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Interesting correlation between physicomechanical and in vitro release behavior of diltiazem hydrochloride has been obtained in physically treated poly(vinyl alcohol) (PVA) membranes of widely different molecular weights. Physical treatment could not raise crystallinity in dry state, but some of them show significant postswelled crystallinity and achieves elastomeric character. They also retain lot of equilibrium water, ideally suited for drug-impregnated transdermal patches. In effect, low molecular weight PVA and dimethyl sulfoxide-modified high molecular weight PVA membranes have shown acceptable release of diltiazem hydrochloride when compared with thermally treated high molecular weight PVA membrane. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Abstract: Extremely fast release of diltiazem hydrochloride (water soluble, anti anginal drug used to treat chest pain) together with its faster erosion has been the primary problem in conventional oral therapy. It has been addressed in this paper by encapsulating the drug in electron beam irradiated various poly (vinyl alcohol) hydrogel membranes and delivering it through transdermal route. Results show excellent control over the release of diltiazem hydrochloride through these membranes subject to their physico-mechanicals. [Copyright &y& Elsevier]

Aqueous nanosilica sol (particle size range: 9-13 nm, pH: 9.0) was added at various low concentration range (0.5-2 wt.%) into aqueous poly (vinyl alcohol) (PVA) of different molecular weight (98% hydrolyzed, 20 wt.%) (pH: 5.0) at room temperature under constant stirring to synthesize organic-inorganic hybrid hydrogels in presence of sodium lauryl sulphate as a silica dispersant. Buffer tablets were added to arrest the pH at 9.0 (to prevent any silica aggregation due to change in pH). The resultant hybrids were cast on Teflon sheets and dried in an oven at 50°C to drive out all the unbound water. Those films were then subjected to freese-thaw treatment continuously for 5 h. The freese-thawed films appeared opaque. The swelling-de swelling experiments with the hydrogels were carried out in distilled water at room temperature and consequently allowed to de-swell naturally. Those observations were correlated with the microstructures of the hybrid hydrogels. [ABSTRACT FROM AUTHOR]