New Test Method for New Standard Test Method for Measuring Sulfate and Ammonium Ion Concentrations in Liposome Drug Formulations
1. Scope
Standard test method for determination of ammonium and sulfate ions in liposomal-doxorubicin formulation in three different cases: 1) total amount of ammonium and sulfate, 2) amount of ammonium and sulfate inside liposome, and 3) amount of ammonium and sulfate outside liposome.
Keywords
entrapped ions; ion chromatography; separating entrapped and free ions
Rationale
Doxorubicin is actively loaded into liposomes by using transmembrane ammonium sulfate gradient. Ammonium and sulfate ion are important in determining stability of the doxorubicin liposomal formulation therefore a robust and standardized analytical method for determining their concentration is useful for drug manufacturers, clinicians as well as academic researchers.