Matias R. Lanfranconi; Vera A. Alvarez;Leandro N. Ludue
Abstract
In this work, Differential Scanning Calorimetry (DSC) was used to study the crystallization behavior of nanocomposites based on polycaprolactone (PCL) reinforced with organo-montmorillonite (C20A) and organo-bentonite (B-THBP) under non-isothermal conditions. The effect of clay content (0.0, 2.5, 5.0 ...
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In this work, Differential Scanning Calorimetry (DSC) was used to study the crystallization behavior of nanocomposites based on polycaprolactone (PCL) reinforced with organo-montmorillonite (C20A) and organo-bentonite (B-THBP) under non-isothermal conditions. The effect of clay content (0.0, 2.5, 5.0 and 7.5 wt.%) was analysed. Linear and non-linear regression methods were used to calculate theoretical kinetic parameters. The study was focused on the correlation between the non-isothermal crystallization process and the morphology of the clay inside the PCL matrix. Continuous cooling transformation diagrams were obtained by means of a mathematical model that involves both induction and growth of the crystal during cooling. For the construction of these diagrams, both crystallization steps, crystals induction (analysed by the induction time equation) and growing (studied by a crystal growth model), were considered.
Himansu Sekhar Nanda; Naoki Kawazoe; Guoping Chen
Abstract
Biodegradable polymeric microspheres have been used for microencapsulation of number of drugs for controlled delivery applications. Water-in-oil-in-water (w/o/w) double emulsion has been employed for preparation of drug incorporated poly(lactic-co-glycolic acid) (PLGA) microspheres. In the present ...
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Biodegradable polymeric microspheres have been used for microencapsulation of number of drugs for controlled delivery applications. Water-in-oil-in-water (w/o/w) double emulsion has been employed for preparation of drug incorporated poly(lactic-co-glycolic acid) (PLGA) microspheres. In the present study, existing double emulsion method was modified by introducing ionic salt in continuous phase of emulsion process. Insulin incorporated microspheres were prepared from wide range of PLGA concentrations under an identical preparation condition and the influence of varied concentration of salt on microsphere characteristics was studied. The results demonstrated, the degree of solidification of PLGA was controlled using ionic salt and the prepared formulations showed improved morphology, enhanced encapsulation efficiency and a positive modulation over the drug release characteristic compared to control. The modified method should be useful for elimination of highly porous and collapsed microspheres in the formulations prepared from low range PLGA concentration and should pave the way to improve several microsphere formulations for controlled drug delivery applications.
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