FOOD-GRADE SOLVENT

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present patent application claims the priority benefit of U.S. provisional patent application number 62/663,540 filed April 27, 2018, the disclosure of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field Of The Disclosure

[0002] The present disclosure is generally related to a method for extracting pharmacologically active compounds. More particularly, the present disclosure relates to extraction of Delta-9- Tetrahydrocannabinol (THC) and related compounds from cannabis biomass.

2. Description of the Related Art

[0003] Cannabis is a genus belonging to the family of cannabaceae. Three common species include Cannabis sativa, Cannabis indica, and Cannabis ruderalis. The genus has been indigenous to Central Asia and the Indian subcontinent. Cannabis has a long history being used for medicinal, therapeutic, and recreational purposes. The importance of cannabis in therapeutics is emphasized by the ever-increasing number of research publication related to the new indications for cannabis. For example, pharmaceutical research companies are presently developing new natural cannabinoid formulations and delivery systems to meet various regulatory requirements. Cannabis is known, for example, to be capable of relieving nausea (such as that accompanying

chemotherapy), pain, vomiting, spasticity in multiple sclerosis, and increase hunger in anorexia.

[0004] The term cannabis or "cannabis biomass" encompasses the Cannabis sativa plant and also variants thereof, including subspecies sativa, indica and ruderalis, cannabis cultivars, and cannabis chemovars (varieties characterised by chemical composition), which naturally contain different amounts of the individual cannabinoids, and also plants which are the result of genetic crosses. The term "cannabis biomass" is to be interpreted accordingly as encompassing plant material derived from one or more cannabis plants.

[0005] Cannabis biomass contains a unique class of terpeno-phenolic compounds known as cannabinoids or phytocannabinoids, which have been extensively studied since the discovery of the chemical structure of tetrahydrocannabinol (Delta-9-THC), commonly known as THC. Over 113 phytocannabinoids have been identified. Such cannabinoids are generally produced by glandular trichomes that occur on most aerial surfaces of the plant. The cannabinoids are biosynthesized in the plant in addic forms known as acidic cannabinoids. The acidic cannabinoids may be slowly decarboxylated during drying of harvested plant material. Decarboxylation may be hastened by heating the cannabis biomass, such as when the cannabis biomass is smoked or vaporized.

[0006] The principle cannabinoids present in cannabis are the Delta-9-tetrahydrocannabinolic acid (Delta-9-THCA) and cannabidiolic acid (CBDA). The Delta-9-THCA does not have its own psychoactive properties as is, but may be decarboxylated to Delta-9-tetrahydrocannabinol (Delta-9- THC), which is the most potent psychoactive cannabinoid among known cannabinoids. The neutral form of CBDA is cannabidiol (CBD), which is a major cannabinoid substituent in hemp cannabis. CBD is non-psychoactive and is widely known to have therapeutic potential for a variety of medical conditions. The proportion of cannabinoids in the plant may vary from species to spedes, as well as vary within the same species at different times and seasons. Furthermore, the proportion of cannabinoids in a plant may further depend upon soil, climate, and harvesting methods. Thus, based on the proportion of the cannabinoids present in a plant variety, the psychoactive and medicinal effects obtained from different plant varieties may vary.

[0007] Depending upon the psychoactive and medicinal effects obtained from different varieties of the cannabis plant or the different methods of cultivation for cannabis, a specific variety of cannabis may be considered more effective or potent than others ( e.g ., in providing the desired physiological effect at a desired level in an individual). Similarly, some specific combinations of pharmacologically active compounds in a cannabis variety may be more desirable in comparison to other varieties. When preparing cannabis plant extracts, the retention of the full mix of cannabinoids present in the original plant may be desirable for some varieties, while other varieties may be preferred in altered form due to the variances in the specific cannabinoid composition and concentrations. Such variance is further exacerbated by the presence of certain terpenoid or phenolic compounds, which may have pharmacological activity of their own and which may be desired at different concentrations in different combinations.

[0008] Historical delivery methods have involved smoking ( e.g. _r combusting) the dried cannabis plant material. Smoking results, however, in adverse effects on the respiratory system via the production of potentially toxic substances. In addition, smoking is an inefficient mechanism that delivers a variable mixture of active and inactive substances, many of which may be undesirable. Alternative delivery methods such as ingesting typically require extracts of the cannabis biomass (also known as cannabis concentrates or cannabis oils). Often, cannabis extracts are formulated using any convenient pharmacologically acceptable diluents, carriers or exdpients to produce a composition. Raw cannabis biomass may also be more susceptible to possible biological contaminants such as fungi and bacteria than extracts.

[0009] Previously, compounds may be extracted from cannabis by using conventional methods of extraction, such as maceration, decoction, or solvent extraction. Such conventional methods may suffer from various limitations and disadvantages ( e.g ., extraction times may be very high so as to be impractical to scale). For example, subjecting the biomass to a prolonged extraction process may risk modification of the plant profile, negative effects on terpenes, or otherwise cause other undesirable effects that lower the quality or purity of the end product. Traditional methods of extraction may therefore hamper quality and purity of the final product. Further, final concentrated or purified active compounds are often diluted or dispersed into an oil, fat or other lipid-based excipient or carrier to a desired concentration for certain uses (e.g., in a pharmaceutical, food, or cosmetic formulation).

[0010] Other methods such as supercritical fluid extraction (SFE) make use of supercritical fluids to selectively remove compounds from solid, semisolid, and liquid matrices in a batch process. SFE is, however, dangerous and requires very high pressures to be employed (> 70 atm).

In addition, SFE is also inefficient and therefore not conducive to high throughputs, as well as environmentally damaging ( e.g ., producing large amounts of the greenhouse gas carbon dioxide as a by-product).

[0011] Meanwhile, traditional solvent extraction methods used for extraction of cannabinoids tend to be complex, multi-step processes that involve the use of large amounts of organic solvents and multiple steps of selective solvent removal, separation, and refinement. Such processes therefore may require expensive equipment to evaporate and recover as much of the solvent as possible and to remove most of the residual solvent from the final product and extracted spent solid residue. The flammable nature of the organic solvents employed also necessitates expensive control systems and procedures to limit combustion risk and environmental impact and to ensure worker safety. Further, the need to remove solvents from treated biomass gives rise to significant power requirements that in turn represent additional resources, as well as contributing

significantly to environmental pollution derived from the production of said energy.

[0012] Meanwhile, traditional methods of extracting inactive cannabinoids from a raw cannabis biomass typically involve subjecting the raw cannabis biomass to a heating process in order to decarboxylate the cannabinoids prior to extraction. The cannabinoids are generally extracted using traditional solvent, such as alkane hydrocarbons (e.g., hexane or butane), or alcohols (e.g., ethanol). Such traditional solvents may be expensive and undesirable to end-users. Notwithstanding that the solvent may be completely removed from the end product, end-users may be wary of the risk presented by the use of solvent for health and environmental reasons.

[0013] When used as a solvent, ethanol has many of the benefits of SCF extraction without requiring high pressures in the extractor. Further, ethanol extraction has shown efficiency comparable to hydrocarbon extraction (e.g., butane), which has an increased level of safety concerns (e.g., solvent combustion) and health-related concerns as customers may perceive a hydrocarbon-extracted product as less healthful. The ethanol extraction technique may be used for selective extraction of pharmacologically relevant chemicals from various natural, as well as synthetic, matrices under environmentally safe operation. The selective extraction may be performed, for example, using a composite device having several components, such as a high- pressure pump, an extraction vessel, a back-pressure regulator, analyte collection vessel, and a source of solvent (e.g., C2H5OH). The ethanol extraction technique may be used for commercial applications that may involve biologically produced materials. Such ethanol extraction may be relevant to extraction of biological compounds in cases where a low temperature processing, high mass transfer rates, and negligible carry over of solvent into a final product may be desired.

[0014] Thus, there is a need for improved methods and systems of direct extraction of bioactive components from a given biomass, as well as a need to provide concentration of such bioactive components to the final desired concentration in a dispersion or solution medium while reducing or eliminating intermediate steps and use of organic solvents including those derived from petroleum or petrochemical products.

SUMMARY OF THE CLAIMED INVENTION

[0015] Embodiments of the present invention provide extraction methods that remove the need for an intermediate solvent. Instead, a carrier fluid suitable for inclusion in a final formulation may be used as the solvent for cannabis extraction. Thus, a novel approach is provided for cannabis extraction using alternate method to differentiate the product in the market by way of decreased risk ( e.g. _r from use of non-food-grade solvents).

[0016] Exemplary methods for extracting pharmacologically active compounds from a biomass may therefore include preparing cannabis biomass, adding a carrier fluid to the prepared cannabis biomass to form a slurry where the carrier fluid is a solvent that is suitable for inclusion in a final formulation, and extracting target compounds from the slurry using a continuous flow extraction apparatus, and separating a spent biomass from the carrier fluid by a downstream process. Such extracted target compounds may include Delta-9-THC, Delta-9-THCA, CBDA, CBD, other cannabinoids, and terpenes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a block diagram representation of an exemplary system for extracting pharmacologically active compounds from biomass.

[0018] FIG. 2 is a flow chart illustrating an exemplary method for extracting pharmacologically active compounds from biomass.

[0019] FIG. 3A and FIG. 3B are tables that provide a comparison of different solvents that may be used in biomass extraction of pharmacologically active compounds under different conditions to provide different results.

[0020] FIG. 4 is a flow chart illustrating an alternative exemplary method for extracting pharmacologically active compounds from biomass.

DETAILED DESCRIPTION

[0021] Embodiments of the present disclosure include systems and methods for extracting pharmacologically active compounds from a biomass may therefore include preparing cannabis biomass, adding a carrier fluid to the prepared cannabis biomass to form a slurry where the carrier fluid is a solvent that is suitable for inclusion in a final formulation, extracting target compounds from the slurry using a continuous flow extraction apparatus, and separating a spent biomass from the carrier fluid by a downstream process. Such extracted target compounds may include Delta-9- THC, Delta-9-THCA, CBDA, CBD, other cannabinoids, and terpenes.

[0022] Method of extracting pharmacologically active compounds from cannabis biomass will now be explained with reference to various units shown in the block diagram of FIG. 1 and the flow chart 200 of FIG. 2. FIG. 1 is a block diagram representation of an exemplary system 100 for extracting pharmacologically active compounds from biomass, and FIG. 2 is a flow chart illustrating an exemplary method 200 for extracting pharmacologically active compounds from biomass.

[0023] System 100 of FIG. 1 includes a raw biomass holding chamber 102, into which a raw biomass may be provided in step 202 of FIG. 2. Such raw biomass may be present in form of dried, ground, non-decarboxylated flowers (buds) of cannabis plants. Any part of the cannabis biomass that contains cannabinoids can be used or included in the raw biomass that is provided to raw biomass holding chamber 102. In some embodiment, average particle size of the raw biomass may lie between 0.5 - 10 mm. The raw biomass may contain target compounds that need to be extracted. In one embodiment, the raw biomass may be heated to approximately 125° C for approximately 45 minutes to decarboxylate the cannabinoid carboxylic acids into neutral cannabinoid forms. The mass of decarboxylated cannabis following such treatment may get reduced ( e.g ., 11.7% weight loss). In an embodiment, the raw biomass may be dried, non-decarboxylated cannabis biomass. In another embodiment, the raw biomass may be fresh, non-dried, non-decarboxylated cannabis biomass.

[0024] Successively in step 204, the raw biomass may be sampled and analyzed in sampling chamber 120. In a preferred embodiment, the raw biomass may be analyzed to determine cannabinoid content, and a cannabinoid profile (of the specific cannabinoids and concentrations thereof) of the sampled raw biomass may be generated. Such analysis may be performed using an Ultra High Performance Liquid Chromatography coupled with Mass Spectroscopy (UPLC-MS) detection technique. Further, a terpene profile of the raw biomass may be determined using a Gas Chromatography-Mass Spectroscopy Detection (GC-MS). The sampling techniques may help in determining the cannabinoid content and the cannabinoid profile of the raw biomass ( i.e ., THCA, THC, CBDA, CBD, and total cannabinoids present in the raw biomass).

[0025] Further in step 206, the raw biomass may be ground into small particles to obtain a prepared biomass in biomass preparation chamber 104. The prepared biomass may then be provided from biomass preparation chamber 104 to a prepared biomass holding chamber 106.

[0026] The prepared biomass may be used to form a slurry in step 208. The slurry may be formed in a slurry formation chamber 108 where one or more solvents may be added to the prepared biomass from a solvent holding chamber 110. The solvent added to the prepared biomass may be selected with different dielectric and solvent parameter properties. The solvent may be, for example, a Medium Chain Triglyceride (MCT) ( e.g ., coconut oil) or other edible and food-grade solvent or emulsifier used to standardize active compounds in pharmaceutical, nutraceutical, functional, food, or cosmetic formulations. Such solvent may therefore further be pharmaceutical- grade and.or cosmetics-grade. Further, the solvent may be a polyunsaturated fatty acid (PUFA), com oil, safflower oil, borage oil, flax oil, canola oil, cottonseed oil, soybean oil, olive oil, sunflower oil, coconut oil, palm oil, monoglycerides, diglycerides, triglycerides, medium chain or long chain triglycerides, ledthin, limonene, essential oils of spices, herbs or other plants, fish oil, glycerol, glycols, or any other, or mixtures thereof. In a preferred embodiment, MCT may be used as the solvent. It may be understood that certain solvents may be preferable from a marketing standpoint and/or cost standpoint. The solvent-to-raw biomass ratio may be maintained at approximately 5-10 l/kg to ease the pumping operation of the slurry. In an embodiment, the solvent-to-raw biomass ratio may be maintained as low as possible so as to maximize the concentration of the

pharmacologically active compounds in the extract product.

[0027] Thereafter, the slurry may be transferred from the slurry formation chamber 108 to an extraction chamber 112 where such slurry is subject to heat at step 210. The slurry may be transported using a set of mechanical conveyors ( e.g ., slurry pump, screw conveyor or worm gear). In the extraction chamber 112, the slurry may be subjected to a thermal process, such as provided by a microwave generator 114. It may be understood that the selected solvent(s) may require a specific temperature to facilitate efficient transportation through the set of mechanical conveyors.

In a preferred embodiment, the solvent (e.g., MCT) is heated with thermal energy (e.g., from microwave generator 114) to a temperature that meets or exceeds the solvent ⁷ s melting point. In one case, the slurry may be transported into an extraction chamber 112 through a tube. Extraction chamber 112 may include a portion that is microwave transparent, which may allow microwaves (e.g., generated using a magnetron of microwave generator 112) to pass through and heat the slurry inside the extraction chamber 112. The slurry may be heated within the extraction chamber 112 to a certain temperature by exposing the slurry to the microwave to a predefined time with a predefined microwave energy density range. In a preferred embodiment, the slurry may be heated to a temperature range of 25 - 75° C with a contact time of 1 - 30 minutes, and microwave energy density range of 0.1 - 10 kW/kg. Such heating may facilitate the extraction of various

(pharmacologically active) compounds from the prepared biomass into the solvent.

[0028] Post heating the slurry and extraction of compounds from the biomass, the now-spent biomass and solvent(s) may be transferred to separation chamber 116, where the slurry is subject to filtration and separation at step 212. Such filtration and separation within filtration unit 116 may result in isolating the slurry components from each other: the spent biomass and the solvent(s) containing the extracted compounds. Once isolated, the spent biomass and the solvent(s) containing the extracted compounds may be transferred into spent biomass storage unit 118 and solvent recovery chamber 122, respectively. The separation process may be performed using one or more of several methods, such as filtration, centrifugation, and other similar processes. In a preferred embodiment, the separation process may include use of a filter press.

[0029] In an embodiment, the spent biomass may be sampled at step 214. Sampling of the spent biomass may be performed in a sampling chamber 120. The spent biomass may be sampled and analyzed to determine remaining cannabinoid content and cannabinoid profile. The spent biomass may be sampled and analyzed using several methods. The analysis may be performed using an Ultra High Performance Liquid Chromatography coupled with Mass Spectroscopy detection (UPLC-MS). Further, terpene profile of the raw biomass may be determined using a Gas Chromatography-Mass Spectroscopy Detection (GC-MS). The sampling and analytical techniques may help in determining cannabinoid content and profile of the raw biomass (e.g., THCA, THC, CBDA, CBD, and total cannabinoids).

[0030] Post sampling and analysis of the spent biomass, waste spent biomass may be incinerated or mixed with a deactivating agent by a disposal system 128. In one case, clay may be used as the deactivating agent.

[0031] In a traditional solvent (e.g., ethanol) extraction process, an extract/solvent mixture may first be separated from the spent biomass, and the solvent may then be separated from the extract/solvent mixture and recovered by a solvent recovery chamber 122 at step 216. As a result, a desolvenized extract may be obtained. The solvent may be recovered from the extract/solvent mixture by a distillation or evaporation process, so that the solvent may be used in another extraction process.

[0032] In a preferred embodiment, however, the carrier fluid used to form the slurry (e.g., "MCT solvent") with the raw biomass may not be subject to solvent separation and removal, providing an improvement over the traditional extraction method. The MCT solvent— now containing extracted pharmacologically active compounds— may simply be separated from the spent biomass and incorporated directly into a formulation without the need for extensive solvent removal (e.g., vacuum evaporation or distillation). Post separation from the spent biomass, the MCT solvent containing pharmacologically active compounds may then be combined with additional carrier fluid or excipients or other additives to create a specified formulation at step 218. The formulation— combination of the MCT solvent (including extracts) with additional carrier fluid— may be performed in a formulation chamberl24. The resulting formulation product may then be provided to a product holding chamber 126.

[0033] In an embodiment, the MCT solvent containing pharmacologically active compounds may be recirculated for re-use as solvent in a slurry with freshly prepared (non-extracted) biomass at step 208. Such recirculation and re-use may repeat multiple times so as to increase the concentration of the pharmacologically active compounds in the carrier fluid to a desired level (as determined from sampling chamberl20). In an embodiment, the MCT solvent containing pharmacologically active compounds could be subjected to a controlled decarboxylation process.

[0034] Thereafter, sampling of the formulation product may be performed at step 220.

Sampling of the formulated extract may be performed in the sampling chamber 120. The formulated extract may comprise Delta-9-THC, Delta-9-THCA, CBDA, CBD, other cannabinoids, terpenes, or other medicinal value compounds. The formulated extract may be sampled and analyzed using several methods. In a preferred embodiment, analysis of the formulated extract may be done to determine cannabinoid content and cannabinoid profile. The analysis may be performed using an Ultra High Performance Liquid Chromatography coupled with Mass

Spectroscopy detection (UPLC-MS). Further, terpene profile of the raw biomass may be determined using a Gas Chromatography-Mass Spectroscopy Detection (GC-MS). Such sampling techniques may help in determining cannabinoid content and profile of the raw biomass (i.e., THCA, THC, CBDA, CBD, and total cannabinoids).

[0035] FIG. 3A and FIG. 3B are tables that provide a comparison of different solvents that may be used in biomass extraction of pharmacologically active compounds under different conditions to provide different results. Such comparison may include, for example, test data obtained regarding usage of typical solvents for a biomass extraction process and usage of edible or food grade oil for a biomass extraction process.

[0036] FIG. 3A pertains to slurries that may be formed using such solvents as, for example, alcohols ( e.g ., ethanol), alkanes (e.g., pentane), or any suitable organic solvent as the extraction solvent (e.g., suitable organic solvent and MCT oil or any suitable carrier fluid). The extracted solids (marc) may be separated from the extract/solvent mixture (miscella) in separation chamber 116, and provided to spent biomass holding chamber 118. Residual solvent held up in the marc may be recovered in solvent recovery chamber 122, and the spent biomass solids may be collected for disposal by way of disposal system 128. The miscella may be concentrated by a vacuum evaporator (e.g., in separation chamber 116), and the mixture may be condensed and collected for re-use (e.g., solvent recovery chamber 122). An example of extraction parameters may include the solvent-to-solid ratio and the extraction temperature used (e.g., as provided by microwave generator 114) . The extraction efficiency (percent recovery of available cannabinoids) may be the percentage recovery of THCA recovered in the final extract, in order to show loss of quantities of THCA during the extraction process. The extraction may involve heating using microwave energy.

[0037] FIG. 3B pertains to slurries that may be extracted using MCT oil or any suitable carrier fluid. The extracted solids (marc) may be separated from the solvent (miscella) in separation chamber 116 and provided to spent biomass holding chamber 118. Residual solvent may be held up in the marc, recovered, and provided to solvent recovery chamber 122 . The spent biomass solids may be collected for disposal by disposal system 128. The extraction efficiency (percent recovery of available cannabinoids) may be the percentage recovery of THCA recovered in the final extract, in order to show loss of quantities of THCA during the extraction process. Exposing these solvent mixtures to a microwave field ( e.g ., from microwave generator 114) may produce higher recovery percentages of cannabinoids, and/or may allow for a quicker extraction time.

[0038] Whereas FIG. 2 illustrates one exemplary method, FIG. 4 is a flow chart illustrating an alternative exemplary method 400 for extracting pharmacologically active compounds from biomass. It should also be noted that in some implementations, the functions noted in the method blocks illustrated herein may occur out of the order illustrated in the drawings. For example, two blocks shown in succession may in fact be executed substantially concurrently or in a different order, depending upon the functionality involved. In addition, the process descriptions or blocks in flow charts should be understood as representing decisions made by a hardware structure, such as a state machine.

[0039] At step 402, a prepared biomass may be provided. The prepared biomass may comprise cannabis plant components that include target compounds for extraction. The prepared biomass may be obtained by processing raw biomass into particles of a desired size. The raw biomass may be present in the form of dried, ground, and non-decarboxylated flowers (buds) of cannabis plants.

[0040] At step 404, a slurry may be formed by adding one or more solvents to the prepared biomass. The solvent added to the prepared biomass mass may be selected with different dielectric and solvent parameter properties. The solvent may be a Medium Chain Triglyceride (MCT) or different edible and food-grade solvents or emulsifier used to standardize active compounds in pharmaceutical, nutraceutical, functional, food, or cosmetic formulations. Further, the solvent may be a polyunsaturated fatty acid (PUFA), com oil, safflower oil, borage oil, flax oil, canola oil, cottonseed oil, soybean oil, olive oil, sunflower oil, monoglycerides, diglycerides, triglycerides, lecithin, limonene, essential oils of spices, herbs or other plants, fish oil, glycerol, glycols, or any other, or mixtures thereof.

[0041] At step 406, the slurry may be transferred to an extractor for extraction of the target components. The slurry may be transported using a set of mechanical conveyors. The slurry may be heated to a certain temperature by exposing the slurry to microwaves, for a predefined time with a predefined microwave energy range.

[0042] At step 408, the solvent may be recovered back to the slurry form and a de-solvenized extract may be obtained. The solvent may be recovered from the extract mixture by distillation process. The solvent recovered may be used in another extraction process. In a preferred embodiment, MCT solvent used to form the slurry with the raw biomass may not need a recovery, and may be directly inputted into a formulation or other downstream process.

[0043] The foregoing detailed description of the technology has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the technology to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the technology, its practical application, and to enable others skilled in the art to utilize the technology in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the technology be defined by the claim.