Influence of isolation and decarboxylation on the chemical stability of industrial cannabis extract

Tradicionalna uporaba konoplje sega daleč v zgodovino, ko so ugotovili njene številne uporabne lastnosti, zato se uporablja še danes v industrijske, prehranske, kozmetične ter medicinske namene. Odkritju kemijske strukture kanabinoida ⠆9-THC ter kasneje še endokanabinoidnega sistema v 2. polovici 20. stoletja so sledile številne raziskave, ki še vedno poskušajo razložiti ter čim bolje opisati terapevtsko delovanje rastline ter optimizirati farmacevtske formulacije. Eden izmed pripravkov iz konoplje je ekstrakt. V tej magistrski nalogi smo ugotavljali, kateri dejavniki ekstrakcije in dekarboksilacije najbolj vplivajo na stabilnost kanabinoidov v ekstraktu industrijske konoplje. Sprva nas je zanimalo, katero ekstrakcijsko topilo je ustreznejše za ekstrakcijo industrijske konoplje. Spoznali smo, da je bilo v naših poskusih boljše topilo heksan kot etanol, saj se je etanol počasneje odparil pri rotavapiranju in med testiranjem stabilnosti je v etanolnem ekstraktu nastala oborina. Oba ekstrakta smo raztopili v propilen glikolu ter sezamovem olju, etanolni se je bolje raztopil v propilen glikolu, saj je ostalo manj neraztopljenega ekstrakta, heksanski pa v sezamovem olju. Kanabinoidi so bili po 4 mesecih stabilnejši v heksanskem ekstraktu. Primerjali smo tudi heksanske ekstrakte, v katerih smo izvedli dekarboksilacijo v različnih fazah priprave ekstrakta. En alikvot ekstrakta smo dekarboksilirali v pečici na 130 °C eno uro, drugega smo raztopili v sezamovem olju ter ga dekarboksilirali v kaloti pri isti temperaturi, tretji ekstrakt je bil narejen iz dekarboksiliranega rastlinskega materiala. Ugotovili smo, da so bili vzorci najmanj stabilni pri ekstraktu, ki se je dekarboksiliral v pečici brez olja. V drugem delu poskusov smo izdelali heksanski ekstrakt, iz katerega smo naredili več vzorcev, ki smo jih izpostavili različnim razmeram dekarboksilacije. Ta je potekala v kaloti pri 110 °C 4 ure ali pri 130 °C 1 uro v atmosferi argona ali zraka, pri čemer smo ekstrakte predhodno raztopili v oljih (olivno olje, MCT olje, sezamovo olje) ali pa smo jih dekarboksilirali brez olja. Nato smo 7 mesecev spremljali koncentracijo kanabinoidov v njih. Ugotovili smo, da so bili ekstrakti, ki so se dekarboksilirali brez olja, najmanj stabilni. CBD je bil dokaj stabilen, na začetku je celo prišlo do povišanja koncentracije zaradi izhlapevanja vzorca skozi luknje pokrovčka, nastale pri vzorčenju. Najmanj stabilen je bil ⠆9-THC, ki je razpadal na CBN in tudi druge razpadne produkte, saj je njegova koncentracija padala veliko hitreje, kot je naraščal CBN.The usage of traditional cannabis has a long history. Its beneficial properties have already been discovered and are of great importance and nowadays are used for industrial, nutritional, cosmetic and medical purposes. The chemical structure of the cannabinoid ⠆9-THC and endocannabinoid system have been discovered in the second half of the 20th century. Therefore, numerous studies about the therapeutic effect of the plant were followed along with pharmaceutical formulation optimizations. One of the cannabis samples preparation is an extraction. In the present Master’s thesis we have done a research which factors of extraction and decarboxylation have the main influence on the stability of cannabinoids in the extract of industrial cannabis. Our initial experiments were focused on finding the most suitable solvent for the extraction. However, ethanol has shown to be less appropriate than hexane since its evaporation at rotavapor was slower and the precipitate was formed during the time. Both extracts were dissolved in propylene glycol and sesame oil. Ethanol extract solves better in propylene glycol while the hexane extract in sesame oil. Furthermore, the cannabinoids were more stable in the hexane extract after 4 months. During the research, we compared hexane extracts in different stages of the decarboxylation of extract preparation. One aliquot of the extract was decarboxylated in the oven at 130 °C for 1 hour. The second was dissolved in sesame oil and decarboxylated in the calotte at 130 °C and the last one was prepared from decarboxylated plant material. However, the less stable samples were found to be the ones decarboxylated in the oven without oil. The second part of this work is focused to the research of hexane extracts. The samples were exposed to different decarboxylation conditions. The experiment was carried out in the calotte at 110 °C for 4 hours or at 130 °C for 1 hour in either argon or air atmosphere. The extracts were pre-dissolved in different oils (olive oil, MCT oil, sesame oil) or were decarboxylated without oil. We monitored the concentration of cannabinoids for next 7 months. The research concluded that the decarboxylated extracts without the oil addition were less stable. CBD was fairly stable and the increase in concentration occurred at the beginning due to the evaporation through the holes at the caps (the holes were the consequence of sampling). The most unstable was ⠆9-THC which degradates to CBN and other side products. Its concentration decreased faster compared to the formation of CBN