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In- vitro dissolution testing of oral thin films: a comparison between USP 1, USP 2 apparatuses and a new millifluidic flow-through device
No full textThin strips of polymeric films have been recently proposed as a promising drug delivery alternative for non-compliant patients (geriatric, children, bedridden) and different therapeutic classes (e.g. vaccines, peptides and nanoparticles).In this work, a new millifluidic continuous flow-through device is proposed for dissolution studies of oral dissolving strips. The millifluidic device is covered by patent. The flow-through device mimics mouth physiological conditions thanks to the laminar tangential solvent flow, flow rates order of 1 mL/min and low hold-up volume (1 cm3). Pilot dissolution tests have been performed on commercially available melatonin strips with different initial drug loadings and thicknesses. Dissolution profiles obtained with the flow-through device are compared with those obtained using the official USP XXXVII basket (USP 1) and paddle (USP 2) apparatuses
Alternating Magneting Field for Controlled Release from Iron Oxide Nanoparticle Entrapping Extruded Liposomes: Vesicles Characterization an Generator Apparatus Development
No full textNon-phase transition magnetic-responsive liposomes controlled by low intensity magnetic stimuli
No full textControllable release from high-transition temperature magnetoliposomes by low-level magnetic stimulation
No full textHigh-transition temperature liposomes with embedded coated magnetite nanoparticles were prepared using the thin lipid film hydration method in order to obtain magnetoliposomes not sensitive to temperature increase (at least up to 50 degrees C). Accordingly, drug can be released from such magnetoliposomes using a low-level electromagnetic field as triggering agent, while no delivery would be obtained with temperature increase within the physiological acceptable range. The hypothesized release mechanism involves mechanical stress of the liposome membrane due to nanoparticles oscillations and it is investigated by means of a numerical model evaluated using multiphysics simulations. The carrier content was repetitively released by switching on and off a 20 kHz, 60 A/m magnetic field. The results indicated high reproducibility of cycle-to-cycle release induced by the magnetic-impelled motions driving to the destabilization of the bilayer rather than the liposome phase transition or the destruction of the liposome structur
Preparation and characterization of lipid vesicles entrapping iron oxide nanoparticles
No full textNanometric assemblies, activated and controlled through external stimuli, represent an innovative stage in the development of multifunctional therapeutics. In particular, magnetite nanoparticles embedded in liposomes represent submicrometric carriers that can be activated by external magnetic fields, showing high efficacy in reaching tumor cells offering new exciting opportunities towards the development of active targeting systems. Actually, synthesis and characterization of such nanoscale carriers, as well as the assessment of their entrapment capacity, is of great interest for the scientific community. We report here the formation and the characterization of magnetoliposomes (MLs): phospholipid vesicles encapsulating magnetite nanoparticles. MLs were prepared by embedding hydrophilic nanoparticles of commercially available carboxymethyl-dextran coated superparamagnetic iron oxide particles inside the vesicles at different lipid/nanoparticles ratios. Liposomes were prepared by the thin lipid film hydration method: a fixed amount of lipids was dissolved in organic solvent and the obtained solution was evaporated until dryness. Then the dry lipid film was hydrated with a buffered aqueous solution of different concentrations of carboxymethyl-dextran coated magnetite. The resulting MLs, heterogeneous in their size, were extruded through polycarbonate membranes to obtain homogeneous size of unilamellar vesicles. Size exclusion chromatography was used to remove non-entrapped nanoparticles. Magnetite content was determined by 1,10-phenanthroline (Kiwada assay) and Belikov methods and also by flame absorption spectrometry. Physical characterization was performed by dynamic light scattering to determine the mean particles diameter, the size distribution, and the ζ-potential. Physical stability of MLs stored at 4 °C was investigated up to 4 weeks to assess the effect on time of the entrapment of the nanoparticles within the liposomes. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd
CONTROLLED DRUG RELEASE FROM EXTRUDED MAGNETOLIPOSOMES UNDER LOW INTENSITY ALTERNATING MAGNETIC FIELD
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