title: Delivery of a coated bioactive from a rumen controlled-release device

authors: Syzov, Vladyslav

subjects: Eudragit E100

abstract: Ruminants possess a unique digestive system. Using the high metabolic potential of the symbiotic microflora of the rumen, ruminants are capable of digesting plant material and obtaining nutrients and energy from this process. Because of the ruminal fermentation, the most bioactives are not stable in the harsh ruminal environment. Therefore there is a need to improve the bioavailability of a bioactive by protecting it from the ruminal digestion. The formulation of protected bioactive can be delivered in the rumen in a controlled manner and over a long period of time.

In this project the degree of rumen protection was estimated using model substrates (sugar pellets and granules). These materials were coated with the pH-sensitive polymer Eudragit E. The model bioactive (phloridizin) was coated using the coating methodology adopted from exploratory studies with model substrates. The bioavailability of protected (coated) phloridizin was assessed by administering directly into the abomasum of fistulated cows.

Formulation of protected phloridizin was used to demonstrate the feasibility of bioactive controlled delivery based on ART ( Active Rumen Technology ). This technology uses an elevated gas pressure created by a hydrogen-producing cell to drive a plunger which extrudes bioactive formulation from an intraruminal controlled-release device.

Four groups of devices filled with formulation containing different amounts of protected phloridizin were tested. The bioactive was released in a controlled manner over several days. The formulation release profiles were reproducible suggesting that in principle the technology can be further developed to use in a commercial sense or for research purposes. The limitations of the technology, including formulation issues and gas diffusion through barrel walls, were identified.

text: Delivery of a coated bioactive from a rumen controlled-release device Ruminants possess a unique digestive system. Using the high metabolic potential of the symbiotic microflora of the rumen, ruminants are capable of digesting plant material and obtaining nutrients and energy from this process. Because of the ruminal fermentation, the most bioactives are not stable in the harsh ruminal environment. Therefore there is a need to improve the bioavailability of a bioactive by protecting it from the ruminal digestion. The formulation of protected bioactive can be delivered in the rumen in a controlled manner and over a long period of time.

In this project the degree of rumen protection was estimated using model substrates (sugar pellets and granules). These materials were coated with the pH-sensitive polymer Eudragit E. The model bioactive (phloridizin) was coated using the coating methodology adopted from exploratory studies with model substrates. The bioavailability of protected (coated) phloridizin was assessed by administering directly into the abomasum of fistulated cows.

Formulation of protected phloridizin was used to demonstrate the feasibility of bioactive controlled delivery based on ART ( Active Rumen Technology ). This technology uses an elevated gas pressure created by a hydrogen-producing cell to drive a plunger which extrudes bioactive formulation from an intraruminal controlled-release device.

Four groups of devices filled with formulation containing different amounts of protected phloridizin were tested. The bioactive was released in a controlled manner over several days. The formulation release profiles were reproducible suggesting that in principle the technology can be further developed to use in a commercial sense or for research purposes. The limitations of the technology, including formulation issues and gas diffusion through barrel walls, were identified.

year: 2008

title: Novel six-coordinate Aryl- and Alkyltin  complexes

authors: Lloyd, Nicholas C.

subjects: chemistry

abstract: Organo-tin compounds have wide applications as pesticides and as intermediates for organic synthesis.¹ They are invariably Sn(IV) derivatives and are generally four-coordinate.² The mixed organo/chioro compounds of the type RnSnCI4-n do however have the ability to expand their coordination numbers to five or six. This depends critically on the substituents - with four organic groups, R₄Sn, there is no tendency at all to coordinate extra ligands, while at the other extreme SnCl₄ readily forms six-coordinate [SnC1₄L₂] complexes since the electronegative halo groups increase the Lewis acidity of the tin centre.

text: Novel six-coordinate Aryl- and Alkyltin  complexes Organo-tin compounds have wide applications as pesticides and as intermediates for organic synthesis.¹ They are invariably Sn(IV) derivatives and are generally four-coordinate.² The mixed organo/chioro compounds of the type RnSnCI4-n do however have the ability to expand their coordination numbers to five or six. This depends critically on the substituents - with four organic groups, R₄Sn, there is no tendency at all to coordinate extra ligands, while at the other extreme SnCl₄ readily forms six-coordinate [SnC1₄L₂] complexes since the electronegative halo groups increase the Lewis acidity of the tin centre.

year: 2002

title: Te Mātaiaho as curricular justice?

authors: Shafer, Derek

abstract: Te Mātaiaho produces a version of curricular justice which aims to give effect to Te Tiriti and address long-standing inequities in education in Aotearoa New Zealand. We examine Te Mātaiaho’s vision for subject English and its construction of students’ identities as fundamental to a curriculum that advances both bicultural nationhood and just outcomes for all students. We draw on Raewyn Connell’s (2010) model of curricular justice, and Nancy Fraser's (2017) notion of progressive neoliberalism to explore the opportunities and implications for subject English within Te Mātaiaho's vision. How might these frameworks for justice help to critique the development of educational policy and support the implementation of Te Mātaiaho's vision for biculturalnationhood and just outcomes for all students.

text: Te Mātaiaho as curricular justice? Te Mātaiaho produces a version of curricular justice which aims to give effect to Te Tiriti and address long-standing inequities in education in Aotearoa New Zealand. We examine Te Mātaiaho’s vision for subject English and its construction of students’ identities as fundamental to a curriculum that advances both bicultural nationhood and just outcomes for all students. We draw on Raewyn Connell’s (2010) model of curricular justice, and Nancy Fraser's (2017) notion of progressive neoliberalism to explore the opportunities and implications for subject English within Te Mātaiaho's vision. How might these frameworks for justice help to critique the development of educational policy and support the implementation of Te Mātaiaho's vision for biculturalnationhood and just outcomes for all students.

year: 2023-11-22