- 188 views
- 393 downloads
Engineering Stable Bacteriophage Dosage Forms Active Against Antibiotic-Resistant Bacteria for Respiratory Delivery and Food Safety Applications
-
- Author / Creator
- Carrigy, Nicholas B.
-
The topic of this thesis is the engineering of stable bacteriophage dosage forms that are active against antibiotic-resistant bacteria for applications in respiratory delivery and food safety. Experimental methods and theoretical models are developed to test and understand the effects that various factors have on the biological stability and delivery of bacteriophages manufactured and aerosolized by various techniques.
Chapter 1 provides an introduction to the engineering of stable spray dried biologic powder for respiratory delivery. Descriptions of the processes that spray dried powder undergoes during development, manufacturing, and delivery are discussed. Processes covered include purification and formulation, atomization, solvent evaporation and particle formation, particle collection and analysis, aerosolization, and lung deposition. Additionally, particle engineering models, amorphous glass stabilization, spray dryer process models, and development of a supplemented phase diagram are reviewed.
Chapter 2 describes the development of a solid dosage form of anti-Campylobacter bacteriophages produced by spray drying. The effect that various factors such as purification technique, temperature, formulation, and atomization method have on bacteriophage inactivation are explored. Development of a method for packaging, shipping, and storing the powder at ambient temperature without inactivating the bacteriophage is detailed. The main inactivating stress is shown to be desiccation. The use of amorphous shell forming excipients is proposed to counter this stress and increase biological stability. Two fully amorphous formulations, trileucine and trehalose, and pullulan and trehalose, prove to outperform the standard leucine and trehalose formulation commonly used in the literature. Particle formation mechanisms are proposed for the different formulations tested.
Chapter 3 provides further characterization of the fully amorphous dry dosage form containing pullulan and trehalose in terms of manufacturability, physical stability, device compatibility, and aerosol performance. A multi-component analytical particle formation model is developed to estimate the time that a microdroplet evaporates prior to co-solidification into an amorphous solid phase at the surface. The model is used to predict normalized volume equivalent diameter to reasonable accuracy relative to experimental measurements performed with a monodisperse droplet chain. A radial glass transition temperature model is developed and the model predictions are shown to qualitatively match experimental modulated differential scanning calorimetry measurements on spray dried powder. The solid dosage form is promising for respiratory delivery, as aerosol performance using a dry powder inhaler is better than many commercial solid dosage forms. The powder is also found to be physically stable in propellant loaded into a pressurized metered-dose inhaler.
Chapter 4 provides a comparison of three commercial inhalation devices for the delivery of anti-tuberculosis bacteriophage D29 liquid lysate as an aerosol. A jet nebulizer, vibrating mesh nebulizer, and soft mist inhaler are compared in terms of bacteriophage inactivation and active bacteriophage delivery rate. A mathematical model of liquid recirculation in the jet nebulizer is used to quantify the renebulization and repeated baffle impaction processes the bacteriophage is exposed to in the device. The soft mist inhaler is shown to quickly deliver active bacteriophage, which is useful for self-administration. The vibrating mesh nebulizer is shown to be the best option for delivering large amounts of bacteriophage aerosol for animal studies.
Chapter 5 describes the delivery of active bacteriophage D29 aerosol to the lungs of mice using a nose-only inhalation device adapted for use with a vibrating mesh nebulizer. A dose simulation technique, involving experimental work aerosolizing a tryptophan tracer through the device with simulated mouse inhalation, is combined with theoretical modeling to predict the dose reaching the lungs of mice. In vivo measurements of bacteriophage D29 delivery to the lungs of mice with the nose-only inhalation device are shown to match model predictions. Prophylactic respiratory delivery of active bacteriophage D29 is found to offer significant protection to mice that are subsequently exposed to Mycobacterium tuberculosis aerosol.
Chapter 6 summarizes the main conclusions of this research, the new contributions to knowledge, and provides recommendations for future work. -
- Graduation date
- Fall 2019
-
- Type of Item
- Thesis
-
- Degree
- Doctor of Philosophy
-
- License
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.