Phytocannabinoids Profile in Medicinal Cannabis Oils: The Impact of Plant Varieties and Preparation Methods

Abstract

Cannabis (Cannabis sativa L.) is a highly promising medicinal plant with well-documented effectiveness and growing use in the treatment of various medical conditions. Cannabis oils are mostly used in galenic preparations, due to their easy adjustment of the administration dose, together with the enhanced bioavailability of its active compounds. As stated by the Italian Law (9/11/2015, 279 Official Gazette), "to ensure the quality of the oil-based cannabis preparation, the titration of the active substance(s) should be carried out." This study aims to represent the Italian panorama of cannabis oils, which were analyzed (8,201) to determine their cannabinoids content from 2017 to 2019. After application of the exclusion criteria, 4,774 standardized cannabis oils were included, which belong to different medicinal cannabis varieties and prepared according to different extraction methods. The concentration of the principal cannabinoids was taken into account dividing samples on the basis of the main extraction procedures and cannabis varieties. According to this analysis, the most substantial variations should be attributed to different cannabis varieties rather than to their extraction protocols. This study may be the starting point of preparatory pharmacists to assess the correct implementation of the preparation procedures and the quality of the extracts.

Keywords: cannabinoids; chemometrics methods; medical cannabis; pharmaceutical chemistry; phytochemistry.

FIGURE 1

The distribution, between 2017 and 2019, of the total amount of cannabis oil extracts recruited by our laboratory (8,201) by preparation methods (A) and varieties of Cannabis sativa (B). The distribution of standardized cannabis oil extracts selected for this study (4,774) by preparation methods (C) and varieties of Cannabis sativa (D). n.d. not determined since those details were not indicated in the sample’s addendum. For details on preparation methods, see the following references: Method A (Romano and Hazekamp, 2013), Method B (Citti et al., 2016), Method C (Società Italiana Farmacisti Preparatori (SIFAP), 2016; Casiraghi et al., 2018), and Method D (Calvi et al., 2018).

FIGURE 2

Mean percentage of acidic and neutral form of phytocannabinoids in 4,774 samples according to the extraction method: (A) THC and THCA; (B) CBD and CBDA. The values are expressed as mean normalized to 100: % acidic form = [Mean_acid/(Mean_acid + Mean_neutral)] × [100/(Mean_acid + Mean_neutral)]; % neutral form = [Mean_neutral/(Mean_acid + Mean_neutral)] × [100/(Mean_acid + Mean_neutral)]. For details on preparation methods, see the following references: Method A (Romano and Hazekamp, 2013), Method B (Citti et al., 2016), Method C (Società Italiana Farmacisti Preparatori (SIFAP), 2016; Casiraghi et al., 2018), and (Method D (Calvi et al., 2018).

FIGURE 3

Distribution of phytocannabinoids among Cannabis sativa varieties (4,774, mean ± SD).

FIGURE 4

Extraction efficiency (EE%) of THC (up) and CBD (down) measured in cannabis oil samples (4,774) obtained using different cannabis varieties and preparation methods. The error bars that exceed the axis limit are represented as clipped. The theoretical extraction rate was set as the mean of the declared range content as follows: Bedrocan THC 2.05 (% w/w); Bediol THC 0.65 (% w/w), CBD 0.75 (% w/w); FM2 THC 0.65 (% w/w); CBD 1.05 (% w/w); and Bedrolite CBD 0.85 (% w/w). For details on preparation methods, see the following references: Method A (Romano and Hazekamp, 2013), Method B (Citti et al., 2016), Method C [Società Italiana Farmacisti Preparatori (SIFAP), 2016; Casiraghi et al., 2018)], and Method D (Calvi et al., 2018). The values are expressed as mean ± SD and calculated according to the equation EE% = (conc. Exp/conc. Theo) × 100.

FIGURE 5

Distribution of phytocannabinoids among extraction methods from plant materials and varieties (4,774, mean ± SD). The columns represented the cannabis sativa varieties (sx to dx) Bedrocan, Bediol, FM2, and Bedrolite and the rows the Method of extraction (up to down) [Method A (Romano and Hazekamp, 2013), Method B (Citti et al., 2016), Method C (Società Italiana Farmacisti Preparatori (SIFAP), 2016; Casiraghi et al., 2018), and Method D (Calvi et al., 2018)].

FIGURE 6

3D Principal component analysis (PCA) plot of cannabis oil extracts divided into groups according to the plant varieties and extraction method (4,774). In the panel, the plant varieties are evidenced, whereas the extraction adopted was color coded (according to the legend). In the panel, (A) Bedrocan, (B) Bediol, (C) FM2, (D) Bedrolite, and (E) the entire data set overview are evidenced. For details on preparation methods, see the following references: Method A (Romano and Hazekamp, 2013), Method B (Citti et al., 2016), Method C [Società Italiana Farmacisti Preparatori (SIFAP), 2016; Casiraghi et al., 2018], and Method D (Calvi et al., 2018).

FIGURE 7

A heatmap overview (showing only group average) with hierarchical clustering of the 4,774 cannabis oils. The first cluster (#1) included Bedrocan variety and the second one (#2) the other varieties, which in particular consisted of (#2A) Bedrolite and (#2B) Bediol and FM2. In respect to other varieties, Bedrocan displayed a lower concentration of CBD (tot, neutral, and acid) and Bedrolite of THC (tot and neutral). The color-scale differentiates values as high (red), mid (gray), and low (blue). For details on preparation methods, see the following references: Method A (Romano and Hazekamp, 2013), Method B (Citti et al., 2016), Method C [Società Italiana Farmacisti Preparatori (SIFAP), 2016; Casiraghi et al., 2018], and Method D (Calvi et al., 2018).