On the basis of the present experimental results, the desorption of high-mass neutral molecules from the film to the gas phase is concluded. (C) 2011 American Institute

of Physics. [doi:10.1063/1.3605543]“
“Hydrophobically substituted water-soluble polymers (HSWSP) act as associative thickeners through the reversible crosslinking from noncovalent interactions between the various groups on the polymer chains in aqueous solution. This article shows how the intrinsic viscosity (IV) of nonionic HSWSP can be used to define the thermodynamics of these interactions. Literature data on the IV of pullulans substituted by nucleobase ester groups (thyminyl-butyryl and adeninylbutyryl) (Mocanu et al., Can J Chem, 1995, 73, 1933) are used as an exemplar of these procedures. The intramolecular crosslinking in these substituted pullulans is deduced to be “”unimolecular”" (association constant K(1) Sapanisertib nmr = 1 M(-1)), as contrasted with the “”bimolecular”" behavior expected from the stacking of the free nucleobases; evidently the crosslinking results from hydrophobic interactions between the

butyryl linking groups and the main chain. The results are compared with those from other HSWSP, and from cosolute binding systems. The use of the water-octanol partition coefficients of model systems to elucidate hydrophobic interactions in HSWSP, and of denaturant selleck compound cosolutes (especially urea) to diagnose the presence and strength of these interactions, are also discussed. Emphasis is placed on the need for further such studies to identify the interactions underlying the rheological behavior of the nonionic HSWSP, and of the more common ionic types. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123:657-671, 2012″
“The objective of the current study was to formulate oxybenzone into nanostructured lipid carriers (NLCs) to enhance PF-6463922 research buy its sunscreening efficacy and safety. NLCs of oxybenzone were prepared by the solvent diffusion method. A complete 2(3) factorial

design was used for the evaluation of the prepared oxybenzone NLCs. The study design involves the investigation of the effect of three independent variables namely liquid lipid type (Miglyol 812 and oleic acid), liquid lipid concentration (15% and 30%), and oxybenzone concentration (5% and 10% with respect to total lipids) on the particle size (p.s.), the entrapment efficiency (EE%) and the in vitro drug release after 8 h. The prepared NLCs were spherical in overall shape and were below 0.8 mu m. Miglyol 812 and 30% liquid lipid were found to significantly decrease the p.s. and increase the EE% when compared to oleic acid and 15% liquid lipid. Increasing oxybenzone concentration increased significantly the p.s. but did not affect the EE%. NLCs prepared using Miglyol 812, 15% liquid lipid, and 10% oxybenzone showed slower drug release when compared to those prepared using oleic acid, 30% liquid lipid, and 5% oxybenzone, respectively.