title: Solid-state encapsulation of Ag and sulfadiazine on zeolite Y carrier.
abstract: OBJECTIVE
  A new simplified procedure for encapsulation of antibacterial silver nanoparticles by Solid-state Ion Exchange (SSIE) procedure over zeolite Y, followed by deposition of sulfadiazine (SD) by dry mixing was examined for the preparation of topical antibacterial formulations. The ion-exchange and adsorptive properties of the zeolite matrix were utilized for the bactericidal Ag deposition and loading of antibiotic sulfadiazine.
  
  
  METHODS
  Assessment of the encapsulation efficiency of both active components loaded by solid and liquid deposition methods was made by X-ray diffraction, TEM, FT-IR spectroscopy and thermogravimetric analysis (TGA). SD release kinetics was also determined.
  
  
  RESULTS
  Sustained delivery of sulfadiazine has been observed from the Ag-modified zeolites compared to the parent HY material. It was found that if SD was loaded in solution, part of the zeolite silver ions was released and interacted with SD, forming AgSD. By solid-state SD deposition, the reaction between the drug and the silver was restricted within the limits of inter-atomic interaction, and total but prolonged drug release occurred.
authors.affiliation: Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. Electronic address: vesselinamavrodinova@yahoo.com.
authors.forename: Vesselina
authors.initials: V
authors.lastname: Mavrodinova
authors.affiliation: Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. Electronic address: mpopova@orgchm.bas.bg.
authors.forename: Margarita
authors.initials: M
authors.lastname: Popova
authors.affiliation: Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000 Sofia, Bulgaria. Electronic address: krassi.yoncheva@gmail.com.
authors.forename: Krassimira
authors.initials: K
authors.lastname: Yoncheva
authors.affiliation: Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary. Electronic address: mihaly.judit@ttk.mta.hu.
authors.forename: Judith
authors.initials: J
authors.lastname: Mihály
authors.affiliation: Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary. Electronic address: szegedi.agnes@ttk.mta.hu.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Szegedi
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D002214:Capsules / Q000737:chemistry; D004337:Drug Carriers; D064347:Microscopy, Electrochemical, Scanning; D012834:Silver / Q000737:chemistry*; D013411:Sulfadiazine / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D002214:Capsules; D004337:Drug Carriers; D013411:Sulfadiazine; D017641:Zeolites; D012834:Silver
keywords: Drug release; Solid state Ag ion-exchange; Sulfadiazine encapsulation; Zeolite Y carrier