Synthesis And Controlled Release Properties Of Hydrophobic Drug-Surfactant Micelles Intercalated Layered Double Hydroxide Composite

Four drug-inorganic composites involving hydrophobic drug-surfactant micelles intercalated Mg-Al layered double hydroxide (LDH) have been assembled by coprecipitation method. The selected hydrophobic drugs were prednisone (PNS) and Ethinylestradiol (EE), and sodium cholate (SC) and sodium oleate (SO) were shosen as the surfactants. Powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and UV-vis absorption spectroscopy indicate a successful intercalation of drug-containing micelles into galleries of LDH matrix.The in vitro drug release studies of three composites (PNS/SC-LDHs, PNS/SO-LDHs and EE/SC-LDHs) were investigated in detail. Four kinetic models (first-order equation, Higuchi equation, Bhaskas equation and Ritger-peppas equation) were chosen respectively to study the release kinetics of hydrophobic drugs from LDH carrier, and it was found that this process can be described satisfactorily by Directing Excel-based Solver (DEBS). The drug release mechanism was discussed by the n value in the R-P equation. The release mechanism is based on drug diffusion at high pH value, while the drug release behavior depends on the combination control of ion-exchange and dissolution of the composite at low pH value. Therefore, it is concluded that the MgAl-LDH can be potentially used as an inorganic drug carrier for hydrophobic drugs in a wide pH circumstance.