A stability test has found that Avecho Biotechnology's soft-gel capsule retained its quality after two years stored at room temperature, with negligible degradation of the CBD compound inside.
The capsule, containing a 75mg unit dose of CBD, maintained drug levels at 99.5% of its label claims, according to the company.
Physical characteristics of the capsule, including its hardness and dissolution profile, also remained consistent throughout the testing period.
Avecho said the results confirm the capsule's stability, a requirement for registration with the Therapeutic Goods Administration (TGA).
The findings offer reassurance to the company as it prepares to launch a clinical trial examining whether its product can effectively treat insomnia.
A successful outcome could position Avecho among the first companies to register a schedule 3 over-the-counter CBD product with the TGA.
Chief executive Paul Gavin said: "Cannabinoids are not as stable as everyone assumes, especially when they are held to pharmaceutical standards.
"We saw CBD degradation in early prototypes that required further formulation optimisation to overcome. Passing two-year stability is an important milestone, as it proves the additional formulation work we conducted was successful over the longer timeframe."
Gavin added that the outcome confirms the product can be manufactured consistently while retaining stability and potential effectiveness over time.
"That is an essential requirement of pharmaceutical registration," he said. "In anticipation of our phase III study… we are now manufacturing product for use in the clinical trial as well as formal registration batches that will be included in future TGA and FDA submissions."
Avecho noted that CBD and other cannabinoids are vulnerable to degradation from oxygen, light, and heat, and can convert into psychoactive compounds — including THC — over time.
That conversion did not occur in this case, the company said. The capsule remained within TGA limits, which permit up to 2% non-CBD cannabinoids, with THC capped at 1% or less.
Avecho's phase III clinical trial will enrol 540 patients across three treatment groups, comparing nightly CBD doses of 75mg and 150mg against a placebo over an eight-week dosing period.
The company said the trial is set to begin shortly.
