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The effect of polymer properties on direct compression and drug release from water-insoluble controlled release matrix tablets.

International journal of pharmaceutics (2014-04-22)
Julia Grund, Martin Koerber, Mathias Walther, Roland Bodmeier
RESUMEN

The objective of this study was to identify and evaluate key polymer properties affecting direct compression and drug release from water-insoluble matrices. Commonly used polymers, such as Kollidon(®) SR, Eudragit(®) RS and ethyl cellulose, were characterized, formulated into tablets and compared with regard to their properties in dry and wet state. A similar site percolation threshold of 65% v/v was found for all polymers in dry state. Key parameters influencing polymer compactibility were the surface properties and the glass transition temperature (T(g)), affecting polymer elasticity and particle size-dependent binding. The important properties observed in dry state also governed matrix characteristics and therefore drug release in wet state. A low T(g) (Kollidon(®) SR<Eudragit(®) RS) decreased the percolation threshold, particle size effect and tortuosity, but increased permeability and sensitivity to heat/humidity treatment. Hence, lower permeability and higher stability are benefits of a high-T(g) polymer (ethyl cellulose). However, release retardation was observed in the same order as matrix integrity (Eudragit(®) RS<ethyl cellulose<Kollidon(®) SR), as the high permeability was counteracted by PVP in case of Kollidon(®) SR. Therefore, the Tg and composition of a polymer need to be considered in polymer design and formulation of controlled-release matrix systems.

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Sigma-Aldrich
Magnesium stearate, technical grade
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Sigma-Aldrich
Magnesium stearate, puriss., meets analytical specification of Ph. Eur., BP, ≥90% stearic and palmitic acid basis, ≥40% stearic acid basis (GC), 4.0-5.0% Mg basis (calc on dry sub.)
En este momento no podemos mostrarle ni los precios ni la disponibilidad