Corn starch is modified with citric acid (2.5% w/w) in aqueous, alcoholic media and in solid solid reaction (dry heat condition without any solvent). Degree of substitution is similar for both treatments, independent of use of solvent but higher than for dry heated starch citrate. Apparent amylose content of all starch citrates is higher than for native starch. Molecular weight, as determined by triple detection size exclusion chromatography, also decreases, demonstrating hydrolysis of chains. As a consequence, starch citrate prepared using dry heating and ethanol, as compared to aqueous media, show drastic reduction in pasting viscosity. X-ray diffraction pattern and morphology of the produced starch granules remain unaltered in all three reaction types. Starch citrates prepared using solvent less reactions show similar characteristics as that of conventional hydrolysis performed using concentrated hydrochloric acid. However, the solid solid hydrolytic reaction process using citric acid is far more environmental friendly and less costly than typical conventional hydrolysis processes. The present study is not only useful for starch systems but more generally for studying reactions in, for example, gums and cellulose.

No abstract

The work deals with the preparation of Zinc Oxide (ZnO) thin films on microscopic glass substrate by spray pyrolysis technique. The systematic study on the influence of Mn doping up to 15% has been performed. The structural studies revealed that pure and doped film has hexagonal structure. In order to reduce the internal strain due to Mn doping, the crystallite size decreases. The atomic force microscopy (AFM) measurement shows the decrease in grain size and roughness with doping. The resistivity curve shows a clear hump corresponding to smaller Mn doping ([Formula: see text]) around [Formula: see text]. This hump was found to reduce with the increase in Mn concentration and for [Formula: see text], beyond which it vanishes completely. This is attributed to critical behavior of resistivity and may be due to the scattering of carriers by magnetic spin fluctuation via exchange interaction. The optical measurement shows the shift in absorption edge of Mn doped ZnO films toward the longer wavelength side. This correlates the reduction in grain size as a function of Mn concentration. The optical bandgap goes down, whereas refractive index increases with dopant concentration.

No abstract

: Present review highlights the potential of vermillion border as an administration route for targeting drug delivery. Vermillion border could attract a broad observation of researchers as a convenient, non-invasive, reliable, and safe route to realize faster and better levels of drugs within the targeted site. It is thought to do so through the rich supply of blood vessels and nerve supply following the neural pathway which could bypass the varied physiological barriers and permit the direct transport of drug from the vermillion border to the target site. Herein, authors tried to highlight the prominent aspects and key findings relevant to drug delivery system for targeting drug delivery via transvermillion route of drug administration. Anatomy and physiology of lips, key benefits offered by lips drug delivery system, mechanism of drug absorption across lip skin. The intrinsic advantage of this system results in administration of required drug with its reduced dose and reducing its side effect. This innate advantage of targeted drug delivery system is under high deliberation of research and development in clinical and pharmaceutical fields as backbone of therapeutics and diagnostics too. The goal of a targeted drug delivery system is to extend, localize, target and have a protected drug interaction with the diseased tissue.