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Abstract: This paper reports interesting differences between physical and mechanical properties of various membranes prepared from high and low molecular weight poly (vinyl alcohol) (PVA) and xanthan gum (XG) blends irradiated under low dose electron beam. The membranes were designed for sustained delivery of diltiazem hydrochloride through skin. Electron beam irradiation produced crosslinks and turned PVA into crystalline phase from its amorphous organization in the unirradiated state. PVA crystals were fibrillar at low XG content (1wt.%) when the molecular weight was high while similar orientation at higher XG content (5wt.%) when the molecular weight was low. Low molecular weight PVA–XG membranes showed equivalent physical properties under dry condition but wet-mechanical properties were superior for high molecular weight PVA–XG hybrids. Both of them showed slow and sustained diltiazem release but the later induced slightly slower release despite low drug encapsulation efficiency due to its better wet mechanical strength. [Copyright &y& Elsevier]

Abstract: Membranes with high strength and elasticity are of great demand in patch therapy. Similar membranes have been developed by combining carboxy-functionalized multiwalled carbon nanotube (c-MWCNT) with different poly(vinyl alcohol) (PVA) as potential diltiazem delivery device through aqueous mixing. High molecular weight PVA (PVAH) produced stronger interaction with c-MWCNT than low molecular weight PVA (PVAL) preferably at low concentration. Positive changes in favor of PVAH in infrared and solid state 13C nuclear magnetic resonance spectroscopy, wide angle X-ray scattering, thermal stability, morphology and dry and wet mechanical properties clearly demonstrate that. Fibrillar c-MWCNT array at 1wt.% in PVAH (PVAH/1) has drastically improved PVA crystalline cell dimension, tensile strength (201%) and elongation (196%) than neat PVAH whereas the similar improvement is much less (100% and 185%) in PVAL (PVAL/1) due to globular morphology. Instead, c-MWCNT performed better at 0.5wt.% in PVAL (PVAL/0.5). The kinetic data reflects better encapsulation and slower release by PVAH (5.87%) than PVAL (10.17%) due to greater interfacial interaction. [Copyright &y& Elsevier]

Abstract: Green, hydrophobic device for controlled transdermal release of diclofenac sodium was designed from in situ nanosilica/acrylic acid grafted guargum membranes. Best grafting condition was assigned and nanocomposites were formed in situ using varying proportions of aqueous nanosilica sol. Nanocomposite/drug conjugates were formed by bringing down the medium pH from 9.0 to 7.0. The conjugates were characterized through infrared and solid state NMR spectroscopy, electron microscopy, hydro-swelling, surface contact angle, viscometry and biocompatibility. Most balanced property was exhibited by the membrane containing 1wt% nanosilica. It also had shown the highest encapsulation efficacy vis-à-vis slowest release as compared to others during experimentation in a Franz diffusion cell. [Copyright &y& Elsevier]

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]