Rheological and mechanical properties of hydrophilic dispersions using a new hydrophobically modified polymer and Igepal® CO520

All-natural composite wound dressing films of essential oils encapsulated in sodium alginate with antimicrobial properties

We present natural polymeric composite films made of essential oils (EOs) dispersed in sodium alginate (NaAlg) matrix, with remarkable anti-microbial and anti-fungal properties. Namely, elicriso italic, chamomile blue, cinnamon, lavender, tea tree, peppermint, eucalyptus, lemongrass and lemon oils were encapsulated in the films as potential active substances. Glycerol was used to induce plasticity and surfactants were added to improve the dispersion of EOs in the NaAlg matrix. The topography, chemical composition, mechanical properties, and humidity resistance of the films are presented analytically. Antimicrobial tests were conducted on films containing different percentages of EOs against Escherichia coli bacteria and Candida albicans fungi, and the films were characterized as effective or not. Such diverse types of essential oil-fortified alginate films can find many applications mainly as disposable wound dressings but also in food packaging, medical device protection and disinfection, and indoor air quality improvement materials, to name a few.

Drug diffusion from disperse systems with a hydrophobically modified polysaccharide: Enhancer vs Franz cells

This study assesses the capacity of a new hydrophobically modified polysaccharide -hydroxypropyl cellulose-methyl methacrylate - to control drug release in semisolid formulations. The dispersed systems contain the new polymer, Igepal CO520 as surfactant and theophylline as model drug at three concentrations (0.5, 1 and 1.5%, w/w). Drug release study shows that the systems containing 0.5% (w/w) of drug have faster release and higher diffusion coefficient than the other two concentrations. These results can be explained by two different structures ("relaxed" and "structured") found from a rheological point of view. Also, this paper compares two different devices for testing drug release and diffusion. It has been obtained more reliable and reproducible results with Enhancer Cell respect to Franz diffusion cell. In both cases, Fickian diffusion was the mechanism predominant for all systems. Finally, the utility of this polymer has been demonstrated to make three-dimensional gel structure and control theophylline release from systems in topical application.