methods of delivery

I want to catagorise some known and unknown influencing factors on the half-life and potency of injected steroids.

Many factors determen the effect of a active componenet solved in an oily depot. That is the oily carrier itself, the preservative that is used to protect the oily injectable against bacteria and fungus. Then sometimes a solvent and a co-solvent is used, these solvents are also responsible for the viscosity and syringability. Meaning? The viscosity (thickness) of the oily injectable comes from the oily carrier, the solvent mostly benzyl benzoate and some co-solvents such as Ethanol, isopropyl alcohol, gauiacol and co-solvents such as Ethyl Oleate.