PURPOSE The objective of this study was to prepare a suitable form of nanofiber for indomethacin using polymers Eudragit RS100 (ERS) and Eudragit S100 (ES) and to evaluate the effect of some variables on the characteristics of resulted electrospunnanofibers. METHODS Electrospinning process was used for preparation of nanofibers. Different solutions of combinations of ERS, ES and indomethacin ...

Recently, ethylcellulose/guar gum blends have been reported to provide ethanol-resistant drug release kinetics from coated dosage forms. This is because the ethanol insoluble guar gum effectively avoids undesired ethylcellulose dissolution in ethanol-rich bulk fluids. However, so far the importance of crucial formulation parameters, including the minimum amount of guar gum to be incorporated an...

One important class of hydrogels based on natural polymers is the Glycosaminoglycan (GAG)-based hydrogels. In hydrogels biomaterial science, the mathematical modeling and computer simulation plays a complementary interpretative role in deciphering the complex physical/chemical and biological properties of this class of substances. Aim: the molecular modeling studies presented here aimed the inf...

This paper describes an experimental study of the stability of a hydrolyzed polyacrylamide (HPAM) polymer and an HPAM-2acrylamido-tertbutylsulfonic acid (ATBS) terpolymer in the presence of varying initial levels of dissolved oxygen (0 to 8,000 ppb), Fe2þ (0 to 220 ppm), and Fe3þ (0 to 172 ppm). A special method was developed to attain and confirm dissolved-oxygen levels. Stability studies were...

Melt flow and dripping of the pyrolysing polymer melt can be both a benefit and a detriment during a fire. In several small-scale fire tests addressing the ignition of a defined specimen with a small ignition source, well-adjusted melt flow and dripping are usually beneficial to pass the test. The presence of flame retardants often changes the melt viscosity crucially. The influence of certain ...

The association of natural polymers with silica is a fruitful strategy to design novel hybrid structures with potential applications in the fields of biotechnology, medicine, and environmental sciences. Here we illustrate the principles of formation, the structure, and the properties of such biohybrid systems by the specific example of silica–pectin porous materials. The influence of the silica...

There are several different “types” of viscosities that one may encounter in fluid dynamics. First, we differentiate between the kinematic and dynamic viscosities, referred to by symbols ν and μ or η. They are related via the density of the medium, with ν = η/ρ. The units of dynamic viscosity are Poise or Pa.s and the dimensions are [ML−1T−1]. Kinematic viscosity has dimensions of [L2T−1] and i...

maybe viscosity in drilling fluid is the most important parameter because cutting removal from well are task of viscose fluid. if viscosity of fluid is less than particular value, cutting will settle down in well and drilling operation will be stopped. in this study, synthesis of alumina/polyacrylamide nanocomposite through solution polymerization method was performed. rheological behavior of m...

to describe the rheological behavior of polymer blends using emulsionbased (palierne theory) as well as micromechanical models (coranapproach), two immiscible polymeric blend systems of poly(trimethylene terephthalate) (ptt)/polyamide-12 (pa12) and ptt/polyethylene (pe) having different levels of molecular interactions were investigated as model systems. the role of interfacial interactions, vi...

mulation of semisolid bases, generally with a significant influence on their rheological properties. When organic amines are employed as neutralizing agents of carbopols, it is possible to gel many semipolar liquids and mixtures of these liquids with water. Compatibility of the polymer and non-polar solvents depends on the formation of ion pairs with the amine. Although alcohols are useful for ...