Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"Hydroxypropyl cellulose"”.
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Towards Mechanochromic Devices using Biocompatible Hydroxypropyl Cellulose
Hydroxypropyl cellulose (HPC) is a widely utilised, low environmental impact material. When dissolved at high concentrations it forms structural colours via the formation of a cholesteric, liquid crystalline mesophase, termed photonic HPC. Intrinsically biodegradable, edible and mechanochromic, …
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Photonic Properties of Liquid Crystalline Hydroxypropyl Cellulose in the Solid-state
… architectures. More specifically, several cellulose derivatives exhibit a cholesteric liquid crystalline phase in solution, displaying vibrant structural colours. Amongst them, water-soluble hydroxypropyl cellulose (HPC) is ideal for developing sustainable photonic materials to replace …
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The interplay between order and disorder in cholesteric hydroxypropyl cellulose films
… nanoscale. An especially promising candidate is hydroxypropyl cellulose (HPC), a bio-sourced, bio-compatible and water-soluble polymer, which spontaneously assembles into a cholesteric mesophase reflecting bright and intense colours. Previous work has often assumed that the structure is a perfect …
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USE OF HYPROMELLOSE AND HYDROXYPROPYL CELLULOSE TO DEVELOP AN AGE APPROPRIATE PLATFORM TECHNOLOGY FOR THE ADMINISTRATION OF MEDICINES TO CHILDREN
… effect of temperature on aqueous hydroxyl propylcellulose (HPC) solutions showed that heating causes a reduction in solubility of HPC in water which results in its precipitation and the formation of liquid crystals. Consequently, the aqueous HPC solutions appear ‘cloudy’ and their viscosity …
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Polymer hydrogel nanoparticles and their networks
The thermally responsive hydroxypropyl cellulose (HPC) hydrogel nanoparticles have been synthesized and characterized. The HPC particles were obtained by chemically crosslinking collapsed HPC polymer chains in water-surfactant (dodecyltrimethylammonium bromide) dispersion above the lower critical …
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Design and Synthesis of Complex and Fluorescent Labeled Cellulose-Based Derivatives for Orally Administered Drug Delivery Systems
Cellulose ethers are valuable matrices for drug-delivery systems (DDS), namely amorphous solid dispersions (ASD). ASD are efficient vehicles that can solubilize and stabilize poorly soluble drugs by increasing the time that it takes for drugs to crystallize, thereby allowing higher drug …
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Thermoplastic xylan derivatives and related blends
… temperatures well above Tg. The ether derivative hydroxypropyl xylan was found to flow at substitution levels higher than 0.5 degree of substitution, with melt viscosity decreasing as the degree of substitution increased. The influence of viscosity ratio and composition on the texture of …
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CAPSULAR DEVICES FOR ORAL MODIFIED RELEASE OF DRUGS PREPARED BY INJECTION MOLDING
… It consists of a capsule shell, made of hydroxypropyl cellulose (HPC), prepared by injection molding (IM); it is intended to be filled with different types of drug preparations and to delay their liberation after oral administration. Such devices prepared by means of a prototype mold were …
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Cellulose-based amorphous solid dispersions enhance rifapentine delivery characteristics and dissolution kinetics in vitro
… pH-responsive amorphous solid dispersions with cellulose derivatives including: hydroxypropylmethylcellulose acetate succinate (HPMCAS), cellulose acetate suberate (CASub), and 5-carboxypentyl hydroxypropyl cellulose (CHC). Most amorphous solid dispersions reduced rifapentine release at gastric …
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Fused deposition modelling three-dimensional printing of solid dosage forms
… polymeric carriers (Polyvinyl alcohol (PVA), Hydroxypropyl Cellulose (HPC), and Soluplus®). FDM-3DP enabled the manufacture of monolithic and non-monolithic floating drug delivery systems using a sandwich design. The tablet design showed the ability to achieve prolonged gastric floating (12 …
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Characterizing Interfacial and Bulk Interactions Between Cellulose Ethers and Bile Salts: Impact on In Vitro Lipid Digestion
… limiting the access of BS to the lipid surface. Cellulose ethers (CEs), surface-active dietary fibers and common food additives, might be promising ingredients to control lipid digestion either by creating surface layers around lipid droplets that hinder adsorption of BS, or by sequestering BS in …
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Synthesis of Polysaccharide-based Biomaterials for Drug Delivery
… and pH-responsive hydrogels using oxidized hydroxypropyl cellulose (Ox-HPC)/carboxymethyl chitosan (CMCS) crosslinked by imine bond. Phenylalanine as a model amine-containing drug was chemically bonded to the Ox-HPC hydrogel component and was observed to release faster at the pH of a tumor …
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Adsorption/Desorption Process of Stimuli-Responsive Polymers on Simulated Natural Surfaces Using QCM-D & AFM Analysis
… The dispersing agent is largely comprised of hydroxypropyl cellulose and lecithin, agriculturally derived chemicals commonly used in the food industry. Spilled or leaked oil is a continued threat to the environment and wildlife. Though dispersants are commonly used to combat oil spills in the …
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Fabrication and light scattering study of multi-responsive nanostructured hydrogels and water-soluble polymers.
… (LCST) of the PNIPAM. Surfactant-free hydroxypropyl cellulose (HPC) microgels have been synthesized in salt solution. In a narrow sodium chloride concentration range from 1.3 to 1.4 M, HPC chains can self-associate into colloidal particles at room temperature. The microgel particles …
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Development of supercritical processes for particle coating / encapsulation with polymers
… poly vinyl chloride-co-vinyl acetate (PVCVA) and hydroxypropyl cellulose (HPC) although the coating was not uniform and not continuously distributed over the surface of the particles. The main part of this work is the study of the SAS process for particle coating. The supercritical fluid worked as …
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Cure studies of network-forming polyurethanes
… of polyurethanes. The cure characteristics of hydroxypropyl-cellulose and hydroxypropyl lignin (HPC and HPL, respectively) with polymeric methylene diphenyl diisocyanate (MDI) was studied via dynamic mechanical thermal analysis (DMTA). HPC/MDI and HPL/MDI resins flow at 30°C and proceed to cure …
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Secondary interactions in blends of lignin and cellulose derivatives: composite morphology and properties
… to characterize the morphology of solvent cast hydroxypropyl cellulose (HPC) films. These techniques revealed the existence of three phases in the bulk material: 1) an amorphous phase, 2) a crystalline phase, and 3) a phase of intermediate order which arises as a consequence of liquid crystal …
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Synthesis and characterization of fluorinated cellulose derivatives
The synthesis of fluorinated cellulose derivatives was pursued for the purpose of investigating the effects of fluorine on the interfacial properties of cellulose derivatives, in multiphase materials. Synthetic approaches included: 1) the replacement of hydroxyl groups on cellulose with fluorine …
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Synthesis of Polysaccharide Aldehydes or Ketones and Fabrication of Derived Hydrogels or Microgels
… of nanometer to micron diameters) using oxidized hydroxypropyl cellulose (Ox-HPC), carboxymethyl chitosan (CMCS), and calcium chloride. By tuning the calcium concentration, uniform microgels can be obtained with gel size in the hundreds of nanometers. Model amine-containing drugs such as picloram …
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Assessment of nanocomposites vs. amorphous solid dispersions for dissolution enhancement of bcs class ii drugs
… via combined use of a polymer (HPC: hydroxypropyl cellulose)-anionic surfactant (SDS: sodium dodecyl sulfate). A microhydrodynamic model is used for enhanced process understanding of the wet media milling process and rational selection of bead sizes. Then, the media milling process is …
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