APPARATUS AND METHOD FOR SOLID PHASE EXTRACTION

Abstract

The present invention provides a cassette for determining optimised solid phase extraction (SPE) purification conditions, wherein said cassette comprises: (i) a flowpath comprising a first end and a second end; and (ii) a plurality of valves oriented along said flowpath, wherein each of said plurality of valves is selectively fluidly connected to one of a number of components, wherein said components comprise: (a) 1-5 composition vials; (b) 1-3 SPE cartridges; (c) 4-10 solvent vials; (d) a water vial; and (e) a transfer line.

The present invention also provides a method for determining optimised SPE purification conditions for a compound from a composition, the method comprising: (i) provision of a cassette as defined in any of claims 1 to 7; (ii) the cassette comprising a composition of the compound in said composition vial(s) or addition of such a composition to said crude reaction vial(s); (iii) passing an aliquot of said composition into each of said 1-3 SPE cartridges; (iv) passing a particular combination of aliquots of solvent from at least 4 of said 4-10 solvent vials into one or more of the SPE cartridges, wherein the solvent in each of said 4-10 solvent vials is either a different solvent or the same solvent at different concentration; (v) eluting the compound to be purified from the or each SPE cartridge; (vi) evaluating the eluted products of step (v); and (vii) determining the optimised purification conditions by comparing the eluted products of step (v) from each cartridge and each solvent.

Claims

1. A cassette for determining optimised solid phase extraction (SPE) purification conditions, wherein said cassette comprises: (i) a flowpath comprising a first end and a second end; and (ii) a plurality of valves oriented along said flowpath, wherein each of said plurality of valves is selectively fluidly connected to one of a number of components, wherein said components comprise: (a) at least one composition vial; (b) 1-3 SPE cartridges; (c) 4-10 solvent vials; (d) a water vial; and (e) a transfer line.

2. The cassette of claim 1, wherein the cassette does not include any means for processing [.sup.18F]fluoride.

3. The cassette of claim 1, wherein the cassette is selected from cassettes (I), (II), or (III): (I) 3 SPE cartridges and 6 solvent vials; or (II) 2 SPE cartridges and 8 solvent vials; or (III) 1 SPE cartridge and 10 solvent vials.

4. The cassette of claim 3, part (i), wherein the cassette is cassette (I), and has 25 valves in a linear array, and (i) the at least one composition vials are fluidly connected to the 2.sup.nd, 12.sup.th, 13.sup.th, 14.sup.th and/or 16.sup.th valve; (ii) the 3 SPE cartridges are fluidly connected to the 18.sup.th, 20.sup.th and 22.sup.nd valves; (iii) the 6 solvent vials are fluidly connected to the 4.sup.th, 5.sup.th, 7.sup.th, 8.sup.th, 9.sup.th and 10.sup.th valves; and (iv) the water vial is fluidly connected to the 15.sup.th valve.

5. The cassette of claim 3, part (ii), wherein the cassette is cassette (II), and has 25 valves in a linear array, and (i) the at least one composition vials are fluidly connected to the 2.sup.nd, 12.sup.th, 13.sup.th, 14.sup.th and/or 16.sup.th valve; (ii) the 2 SPE cartridges are fluidly connected to the 20.sup.th and 22.sup.nd valves; (iii) the 8 solvent vials are fluidly connected to the 4.sup.th, 5.sup.th, 7.sup.th, 8.sup.th, 9.sup.th, 10.sup.th, 17.sup.th and 18.sup.th valves; and (iv) the water vial is fluidly connected to the 15.sup.th valve.

6. The cassette of claim 3, wherein the cassette is cassette (III), and has 25 valves in a linear array, and (i) the at least one composition vials are fluidly connected to the 2.sup.nd, 12.sup.th, 13.sup.th, 14.sup.th and/or 16.sup.th valve; (ii) the 1 SPE cartridge is fluidly connected to the 22.sup.nd valve; (iii) the 10 solvent vials are fluidly connected to the 4.sup.th, 5.sup.th, 7.sup.th, 8.sup.th, 9.sup.th, 10.sup.th, 17.sup.th, 18.sup.th, 19.sup.th and 20.sup.th valves; and (iv) the water vial is fluidly connected to the 15.sup.th valve.

7. The cassette of claim 4, wherein the cassette further comprises: (i) a syringe fluidly connected to the 3.sup.rd valve; and (ii) a syringe fluidly connected to the 11th valve; and (iii) a syringe fluidly connected to the 24.sup.th valve.

8. A method for determining optimised SPE purification conditions for the isolation of a compound from a composition, the method comprising: (i) provision of the cassette of claim 1; (ii) the cassette comprising a composition of the compound in each of said at least one composition vials or addition of such a composition to each of said at least one composition vials; (iii) passing an aliquot of said composition into each of said 1-3 SPE cartridges; (iv) passing a particular combination of aliquots of solvent from at least 4 of said 4-10 solvent vials into one or more of the SPE cartridges, wherein the solvent in each of said 4-10 solvent vials is either a different solvent or the same solvent at different concentration; (v) eluting the compound to be purified from the or each SPE cartridge; (vi) evaluating the eluted products of step (v); and (vii) determining the optimised purification conditions by comparing the eluted products of step (v) from each cartridge and each solvent.

9. The method of claim 8, wherein the method further comprises a step of eluting impurities.

10. The method of claim 8, wherein the at least one solvent is selected from: (i) ethanol, (ii) methanol, (iii) acetonitrile, or combinations thereof.

11. The method of claim 8, wherein the method further comprises a step of conditioning the 1-3 SPE cartridges before step (ii).

12. The method of claim 8, wherein the evaluation in step (vi) is performed using HPLC, LC-MS or TLC.

13. The method of claim 8, wherein the eluting is carried out by passing organic solvent through the SPE cartridge and through the transfer line for collection.

14. The cassette of claim 1, wherein the at least one composition vials are: (i) at least one crude reaction mixture vials; (ii) at least one single reference standard vials; or (iii) at least one reference standard mixture vials.

15. A kit comprising: (i) the cassette as defined in claim 1, (ii) at least one composition vials; (iii) 1-3 SPE cartridges; (iv) 4-10 solvent vials; (v) a water vial; and (vi) a transfer line.

16. The cassette of claim 4, wherein a maximum of 3 composition vials are used.

17. The cassette of claim 5, wherein a maximum of 2 composition vials are used.

18. The cassette of claim 6, wherein a maximum of 1 composition vial is used.

19. The method of claim 9, wherein the step of eluting impurities is carried out before and/or after step (v).

20. The method of claim 13, wherein the collection is in a 96 well plate.

Description

FIGURES

[0079] FIGS. 1 to 6 are provided to exemplify the invention in a non-limiting fashion:

[0080] FIG. 1 provides an example of an embodiment of the cassette of the invention including 3 SPE cartridges and 6 solvent vials (labelled as mobile phases).

[0081] FIG. 2 provides an example of an embodiment of the cassette of the invention including 2 SPE cartridges and 8 solvent vials (labelled as mobile phases).

[0082] FIG. 3 provides an example of an embodiment of the cassette of the invention including 1 SPE cartridge and 10 solvent vials (labelled as mobile phases).

[0083] FIG. 4 provides an example of a cassette that is typically used with a FASTIab system for comparison with the invention.

[0084] FIG. 5 shows the results of an embodiment of the method of the invention applied to a hydroxy impurity in the Flurpiridaz crude product.

[0085] FIG. 6 shows the results of an embodiment of the method of the invention applied to a crude reaction mixture of Flurpiridaz. In FIG. 6, the x axis is the volume (1-41 ml) and the y axis is ug (0-25).

EXAMPLES

[0086] The following examples describe the invention in a non-limiting fashion:

[0087] The first experiments were done using crude samples comprising the compound GE-179 with mobile phase consisting of 20, 30 and 40% ethanol in 0.1% aqueous formic acid solution. The structure of GE-179 is as follows:

##STR00001##

[0088] The FASTIab cassette was set-up as shown in FIG. 1. All 3 cartridges were conditioned with 100% ethanol (2 mL) followed by 100% water (7 mL). Crude product (dissolved in 10% ethanol 90% water) was loaded onto 3×tC18 cartridges. The first cartridge was washed with 20% ethanol, the second with 30% ethanol and the third with 40% ethanol (18 mL through each, 1 mL fractions collected). 54 samples were collected in a 96 well plate and analysed using an analytical HPLC system with an autosampler. The data generated showed that with 40% EtOH, everything got eluted from the cartridge in the first 6 mL, whereas with 20%, the desired product and all later eluting peaks were trapped on the cartridge after 18 mL wash. These results reveal that the optimum conditions for washing the cartridge would be greater than 20% but lower than 40% EtOH. Further experiments using the same technique are required to determine the optimum selective elution of the product.

[0089] Experiments were also performed directed to the purification of Flurpiridaz, which has the following structure:

##STR00002##

[0090] The main impurity in the Flurpiridaz crude product is a hydroxy impurity, which has the following structure:

##STR00003##

[0091] The FASTIab cassette was set up as shown in FIG. 2. Both cartridges were conditioned with 100% ethanol (7 mL) followed by 100% water (7 mL). The hydroxy impurity (dissolved in 1:10 ethanol:water) was loaded onto 2×tC18 cartridges. The first cartridge was washed with 40% acetonitrile and the second with 35% ethanol (41 mL through each, 1 mL fractions collected). 82 samples were collected in a 96 well plate and analysed using an analytical HPLC system with an autosampler.

[0092] FIG. 5 shows that the hydroxy impurity elutes in a tighter band with 40% acetonitrile (dotted line) compared to 35% ethanol (solid line). These results confirmed that 40% acetonitrile is better than 35% ethanol and that a wash volume of 14-21 mL was sufficient to remove the major impurity from the crude product. It is noted that the line in FIG. 5 corresponding to the 35% ethanol elution includes a sharp dip, which is due to an erroneous data point.

[0093] The experiment was repeated with a crude reaction mixture of Flurpiridaz:

[0094] The FASTIab cassette was set-up as shown in FIG. 3. The cartridge was conditioned with 100% ethanol (7 mL) followed by 100% water (7 mL). Crude product (dissolved in ca.20% acetonitrile 80% aqueous solution) was loaded onto a tC18 cartridge. The cartridge was washed with 40% acetonitrile (41 mL, 1 mL fractions collected). 41 samples were collected in a 96 well plate and analysed using an analytical HPLC system with an autosampler. When combined with the information from the hydroxy standard experiment above, these results, shown in FIG. 6, confirmed that a wash volume of ca. 16 mL was sufficient to remove the hydroxy impurity without eluting the product. Other impurities present in very small amounts were a cyano impurity and a chloro impurity.

[0095] It will be readily understood by those persons skilled in the art that the embodiments of the inventions described herein are capable of broad utility and application. Accordingly, while the invention is described herein in detail in relation to the exemplary embodiments, it is to be understood that this disclosure is illustrative and exemplary of embodiments and is made to provide an enabling disclosure of the exemplary embodiments. The disclosure is not intended to be construed to limit the embodiments of the invention or otherwise to exclude any other such embodiments, adaptations, variations, modifications and equivalent arrangements. The scope of the invention is defined by the appended claims.