Dissolution behavior of porcine somatotropin with simultaneous gel formation and lysine Schiff-base hydrolysis.

摘要: The primary goal of this work was to develop a reliable in vitro dissolution model evaluate the effects Schiff-base hydrolysis and gel formation on kinetics pellets porcine somatotropin (pST) pST conjugated with ortho-vanillin (ov-pST) via formation, an effort extended-release implant. Experimentally, investigated as function ov concentration pH 7.4, phosphate buffered saline under sink conditions where steady-state (constant flux) is typically observed. However, resulting profiles displayed variable release rates due at solid-liquid interface, which impeded release. Chemical modification reduced also resulted much lower rates. A mathematical developed that quantitatively accounts for changes transient irreversible aggregation, along reversible involving ov, predicts presence decrease solubility ov-pST. Our results indicate although ov-pST less prone aggregate, pST/ov-pST equilibration rapid compared therefore aggregation remains limiting factor, ultimately precludes approach viable delivery system.