How oromucosal administration of cannabinoids works

Oromucosal dose forms are relatively easy to administer. The ease of dosing and rapid onset of action means oromucosal administration, via the sublingual or buccal surface, is the preferred choice for many physicians and patients.

THC and CBD are highly lipophilic compounds, which are rapidly absorbed by the oromucosa (in particular, the sublingual surface), entering the bloodstream and bypassing the liver. Bioavailability generally ranges between about 5% and 20% and varies according to the dose form (viscous solutions, sprays, wafers), the vitality of mucosa, and the accuracy of dosing by the patient. Inevitably some of the administered doses will be swallowed, resulting in
first-pass metabolism.

Oromucosal pharmacokinetic profile

Plasma concentrations

Peak plasma concentrations vary according to the dose form and concentration, and may be reached between 30-120 minutes minutes, resulting in onset of clinical effects after about 30-90 minutes and taper off within 6-8 hours.

Spray, sublingual drops and then wafer dose forms, respectively, appear to increasingly reduce variability in Tmax and to reach higher Cmax with similar doses. Plasma concentrations of THC tend to be higher than corresponding CBD after administration of CBD:THC medicines. The plasma increase of cannabinoids is dose-dependent.

Reducing variability in oromucosal dosing

The dose format can introduce or reduce variability in the taken dose, for example:

• Actuated, metered dose sprays are a precise dosing format, with a specific dose per spray. A 10.8 mg THC and 10 mg CBD dose may reach a Cmax of 5.5 ng/ mL and 2.5 ng/mL, respectively, after 1.6 hours. Formulations may contain alcohol in the solution, which can be unpleasant for patients or cause mild site-specific ulceration.
• Sublingual wafers provide highly consistent dosing and rapidly dissolve with a good absorption rate. A 50 mg CBD dose may reach a Cmax of 19.84 ng/mL after 3.3 hours.
• With sublingual solutions, frail or elderly patients may find it hard to squeeze a dropper under the tongue, and under or over-dose may occur. A syringe helps the accuracy of dose amount but may be fiddly for frail or elderly patients. Some oromucosal solutions contain chlorophyll, which may cause an unpleasant taste. Post-administration, consuming a banana or boiled sweet may help.

Also read