of the insulator polymer 9. FIG. 7b illustrates embodiments of the heat pad 5 comprising an insulator polymer 98 and an etched foil element 6. In such embodiments, the element is preferably created by acid etching a pattern in nickel alloy resistance foil, the pattern being a circuit. However, other ways of creating such elements as known to the skilled person may be considered. In example embodiments, the pattern relates to a curbed path or spiral comprising a large number of turns, e.g. more than ten turns.

[0422] In embodiments, the pattern is such that the total length of the resistive conductor maximum exceeds a maximal dimension of the heating means by a factor of at least two, preferably by a factor of at least five, more preferably by a factor of about ten. In example embodiments, the heating means has a maximum dimension of 50 mm, with a size of, e.g. 10 mm×50 mm or 25 mm×50 mm or 40 mm×50 mm. In other example embodiments, the heating means has a maximum dimension of 30 mm, with a size of, e.g. 5 mm×30 mm or 15 mm×30 mm or 20 mm×30 mm. In embodiments, the heating means has a maximum dimension from 10 mm up to 200 mm, preferably from 20 mm up to 100 mm. In embodiments, the total length of the resistive conductor maximum exceeds a maximal dimension of the heating means by a factor of at least two, with a length of, e.g., more than 50 mm or 100 mm or 200 mm or 300 mm or 500 mm or 800 mm. In embodiments, the minimal dimension, i.e. the thickness of the heating means, is from 0.1 mm up to 3.0 mm, preferably from 0.5 mm up to 1 mm, preferably about 0.6 mm or 0.7 mm or 0.8 mm or 0.9 mm.

[0423] In example embodiments, including the first and second embodiments of this example, the convex hull of said pattern covers at least 50% of the surface of the insulator polymer 9, more preferably at least 80% of the surface of the insulator polymer 9. In embodiments, the one or more respective spirals or curbed paths, preferably one, two, more than two, four, or more than four in number, extend over respective portions of the insulator polymer 9 that are non-overlapping for at least 50% of their respective surfaces, preferably at least 80%.

[0424] Electrical power is supplied to the heat pad via a conducting wire, attached to the heat pad 5 via a hole in the cover 6, causing the heating of the heating pad. When the heat pad is used in a device and/or system such as that of Example 1, heat is transferred via conduction to the chemical reaction vessel. The heating of the chemical reaction vessel via the supply of electrical power to the heat pad 5 is controlled by means of a control unit and a temperature sensor.