I have been using fentanyl HCL for several months now. I usually just dissolve the fentanyl in a saline nasal spray that can be obtained from any pharmacy. However the fentanyl I just got is the freebase rather than the HCl salt that I am used to. I know that I dont need to use as much because the freebase weighs less than the salt. What I want to know is what the best/safest acid to use, to convert the freebase to a more soluble salt would be. I assume citric acid would be fine but I want to hear from anyone else that has experience preparing fentanyl nasal spray using the freebase form.
