Table 1.

Effect of various dosage forms on pharmacokinetics parameters (PKM) of cannabinoids.

	PKM	Absorption	Bioavailability	Peak Plasma Concentration	Duration of Action	Advantages	Disadvantages
Dosage Form
Inhalation		High absorption = 10–60%	THC = 2–65%, CBD = 6–31%	Peak plasma concentrations of THC and CBD are reached quickly, within 3–10 min.	1–4 h	Suitable bioavailability and rapid onset of action.	Variability between patients based on lung function.
Oral		Low absorption = 2–14%	THC = 5–10%, CBD = 6–20% Due to the effect of 1st pass metabolism.	Achieve peak concentration (60–120 min).	6 h	It provides a sufficient duration of action.	Delayed onset of action.
Topical		Irregular absorption	Skin barriers hinder bioavailability due to the lipophilic nature of the drug.	Steady-state condition is achieved within = 17 h.	THC = 14 h, CBD = 72 h	Reduction in the side effects associated with systemic administration of the drugs.	Poor bioavailability due to skin barrier.
Systemic intravenous		High absorption rate	High bioavailability like inhaled dosage form.	Within 10 min.	4 h	Rapid action and high bioavailability.	Require an aqueous vehicle due to poor water solubility.
Ref.		[15,43,44]	[15,47,48]	[15,49]	[49,50]	[50,51]	[15,52]