I am concerned about Codeine medication. What are the differences between the two medications Codeine Phosphate and Codeine Sulphate and why are these two different types available as medication? Are they both equally water soluble?
Both have high water solubility of greater than 100mg/ml. According to this ref. the sulfate has enhanced stability over the phosphate https://doi.org/10.1002/jps.2600750917