Processes and apparatus for extraction of active substances and enriched extracts from natural products

• US 20040147767A1
• Filed: 11/04/2003
• Published: 07/29/2004
• Est. Priority Date: 05/04/2001
• Status: Active Grant

• Current Assignee: GW Pharmaceuticals Limited (Jazz Pharmaceuticals Plc)
• Original Assignee: GW Pharmaceuticals Limited (Jazz Pharmaceuticals Plc)
• Inventors: Guy, Geoffrey, Whittle, Brian, Downs, David
• Granted Patent: US 7,622,140 B2
• Time in Patent Office: Days
• US Class Current: 549/390
• CPC Class Codes: A61K 31/05 Phenols cannabinoids A61K31/658
• CPC Class Codes: A61K 31/352 condensed with carbocyclic rings, e.g. methantheline cannabinoids A61K31/658
• CPC Class Codes: A61K 36/185 Magnoliopsida (dicotyledons)
• CPC Class Codes: B01D 11/0242 in towers, e.g. comprising contacting elements
• CPC Class Codes: B01D 11/0273 in rotating drums
• CPC Class Codes: B01D 11/028 Flow sheets
• CPC Class Codes: B01D 11/0288 Applications, solvents
• CPC Class Codes: B01D 2011/007 Extraction using a solvent in the gas phase

Abstract

Processes for preparing extracts of natural products such as plant material, and for preparing purified extracts from crude extracts of natural products, by extraction with hot gas. Apparatus suitable for use in preparing extracts of natural products are also described.

Claims

1. A process for preparing a cannabinoid-rich extract from cannabis plant material or a primary extract thereof loaded onto an inert matrix material, comprising contacting the cannabis plant material or primary solvent extract with a heated gas at a temperature which is greater than 100°

C. and sufficient to volatilise one or more cannabinoids but does not cause pyrolysis of the cannabis plant material or primary solvent extract thereby volatising one or more cannabinoids to form a vapour, and condensing the vapour to form an extract rich in cannabinoids.

2. A process according to claim 1 wherein the extract rich in cannabinoids is substantially free of ballast.

3. A process according to claim 2 wherein the extract rich in cannabinoids is substantially free of fats, waxes, carbohydrates, proteins and sugars.

4. A process according to any of the preceding claims wherein the extract rich in cannabinoids is substantially free of terpenes.

5. A process according to any of the preceding claims wherein the extract rich in cannabinoids is substantially free from waxes, sterols and other lipid soluble components which characterise solvent extracts.

6. A process according to any of the preceding claims wherein the cannabinoid-rich extract is rich in THC.

7. A process according to any of claims 1 to 5 wherein the cannabinoid-rich extract is rich in CBD.

8. A process according to any of the preceding claims wherein the heated gas is forced upwardly through the cannabis plant material, which is retained in a perforated container, or the primary solvent extract.

9. A process according to any of the preceding claims wherein the heated gas is blown onto the cannabis plant material or primary solvent extract.

10. A process according to any of the preceding claims wherein the cannabis plant material or primary solvent extract is subjected to continuous agitation.

11. A process according to claim 10 wherein the continuous agitation is effected by subjecting the cannabis plant material or primary solvent extract to a rotary action.

12. A process according to any of claims 1 to 9 wherein the cannabis plant material or primary solvent extract is presented to the heated gas in a counter-current manner.

13. A process according to any of the preceding claims wherein the cannabis plant material is freshly harvested plant material and the process further includes a pre-treatment step in which the cannabis plant material is contacted with a heated gas at a temperature which is sufficient to dry the cannabis plant material.

14. A process according to any one of claims 1 to 13 wherein the heated gas is a reducing gas or a non-oxidising gas.

15. A process according to claim 14 wherein the reducing gas is nitrogen, carbon dioxide, helium or argon.

16. A process according to claim 14 wherein the non-oxidising gas is dry steam.

17. A process according to claim 14 wherein the reducing gas is steam to which has been added sodium metabisulphite in a quantity sufficient to produce 10-500 parts of sulphur dioxide per million parts of the cannabis plant material or primary solvent extract.

18. A process according to any one of the preceding claims wherein the vapour is treated to remove any particulate matter prior to the condensation step.

19. A process according to any of the preceding claims wherein the temperature of the heated gas used to volatilise the cannabinoids is selected to effect decarboxylation of cannabinoid acids present to free cannabinoids and to volatilise the free cannabinoids.

20. A process according to claim 19 wherein the temperature of the heated gas used to volatilise the cannabinoids is in the range of from 105°

C. to 450°

C.

21. A process according to claim 20 wherein the temperature of the heated gas used to volatilise the cannabinoids is in the range of from 105°

C. to 225°

C.

22. A process according to claim 21 wherein the cannabis plant material or primary solvent extract is a high CBD cannabis plant or a primary solvent extract thereof and the temperature of the heated gas used to volatilise the cannabinoids is in the range of from 120°

C. to 140°

C.

23. A process according to claim 21 wherein the cannabis plant material or primary solvent extract is a high THC cannabis plant or a primary solvent extract thereof and the temperature of the heated gas used to volatilise the cannabinoids is in the range of from 105°

C. to 120°

C.

24. A process according to any one of claims 1 to 19 wherein the temperature of the heated gas used to volatilise one or more constituents of the natural product is varied in two or more discrete steps.

25. A process according to claim 24 which comprises contacting the cannabis plant material or primary solvent extract with a heated gas at a first temperature and then with a heated gas at a second temperature which is greater than the first temperature, greater than 100°

C. and sufficient to volatilise one or more cannabinoids but does not cause pyrolysis of the cannabis plant material or primary solvent extract, and condensing any vapour formed at the first and/or the second temperature.

26. A process according to claim 25 wherein vapours formed at the first and the second temperatures are condensed and collected in separate fractions.

27. A process according to claim 25 or 26 wherein the cannabis plant material or primary solvent extract is a high CBD cannabis plant or primary solvent extract thereof, the first temperature is in the range of from 125°

C. to 150°

C., and the second temperature is in the range of from 175°

C. to 200°

C.

28. A process according to claim 25 or claim 26 wherein the cannabis plant material or primary solvent extract is a high THC cannabis plant or primary extract thereof, the first temperature is in the range of from 60°

C. to 90°

C., and the second temperature is in the range of from 130°

C. to 175°

C.

29. A cannabinoid-rich extract which is substantially free of volatile terpenes, has a high content of cannabidiol (CBD) and wherein the majority of the cannabinoids are present in the decarboxylated neutral form, said extract having a profile by gas chromatographic analysis substantially as illustrated in FIG. 6 fraction B, FIG. 7 fraction B, FIG. 8 fraction A or FIG. 8 fraction B.

30. A cannabinoid-rich extract according to claim 29 which has a profile by gas chromatographic analysis substantially as illustrated in FIG. 8, fraction A.

31. A cannabinoid-rich extract which is substantially free of volatile terpenes, has a high content of tetrahydrocannabinol (THC) and wherein the majority of the cannabinoids are present in the decarboxylated neutral form, said extract having a profile by gas chromatographic analysis substantially as illustrated in FIG. 10, fraction B.

32. A cannabinoid-rich extract which is substantially free of volatile terpenes and which comprises about 98% tetrahydrocannabinol (THC), 2.5% cannabidiol (CBD), 0.5% cannabinol (CBN) and only trace amounts of tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) and ballast.

33. A cannabinoid-rich extract which is substantially free of volatile terpenes and which comprises about 98% cannabidiol (CBD), 1.5% tetrahydrocannabinol (THC), 0.5% cannabinol (CBN) and only trace amounts of tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) and ballast.

34. A cannabinoid-rich extract which is substantially free of volatile terpenes and has a ratio of tetrahydrocannabinol (THC):

cannabinol (CBN) in the range of from 12.6;

1 to 5.5;

1 and a Δ

⁸ tetrahydrocannabinol content of less than 0.7%.