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Journal ArticleDOI

Solute diffusion in swollen membranes. IV. Theories for moderately swollen networks

Nicholas A. Peppas, +1 more
- 01 Jun 1985 - 
- Vol. 30, Iss: 6, pp 2589-2606
TLDR
In this article, a theoretical model was developed to describe solute transport through moderately swollen networks, which is an extension of the previous analysis of Peppas and Reinhart (1983), and it describes the normalized effective diffusion coefficient of the solute through the network as a function of the equilibrium degree of swelling.
Abstract
A theoretical model was developed to describe solute transport through moderately swollen networks. The model is an extension of the previous analysis of Peppas and Reinhart (1983), and it describes the normalized effective diffusion coefficient of the solute through the network as a function of the equilibrium degree of swelling, Q, the hydrodynamic radius of the solute, rs, the number average molecular weight between crosslinks, M¯c, and a function f(ξ) of the mesh size ξ, which takes into consideration barriers due to crosslinks, entanglements, etc. For the development of this model, the Cohen–Turnbull (1958) free volume theory was modified to incorporate topological and mobility characteristics from de Gennes' analysis (1979).

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Hydrogels in pharmaceutical formulations.

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Physical models of diffusion for polymer solutions, gels and solids

TL;DR: A review of physical models and theories of diffusion and their uses in describing the diffusion in polymer solutions, gels and even solids can be found in this article, where the applicability of the physical concepts is discussed.
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Higuchi equation: derivation, applications, use and misuse.

TL;DR: The aim of this review is to highlight the assumptions the derivation of the classical Higuchi equation is based on and to give an overview on the use and potential misuse of this equation as well as of related theories.
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Mathematical models in drug delivery: how modeling has shaped the way we design new drug delivery systems.

TL;DR: In this review, some of the seminal contributions that have established the mathematical foundations of controlled drug delivery and led to the modern models are presented.
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Solute and penetrant diffusion in swellable polymers. IV. Semicrystalline, swelling-controlled release systems of poly(ethylene-co-vinyl alcohol)

TL;DR: In this paper, the porosity and the degree of crystallinity of poly(ethylene-co-vinyl alcohol) copolymer were investigated for controlled release of theophylline.