Disproportionation of salts to their free acid or free base forms in aqueous suspensions or in the formulation media is a common problem encountered in the pharmaceutical industry.  Typically the rate at which disproportionation occurs is an important quantity that must be measured to determine if the salt candidate possesses adequate properties to be carried further or if a new candidate is required.  Crystal Pharmatech has experience in designing multi-nuclear ssNMR experiments that monitor disproportionation kinetics in API systems.