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A protocol for the delivery of cannabidiol (CBD) and combined CBD and ∆9-tetrahydrocannabinol (THC) by vaporisation.

Solowij N, Broyd SJ, van Hell HH, Hazekamp A - BMC Pharmacol Toxicol (2014)

Bottom Line: Significant interest has emerged in the therapeutic and interactive effects of different cannabinoids.Cannabidiol (CBD) has been shown to have anxiolytic and antipsychotic effects with high doses administered orally.Preliminary studies determined 200 mg CBD to be the highest dose effectively vaporised at 230 ° C, yielding an availability of approximately 40% in the vapour phase.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Psychology, Ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia. nadia@uow.edu.au.

ABSTRACT

Background: Significant interest has emerged in the therapeutic and interactive effects of different cannabinoids. Cannabidiol (CBD) has been shown to have anxiolytic and antipsychotic effects with high doses administered orally. We report a series of studies conducted to determine the vaporisation efficiency of high doses of CBD, alone and in combination with ∆9-tetrahydrocannabinol (THC), to achieve faster onset effects in experimental and clinical trials and emulate smoked cannabis.

Methods: Purified THC and CBD (40 mg/ml and 100 mg/ml respectively) were loaded onto a liquid absorbing pad in a Volcano vaporiser, vaporised and the vapours quantitatively analysed. Preliminary studies determined 200 mg CBD to be the highest dose effectively vaporised at 230 ° C, yielding an availability of approximately 40% in the vapour phase. Six confirmatory studies examined the quantity of each compound delivered when 200 mg or 4 mg CBD was loaded together with 8 mg of THC.

Results: THC showed 55% availability when vaporised alone or with low dose CBD, while large variation in the availability of high dose CBD impacted upon the availability of THC when co-administered, with each compound affecting the vaporisation efficiency of the other in a dynamic and dose-dependent manner. We describe optimised protocols that enable delivery of 160 mg CBD through vaporisation.

Conclusions: While THC administration by vaporisation is increasingly adopted in experimental studies, often with oral predosing with CBD to examine interactive effects, no studies to date have reported the administration of CBD by vaporisation. We report the detailed methodology aimed at optimising the efficiency of delivery of therapeutic doses of CBD, alone and in combination with THC, by vaporisation. These protocols provide a technical advance that may inform methodology for clinical trials in humans, especially for examining interactions between THC and CBD and for therapeutic applications of CBD.

Trial registration: Current Controlled Trials ISRCTN24109245.

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Related in: MedlinePlus

HPLC quantification of THC and CBD in vapour delivered into a 60 cm (approximately 10 litre) balloon after vaporisation of 8 mg THC, and 4 mg CBD or 200 mg CBD, loaded alone and in combination onto the liquid pad of a Volcano® vaporiser and vaporised at 230°C. Data represent averages across three repetitions; error bars are SEM.
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Figure 1: HPLC quantification of THC and CBD in vapour delivered into a 60 cm (approximately 10 litre) balloon after vaporisation of 8 mg THC, and 4 mg CBD or 200 mg CBD, loaded alone and in combination onto the liquid pad of a Volcano® vaporiser and vaporised at 230°C. Data represent averages across three repetitions; error bars are SEM.

Mentions: Results from the series of 6 experiments are depicted in Figure 1. Each column shows the average amount of THC or CBD (mg, SEM), HPLC quantified from the vapour delivered into the balloon from three repetitions.Experiment 1 indicated that 8 mg THC when vaporised alone delivered approximately 6.3 (SD 0.53) mg THC into the balloon for inhalation. Experiment 2 indicated that 4 mg CBD when vaporised delivered approximately 3.9 (SD 0.13) mg CBD into the balloon. When 4 mg CBD was combined with 8 mg THC (Experiment 3), there was no significant change to the amount of each compound delivered from when each was delivered alone (THC: p > 0.96; CBD: p > 0.65). Experiment 4 determined that when 200 mg CBD was vaporised, almost 82 mg CBD (41%) was delivered into the balloon on average, but there was significant variability (large standard errors). In Experiment 6, the combination of 8 mg THC with 200 mg CBD when vaporised, resulted in reduced delivery of each compound into the balloon relative to when each was vaporised alone: 4.4 (SD 0.22) mg THC was delivered (55%) (significantly different from Experiment 1, p < 0.05; and Experiment 3, p < 0.015), and 74.3 (SD 18.17) mg CBD was delivered (37.2%) (but this did not differ statistically from Experiment 4, p > 0.79); again there was large variation for CBD. Experiment 5 was subsequently conducted to establish what would happen if half the quantity of THC (4 mg) were combined with 200 mg CBD. This was performed in order to determine whether a second balloon could be administered to participants with additional THC to equalise the quantity of THC delivered when in combination with high dose CBD, to that when administered alone. Again the quantity of THC delivered into the balloon was approximately halved: 2.2 (SD 0.28) mg (55%), and slightly more CBD was delivered: 77.6 (SD 12.06) mg (38.9%). Experiments 5 and 6 indicated that a saturation effect in the vapour may occur when the two compounds are vaporised together at high CBD doses (but not at low CBD doses as in Experiment 3). Despite the trend evident in Figure 1, the quantity of CBD delivered across experiments 4, 5 and 6 did not differ statistically (p > 0.94).


A protocol for the delivery of cannabidiol (CBD) and combined CBD and ∆9-tetrahydrocannabinol (THC) by vaporisation.

Solowij N, Broyd SJ, van Hell HH, Hazekamp A - BMC Pharmacol Toxicol (2014)

HPLC quantification of THC and CBD in vapour delivered into a 60 cm (approximately 10 litre) balloon after vaporisation of 8 mg THC, and 4 mg CBD or 200 mg CBD, loaded alone and in combination onto the liquid pad of a Volcano® vaporiser and vaporised at 230°C. Data represent averages across three repetitions; error bars are SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4274767&req=5

Figure 1: HPLC quantification of THC and CBD in vapour delivered into a 60 cm (approximately 10 litre) balloon after vaporisation of 8 mg THC, and 4 mg CBD or 200 mg CBD, loaded alone and in combination onto the liquid pad of a Volcano® vaporiser and vaporised at 230°C. Data represent averages across three repetitions; error bars are SEM.
Mentions: Results from the series of 6 experiments are depicted in Figure 1. Each column shows the average amount of THC or CBD (mg, SEM), HPLC quantified from the vapour delivered into the balloon from three repetitions.Experiment 1 indicated that 8 mg THC when vaporised alone delivered approximately 6.3 (SD 0.53) mg THC into the balloon for inhalation. Experiment 2 indicated that 4 mg CBD when vaporised delivered approximately 3.9 (SD 0.13) mg CBD into the balloon. When 4 mg CBD was combined with 8 mg THC (Experiment 3), there was no significant change to the amount of each compound delivered from when each was delivered alone (THC: p > 0.96; CBD: p > 0.65). Experiment 4 determined that when 200 mg CBD was vaporised, almost 82 mg CBD (41%) was delivered into the balloon on average, but there was significant variability (large standard errors). In Experiment 6, the combination of 8 mg THC with 200 mg CBD when vaporised, resulted in reduced delivery of each compound into the balloon relative to when each was vaporised alone: 4.4 (SD 0.22) mg THC was delivered (55%) (significantly different from Experiment 1, p < 0.05; and Experiment 3, p < 0.015), and 74.3 (SD 18.17) mg CBD was delivered (37.2%) (but this did not differ statistically from Experiment 4, p > 0.79); again there was large variation for CBD. Experiment 5 was subsequently conducted to establish what would happen if half the quantity of THC (4 mg) were combined with 200 mg CBD. This was performed in order to determine whether a second balloon could be administered to participants with additional THC to equalise the quantity of THC delivered when in combination with high dose CBD, to that when administered alone. Again the quantity of THC delivered into the balloon was approximately halved: 2.2 (SD 0.28) mg (55%), and slightly more CBD was delivered: 77.6 (SD 12.06) mg (38.9%). Experiments 5 and 6 indicated that a saturation effect in the vapour may occur when the two compounds are vaporised together at high CBD doses (but not at low CBD doses as in Experiment 3). Despite the trend evident in Figure 1, the quantity of CBD delivered across experiments 4, 5 and 6 did not differ statistically (p > 0.94).

Bottom Line: Significant interest has emerged in the therapeutic and interactive effects of different cannabinoids.Cannabidiol (CBD) has been shown to have anxiolytic and antipsychotic effects with high doses administered orally.Preliminary studies determined 200 mg CBD to be the highest dose effectively vaporised at 230 ° C, yielding an availability of approximately 40% in the vapour phase.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Psychology, Ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia. nadia@uow.edu.au.

ABSTRACT

Background: Significant interest has emerged in the therapeutic and interactive effects of different cannabinoids. Cannabidiol (CBD) has been shown to have anxiolytic and antipsychotic effects with high doses administered orally. We report a series of studies conducted to determine the vaporisation efficiency of high doses of CBD, alone and in combination with ∆9-tetrahydrocannabinol (THC), to achieve faster onset effects in experimental and clinical trials and emulate smoked cannabis.

Methods: Purified THC and CBD (40 mg/ml and 100 mg/ml respectively) were loaded onto a liquid absorbing pad in a Volcano vaporiser, vaporised and the vapours quantitatively analysed. Preliminary studies determined 200 mg CBD to be the highest dose effectively vaporised at 230 ° C, yielding an availability of approximately 40% in the vapour phase. Six confirmatory studies examined the quantity of each compound delivered when 200 mg or 4 mg CBD was loaded together with 8 mg of THC.

Results: THC showed 55% availability when vaporised alone or with low dose CBD, while large variation in the availability of high dose CBD impacted upon the availability of THC when co-administered, with each compound affecting the vaporisation efficiency of the other in a dynamic and dose-dependent manner. We describe optimised protocols that enable delivery of 160 mg CBD through vaporisation.

Conclusions: While THC administration by vaporisation is increasingly adopted in experimental studies, often with oral predosing with CBD to examine interactive effects, no studies to date have reported the administration of CBD by vaporisation. We report the detailed methodology aimed at optimising the efficiency of delivery of therapeutic doses of CBD, alone and in combination with THC, by vaporisation. These protocols provide a technical advance that may inform methodology for clinical trials in humans, especially for examining interactions between THC and CBD and for therapeutic applications of CBD.

Trial registration: Current Controlled Trials ISRCTN24109245.

Show MeSH
Related in: MedlinePlus