title: Inorganically modified diatomite as a potential prolonged-release drug carrier.
abstract: Inorganic modification of diatomite was performed with the precipitation product of partially neutralized aluminum sulfate solution at three different mass ratios. The starting and the modified diatomites were characterized by SEM-EDS, FTIR, thermal analysis and zeta potential measurements and evaluated for drug loading capacity in adsorption batch experiments using diclofenac sodium (DS) as a model drug. In vitro drug release studies were performed in phosphate buffer pH6.8 from comprimates containing: the drug adsorbed onto the selected modified diatomite sample (DAMD), physical mixture of the drug with the selected modified diatomite sample (PMDMD) and physical mixture of the drug with the starting diatomite (PMDD). In vivo acute toxicity testing of the modified diatomite samples was performed on mice. High adsorbent loading of the selected modified diatomite sample (~250mg/g in 2h) enabled the preparation of comprimates containing adsorbed DS in the amount near to its therapeutic dose. Drug release studies demonstrated prolonged release of DS over a period of 8h from both DAMD comprimates (18% after 8h) and PMDMD comprimates (45% after 8h). The release kinetics for DAMD and PMDMD comprimates fitted well with Korsmeyer-Peppas and Bhaskar models, indicating that the release mechanism was a combination of non-Fickian diffusion and ion exchange process.
authors: Department of Pharmaceutical Technology and Cosmetology, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe No. 450, 11221 Belgrade, Serbia. Electronic address: zoran.jan@ikom.rs.
authors: Jelena
authors: J
authors: Janićijević
authors: Department of Pharmaceutical Technology and Cosmetology, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe No. 450, 11221 Belgrade, Serbia.
authors: Danina
authors: D
authors: Krajišnik
authors: Department of Pharmaceutical Technology and Cosmetology, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe No. 450, 11221 Belgrade, Serbia.
authors: Bojan
authors: B
authors: Calija
authors: Department of Pharmaceutical Chemistry, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe No. 450, 11221 Belgrade, Serbia.
authors: Vladimir
authors: V
authors: Dobričić
authors: Institute for the Technology of Nuclear and Other Mineral Raw Materials, Bulevar Franš d'Eperea No. 86, 11000 Belgrade, Serbia.
authors: Aleksandra
authors: A
authors: Daković
authors: Institute for Chemistry, Technology & Metallurgy, University of Belgrade, Department of Catalysis & Chemical Engineering, Njegoševa No. 12, 11000 Belgrade, Serbia.
authors: Jugoslav
authors: J
authors: Krstić
authors: Institute for the Technology of Nuclear and Other Mineral Raw Materials, Bulevar Franš d'Eperea No. 86, 11000 Belgrade, Serbia.
authors: Marija
authors: M
authors: Marković
authors: Department of Pharmaceutical Technology and Cosmetology, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe No. 450, 11221 Belgrade, Serbia.
authors: Jela
authors: J
authors: Milić
mesh_terms: D000327:Adsorption; D000818:Animals; D003692:Delayed-Action Preparations / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity; D007692:Diatomaceous Earth / Q000737:chemistry* / Q000633:toxicity; D004008:Diclofenac / Q000737:chemistry / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D008422:Materials Testing; D051379:Mice
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004008:Diclofenac; D007692:Diatomaceous Earth; C033787:diatomite
keywords: Adsorption; Diatomite; Diclofenac sodium; Inorganic modification; Prolonged drug release