1,874 research outputs found
In vitro evaluation of a system for pH-controlled peroral delivery of metformin
No full textOral absorption of the antihyperglycaemic agent metformin (MF·HCl) is confined to the upper part of the intestine, therefore controlled-release oral formulations of this drug should ensure a complete release during transit from stomach to jejunum. Compressed matrix tablets based on pH-sensitive poly(ethylene oxide) (PEO)-Eudragit L100 (EUD L) compounds have shown in vitro a compliance with the above requirement. The polymer compounds were prepared by a coevaporation process. The release pattern of MF·HCl from matrices depended on the PEO-EUD L ratio in the coevaporate. The 1:1 (w/w) ratio was unable to control MF·HCl release in simulated gastric fluid (SGF, pH 1.2), because the matrix material was excessively hydrophilic. Nevertheless, the release rate in SGF could be modulated by increasing the EUD L fraction in the coevaporate. With a PEO (Mw, 400 kDa)-EUD L (1:2, w/w) ratio the percent dose released in 2 h to SGF, where the coevaporate was insoluble, was around 23 or 50% with 10 or 20% loading dose. The release was then completed within the successive 2 h of elution with simulated jejunal fluid (SJF, pH 6.8) where EUD L and the coevaporate gradually dissolved. Release in SGF was controlled by matrix swelling and/or drug diffusion in matrix, whereas matrix dissolution controlled release in SJF. The unique release-controlling properties of the polymer compounds were due to PEO-EUD L macromolecular interactions. Matrices show promise of a gradual and complete release of MF·HCl from stomach to jejunum, unaffected by gastric pH fluctuations. This mode of administration might allow the use of lower therapeutic doses compared to existing immediate- or sustained-release products, thus minimising side effects
Functional outcome after lower limb legthening in short stature using the callotasis method.
No full text“Acondroplasia: valutazioni auxometriche in 20 soggetti”. Rivista Italiana di Ortopedia e Traumatologia Pediatrica, Vol. XIII, Fascicolo 1, anno 1997.
No full textGli autori espongono i segni clinici e radiografici necessari a far diagnosi di acondroplasia. Sono stati studiati con metodo auxometrico 20 soggetti affetti da acondroplasia (10 maschi e 10 femmine) a fine accrescimento
A systematic review of catechol-o-methyltransferase inhibitors: efficacy and safety in clinical practice.
No full textCatechol-O-methyltransferase (COMT) inhibitors are drugs commonly used in the management of patients with Parkinson disease complicated by motor fluctuations. Among them, entacapone is the most commonly used. Tolcapone has been reintroduced in patients where entacapone has proved to be ineffective after being withdrawn from the market because of sporadic cases of hepatotoxicity. The last COMT inhibitor is nebicapone, which use in clinical practice is still under study.
OBJECTIVES: The objectives of this study were to analyze the clinical efficacy in reducing motor complications and to evaluate their use in clinical practice and the adverse events reported in the literature.
METHODS: Scientific articles of the main previously mentioned drugs have been reviewed.
RESULTS: All these 3 drugs have proved to be effective in improving wearing-off and significantly reduce the daily dose of levodopa at the number of daily intakes. Tolcapone is undoubtedly the most effective drug, although in clinical practice sporadic cases of hepatotoxicity have limited its use in patients unresponsive to entacapone. Nebicapone is effective, and its safety is still under evaluation. Entacapone is generally well tolerated, and no significant adverse events are reported.
CONCLUSIONS: To manage motor fluctuations, the use of COMT inhibitors is now consolidated in the common clinical practice. Tolcapone is used as a second choice in patients with severe motor fluctuations not responsive to entacapone
Allungamento degli arti inferiori mediante callotasi e condrodiatasi: programma di Rieducazione Funzionale.
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GELLAN GUM MICROPARTICLES FOR INTESTINE-TARGETED DELIVERY OF PROBIOTICS
No full textThis study focuses on developing carriers for probiotic formulations to create innovative functional foods. Among biobased polymers, gellan gum was chosen for encapsulating probiotic microorganisms due to its widespread use as a gelling agent in various foods and as an agar substitute for microbiological plate assays. Additionally, gellan gum microparticles have demonstrated cryoprotective and gastroretentive properties.
Lactobacillus Fermentum was used as model probiotic for this work. Gellan gum microparticles were produced by electrohydrodinamic microdripping. Gellan gum powder was disselved in distilled water at different concentrations (0.5, 1, 1.25 %wt) by stirring at 90°C. Solutions were autoclaved and pumped throug a stainless steel needle (positive high voltage). Microparticles were directly collected in 20 mL of 1%wt CaCl2 crosslinking bath (grounded). L. Fermentum was inoculated in De Man, Rogosa and Sharpe (MRS) broth and plated on MRS agar to determine colony-forming units (CFU). Bacterial suspensions were prepared determining OD600, centrifuged and resuspended in 1% wt gellan gum (GG1), to achieve probiotic loads of 106 CFU/mL (GG1-low) and 109 CFU/mL (GG1-high). GG1-low was re-incubated in MRS broth for 24 and 48h, and stained with Syto9 fluorescent dye to assess bacterial growth inside the particles.
A 1% wt gellan gum solution was identified and tested for probiotic entrapment. Wet particle size distributions were systematically studied at an optimized flow rate (1 mL/h) and voltage (25 kV) to evaluate the effect of probiotic inclusion. Empty particles had a mean size of 250 ± 50 μm, while GG1-low (106 CFU/mL) and GG1-high (109 CFU/mL) had sizes of 300 ± 40 μm and 450 ± 100 μm, respectively. Plating of the particles showed high probiotic viability post-encapsulation. Plating of the crosslinking bath after filtration displayed at least 2-log units less CFU with respect the dripped ones, indicating high encapsulation efficiency.
The obtained particles exhibited a size range suitable for the food industry, and various concentrations of microorganisms were successfully trapped inside the hydrogel matrix. Re-incubation of GG1-low and Syto9 staining demonstrated the ability of probiotics to grow both inside and on the surface of the particles. Overall, the tested processes proved effective for directly encapsulating high probiotic loads and regrowing probiotics within the particles. The latter method may potentially be utilized to produce particles containing both high loads of probiotics and postbiotics in a single formulation
Donepezil-loaded liposomes as innovative strategy to overcome P.gp dependent resistance in neurodegeneration
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