CANNABIDIOL-TYPE CANNABINOID COMPOUND

Abstract

The present invention relates to a cannabidiol (CBD) type cannabinoid compound for use as a medicament. The CBD-type cannabinoid, cannabidiol-C6 (CBD-C6), is a naturally occurring cannabinoid that can be found in minor quantities in the cannabis plant. Furthermore, the cannabinoid can be produced by synthetic means and a method for the production of CBD-C6 is described herein. In addition, disclosed herein are data which demonstrate the efficacy of CBD-C6 in models of disease.

Claims

1. A method of treating epilepsy in a subject in need thereof, comprising administering a therapeutically effective amount of cannabidiol-C6 (CBD-C6).

2. The method of claim 1, wherein the CBD-C6 is in the form of a plant extract.

3. The method of claim 2, wherein the CBD-C6 is in the form of a highly purified plant extract.

4. The method of claim 3, wherein the highly purified plant extract comprises at least 80% (w/w) CBD-C6.

5. The method of claim 3, wherein the highly purified plant extract comprises at least 95% (w/w) CBD-C6.

6. The method of claim 1, wherein the CBD-C6 is in the form of a synthetic compound.

7. The method of claim 1, wherein the dose of CBD-C6 is greater than 100 mg/kg/day.

8. The method of claim 1, wherein the dose of CBD-C6 is less than 100 mg/kg/day.

9. A composition for use as a medicament comprising cannabidiol-C6 (CBD-C6) and one or more pharmaceutically acceptable excipients.

10. (canceled)

11. The method of claim 1, wherein the epilepsy treated is in a mammal.

12. The method of claim 11, wherein the mammal is a human.

13. The method of claim 11, wherein the mammal is a dog.

14. A process for the preparation of cannabidiol-C6 (CBD-C6).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

[0035] FIG. 1 shows the effect of Cannabidiol-C6 (CBD-C6) in the MEST test in the mouse as described in Example 2.

[0036] FIG. 2 shows the effect of CBD-C6 on the electroshock-induced generalised seizure threshold (M EST) in the mouse as described in Example 3.

[0037] Cannabinoids and their Abbreviations

[0038] The cannabinoids described in the present application are listed below along with their standard abbreviations.

TABLE-US-00001 CBD Cannabidiol [00001] CBD-C6 Cannabidiol-C6 [00002]

DETAILED DESCRIPTION

Example 1: Synthetic Production Method for Cannabidiol-C6 (Cbd-C6)

[0039] As previously described the compound CBD-C6 may be produced as a minor cannabinoid in the cannabis plant. In a highly purified extract of cannabidiol the amount of CBD-C6 which remains in the extract is not more than 0.15% (w/w).

[0040] As such the synthetic pathway described below details a methodology that can be used in order to produce the cannabinoid CBD-C6 in larger quantities.

[0041] On the scheme R═C.sub.6H.sub.14

##STR00003##

Example 2: Evaluation of Cannabidiol-C6 (Cbd-C6) for Anticonvulsant Activity Using the Maximal Electroshock Seizure Threshold (Mest) Test in the Mouse

[0042] The efficacy of CBD-C6 was tested in a mouse model of seizure, the maximal electroshock seizure threshold (MEST) test.

[0043] The maximal electroshock seizure threshold (MEST) test is widely utilized preclinically to evaluate pro- and anti-convulsant properties of molecules (Loscher et al., 1991).

[0044] In the MEST test the ability of a drug to alter the seizure threshold current required to induce hind limb tonic extensor convulsions is measured according to an “up and down” method of shock titration (Kimball et al., 1957). An increase in seizure threshold is indicative of anti-convulsant effect. Antiepileptic drugs including the sodium channel blockers (e.g. lamotrigine) with clinically proven efficacy against generalised tonic-clonic seizures all exhibit anti-convulsant properties in this test in the mouse.

[0045] Conversely, a reduction in seizure threshold is indicative of a pro-convulsant effect as observed with known convulsant agents such as picrotoxin.

Methods

[0046] Naïve mice were acclimatised to the procedure room in their home cages, with food and water available ad libitum.

[0047] Animals were dosed i.p. according to dose group.

[0048] The vehicle (10 ml/kg i.p. 60 min pre-treatment time) was 1:1:18 vehicle 5% ethanol, 5% kolliphor EL, 90% saline.

[0049] The test compound, CBD-C6 was administered at doses of 10, 30 and 100 mg/kg given at 10 ml/kg i.p. 180 min pre-treatment time.

[0050] The positive control diazepam was used at 2.5 mg/kg (10 ml/kg i.p. 30 min pre-treatment time)

[0051] Mice were individually assessed for the production of a tonic hind limb extensor seizure using a Hugo Sachs Electronik stimulator, which delivered an adjustable constant current (1-300 mA) of 0.1 s duration via corneal electrodes.

[0052] The stimulus intensity was varied by an ‘up and down’ method of shock titration. Thus, the first mouse within a treatment group was given a shock at the expected or estimated seizure threshold (CC.sub.50) current, that is, the current producing tonic hind limb extensor seizure in 50% of animals. For subsequent animals, the stimulus intensity was lowered or raised in 2 mA intervals if the preceding mouse did or did not show tonic hind limb extension, respectively.

[0053] This procedure continued for all mice within the treatment group. Data generated from treatment group of n=12 was used to calculate the CC.sub.50±s.e.m. values according to the method of Kimball et al. (1957).

[0054] Animal were culled immediately by concussion of the brain by striking the cranium, followed by dislocation of the neck.

[0055] Induction of seizure is measured as an all-or-nothing effect scored as either present (+) or absent (0) for each animal.

[0056] The data for each treatment group were recorded as the number of +'s and 0's at each current level employed and this information is then used to calculate the CC.sub.50 value (current required for 50% of the animals to show seizure behaviour)±standard error.

[0057] Data was analysed by comparing treated groups with the appropriate vehicle control using Fisher's Exact Probability tests.

Results

[0058] FIG. 1 and Table 1 below demonstrates the data produced in this experiment.

[0059] In the vehicle group, the CC.sub.50 value was calculated to be 21 mA.

[0060] In the diazepam (2.5 mg/kg) treated group, administered i.p. 30 minutes before the test, the CC.sub.50 value was 29.5 mA. This result was statistically significant (p<0.001) compared to the vehicle control.

[0061] In the CBD-C6 treatment groups, administered i.p. 180 minutes before the test, the doses of 10 and 30 mg/kg CBD-C6 produced a statistically significant CC.sub.50 value compared to vehicle.

[0062] In the mice treated with the higher doses of CBD-C6 there was a very large (376%) difference from vehicle and as such the significance value could not be calculated. However, the effect seen should be considered to be of therapeutic benefit.

TABLE-US-00002 TABLE 1 Evaluation of effect of CBD-C6 in the MEST test % Dose CC.sub.50 change Treat- (mg/ +/− Signif- from ment kg) N SEM icance vehicle Vehicle — 12 21.0 +/− — — 0.5 Diaze- 2.5 12 29.5 +/− P < 0.001 40% pam 2.4 CBD- 10 12 23.4 +/− P < 0.05  11% C6 0.9 CBD- 30 12 34.3 +/− P < 0.001 63% C6 2.8 CBD- 100 12 >100 — 376%  C6

Conclusions

[0063] These data demonstrate for the first time a therapeutic effect for the compound CBD-C6.

[0064] These data are significant as they provide heretofore unknown evidence that this cannabinoid which is found in minor quantities in extracts of cannabis plant may be of therapeutic value.

Example 3: Evaluation of Cannabidiol-C6 (Cbd-C6) for Anticonvulsant Activity Using the Maximal Electroshock Seizure Threshold (Mest) Test in the Mouse

[0065] The efficacy of CBD-C6 was tested in a mouse model of generalised seizure, the maximal electroshock seizure threshold (M EST) test as described in Example 2.

Methods

Study Details:

[0066] Naïve mice were acclimatised to the procedure room in their home cages for up to 7 days, with food and water available ad libitum.

[0067] All animals were weighed at the beginning of the study and randomly assigned to treatment groups based on a mean distribution of body weight across groups. All animals were dosed at 10 mL/kg via intraperitoneal (i.p) injection, with either vehicle, CBD-C6 at 10, 30 or 100 mg/kg, diazepam at 2.5 mg/kg or sodium valproate at 250 mg/kg.

[0068] Animals were individually assessed for the production of a tonic hind limb extensor convulsion at 60 min post-dose for vehicle, at 60, 60 and 120 min post-dose for CBD-C6 at 10, 30 and 100 mg/kg respectively, and 30 min post-dose for diazepam and sodium valproate, from a single electroshock.

[0069] The first animal within a treatment group was given a shock at the expected or estimated CC.sub.50 current. For subsequent animals, the current was lowered or raised depending on the convulsions outcome from the preceding animal.

[0070] Data generated from each treatment group were used to calculate the CC.sub.50±SEM values for the treatment group.

Test Compounds:

[0071] Vehicle: (5% ethanol, 5% solutol, 90% Saline) was prepared as follows: 1 mL of ethanol, 1 mL of solutol were warmed to 60° C., in 18 mL of saline (1:1:18).

[0072] Positive controls: diazepam was used at 2.5 mg/kg and sodium valproate at 250 mg/kg.

[0073] The test compound, CBD-C6 was prepared according to the method described in Example 1. CBD-C6 was administered at 10, 30 and 100 mg/kg (i.p.) in a 1:1:18 ethanol:solutol:0.9% saline formulation.

Sample Collection:

[0074] Each animal was humanely killed immediately after production of a convulsion by destruction of the brain from striking the cranium, followed by the confirmation of permanent cessation of the circulation from decapitation under The Humane Killing of Animals under Schedule 1 to the Animals (Scientific Procedures) Act 1986. Terminal blood and brain collection were performed following decapitation.

[0075] Blood was collected in Lithium-heparin tubes and centrifuged at 4° C. for 10 minutes at 1500×g. The resulting plasma was removed (>100 μL) and split into 2 aliquots of 0.5 mL Eppendorf tubes containing 100 μL of ascorbic acid (100 mg/mL) for stabilisation. Brains were removed, washed in saline and halved. Each half was placed into separate 2 mL screw cap cryovials, weighed and frozen on cardice.

Statistical Analysis

[0076] The data for each treatment group were recorded as the number of +'s and 0's at each current level employed and this information is then used to calculate the CC.sub.50 value (current required for 50% of the animals to show seizure behaviour)±standard error.

[0077] CBD-C6 effects were also calculated as percentage change in CC.sub.50 from the vehicle control group. Significant difference between drug-treated animals and controls were assessed according to Litchfield and Wilcoxon (1949).

Results

[0078] Table 2 below demonstrates the data produced in this experiment, and FIG. 2 illustrates these results.

[0079] In the vehicle group, the CC.sub.50 value was calculated to be 24.3 mA.

[0080] In the positive control diazepam (2.5 mg/kg) treated group, administered i.p. 30 minutes before the test, the CC.sub.50 value was 86.5 mA. In the sodium valproate (250 mg/kg) treated group, administered i.p. 30 minutes before the test, the CC.sub.50 value was 281.5 mA. These results were statistically significant (p<0.001) compared to the vehicle control.

[0081] In the CBD-C6 treatment groups, administered i.p. 60, 60, and 120 minutes before the test, the doses of 10, 30 and 100 mg/kg CBD-C6 produced a statistically significant CC.sub.50 value compared to vehicle at all three doses of the compound.

[0082] Such data are indicative that this compound will be of therapeutic benefit.

TABLE-US-00003 TABLE 2 Evaluation of effect of CBD-C6 in the MEST test Pre- treat- % ment change Dose time from Treatment (mg/kg) N (mins) CC.sub.50 ± SEM vehicle Significance Vehicle — 12 60 24.3 ± 0.4  — — Diazepam 2.5 12 30 86.5 ± 1.04  255% P < 0.001 Sodium 250 12 30 281.5 ± 5.84  1057% P < 0.001 Valproate CBD-C6 10 12 60 30.8 ± 1.94  27% P < 0.01  CBD-C6 30 12 60 31.5 ± 1.04  29% P < 0.001 CBD-C6 100 12 120 82.5 ± 0.74  239% P < 0.001

Conclusions

[0083] CBD-C6 produced a dose-related increase in MEST, which provides evidence that this compound exhibits anticonvulsive properties. Significant effects were observed at 10, 30 and 100 mg/kg, when compared to vehicle.

[0084] These data are significant as they provide heretofore unknown evidence that this cannabinoid may be of therapeutic value.