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dc.contributor.authorMarks, Joyann Audreneen_US
dc.date.accessioned2017-03-08T07:00:28Z
dc.date.available2017-03-08T07:00:28Z
dc.date.issued2015-09-14en_US
dc.identifier.othervt_gsexam:6222en_US
dc.identifier.urihttp://hdl.handle.net/10919/75307
dc.description.abstractIn an effort to produce new derivatives of cellulose for drug delivery applications, methods were developed to regioselectively modify C-6 halo cellulose esters to produce cationic derivatives via nucleophilic substitution. Reaction of C-6 substituted bromo and iodo cellulose with trialkylated amines and phosphines produced new cationic ammonium and phosphonium cellulose derivatives which can be explored as delivery agents for nucleic acids, proteins and other anionic drug molecules. It was anticipated that these new derivatives would not only be capable of complexing anionic drug molecules but would have greatly improved aqueous solubility compared to their precursors. The phosphonium derivatives described in this work are an obvious example of such improved solubility properties. Given the importance of cellulose derivatives in making amorphous dispersions with critical drugs, it has also been important to analyze commercially available polymers for the potential impact in oral drug delivery formulations. To do so pairwise blends of cellulosics and synthetic polymers commonly used as excipients were tested for miscibility using techniques such as DSC, mDSC, FTIR and film clarity. Miscible combinations highlight the potential to use combinations of polymers currently available commercially to provide drug delivery solutions for specific drug formulations. The use of melt extrusion in processing some of these drug/polymer dispersions provides a means of highlighting the capability for the use of these cellulosics in melt extruded amorphous dispersions. This solvent free, high pressure method significantly reduces cost and time and can be applied on a large scale. The analysis of long chain cellulose esters and ultimately the novel omega carboxy esters for melt processability significantly impacts the possibilities available for use of those excellent drug delivery agents on a much larger scale.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectpairwise blendsen_US
dc.subjectamorphous solid dispersionen_US
dc.subjectoral drug deliveryen_US
dc.subjectcellulose estersen_US
dc.subjectbioavailabilityen_US
dc.subjectcationic celluloseen_US
dc.subjectextrusionen_US
dc.titleSynthesis and Applications of Cellulose Derivatives for Drug Deliveryen_US
dc.typeDissertationen_US
dc.contributor.departmentLearning Sciences and Technologiesen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMacromolecular Science and Engineeringen_US
dc.contributor.committeechairEdgar, Kevin J.en_US
dc.contributor.committeememberTurner, Sam Richarden_US
dc.contributor.committeememberTaylor, Lynne S.en_US
dc.contributor.committeememberRoman, Marenen_US
dc.contributor.committeememberRiffle, Judy S.en_US


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