distribution is the movement of the drug from the blood into tissue. Blood flow, how lipid soluble the drug is would determine how or pollen on polar would determine how wide it distributes. And then finally, it could be another one, but what I've found is the ability of the drug to be bound to plasma proteins. Ultimately for a drug to work, it needs to be free. It can't be locked onto something. Just like you and I, in order for us to do what we need to do, we need to be free,. We can't be bound by this chains, man. Face out.