title: Design, development and optimisation of veterinary intravaginal controlled release drug delivery systems

authors: Ogle, Colin Roger

abstract: This Thesis begins by discussing the application of controlled drug delivery to the intravaginal delivery of hormones to control the oestrous cycle of farmed animals, with particular emphasis on the delivery of progestagens to cattle and sheep. The introduction highlights the recent advances made by animal physiologists in their knowledge of the oestrous cycle in cattle and sheep and how these advances have impacted upon the manner in which currently available intravaginal controlled release products are used. In addition it discusses the advances pharmaceutical scientists have made in response to the new knowledge.

The CIDR®1900 Cattle insert is a commercially available silicone based intravaginal delivery system containing the natural steroid progesterone for fertility regulation in cattle. It was designed in 1987 to be inserted for 12 days. Advances made in oestrous cycle understanding by animal scientists have resulted in this product being inserted for much shorter treatment periods of 7 days. Rathbone et al. recently optimised the CIDR®1900 Cattle insert for seven day insertion periods. The outcome of these scientists work was a manufactured prototype which, when compared to the CIDR®1900 Cattle insert, contained a reduced initial drug load and a much lower residual drug load after use. For commercial production the prototype insert needed to be scaled up. This process required detailed pharmaceutical characterisation, invitro release assessment, invivo bioequivalency and chemical and physical stability studies to be performed on the scaled up product (CIDR®1380 Cattle insert) to ensure the success of the scale up process. This characterisation process forms Chapters Two and Three of this Thesis.

Knowledge of the mechanism of release of a drug from a pharmaceutical product provides the formulation scientist with the necessary insight to optimise, further develop or recognise the potential and limitations of a product. Chapter Four explores the mechanism of release of progesterone from the silicone based CIDR® Cattle insert both invitro and invivo. Cumulative release data from both invitro and invivo studies were fitted against conventional mathematical models to determine the mechanism of release of progesterone from the CIDR® Cattle insert. In addition, an experimental method was developed to assess the validity of the models. The method involved taking thin consecutive horizontal slices from the surface of CIDR® Cattle inserts after various periods of release. Cumulative release of progesterone, both invitro and invivo, was linear when plotted against the square root of time, suggesting that release from the CIDR® Cattle insert occurred in accordance with the square root of time mechanism. However, experimental evidence from the horizontal slicing technique only supported the curve fitting evidence for invitro release. When the insert was investigated invivo, the slicing method indicated that a novel release mechanism was in operation which was better described by a zero order process.

Chapters Five and Six of this Thesis direct their focus to oestrus control in sheep. Chapter Five utilises information gained from both Rathbone et al. and the work performed in this Thesis on the CIDR® Cattle insert to characterise and optimise the commercially available sheep equivalent of the CIDR ® 1900 Cattle insert (known as the CIDR® Sheep and Goat insert). The Chapter successfully characterises the CIDR® Sheep and Goat insert, defines the parameters of, and tests, an optimised version of this sheep product.

The final Chapter of this Thesis investigates the use of poly-(ε-caprolactone) as a platform for the intravaginal delivery of progesterone to control oestrus in sheep. Silicone has certain limitations as a drug delivery platform, and with animal physiologists recent advances in knowledge, pharmaceutical scientists will need more versatile delivery platforms to develop intravaginal drug delivery systems which fulfil the future demands of the animal scientists.

text: Design, development and optimisation of veterinary intravaginal controlled release drug delivery systems This Thesis begins by discussing the application of controlled drug delivery to the intravaginal delivery of hormones to control the oestrous cycle of farmed animals, with particular emphasis on the delivery of progestagens to cattle and sheep. The introduction highlights the recent advances made by animal physiologists in their knowledge of the oestrous cycle in cattle and sheep and how these advances have impacted upon the manner in which currently available intravaginal controlled release products are used. In addition it discusses the advances pharmaceutical scientists have made in response to the new knowledge.

The CIDR®1900 Cattle insert is a commercially available silicone based intravaginal delivery system containing the natural steroid progesterone for fertility regulation in cattle. It was designed in 1987 to be inserted for 12 days. Advances made in oestrous cycle understanding by animal scientists have resulted in this product being inserted for much shorter treatment periods of 7 days. Rathbone et al. recently optimised the CIDR®1900 Cattle insert for seven day insertion periods. The outcome of these scientists work was a manufactured prototype which, when compared to the CIDR®1900 Cattle insert, contained a reduced initial drug load and a much lower residual drug load after use. For commercial production the prototype insert needed to be scaled up. This process required detailed pharmaceutical characterisation, invitro release assessment, invivo bioequivalency and chemical and physical stability studies to be performed on the scaled up product (CIDR®1380 Cattle insert) to ensure the success of the scale up process. This characterisation process forms Chapters Two and Three of this Thesis.

Knowledge of the mechanism of release of a drug from a pharmaceutical product provides the formulation scientist with the necessary insight to optimise, further develop or recognise the potential and limitations of a product. Chapter Four explores the mechanism of release of progesterone from the silicone based CIDR® Cattle insert both invitro and invivo. Cumulative release data from both invitro and invivo studies were fitted against conventional mathematical models to determine the mechanism of release of progesterone from the CIDR® Cattle insert. In addition, an experimental method was developed to assess the validity of the models. The method involved taking thin consecutive horizontal slices from the surface of CIDR® Cattle inserts after various periods of release. Cumulative release of progesterone, both invitro and invivo, was linear when plotted against the square root of time, suggesting that release from the CIDR® Cattle insert occurred in accordance with the square root of time mechanism. However, experimental evidence from the horizontal slicing technique only supported the curve fitting evidence for invitro release. When the insert was investigated invivo, the slicing method indicated that a novel release mechanism was in operation which was better described by a zero order process.

Chapters Five and Six of this Thesis direct their focus to oestrus control in sheep. Chapter Five utilises information gained from both Rathbone et al. and the work performed in this Thesis on the CIDR® Cattle insert to characterise and optimise the commercially available sheep equivalent of the CIDR ® 1900 Cattle insert (known as the CIDR® Sheep and Goat insert). The Chapter successfully characterises the CIDR® Sheep and Goat insert, defines the parameters of, and tests, an optimised version of this sheep product.

The final Chapter of this Thesis investigates the use of poly-(ε-caprolactone) as a platform for the intravaginal delivery of progesterone to control oestrus in sheep. Silicone has certain limitations as a drug delivery platform, and with animal physiologists recent advances in knowledge, pharmaceutical scientists will need more versatile delivery platforms to develop intravaginal drug delivery systems which fulfil the future demands of the animal scientists.

year: 1999

title: Janetta McStay: A pianist and teacher's legacy

authors: Mo, Heewon Maria

subjects: Janetta McStay

abstract: This thesis investigates the life and legacy of pianist and teacher Janetta Mary McStay (20 May 1917–14 June 2012) as one of the foremost musicians of the twentieth century in New Zealand, exceptional in her achievements and skill. McStay was the country’s first full-time lecturer in piano at the University of Auckland where she taught from 1963 to 1982. The majority of the data was gathered through primary research in a series of interviews with McStay’s former students in order to find out her pedagogical methods, their impressions of McStay as a performer, how her diverse interests and life experiences informed her musicianship, and her enduring legacy on themselves as well as the author.

The first two chapters supply McStay’s biographical information, from her early childhood, to studies in London, followed by years of touring for the Allied troops in the Second World War as part of the Entertainments National Service Association, post-war life, and her return to New Zealand. Interviews with McStay conducted by Catherine Mayo were a great help in constructing this narrative.

Chapter three investigates McStay’s pedagogy in depth, informed by the personal stories told by her former pupils. McStay’s initial years of teaching at the University of Auckland, the general atmosphere and pastoral care, and her methods of cultivating musicianship and technique, and criticisms from the students are discussed.

The last chapter details McStay’s last years and reflections from the students on the legacy she left behind. The thesis culminates with a story of my own experience while getting to know McStay through the stories of others, and the legacy she imparted unto me.

text: Janetta McStay: A pianist and teacher's legacy This thesis investigates the life and legacy of pianist and teacher Janetta Mary McStay (20 May 1917–14 June 2012) as one of the foremost musicians of the twentieth century in New Zealand, exceptional in her achievements and skill. McStay was the country’s first full-time lecturer in piano at the University of Auckland where she taught from 1963 to 1982. The majority of the data was gathered through primary research in a series of interviews with McStay’s former students in order to find out her pedagogical methods, their impressions of McStay as a performer, how her diverse interests and life experiences informed her musicianship, and her enduring legacy on themselves as well as the author.

The first two chapters supply McStay’s biographical information, from her early childhood, to studies in London, followed by years of touring for the Allied troops in the Second World War as part of the Entertainments National Service Association, post-war life, and her return to New Zealand. Interviews with McStay conducted by Catherine Mayo were a great help in constructing this narrative.

Chapter three investigates McStay’s pedagogy in depth, informed by the personal stories told by her former pupils. McStay’s initial years of teaching at the University of Auckland, the general atmosphere and pastoral care, and her methods of cultivating musicianship and technique, and criticisms from the students are discussed.

The last chapter details McStay’s last years and reflections from the students on the legacy she left behind. The thesis culminates with a story of my own experience while getting to know McStay through the stories of others, and the legacy she imparted unto me.

year: 2021

title: Stemming the colonial environmental tide

authors: Joseph, Robert

subjects: human activities

abstract: Stemming the colonial environmental tide supports an Aotearoa New Zealand context that fundamentally acknowledges mātauranga and tikanga Māori law and shared co-governance and concurrent jurisdiction through 7 Aotearoa New Zealand EBM principles.

text: Stemming the colonial environmental tide Stemming the colonial environmental tide supports an Aotearoa New Zealand context that fundamentally acknowledges mātauranga and tikanga Māori law and shared co-governance and concurrent jurisdiction through 7 Aotearoa New Zealand EBM principles.

year: 2022-05