New method for preparation of delivery systems of poorly soluble drugs on the basis of functionalized mesoporous MCM-41 nanoparticles

MCM-41 silica with spherical morphology and small particle sizes (100 nm) was synthesized and modified by post-synthesis method with amino and/or carboxylic groups. Solid state reaction was applied for the first time for loading of poorly soluble drug mesalazine (5-aminosalicylic acid – 5-ASA). Thenon-loaded and drug loaded mesoporous silicas were characterized by XRD, TEM, N2 physisorption, elemental analysis, thermal analysis, FT-IR and solid state NMR spectroscopy. Quantum-chemical calculations were used to predict the interactions between the drug molecule and the functional groups of the carrier. The nanoparticles were post-coated with sodium alginate and the coating modified the rate of mesalazine release from MCM-41NH2 and MCM-41NH2COOH particles. Cytotoxic evaluation on colon adenocarcinoma cell line revealed that the alginate coating reduced cytotoxicity of mesalazine loaded in the post-coated particles compared to the pure mesalazine. The functionalized, polymer coated mesoporous systems are suitable oral drug delivery systems providing an opportunity to modify drug release

Preconcentration Methods for Determination of Thallium in Natural Waters

Two preconcentration procedures for electrothermal atomic absorption (ETAAS) determination of thallium in mineral, spring, tap, river, underground and sea water were developed and compared: (i) Column solid phase extraction with new sandwich type disposable sorbent columns

Preconcentration Methods for Determination of Thallium in Natural Waters

Two preconcentration procedures for electrothermal atomic absorption (ETAAS) determination of thallium in mineral, spring, tap, river, underground and sea water were developed and compared: (i) Column solid phase extraction with new sandwich type disposable sorbent columns