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Highly Soluble (highly + soluble)
Selected AbstractsTowards Understanding of the Selective Precipitation of Alkali Metal Cations in Presence of Dipicrylamine AnionEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 11 2005Suresh Eringathodi Abstract Dipicrylamine anion (DPA,) precipitates out [K(DPA)] with high selectivity from salt bitterns containing Na+, K+, and Mg2+, whereas the same ligand shows poor selectivity towards K+ , and much higher selectivity towards Cs+ , in studies conducted with a mixture of K+, Rb+, and Cs+. Their single-crystal structures reveal that the K+ and Rb+ salts have similar layered structures, with 8 oxygen atoms from seven DPA, anions encapsulating the metal cation, whereas the Cs+ salt possesses a channel-like structure with the metal ion encapsulated by ten oxygen atoms from six DPA,. The conformation of DPA, in the [Cs(DPA)] single crystal matches closely that of DPA in crystalline state. M···O and intermolecular C,H···O interactions together stabilize the structures. The 133Cs NMR spectrum of the poorly soluble [Cs(DPA)] shows an upfield shift of the peak with respect to CsCl as a result of the interaction with the oxygen atoms of DPA,, whereas 23Na NMR spectrum of the highly soluble [Na(DPA)] shows no such upfield shift compared to NaCl. Powder XRD patterns of bulk [M(DPA)] (M = K+, Rb+, and Cs+) precipitates show that these are similar to the patterns obtained by simulation of the single-crystal X-ray data. The selectivity of precipitation correlates qualitatively with the size and hydration enthalpies of the ions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Synthesis of Highly Fluorescent and Soluble 1,2,4-Linking Hyperbranched Poly(arylenevinylene) Featuring Intramolecular Energy FunnelingADVANCED FUNCTIONAL MATERIALS, Issue 10 2010Zengqi Xie Abstract The synthesis and optical properties of a highly soluble (>200,mg,mL,1) and highly fluorescent (,F in film,=,0.64) 1,2,4-linking hyperbranched poly(arylenevinylene) (1,2,4- hb -PAV) prepared via Wittig reaction of A3 (biphenyl-tricarbaldehyde) and B2 (phosphonium salt) monomers is reported. The molecular weight of 1,2,4- hb -PAV can be precisely controlled by the amount of the base (NaOCH3) used in the polymerization. The absorption and photoluminescence (PL) spectra of 1,2,4- hb -PAV shows distinct red-shifts compared to conventional 1,3,5-linking hyperbranched poly(arylenevinylene) (1,3,5- hb -PAV), attributed to the extended ,-conjugation along ortho - (1,2-) and para - (1,4-) links. The inherent energy gradient from the shorter branches to the longer conjugated stem in 1,2,4- hb -PAV enabled a characteristic energy funneling effect, which is absent in conventional hyperbranched polymer of 1,3,5- hb -PAV. [source] Biowaiver monographs for immediate release solid oral dosage forms based on biopharmaceutics classification system (BCS) literature data: Chloroquine phosphate, chloroquine sulfate, and chloroquine hydrochloride,JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2005R.K. Verbeeck Abstract Literature data on the properties of chloroquine phosphate, chloroquine sulfate, and chloroquine hydrochloride related to the Biopharmaceutics Classification System (BCS) are reviewed. The available information indicates that these chloroquine salts can be classified as highly soluble and highly permeable, i.e., BCS class I. The qualitative composition of immediate release (IR) tablets containing these Active Pharmaceutical Ingredients (APIs) with a Marketing Authorization (MA) in Belgium (BE), Germany (DE), Finland (FI), and The Netherlands (NL) is provided. In view of these MA's and the critical therapeutic indication of chloroquine, it is assumed that the registration authorities had evidence that these formulations are bioequivalent to the innovator. It is concluded that IR tablets formulated with these excipients are candidates for a biowaiver. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:1389,1395, 2005 [source] Permeability of a novel ,-lactamase inhibitor LK-157 and its ester prodrugs across rat jejunum in vitroJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2009Petra Igli Abstract Objectives LK-157 is a novel 10-ethylidene tricyclic carbapenem that resembles the structure of the broad-spectrum antibiotic sanfetrinem and acts as a potent inactivator of ,-lactamases of classes A, C and D. LK-157 is a highly soluble but poorly permeable drug. Since most of the ,-lactams are poorly absorbed, ester prodrugs LK-159, LK-157E1 and LK-157E2 were designed to enhance membrane permeability. This study investigated the permeability of LK-157 and the three ester prodrugs across rat intestine in vitro. The morpholinoethyl ester of sanfetrinem was also investigated. Method Permeability across rat jejunum was determined using EasyMount side-by-side diffusion chambers. Key findings The solubility and permeability of morpholinoethyl ester LK-157E2 were superior to those of LK-159 and LK-157E1. The morpholinoethyl ester of sanfetrinem LK-176E1 had the highest observed permeability coefficient and consequently the highest predicted absorption in humans. Conclusions These results suggest that the morpholinoethyl esters of LK-157 and sanfetrinem could be further investigated to assess bioavailability in vivo. [source] Effect of Core Twisting on Self-Assembly and Optical Properties of Perylene Bisimide Dyes in Solution and Columnar Liquid Crystalline PhasesCHEMISTRY - A EUROPEAN JOURNAL, Issue 2 2007Zhijian Chen Abstract A series of highly soluble and fluorescent core-twisted perylene bisimide dyes (PBIs) 3,a,f with different substituents at the bay area (1,6,7,12 positions of the perylene core) were synthesized and fully characterized by 1H,NMR, UV/Vis spectroscopy, MS spectrometry, and elemental analysis. The ,,, aggregation properties of these new functional dyes were investigated in detail both in solution and in condensed phase by UV/Vis and fluorescence spectroscopy, vapor pressure osmometry (VPO), differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and X-ray diffraction. Concentration-dependent UV/Vis measurements and VPO analysis revealed that these core-twisted ,-conjugated systems show distinct self-dimerization equilibria in apolar solvent methylcyclohexane (MCH) with dimerization constants between 1.3×104 and 30,M,1. The photoluminescence spectra of the dimers of PBIs 3,a,f exhibit bathochromic shifts of quite different magnitude which could be attributed to different longitudinal or rotational offsets between the dyes as well as differences in the respective ,,, stacking distance. In condensed state, quite a few of these PBIs form luminescent rectangular or hexagonal columnar liquid crystalline phases with low isotropization temperatures. The effects of the distortion of the , systems on their ,,, stacking and the optical properties of the resultant stacks in solution and in LC phases have been explored in detail. In one case (3,a) a particularly interesting phase change from crystalline into liquid crystalline could be observed upon annealing that was accompanied by a transformation from non-fluorescent H -type into strongly fluorescent J -type packing of the dyes. [source] | ||||||||||