Another forum has a few good threads regarding it.
Copy? It's over at the den, and no one mentioned where to purchase
Castor oil is an excellent excipient. The only issue is castor seeds contain ricin, a toxic protein which can cause serious nerve damage and in high concentrations death. Ricinoleic acid is the chief component of castor oil and it performs very well as a solvent and parenteral injection vehicle. Castor oil has anti inflammatory properties too. I would not inject castor oil into my body unless it was vacuum distilled first.