ABSTRACT
Tromethamine, a UV-transparent amine base excipient, was used in the liquid phase of a self-emulsifying drug delivery system-soft gelatin capsule (SEDDS-SGC) formulation as an emulsification agent and to improve solubilization of the active drug. The level of this excipient was found to be decreasing in aged and stressed drug product capsules. The decrease could potentially affect oral bioavailability of the drug; should the amount of solubilizer decrease enough to lead to precipitation of the active drug from the formulation. Therefore, further investigation was warranted. HPLC coupled with evaporative light scattering detection (ELSD) was used to monitor the physical and chemical stability of tromethamine in the SEDDS-SGC formulation. Confirmation of the tromethamine interaction products was done by LC-MS.
