Abstract
The quality of commercially available semi-alkaline proteinase (SAP) preparations was studied by using high-performance liquid chromatography (HPLC) on a TSK G-3000 SW column, with 0.2M phosphate buffer (pH7.0) containing 0.1% sodium dodecyl sulfate (SDS) as a mobile phase. We could quantitatively separate SAP from enteric coating, excipients and degradation products of SAP in pharmaceuticals of various dosage forms, and follow the changes in their activities during storage. When the content of SAP in pharmaceuticals was determined by this HPLC method, commercially available SAP preparations were found to contain 60-78% of the labeled amount of SAP. HPLC chromatograms obtained in the heat stability test demonstrated that SAP both in the liquid and the solid state is degraded into small fragments in the course of inactivation. Inactivation of powdery SAP by ultraviolet irradiation and by compression force in tabletting could also be followed by using HPLC. This simple and precise HPLC method was proved to be useful for assessing the stability of SAP preparations and for investigating the mechanism of inactivation of this enzyme.
