Study On The Preparation And Release Behavior Of The Temperature-sensitive ZnAl-LDH Drug Release System

Layered double hydroxide has been an important block of building functional composite materials due to its positive charges in the plates and the exchangeability of the interlayer ions.One of which is preparation of drug control-released carriers.Among these studies,preparation of layered double hydroxides responsive to the environment,such as temperature,acid,alkali,magnetic field and optics,is more attractive to the actual demand and development.Therefore this paper is important and has potential application value.In this thesis,3 kinds of thermo-sensitive LDH drug control-released carriers were prepared by coprecipitation and layer-by-layer self-assembly method,using poly(N-isopropyl acrylamide)(PNIPAM)as the temperature responsive matter.Then their release ability was studied in detail.The main work is:(1)ZnAl-(AA + PNIPAM)-LDHs co-intercalated with aspirin(AA)and PNIPAM were prepared via coprecipitation and their release ability for AA was studied.The results indicated that the drug carriers were thermo-sensitive.Then four kinds of models were used to simulate the release of AA data.The data showed that the co-intercalated LDH drug carriers fitted to the Bhaskar equation well,and the release of AA was controlled by its movement within interlayer of LDHs.(2)LDH(AA)-assembly-10 and LDH(AA)-assembly-15 assemblies were prepared by layer-by-layer self-assembly method using partially exfoliated magnetic Zn Al-AA-LDH as core,and AA and PNIPAM micelle as well as completely exfoliated Zn Al-LA–LDH as building blocks.The release behavior of the assemblies was studied at room temperature and 40 ?.Characteristics of responsive to temperature,magnetic field and step-by-step release were observed.The prepared assemblies were functional carriers sensitive to for many factors.(3)LDH(FA)-assemblies intercalated with ferulic acid were prepared by using the same route as preparation of LDH(AA)-assembly.And the drug release behavior of the assemblies was studied.Temperature responsive ability was still observed.