In Australia THC (dronabinol) is produced by Spectrum Therapeutics directly from cannabis flowers. The extracted pure substance is used as a formula in oils and softgels for medical consumption. 

Medical cannabinoids.

Dronabinol (THC) dissolved in oil is not suitable for vaporization and is intended for oral administration. If you have questions on the medical use of cannabinoids or cannabis, please contact your physician, pharmacist, or Spectrum Therapeutics