Preparation Of Polypeptide Drugs Intercalated Layered Double Hydroxides And Investigations On Their Thermal Stability And Release Properties

In this thesis, two kinds of polypeptide drugs have been intercalated into layered double hydroxides, respectively, and the supramolecular structure models have been proposed. The properties including thermal stability of the intercalated materials as well as the drug release behavior have been investigated particularly.L-alanyl-L-glutamine (AlaGln) and glycyl-L-tyrosine (GlyTyr) were intercalated into the Mg-Al layered double hydroxide respectively by the method of coprecipitation. The structures and chemical compositions of these two intercalates were characterized by XRD, UV-vis, FT-IR, ¹³C NMR, ICP, and elemental analysis, and schematic models of the intercalated structures have been proposed respectively. Furthermore, their thermal stability and optical activity have been investigated in detail, by means of TG-DTA, in situ FT-IR, in situ XRD and automatic polarimeter. It was found that the thermolysis of intercalated L-alanyl-L-glutamine and glycyl-L-tyrosine was quite different from that of the pristine polypeptides.MgAl-GlyTyr-LDH film was fabricated by solvent evaporation method. Both the XRD pattern and SEM image demonstrate the extremely well c-oriented assembly of LDH platelets. In addition, in vitro drug release of this composite film was carried out in buffer containing phosphate anions. The results show that this drug-inorganic hybrid film can be used in an effective drug release system. Therefore, this work demonstrates the novel approach both improving thermal stability and achieving contrable release of a polypeptide drug with LDH as a "molecular container".