purpose of this study was to investigate the effect of the presence of the water soluble polymers viz hpmc, pvp and peg 6000 on aqueous solubility and complexation abilities of felodipine with or without presence of β-cyclodextrin (βcd) and hpβcd by phase solubility studies. the data revealed the initial increase in drug solubility followed by plateau in the presence of relatively low polymer c...

Poor aqueous solubility of anticancer drug, albendazole (ABZ), prevents parenteral application. Here, we demonstrate how to increase the aqueous solubility of ABZ to 6- 8 mg/ml using sulfobutylether - β-cyclodextrin (SBE-β-CD) or Hydroxypropyl- β-cyclodextrin (HP- β-CD) by manipulation of complexation parameters such as the physical state of ABZ (ionized in acetic acid), the concentration of io...

The effects of natural organic matter (NOM), ferrozine, and AQDS (anthraquinone-2,6-disulfonate) on the reduction of hematite (alpha-Fe2O3) by Shewanella putrefaciens CN32 were studied. It has been proposed that NOM enhances the reduction of Fe(III) by means of electron shuttling or by Fe(II) complexation. Previously both mechanisms were studied separately using "functional analogues" (AQDS for...

Graft copolymer networks of poly(methacrylic acid-g-ethylene glycol) exhibiting pHdependent swelling behavior due to the formation of interpolymer complexes were prepared by free radical solution polymerization of methacrylic acid and poly(ethylene glycol) monomethacrylate. Dynamic swelling studies established the swelling/deswelling process due to hydrogen bonding. Additionally, the effects of...

Polymer-coated pores play a crucial role in nucleo-cytoplasmic transport and in a number of biomimetic and nanotechnological applications. Here we present Monte Carlo and Density Functional Theory approaches to identify different collective phases of end-grafted polymers in a nanopore and to study their relative stability as a function of intermolecular interactions. Over a range of system para...

We describe single-chain polymer nanoparticles (SCNPs) possessing intramolecular dynamic covalent crosslinks that can transform into polymer films through a molecular recognition-mediated crosslinking process. The SCNPs utilise molecular recognition with surface-immobilised proteins to concentrate upon a substrate, bringing the SCNPs into close spatial proximity with one another and allowing th...

Solid-state NMR was used to establish the specific intermolecular interactions responsible for the miscibility of blends of nylon 6 (PA6) and the zinc salt of lightly sulfonated polystyrene (Zn-SPS) and to characterize the scale of molecular mixing. l 3 C CPIMAS spectroscopy identified the interpolymer interaction as a complex between the Zn2+ cation of the ionomer and the amide nitrogen. Measu...

Coupling of electrostatic complexation with conformational transition is rather general in protein/polyelectrolyte interaction and has important implications in many biological processes and practical applications. This work studied the electrostatic complexation between κ-carrageenan (κ-car) and type B gelatin, and analyzed the effects of the conformational ordering of κ-car induced upon cooli...

In this study we investigated the effects of competing trace metals and Ca2+ on Cd(II), Pb(II), and Cu(II) complexation by humic acid extracted from groundwater in Orange County, California. Two types of titration experiments were conducted, those using a single metal and those in which the humic acid had been preequilibrated with a competing metal (either a trace metal or Ca2+). The labile met...

The complexation of arsenic (As) with dissolved organic matter (DOM), although playing an important role in regulating As mobility and transformation, is poorly characterized, as evidenced by scarce reporting of fundamental parameters of As-DOM complexes. The complexation of arsenite (AsIII) with Aldrich humic acid (HA) at different pHs was characterized using a recently developed analytical te...