# US 11,026,985 B2 · Methods for removing contaminants from plant-derived pharmaceuticals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,026,985 B2 - Document ID: US11026985B2 - Status: Granted - Kind: B2 - Application number: 16/572,678 - Filed: 2019-09-17 - Published: 2020-03-26 - Granted: 2021-06-08 - Earliest claimed: 2018-09-17 - Assignees: Sorbent Technologies Corporation - Applicants: Sorbent Technologies, Inc. - Inventors: Robert Ralph Kerr - Web page: https://patentgrep.com/patent/US11026985B2 ## CPC - A61K 36/3482: {Cannabis} - B01D 3/009: {in combination with chemical reactions} - B01D 3/10: Vacuum distillation (B01D3/12 takes precedence) - B01J 20/103: {comprising silica} - B01J 20/28047: {Gels} - A61K 2236/00: Isolation or extraction methods of medicinal preparations of undetermined constitution containing material from algae, lichens, fungi or plants, or derivatives thereof, e.g. traditional herbal medicine - A61K 2236/33: involving extraction with hydrophilic solvents, e.g. lower alcohols, esters or ketones - A61K 2236/53: Liquid-solid separation, e.g. centrifugation, sedimentation or crystallization - B01J 2220/603: serially disposed columns - B01J 2220/80: Aspects related to sorbents specially adapted for preparative, analytical or investigative chromatography - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract Methods of removing contaminants such as pesticides, herbicides, and fungicides from plant-derived pharmaceuticals, such as Cannabis-derived pharmaceuticals, are disclosed. Plant-derived pharmaceuticals, such as Cannabis-derived pharmaceuticals, and methods of using the plant-derived pharmaceuticals are also disclosed. ## Claims ### Claim 1 A method of removing contaminants from a Cannabis plant-derived pharmaceutical, said method comprising: reacting one or more contaminants within a Cannabis plant-derived extract with an alkali metal hydroxide in a polar solvent to form one or more contaminant by-products in a reaction mixture, wherein said reacting step comprises: adding the Cannabis plant-derived extract to the alkali metal hydroxide in the polar solvent to form the reaction mixture; agitating the reaction mixture with mixing; and adding a neutralizing acid to the reaction mixture, wherein the neutralizing acid comprises glacial acetic acid, or a dilute mineral acid comprising hydrochloric acid, sulfuric acid, or nitric acid; and separating the one or more contaminant by-products from the Cannabis plant-derived extract so as to obtain a contaminant-reduced Cannabis plant-derived extract, wherein said separating step comprises: adding a first alkane to the reaction mixture so as to form a non-aqueous liquid phase within the reaction mixture, wherein the first alkane comprises butane, pentane, cyclopentane, hexane, cyclohexane, heptane, octane, isooctane, or any combination thereof; and separating an upper non-aqueous liquid phase from a lower aqueous liquid phase, the upper non-aqueous liquid phase comprising the first alkane and the contaminant-reduced Cannabis plant-derived extract, wherein the contaminant-reduced Cannabis plant-derived extract comprises one or more cannabinoids. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more contaminants comprise one or more pesticides, one or more herbicides, one or more fungicides, or any combination thereof. ### Claim 3 (depends on 1) The method of claim 1, wherein the one or more contaminants comprise one or more hydrolyzable pesticides. ### Claim 4 (depends on 1) The method of claim 1, wherein the alkali metal hydroxide comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or calcium hydroxide. ### Claim 5 (depends on 1) The method of claim 1, wherein the polar solvent comprises methanol; the neutralizing acid comprises hydrochloric acid; and the first alkane comprises hexane, heptane, or any combination thereof. ### Claim 6 (depends on 1) The method of claim 1, further comprising: passing the upper non-aqueous liquid phase through one or more columns with each column comprising one or more adsorbents; and collecting an effluent exiting the one or more columns. ### Claim 7 (depends on 6) The method of claim 6, wherein the one or more adsorbents comprise magnesium silicate, activated alumina, magnesium salt of activated alumina, sodium sulfate, silica, bonded phase silica, polymeric non-ionic reversed phase resins, or any combination thereof. ### Claim 8 (depends on 7) The method of claim 7, wherein the one or more adsorbents comprise (i) silica gel in a first column, and (ii) magnesium silicate in a second column. ### Claim 9 (depends on 6) The method of claim 6, further comprising: passing one or more column volumes of a rinse mixture through the one or more columns, the rinse mixture comprising heptane and ethyl acetate at a heptane:ethyl acetate ratio of about 80:20 by volume; and collecting the rinse mixture exiting the one or more columns. ### Claim 10 (depends on 9) The method of claim 9, further comprising: evaporating the rinse mixture under reduced pressure so as to (1) remove one or more of: (i) the first alkane, (ii) heptane, (iii) ethyl acetate, and (iv) any residual neutralizing acid, and (2) result in the contaminant-reduced Cannabis plant-derived extract. ### Claim 11 A method of removing contaminants from a plant-derived pharmaceutical, said method comprising: reacting one or more contaminants within a plant-derived extract with an alkali metal hydroxide in a polar solvent to form one or more contaminant by-products in a reaction mixture; and separating the one or more contaminant by-products from the reaction mixture so as to obtain a contaminant-reduced plant-derived extract, wherein said reacting step comprises: adding the plant-derived extract to the alkali metal hydroxide in the polar solvent to form the reaction mixture; agitating the reaction mixture with mixing; and adding a neutralizing acid to the reaction mixture, wherein the neutralizing acid comprises hydrochloric acid; and wherein said separating step comprises: adding a first alkane to the reaction mixture so as to form a non-aqueous liquid phase within the reaction mixture; separating an aqueous liquid phase of the reaction mixture from the non-aqueous liquid phase; passing the non-aqueous liquid phase through one or more columns with each column comprising one or more adsorbents; passing one or more column volumes of a rinse mixture through the one or more columns, the rinse mixture comprising a second alkane and ethyl acetate; and evaporating the rinse mixture under reduced pressure so as to (1) remove one or more of: (i) the first alkane, (ii) the second alkane, (iii) ethyl acetate, and (iv) any residual neutralizing acid, and (2) result in the contaminant-reduced plant-derived extract. ### Claim 12 (depends on 11) The method of claim 11, wherein (a) the second alkane comprises heptane, and (b) the rinse mixture comprises (i) the heptane, and (ii) up to about 20 weight percent (wt %) of the ethyl acetate. ### Claim 13 (depends on 11) The method of claim 11, wherein the one or more contaminants comprise one or more pesticides, one or more herbicides, one or more fungicides, or any combination thereof. ### Claim 14 (depends on 11) The method of claim 11, wherein the one or more contaminants comprise one or more hydrolyzable pesticides. ### Claim 15 (depends on 11) The method of claim 11, wherein the contaminant-reduced plant-derived extract comprises one or more cannabinoids. ### Claim 16 (depends on 14) The method of claim 14, wherein the contaminant-reduced plant-derived extract comprises one or more cannabinoids. ### Claim 17 A method of removing contaminants from a plant-derived pharmaceutical, said method comprising: reacting one or more contaminants within a plant-derived extract with an alkali metal hydroxide in a polar solvent to form one or more contaminant by-products in a reaction mixture, the one or more contaminants comprising one or more pesticides, one or more herbicides, one or more fungicides, or any combination thereof; and separating (i) the one or more contaminant by-products, and (ii) a contaminant-reduced plant-derived extract from the reaction mixture, wherein said separating step comprises: adding a first alkane to the reaction mixture so as to form a non-aqueous liquid phase within the reaction mixture; separating an aqueous liquid phase of the reaction mixture from the non-aqueous liquid phase; passing the non-aqueous liquid phase through one or more columns with each column comprising one or more adsorbents; passing one or more column volumes of a rinse mixture through the one or more columns, the rinse mixture comprising a second alkane and ethyl acetate; and evaporating the rinse mixture under reduced pressure so as to (1) remove one or more of: (i) the first alkane, (ii) the second alkane, (iii) ethyl acetate, and (2) result in the contaminant-reduced plant-derived extract. ### Claim 18 (depends on 17) The method of claim 17, wherein said reacting step comprises: adding the plant-derived extract to the alkali metal hydroxide in the polar solvent to form the reaction mixture; agitating the reaction mixture with mixing; and adding a neutralizing acid to the reaction mixture, wherein the neutralizing acid comprises hydrochloric acid. ### Claim 19 (depends on 18) The method of claim 18, wherein the one or more contaminants comprise one or more hydrolyzable pesticides. ### Claim 20 (depends on 17) The method of claim 17, wherein the contaminant-reduced plant-derived extract comprises one or more cannabinoids.