Search

The silver nanoparticles (AgNPs) were synthesized by reduction in water with/without stabilizing agent, polyethylene glycol (PEG). The UV–Vis Spectroscopy and Scanning Electron Microscopy (SEM) were used to characterize the synthesized silver nanoparticle. The stability of nanoparticles has been studied in sunlight and dark. UV–Vis results showed a clear blue shift in PEG-stabilized nanoparticles, indicating that stabilized Ag particles were narrow in size. SEM results indicated that size of PEG-stabilized AgNPs was comparatively smaller and spherical in shape. AgNPs suspension behaved like non-Newtonian fluid with a certain amount of yield stress. [ABSTRACT FROM AUTHOR]

Quite a high percentage of newly discovered drugs are discarded due to their low aqueous solubility and variable bioavailability. Therefore, it is necessary to explore new methodologies for increasing the aqueous solubility of such drugs. Several procedures have been proposed for this purpose, including salt formation, particle size reduction or using surfactants. In this report, we have improved the aqueous solubility of flurbiprofen by employing aqueous solution of anionic (SDS, SDBS), cationic (DTAB, CTAB, TTAB), non-ionic (Triton X-100 and Triton X-114 and DDAO) and zwitterionic DDAPS surfactants. It is concluded that all of the surfactants increased the solubility of flurbiprofen which increased with the increasing surfactant concentration. The reason behind such a trend was that the drug is partitioned between micelles and the aqueous phase. An increase in aqueous solubility of the drug was correlated with the (molar) solubilization ratio (χ), partition coefficient of drug (KM) between micelle and water, binding constant (K1) and standard state Gibbs energy of solubilization ( Δ G s o ) of the drug in the micelles. The order of drug solubilization in nonionic and zwitterionic surfactants was found as Triton X-114 > Triton X-100 > DDAO > DDAPS. In the case of anionic surfactants, it was noted as SDBS > SDS, whereas cationic surfactants solubilized the drug in the order of CTAB > TTAB > DTAB. The differences in χ and log10KM are attributed to the structural features of the surfactants. The aggregation number, HLB, core volume of micelles and electrostatic interaction between drug and micelles play important roles in solubilization of drugs in micellar solutions. The nonionic surfactants proved to be better, due to their low critical micelle concentrations higher solubilization capability and nontoxic nature; they were also found to have better drug release profiles. [ABSTRACT FROM AUTHOR]

The synthesis and in vitro antifungal activity of some Schiff bases and their Sn (IV) complexes has been tested against plant pathogenic fungi and it is found that they possess excellent fungicidal activity. On the basis of ¹H-, 13C-, 119Sn NMR-, 119Sn Mössbauer, IR and Elemental analysis the tetrahedral geometry is proposed for the synthesized compounds. [ABSTRACT FROM AUTHOR]