EXTRACTION

Abstract

A method of extracting at least one cannabinoid from a biomass comprises the following steps (i) contacting the biomass with a solvent formulation which comprises a C.sub.1-4 fluorinated hydrocarbon or a C.sub.1-4 hydrofluorocarbon ether, thereby to charge the solvent formulation with an extract from the biomass; and (ii) separating charged solvent formulation from the biomass.

Claims

1-41. (canceled)

42. A method of extracting at least one cannabinoid from a biomass, the method comprising the following steps: (i) contacting the biomass with a solvent formulation which comprises a C.sub.1-4 fluorinated hydrocarbon or a C.sub.1-4 hydrofluorocarbon ether, thereby to charge the solvent formulation with an extract from the biomass; and (ii) separating charged solvent formulation from the biomass.

43. The method according to claim 42, wherein, in the method, said biomass is arranged in a receptacle between an inlet and outlet of the receptacle and, in the method, solvent formulation passes into the receptacle via said inlet, through the biomass and out of the receptacle via said outlet, wherein the method involves selecting a biomass which includes components to be extracted and packing the biomass into free space in said receptacle so that said biomass extends over a length of at least 40 cm in said receptacle, wherein said receptacle is a column.

44. The method according to claim 43, wherein said biomass is packed into said receptacle at a density of at least 0.25 g/cm.sup.3, wherein said biomass is substantially immovable when in position and/or the biomass is substantially static during the flow of said solvent formulation therethrough.

45. The method according to claim 44, wherein said solvent formulation is passed through the biomass at a rate of at least 0.02 ml/minute per gram of said biomass; and said rate is less than 1 ml/minute per gram.

46. The method according to claim 43, wherein the flow rate of solvent formulation through the biomass is at least 0.5 BV/hour where “By” refers to the bed volume.

47. The method according to claim 42, wherein said biomass is arranged in a column which has an inside diameter of at least 5 cm and an inside diameter of less than 30 cm; wherein the length of the column between its inlet and outlet is at least 100 cm and is less than 500 cm, wherein the column has a length: inside diameter ratio of greater than 10:1 and less than 100:1.

48. The method according to claim 47, wherein said solvent formulation comprises a said C.sub.1-4 fluorinated hydrocarbon which is non-chlorinated.

49. The method according to claim 44, wherein said solvent formulation comprises 1,1,1,2-tetrafluoroethane.

50. The method according to claim 49, wherein in said biomass prior to any decarboxylation, the sum of the wt % of THCA and CBDA is at least 10 wt %; and said sum is less than 20 wt %; and/or wherein, in said biomass, at least one of THCA or CBDA is present at a level of at least 15 wt %; and wherein said cannabinoid extracted in the method includes one or more cannabinoids selected from THC, THCA, CBD and CBDA.

51. The method according to claim 42, wherein said biomass is derived from a cannabis plant and/or said biomass, prior to any decarboxylation, includes THCA and/or CBDA.

52. A method according to claim 42, wherein the method does not include one or more of the following: (a) subjecting an extract to a temperature less than 0° C. for a period of time of at least 1 hour; (b) treating the extract and precipitating high molecular weight components comprising waxes from the extract; (c) filtering the extract.

53. A method according to claim 42, wherein the total weight of waxes in the charged solvent and/or an extract derived therefrom is less than the total weight of waxes in the biomass after the biomass has been treated in the method and/or after step (ii).

54. A method according to claim 42, wherein the wax ratio, defined as the total weight of waxes in the biomass after treatment in the method and/or after step (ii) divided by the total weight of waxes in the charged solvent, for example after step (ii), is at least 40.

55. The method according to claim 42, wherein an extract produced after step (ii) after removal of said solvent formulation comprises less than 0.5 wt % total waxes.

56. The method according to claim 49, wherein an extract produced after step (ii) after removal of said solvent formulation includes less than 0.5 wt % or less than 0.05 wt % total waxes.

57. The method according to claim 47, wherein, in the extract and/or charged solvent formulation, the cannabinoid ratio, defined as the total weight of non-wax based cannabinoids divided by the total weight of waxes in the extract is at least 100.

58. The method according to claim 42, wherein an extract produced after step (ii) after removal of said solvent formulation is a mobile oil at 25° C.

59. The method according to claim 45, wherein said solvent formulation comprises 1,1,1,2-tetrafluoroethane and wherein the wax ratio, defined as the total weight of waxes in the biomass after treatment in the method and/or after step (ii) divided by the total weight of waxes in the charged solvent after step (ii), is at least 40.

60. An extract from a biomass, wherein said extract includes less than 0.05 wt % of waxes, a cannabinoid ratio, defined as the total weight of non-wax based cannabinoids divided by the total weight of waxes, of at least 100; wherein said extract is a mobile oil at 25° C. and includes at least 0.0001 wt % of HFC134a.

61. A method of extracting at least one cannabinoid from a biomass, the method comprising the following steps: (i) contacting the biomass with a solvent formulation which comprises 1,1,1,2-tetrafluoroethane thereby to charge the solvent formulation with an extract from the biomass; and (ii) separating charged solvent formulation from the biomass; wherein, in the method, said biomass is arranged in a receptacle between an inlet and outlet of the receptacle and, in the method, solvent formulation passes into the receptacle via said inlet, through the biomass and out of the receptacle via said outlet, wherein the method involves selecting a biomass which includes components to be extracted and packing the biomass into free space in said receptacle so that said biomass extends over a length of at least 40 cm in said receptacle, wherein said receptacle is a column; wherein said biomass is packed into said receptacle at a density of at least 0.25 g/cm.sup.3, wherein said biomass is substantially immovable when in position and/or the biomass is substantially static during the flow of said solvent formulation therethrough; wherein said solvent formulation is passed through the biomass at a rate of at least 0.02 ml/minute per gram of said biomass; and said rate is less than 1 ml/minute per gram; wherein said biomass is arranged in a column which has an inside diameter of at least 5 cm and an inside diameter of less than 30 cm; wherein the length of the column between its inlet and outlet is at least 100 cm and is less than 500 cm, wherein the column has a length: inside diameter ratio of greater than 10:1 and less than 100:1; wherein the wax ratio, defined as the total weight of waxes in the biomass after treatment in the method and/or after step (ii) divided by the total weight of waxes in the charged solvent after step (ii) is at least 40; wherein an extract produced after step (ii) after removal of said solvent formulation includes less than 0.5 wt % total waxes.

Description

[0101] Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

[0102] FIG. 1 is a schematic representation of apparatus for carrying out extraction of a cannabinoid-containing biomass;

[0103] FIG. 2 is an alternative apparatus for carrying out extraction of a cannabinoid-containing biomass;

[0104] FIGS. 3(a) and 3(b) are chromatograms for an extract (Fraction No. 2) pre- and post-decarboxylation; and

[0105] FIG. 4 is an alternative apparatus for use in a continuous extraction.

[0106] The following is referred to hereinafter:

[0107] R134—refers to 1,1,1,2-tetrafluoroethane.

[0108] Referring to FIG. 1, apparatus 2 for carrying out extraction of a biomass containing bio-cannabinoids comprises a jacketed stainless steel extraction column 2 having an internal diameter of 4.4 cm and a height of 1 m. Upstream of column 2 is a solvent storage vessel 4 with a liquid metering pump 6 being arranged between vessel 4 and column 2 for circulating liquid within the apparatus in which biomass to be extracted is tightly packed.

[0109] Downstream of column 2 is a collection/evaporation vessel 8 which communicates with the top of column 2 via pipe 10.

[0110] Downstream of vessel 8 is an oil free gas compressor 12 and a monitoring device (not shown) to monitor and analyse fluid flowing downstream of vessel 8. Downstream of the compressor and monitoring device 12 is an in-line heat-exchanger 14 which is arranged to re-liquefy fluid prior to return to vessel 4.

[0111] The apparatus described was used in examples which follow.

Example 1—Decarboxylation of Cannabinoid-Containing Biomass

[0112] 500 g of previously dried cannabis biomass was ground to a powder of average particle size of ≤1 mm and decarboxylated by placing in a sealed oven, and under a nitrogen blanket at 120° C. to 140° C. for 1-2 hours. In the process described, tetrahydrocannabinolic acid (THCA) which is a major component of the biomass is decarboxylated to produce tetrahydrocannabinol (THC) which is an active ingredient.

[0113] The biomass had a post-decarboxylation THC content of 5.9 wt %, measured by reverse-phase HPLC as described in Example 2, and a water content of 3 to 5 wt %.

Example 2—Reverse Phase HPLC

[0114] The biomass and extracts were analysed using HPC as follows:

Equipment Used

[0115] Waters 2695 separations module

Detector: Waters PDA 996

[0116] Column: Phenomenex Kinetex C18 5 μm 250 mm×4.6 mm

Mobile Phase Used

[0117] Mobile Phase A: Deionised water+0.1% formic acid
Mobile phase B: HPLC grade Methanol+0.1% formic acid
Gradient flow rate 1.0 ml/min:

0-10 min:20% A; 80% B

[0118] 10-25 min:20% A; 80% B linear increase to 5% A; 95% B
25-26 min: back to 20% A; 80% B

26-28 min:20% A; 80% B

[0119] Injection volume: 10 ul
PDA scans from 200-400 nm—detection of cannabinoids at 220 nm

Sample Preparation

Plant Biomass:

[0120] 200 mg is weighed in a centrifuge tube and 10.0 ml of methanol:ethyl acetate (9:1) is added.

Cannabis Extract:

[0121] 50 mg is weighed in a centrifuge tube, 10.0 ml of methanol:ethyl acetate (9:1) is added.

[0122] The tubes are vortexed for 15 seconds, then they are put in an ultrasonic bath for 15 minutes while vortexing every 5 minutes. The tubes are then centrifuged for 10 minutes at 5000 rpm. The supernatant is passed through a 0.45 um PTFE filter membrane and diluted to the right amount to fit in the calibration range.

Example 3—Treatment of Biomass

[0123] The decarboxylated biomass from Example 1 was packed tightly in the extraction column 2 and the column was sealed. It was then cooled to −10° C. by placing in a freezer overnight. The equipment was then reassembled, evacuated and storage vessel 4 was charged with HFC134a (approx. 4-6 Kg). Chilled ethylene glycol was circulated through the jackets of the extraction column and the storage vessel, until the temperature of the HFC 134a in the storage vessel reached −5° C. The chilled HFC134a was then percolated through the biomass in column 2 at a flow rate of 5 litres/hour, with the flow being directed out of the column 2 and into vessel 8. The HFC134a was continuously evaporated from the vessel 8 using a gas compressor 12 in FIG. 1 and recycled through a condenser 14 in FIG. 1 back into the vessel 4.

[0124] The elution was carried out for two hours. At the end of the process, product 16, present in vessel 8, was harvested by dissolving it in a minimum volume of ethanol to produce “Extract Part 1” which was removed from vessel 16.

[0125] Elution was then continued except the temperature of the HFC 134a was increased to to 30° C. After a period of 4 hours, product 16 present in vessel 8 was harvested by dissolution in a minimum volume of ethanol to produce “Extract Part 2” which was removed from vessel 16.

Example 4—Separation of Waxes and Isolation of Cannabinoids

[0126] The ethanolic solutions referred to as Extract Part 1 and Extract Part 2 were placed in a freezer at −20° C. to cause precipitation of non-target phytowaxes. The fluids were then filtered through a celite bed and subsequently the ethanol was removed by vacuum distillation to yield products high in desired cannabinoids, referred to as Isolated Extract A1 and Isolated Extract A2.

Example 5—Treatment of Biomass Using a Solvent Formulation B

[0127] A decarboxylated biomass prepared as described in Example 1 was treated as described in Example 3 except that, instead of HFC 134c described in Example 3 being used as the sole solvent, a Solvent Formulation B was used which comprised HFC 134a and 5% wt/wt dimethylether as a co-solvent. The use of the co-solvent modifies the solvating properties of the HFC 134a. The process of Example 4 was used to yield desired cannabinoids, referred to as Isolated Extract B1 and Isolated Extract B2.

Example 6—Treatment of Biomass Using a Solvent Formulation C

[0128] A decarboxylated biomass prepared as described in Example 1 was treated as described in Example 3 except that, instead of HFC 134c described in Example 2 being used as the sole solvent, a Solvent Formulation B was used which comprised HFC 134a and 5 wt % n-butane as a co-solvent. The use of the co-solvent modifies the solvating properties of the HFC 134a. The process of Example 4 was used to yield desired cannabinoids, referred to as Isolated Extract C1 and Isolated Extract C2.

Example 7—Analysis of Isolated Extracts and Results

[0129] Isolated Extracts A1 and A2 were weighed and analysed for THC content (in g) and purity (%) by HPLC analysis, as described in Example 2.

[0130] Based on the biomass having a nominal post decarboxylation THC content of 5.9 wt %, a water content of 3 to 5 wt % and noting that 500 g used in Example 1 contains 29.5 g of THCA, extract purities were calculated as follows:

Weight of THC (g) in extract+Weight extracts (g)×100

[0131] Yields (wt %) were calculated as:

Weight (g) THC (g) in extract+29.5 (g)×100

Isolated Extracts B1 and B2 from Example 5 and Isolated Extracts C1 and C2 from Example 6 were analysed as described for Extracts A1 and A2.

[0132] Results are presented in Table 1.

TABLE-US-00001 TABLE 1 Example Extract Weight No. Reference (g) Observations 4 Isolated 4.1 Almost colourless solid. Some Extract A1 free water but no emulsion- very pure appearance Isolated 26.3 Yellow/honey colour, Extract A2 gummy oil Free water and light emulsion 5 Isolated 6.7 Light honey colour Extract B1 resinate/viscous oil. Free water light emulsion Isolated 27.2 Dark honey colour gummy oil, Extract B2 some free water, significant emulsion 6 Isolated 7.1 Honey colour resinate/ Extract C1 viscous oil. Light emulsion Isolated 28.1 Dark amber colour, gummy oil Extract C2 Free water and heavy emulsion present

[0133] The purity of the extracts was analysed and results are provided in the table below.

TABLE-US-00002 TABLE 2 Blended Fraction Purity % THC Ext. Wt. g Wt. g THC w/w Yield % 1 Example 4 30.4 4.1 Part1-95.3 Calculated 26.3 Part2-84.0 87.3 2 Example 5 33.9 26.2 77.3 88.8 3 Example 6 35.2 27.7 78.7 93.9 Note: the blended Ext. Wt g for Example 4 is the sum of the two parts, 4.1 + 26.3 g.

Example 8—Treatment of Biomass Rich in Cannabidiolic Acid (CBDA)

[0134] 250 g of dried plant material with CBDA content of 3.9% and water content of 3-5% was decarboxylated as described in Example 1, milled to powder particle size of ≤1 mm and packed tightly into a stainless steel extraction column having dimensions of 3.5 cm internal diameter and 1 m length and then placed in a freezer overnight. The experiment was carried out generally using the apparatus described in FIG. 1 and as described in Examples 3 and 4. The extracts were collected in two fractions; part 1 after 1 hour at −6° C. and HFC134a flow rate of 3 Kg/Hr and part 2 collected after a further 6 hours at 25° C. In each case, the product was harvested from the evaporation vessel by dissolving in a minimum volume of ethanol. Both ethanolic fractions were treated as in Example 4.

[0135] Extracts were weighed and analysed to determine the CBD concentration using literature standard HPLC method. Results are presented in the table below, based on a theoretical amount of CBDA in the starting material of 9.75 g.

TABLE-US-00003 TABLE 3 Weight Weight Purity Yield Solvent Ext. g CBD g % % Appearance HFC Part1 2.63 2.60 98.9 26.67 White sticky 134a solid Part2 9.70 6.40 65.98 65.65 Amber oil Total 92.3

[0136] As an alternative to use of the apparatus of FIG. 1, the apparatus described in FIG. 2 may be used.

[0137] Referring to FIG. 2, apparatus for carrying out fractional extraction using a liquefied gas as extraction medium comprises an extraction column 102 in which material to be extracted is tightly packed. The column may be jacketed and include heating/cooling means for temperature control. Upstream of the column 102 is a hold vessel 104 for containing the liquefied gas, for example HFC 134a. The vessel 104 is connected downstream, by pipework 106, to the upper end of the column 102 for transferring the extraction medium into the column 102. A liquid metering pump 108 is provided in pipework 106 for controlling the flow of extraction solvent to the column. Immediately upstream of the column, the pipework includes an in-line heat exchanger 110 arranged to heat (or cool) liquid prior to its passage into the column. Between the pump 108 and heat-exchanger 110, there is a modifier solvent supply pipe 112 which is arranged to deliver a modifier solvent from a storage vessel 114 into the pipework 106 so that it mixes with liquefied gas from vessel 104. A liquid metering pump 116 in supply pipe 112 controls the flow of liquid within the pipe 112.

[0138] Downstream of the vessel 102 are shown three collection/evaporation vessels 120, 122, 124 although more such vessels would generally be provided for collecting more than three different aliquots. Each of the vessels 120, 122, 124 includes an inlet pipe 126 and an outlet pipe 128 each having associated control valves 130. The vessels 120, 122, 124 are arranged to communicate with column 102 via pipeline 132 which is connected to the bottom of the column. A monitoring device 134 is arranged to monitor and/or analyse fluid flowing in pipeline 132. Downstream of pipeline 132 is a pipeline 136 which communicates with vessel 104 and includes an associated gas compressor 138 for liquefying gas prior to its passage back into the vessel 104.

[0139] The apparatus further includes any necessary in-line filters, one-way valves, flow control valves, pressure regulators and pressure release valves and instrumentation for reading temperature, pressure and pH to allow appropriate process control and safe operation of the apparatus.

[0140] In use, a vacuum pump (not shown) is operated to remove air from the apparatus after the material to be extracted has been packed into the column 102. Liquefied gas is then charged to the vessel 104 and co-solvent, if this is used, is charged into vessel 114. With any heating/cooling means of the apparatus appropriately set, liquid is passed from vessel 104 to the column 102. The liquid slowly percolates through the material in the column and extracts compounds from the material as it does so. Initially, the most soluble compounds included in the biomass are extracted preferentially and these are entrained with liquid as it passes from the column into pipeline 132. The liquid (and entrained extract) is then directed into vessel 120 by opening the appropriate valve. After a period of time which may be determined in dependent upon an output from monitoring device 134, subsequent liquid passing out of the column is directed into vessel 122. Subsequently, it is directed into vessel 124 and later to other vessels (if provided). Thus separate aliquots are collected in vessels 120, 122, 124 and the constitution of the extracts therein should differ, with compounds or compositions which are most soluble in liquid passing through the column being more concentrated in the vessels which initially are used for collection and less soluble compounds or compositions being more concentrated in collection vessels used later in the process.

[0141] The constitution of extracts may also be affected by delivering a co-solvent from vessel 114 into pipeline 108 and mixing the co-solvent with liquid from vessel 104. The combined extraction solvent may then be adapted to extract preferentially certain compounds or compositions. The co-solvent may be delivered as described herein for manipulating the extraction of the biomass. Additionally and/or alternatively, the heat-exchanger 10 may be used to adjust the temperature of the extraction solvent thereby to control the nature of compounds or compositions preferentially extracted. Also, the temperature of the column itself (and thereby the biomass therein) may be adjusted as another means of affecting the nature of extracts.

[0142] After the extraction of the biomass has been completed (or prior to completion whilst extraction in the column 102 is ongoing), the control valve to outlet pipe 128 of vessel 120 may be opened and compressor 138 operated to remove liquefied solvent from the vessel 120 and return it to vessel 104, leaving the compound(s)/composition(s) in vessel 20. This process may be repeated to isolate the different extracts in the respective vessels 120, 122, 124.

[0143] The aforementioned examples involve treatment of a cannabinoid-containing biomass which has been decarboxylated (as is conventional in industry) as described in Example 1. However, in some cases, it is found that such decarboxylation can result in charring of the plant material, a darkening in its colour and production of acrid smoke. This may also result in loss of cannabinoid content and production of lower purity extract. Example 8 which follows describes treatment of biomass prior to any decarboxylation.

Examples 8 and 9—Comparison of Treatments of Non-Decarboxylated and Decarboxylated Cannabis Biomasses

[0144] In both examples, respective samples of the same botanical material having a CBDA content of 7.5 wt % were treated.

[0145] In Example 8, the botanical material was treated as described, without any decarboxylation. In Example 9, the botanical material was decarboxylated prior to treatment as described in Example 1. The biomasses of Examples 8 and 9 were treated generally as described in Example 3, with, in each case, respective fractions being collected at different temperatures of HFC 134a as described in Table 4 below.

TABLE-US-00004 TABLE 4 Temperature of HFC 134a at Fraction No. time of collection of fraction 1 −10°.sup.− C. 2 0° C. 3 25° C.

[0146] Fractions were analysed for cannabinoid content using HPLC as described in Example 2. Results are provided in Table 5.

TABLE-US-00005 TABLE 5 Example No. 8 Example No. 9 Weight (g) CBDA (wt %) Weight (g) CBD (wt %) Biomass 166.8 7.5 159.7 5.2 Spent biomass 143 0.8 146.5 0.5 Fraction No. 1 0.62 66.3 1.32 57.9 Fraction No. 2 12.9 59.9 8.55 53.3 Fraction No. 3 4.32 64.3 1.01 50.7 Wash 370 0.4 Total extracts 17.84 10.88 Total recovery 92.0 89.0

[0147] It was noted that the fractions for Example 8 were uniformly lighter in colour and less viscous compared to those for Example 9. In addition, better recovery was achieved for Example 8.

[0148] Note that no “wash” is quoted for Example 8 because the product of Example 8 is a mobile oil whereas Example 9 is a sticky gum and, accordingly, a wash is needed to harvest all extract.

Example 10—Decarboxylation of the Material from Example 8

[0149] Decarboxylation of Example 8, Fraction No. 2 was carried out by exposing the sample at a temperature of 180° C. for 10 minutes, as described in Example 1. HPLC analysis showed that 100% decarboxylation was achieved in total theoretical yield, determined as follows:

[0150] CBD content (by HPLC)=Original CBDA content

[0151] 314.5 (molecular weight) 358.5 (molecular weight)

[0152] Reference is made to FIGS. 3(a) and 3(b). The CBDA peak is lost on decarboxylation as decarboxylation yields CBD, the peak for which is increased as per FIG. 3(b). FIGS. 3(a) and (b) demonstrate that total decarboxylation is readily achieved when the process of Example 4 (referred to as “winterization”) is carried out.

[0153] Examples 3 to 6 above include a conventional “winterization” step, as described in Example 4, to precipitate non-target phytowaxes and/or heavy fatty acids. Example 11 describes an alternative process.

Example 11—Assessment of Winterization of CBD-Rich Extracts

[0154] CBD-rich primary extract produced in a method analogous to that described in Example 3 was dissolved in ethanol in a series of concentrations and the resulting solutions stored in a freezer at −20° C. for 24 hours as per Example 4. The solutions were then clarified by filtration and ethanol was removed by evaporation under a vacuum. The starting materials and products were analysed using reverse phase HPLC.

[0155] Table 6 shows the amount of primary extract used in each sample 1 to 8, the amount of ethanol used to dissolve the extract, the CBD content in each of the products and the loss in CBD content.

TABLE-US-00006 TABLE 6 Amount of Ethanol CBD content Loss in CBD Sample extract (g) ml mg/g Content % Primary extract 659 1 2.5 3.5 635 4 2 2.5 5.25 615 7 3 2.5 7.0 598 9 4 2.5 10.5 622 6 5 2.5 34.0 603 8 6 2.5 28.0 587 11 7 1.15 28.0 440 19 8 1.7 26.0 455 16

[0156] The following observations were made: [0157] Material precipitated on freezing was observed to be light and fluffy in appearance. [0158] Only minimal precipitation was noted when small volumes of ethanol were used (Samples 1, 2 and 3) [0159] Heavier precipitation clearly noted when higher volumes of ethanol were used (Samples 6, 7, and 8). [0160] No change in viscosity or colour was observed in any of the treated samples when compared to the untreated primary extract. [0161] All trials resulted in appreciable loss of CBD.

[0162] It is clear from the above observations that no waxes or heavy fatty acids were precipitated as expected and that the products that were precipitated during freezing were CBD. Therefore, in preferred embodiments, winterization (e.g. as described in Example 4) may not be necessary and may be disadvantageous. Thus, the process described herein can be used to make high purity products in high yield without the need to isolate an intermediate which needs further treating in a winterization step.

Example 12—Further Analysis of Extracts

[0163] A number of previously prepared extracts were submitted for external contract analysis by a validated third party in order to identify some of the spectrum of compounds present in the extracts and also to validate results reported in the foregoing examples. Table 7 provides results of an analysis of an extract prepared as described herein of decarboxylated Bedrocan hybrid biomass rich in cannabidiol.

TABLE-US-00007 TABLE 7 Amount determined in Compound assessed analysis by third party in analysis (wt %) CBD 85.139 d8-THC 1.273 d9-THC 3.544 CBG 0.200 CBN 0.913 CBC 3.394 CBDV 1.897 THCV 0.185 Total cannabinoids 96.5 Total cannabinoid 11.4 content other than CBD

[0164] It was found, in general, that the analysis by the third party identified higher levels of desirable extracted compounds (eg >10 wt % higher) than identified by Applicant. Thus, Applicant believes the process described may be even more advantageous than implied by the results in prior examples herein.

[0165] In addition, the third party analysis identified a range of other compounds (identified in Table 7).

[0166] In a further analysis, another extract of decarboxylated Bedrocan hybrid biomass rich in cannabidiol was analysed for terpenes and it was determined that desirable terpene compounds were extracted, as detailed in Table 8. Such compounds may act synergistically with cannabinoids to produce an advantageous mixture which may be highly useful as a BDS.

TABLE-US-00008 TABLE 8 Amounts of terpenes present in analysis by third party Terpene Content % Alpha-Pinene 0.36 Beta-Pinene 0.21 Delta-3-Carene 0.12 Eucalyptol 0.46 Beta-caryophyllene 1.04 Myrcene 2.17 limonene 0.06 linalool 0.04 terpineol 0.04 humulene 0.32 Total terpenes present = 4.8 wt %.

[0167] As an alternative to the apparatus described above, a continuous extraction process may be undertaken, as described below with reference to FIG. 4.

[0168] The apparatus includes a series of between two to five extraction columns, shown in diagrams 101, 102 and 103, all being of the same size and each being fitted with a jacket that allows heating/cooling of each column independently. Each column has a working volume of between 0.5 L-100 L, preferably between 2-50 L and dimension of between 5 cm-50 cm diameter and between 80 cm-150 cm length. Each column incorporates an inlet and an outlet valve and is fitted with a sampling port at its outlet. Optionally, a second flow inlet valve may be incorporated to each column inlet to allow the introduction of a co-solvent (not shown).

[0169] There are optionally between 2-5 evaporation/extract collection vessels, shown in the diagram as 111, 112, and 113. The vessels are jacketed to allow heating/cooling independently of each other and are fitted with flow restriction nozzles at their inlets to control pressure drops. The size of each vessel is determined by the scale of operation and may nominally be between 2 L-50 L in volume.

[0170] A solvent recycling vessel shown in the diagram as 116 is fitted with a heating or cooling jacket and has a size determined by the scale of operation. It may optionally have a volume of between 5 L-200 L.

[0171] The equipment also incorporates two, or optionally up to four, oil free compressors, each with a gas flow capacity of between 50 Kg/Hr-1000 Kg/Hr dependant on the scale of operation. It also includes two or optionally up to four liquid feed pumps each with a capacity of between 50 Kg/Hr-1000 Kg/Hr. The primary elements of the equipment are in communication with each other via a programmable system of heat exchangers, flow control valves, flow measuring devices, thermometers, pressure gauges and pressure release valves to allow flexible and safe control of flows, operating pressures and temperatures that are appropriate in each element of the equipment at each stage of the process. All the elements of the apparatus are in communication with each other via a series of programmable valves (V−1 to V18) to allow a continuous extraction operation.

[0172] The following describes a production scale continuous extraction process comprising your columns (the fourth column has been omitted from FIG. 4) and three extract fractions collected in three collection vessels. For the purpose of clarity, flows through each column are shown to be from top to bottom (down-flow). It is however preferable in practice to carry out the extraction in an up-flow mode. Also, not all process valves and process controls and instrumentation are shown.

[0173] Each column is packed with previously dried and powdered cannabis biomass. The cannabis beds are packed down tightly using mechanical means and the columns reassembled. The apparatus is then sealed and air is removed from the entire apparatus with the aid of a vacuum pump. Vessel 116 is then isolated and charged with the extraction medium, a hydrofluorocarbon such as HFC134a. Cooling and heating fluids are pumped through the various jackets to attain the required temperature in each element of the equipment. Once required temperatures are attained the extraction is commenced as follows:

[0174] Step 1:

[0175] With valves V13, V18, V14, open and all other valves closed liquefied, extraction medium is charged from the recycling vessel 116 to column 101 using the liquid flow pump. When column 101 is full, valves V1, V2 (inlet to vessel 101) and valve V8 are opened and flow is maintained using the appropriate flow, temperature and pressure control measures to maintain a pre-determined steady state. Extract flow samples are collected and analysed at regular intervals. With the aid of the compressor, the extraction medium is continuously evaporated, re-liquefied and charged back into recycling vessel 116.

[0176] At an appropriate stage, for example when a first component has been eluted from column 101, the temperature/pressure conditions (or optionally the extraction fluid composition) is altered to enable the elution of a second component. Simultaneously, flow through valve V−2 is diverted into vessel 112, valves V−4 and V−7 are opened and second compressor is started.

[0177] Step 2: Whilst extract from column 101 is collecting in vessel 112, extraction of column 102 is commenced using a second liquid flow pump directing the eluate into vessel 111 (following the procedure described in step 1). Now fraction 2 eluating from column 101 is collecting in vessel 112 and column 102 is collecting fraction 1 in vessel 111. At an appropriate time, temperature/pressure conditions (or optionally extraction fluid compositions) are altered.

[0178] Step 3: Valves sequence is changed so that flow from column 101 is redirected to collect extract fraction 3 in vessel 113 and the flow from column 102 is redirected to collect fraction 2 in vessel 112 and column 103 extraction is commenced directing the flow from 102 into vessel 111. At an appropriate time, flow into column 101 is terminated and temperature/pressure conditions (or optionally extraction fluid compositions) for 102 and 103 are altered. Flow out of column 101 continues until its now spent biomass content is completely degassed.

[0179] Step 4: Flow from column 102 is directed to vessel 113 and from column 103 into vessel 2. Extraction of a fourth column (not shown) is commenced and, as previously, fraction one is collected in vessel 111. Simultaneously, column 101 is cleaned, repacked and made ready for extraction in step 5, and so on.

[0180] The process steps described are shown in a simplified form below

TABLE-US-00009 Step 1 Step 2 Step 3 Step 4 Step 5 Vessel 111 Col 101 Col 102 Col 103 Column 4 Col 101 Vessel 112 X Col 100 Col 102 Col 103 Column 4 Vessel 113 X X Col 101 Col 102 Col 103 Column X X X Col 101 Col 102 Repacking

[0181] The process sequence is controlled by a programmable system of valves and flow, temperature and pressure control measures. The process may require minimal operator involvement.

[0182] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.