Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods

Silicone elastomer systems have previously been shown to offer potential for the sustained release of protein therapeutics. However, the general requirement for the incorporation of large amounts of release enhancing solid excipients to achieve therapeutically effective release rates from these othe...

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Main Authors: McConville, Christopher, Andrews, G., Woolfson, A., Malcolm, R.
Format: Journal Article
Published: John Wiley and Sons Inc 2011
Online Access:http://hdl.handle.net/20.500.11937/43153
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author McConville, Christopher
Andrews, G.
Woolfson, A.
Malcolm, R.
author_facet McConville, Christopher
Andrews, G.
Woolfson, A.
Malcolm, R.
author_sort McConville, Christopher
building Curtin Institutional Repository
collection Online Access
description Silicone elastomer systems have previously been shown to offer potential for the sustained release of protein therapeutics. However, the general requirement for the incorporation of large amounts of release enhancing solid excipients to achieve therapeutically effective release rates from these otherwise hydrophobic polymer systems can detrimentally affect the viscosity of the precure silicone elastomer mixture and its curing characteristics. The increase in viscosity necessitates the use of higher operating pressures in manufacture, resulting in higher shear stresses that are often detrimental to the structural integrity of the incorporated protein. The addition of liquid silicones increases the initial tan δ value and the tan δ values in the early stages of curing by increasing the liquid character (G″) of the silicone elastomer system and reducing its elastic character (G′), thereby reducing the shear stress placed on the formulation during manufacture and minimizing the potential for protein degradation. However, SEM analysis has demonstrated that if the liquid character of the silicone elastomer is too high, the formulation will be unable to fill the mold during manufacture. This study demonstrates that incorporation of liquid hydroxy-terminated polydimethylsiloxanes into addition-cure silicone elastomer-covered rod formulations can both effectively lower the viscosity of the precured silicone elastomer and enhance the release rate of the model therapeutic protein bovine serum albumin.
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spelling curtin-20.500.11937-431532017-09-13T15:51:40Z Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods McConville, Christopher Andrews, G. Woolfson, A. Malcolm, R. Silicone elastomer systems have previously been shown to offer potential for the sustained release of protein therapeutics. However, the general requirement for the incorporation of large amounts of release enhancing solid excipients to achieve therapeutically effective release rates from these otherwise hydrophobic polymer systems can detrimentally affect the viscosity of the precure silicone elastomer mixture and its curing characteristics. The increase in viscosity necessitates the use of higher operating pressures in manufacture, resulting in higher shear stresses that are often detrimental to the structural integrity of the incorporated protein. The addition of liquid silicones increases the initial tan δ value and the tan δ values in the early stages of curing by increasing the liquid character (G″) of the silicone elastomer system and reducing its elastic character (G′), thereby reducing the shear stress placed on the formulation during manufacture and minimizing the potential for protein degradation. However, SEM analysis has demonstrated that if the liquid character of the silicone elastomer is too high, the formulation will be unable to fill the mold during manufacture. This study demonstrates that incorporation of liquid hydroxy-terminated polydimethylsiloxanes into addition-cure silicone elastomer-covered rod formulations can both effectively lower the viscosity of the precured silicone elastomer and enhance the release rate of the model therapeutic protein bovine serum albumin. 2011 Journal Article http://hdl.handle.net/20.500.11937/43153 10.1002/app.35080 John Wiley and Sons Inc restricted
spellingShingle McConville, Christopher
Andrews, G.
Woolfson, A.
Malcolm, R.
Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods
title Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods
title_full Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods
title_fullStr Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods
title_full_unstemmed Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods
title_short Effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods
title_sort effect of the incorporation of hydroxy-terminated liquid silicones on the cure characteristics, morphology and release of a model protein from silicone elastomer covered rods
url http://hdl.handle.net/20.500.11937/43153