Tuning the pKa of the antihistaminic drug chlorpheniramine maleate by supramolecular interactions with water-soluble polymers

The interaction of the pharmacologically important chlorpheniramine maleate (CPM) with polyanions containing sulfonate groups such as poly(sodium 4-styrenesulfonate) (PSS), poly(sodium vinylsulfonate) (PVS), and the more hydrophobic poly(sodium 2-(N-acrylamido)-2-methyl-propanesulfonate) (PAMPS) has been studied by ¹H NMR. It was found that the pK_a of the low-molecular weight molecule (LMWM) may be modified by its interaction with the polyanions, changing from 3 to 5, due to electric charge compensation. Interestingly, the interaction of CPM with PSS produces changes in CPM resonances, such as a general broadening and upfield shifts of the signals, and NOE effects between the LMWM and the water-soluble polymer (WSP) that indicate the presence of π-π interactions.     

Solubility of chlorpheniramine maleate in supercritical carbon dioxide

Solubility of chlorpheniramine maleate in supercritical carbon dioxide at different temperatures (308–338 K) and pressures (160–400 bar) is measured using static method coupled with gravimetric method. The measured solubility data demonstrated that the solubility of chlorpheniramine maleate was changed between 1.54 × 10⁻⁵ and 4.26 × 10⁻⁴ based on the mole fraction as the temperature and pressure are changed. The general trend of measured solubility data shows a direct effect of pressure and temperature on the solubility of chlorpheniramine maleate. Finally, the obtained solubilities correlated using four semi-empirical density-based correlations including Mendez Santiago–Teja (MST), Kumar and Johnston (KJ), Bartle et al., and Chrastil models. Although the results of modeling showed that the KJ model leads to the average absolute relative deviation percent (AARD %) of 8.1% which is the lowest AARD %, deviation of other utilized correlations are rather the same.     

Synthesis and characterisation of poly(sodium 4-styrenesulfonate) combs

A series of poly(sodium 4-styrenesulfonate) (NaPSS) combs has been synthesized. Architecturally and molecularly well-defined polystyrene combs were initially produced with the branch molecular mass fixed at 30,000 g/mol, the average number of branches being the major variable. Conditions were established whereby linear polystyrene (PS) synthesized via anionic polymerization was chloromethylated using zinc (II) chloride, side-reactions such as Friedel-Crafts alkylation being suppressed. An excess of diphenylethylene-capped polystyryllithium (PSLi) was then reacted with the functionalized backbone to yield materials having long chain branches. The polystyrene combs were then reacted with sulfuric acid to yield water-soluble poly(styrenesulfonic acid) combs and subsequently neutralized with sodium hydroxide to give the corresponding sodium 4-styrene sulfonate species. The extent of sulfonation was determined via titration and nuclear magnetic resonance spectroscopy (NMR). Aqueous triple-detector size exclusion chromatography (SEC) was used to characterize the sulfonated combs. Although the SEC traces were monomodal and the M_n values agreed well with the expected values, an increase in the polydispersity index compared to the polystyrene combs may reflect the susceptibility of the sulfonation reaction to cross-linking.     

Poly(sodium 4-styrenesulfonate)–metal ion interactions

The metal ion-binding properties of poly(sodium 4-styrenesulfonate) in conjunction with membrane filtration were investigated for Cu(II), Cd(II), Co(II), Cr(III), Hg(II), Ni(II), Pb(II), Zn(II), and Fe(II). Different experiments were carried out at different pH's, metal ion concentrations, polymer concentrations, and molecular weight fractions. Only Fe(II) and Cr(III) were retained at pH 1, which allows a selective separation of these metals from all the other metal ions. At pH 3 the retention ability of this polymer increased for all the metal ions. On the other hand, the metal ion-retention properties are dependent on the polymer/metal ratio. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 219–225, 1998     

Polymerization of sodium 4-styrenesulfonate via atom transfer radical polymerization in protic media

The homopolymerization of sodium 4-styrenesulfonate (NaStS) in both aqueous and water/methanol solutions at 20 °C using atom transfer radical polymerization (ATRP) is described. Syntheses conducted using a sodium 4-bromomethylbenzoate initiator were poorly controlled in water but reasonably well-controlled in 1:1 water/methanol mixtures, with 3:1 water/methanol mixtures exhibiting intermediate behavior. In 1:1 water/methanol mixtures aqueous GPC analyses indicated polydispersities as low as 1.26 and conversions reached 80-90% within 18-20 h at 20 °C. Self-blocking experiments were conducted in 1:1 water/methanol mixtures, with the chain-extended NaStS polymers exhibiting unimodal GPC traces but relatively high polydispersities (M_w/M_n=1.61). The use of poly(ethylene oxide)-based (PEO) macro-initiators yielded novel PEO-NaStS diblock copolymers of low polydispersity. Diblock copolymer syntheses via sequential monomer addition were less satisfactory, although one example of a polydisperse pH-responsive diblock copolymer was obtained.     

Synthesis and electrochemical capacitance of core-shell poly (3,4-ethylenedioxythiophene)/poly (sodium 4-styrenesulfonate)-modified multiwalled carbon nanotube nanocomposites

A noncovalent method was used to functionalize multiwalled carbon nanotubes with poly (sodium 4-styrene sulfonate). And then, the core-shell poly (3,4-ethylenedioxythiophene)/functionalized multiwalled carbon nanotubes (PEDOT/PSS-CNTs) nanocomposite was successfully realized via in situ polymerization under the hydrothermal condition. In the process, PSS served for not only solubilizing and dispersing CNTs well into an aqueous solution, but also tethering EDOT monomer onto the surface of CNTs to facilitate the formation of a uniform PEDOT coating. Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM) were used to characterize the resultant PEDOT/PSS-CNTs. In addition, the PEDOT/PSS-CNTs nanocomposite (50 wt.% PEDOT) had a specific capacitance (SC) of 198.2 F g⁻¹ at a current density of 0.5 A g⁻¹ and a capacitance degradation of 26.9% after 2000 cycles, much better than those of pristine PEDOT and PEDOT/CNTs (50 wt.% PEDOT). The enhanced electrochemical performance of the PEDOT/PSS-CNTs nanocomposite (50 wt.% PEDOT) should be attributed to the high uniform system of the nanocomposite, resulting in the large surface easily contacted by abundant electrolyte ions through the three-dimensional conducting matrix.     

马来酸酐淀粉酯-丙烯酸共聚物的合成及吸水性能的研究

通过马来酸酐淀粉酯与丙烯酸共聚来合成吸水材料,研究了温度、时间、交联剂用量、引发剂用量、马来酸酐淀粉酯用量和蒙脱土用量等对材料吸水倍率的影响。结果表明当反应温度为60℃、反应时间为4h、N,N-二甲基丙烯酰胺为0．02％、过硫酸钾为0．47％、马来酸酐淀粉酯用量为13．6％和蒙脱土用量为13．5％时,得到材料的吸水倍率为：746g／g。     

Layer-by-layer assembly of poly(sodium 4-styrenesulfonate) wrapped multiwalled carbon nanotubes with polyaniline nanofibers and its electrochemistry

A simple and versatile method based on noncovalent supramolecular attachment and layer-by-layer (LBL) assembly is proposed to prepare nanostructured hybrid conducting polymer. The negatively charged poly(sodium 4-styrenesulfonate) (PSS) wrapped multiwalled carbon nanotubes (MWCNTs) is doped with cationic polyaniline (PANI) nanofibers via LBL assembly, and a well-defined PANI/MWCNTs composite was obtained. The LBL assembly process is characterized by scanning electron microscopy, energy dispersive spectrometry and electrochemical methods. It was found that PSS wrapped MWCNTs inside the multilayer film can dope nanostructured PANI effectively and shift its electroactivity to a neutral pH environment. Moreover, the conducting composites show amperometric response for hydrogen peroxide with a linear range of 2.0 × 10⁻⁷-1.0 × 10⁻³ mol L⁻¹.     

一种氧化还原石墨烯的稳定水溶液分散体的合成方法

提供了一种在聚苯乙烯磺酸钠（PSS）的帮助下,合成氧化还原石墨烯稳定水溶液分散体的简单方法。这种方法制备的分散体非常稳定,长达几个星期都没有聚集或者沉淀。通过各种方法对材料进行了表征。扫描电子显微镜（SEM）和紫外-可见光吸收光谱的结果表明PSS紧密地包裹住了石墨烯,形成功能化石墨烯;石墨烯的亲水性大大提高。傅里叶变换红外光谱（FTIR）表明O=S=O官能团的存在,说明石墨烯中存在PSS。X射线光电子能谱（XPS）提供了C/S的原子浓度比等,进一步说明了PSS的存在。结果表明,覆盖有PSS的氧化还原石墨烯能够应用于石墨烯的复合材料中。     

Facile fabrication of pH-responsive and swellable slow release microparticles of chlorpheniramine maleate with chitosan-starch matrices and their crosslinks

Abstract

We synthesized chitosan and modified same by blending with starch, crosslinking the matrices with sodium tripolyphosphate (TPP) and encapsulation with the drug chlorpheniramine maleate (CPM). These microparticles were characterized by FTIR, TGA, and SEM techniques. The amounts of CPM released from the microparticles generally decreased for the TPP-crosslinked beads but increased as the starch composition increased. Their release rates were best described by zero-order kinetics while their release mechanisms followed less-Fickian diffusional release. Our findings show that both the uncrosslinked and crosslinked chitosan-starch beads are promising carriers for the slow release of CPM.     

Characterization and In Vitro Evaluation of Freeze-Dried Nasal Insert Composed of Chlorpheniramine Maleate with Ionic and Nonionic Polymer for Intranasal Delivery

In this study, the authors report the fabrication of nasal delivery system, termed nasal insert, and was carried out with ionic and nonionic polymer(s). The data revealed that nonionic polymer has less water uptake and low mucoadhesion time in comparison to the ionic polymers. With ionic polymers, relaxation of entangled polymer from the gel was toward lesser extent, thereby providing sustained release during in vitro release. The SEM images show more compact nature of ionic polymer when compared with nonionic polymer. Histopathology and in vitro permeation study conducted using sheep nasal mucosa showed significantly higher drug permeation from nonionic polymer.     

Stimuli-induced core-corona inversion of micelles of water-soluble poly(sodium 2-(acrylamido)-2-methyl propanesulfonate-b-N-isopropylacrylamide)

Micelles of poly(sodium 2-(acrylamido)-2-methylpropanesulfonate-b-N-isopropylacrylamide) (PAMPS-b-PNIPAM) have been investigated in aqueous solutions using various techniques including dynamic light scattering, scanning electron microscopy, transmission electron microscopy and ζ-potential measurements. It was found that PAMPS-b-PNIPAM produces two distinct types of micelle structures; one is a PAMPS-core/PNIPAM-corona structure and the other is a PNIPAM-core/PAMPS-corona structure. The PAMPS-core micelle with the PNIPAM-corona was obtained by insolubilizing the PAMPS block with ferric ion (Fe³⁺) at room temperature, and the PNIPAM-core micelle with the PAMPS-corona was obtained by increasing the solution temperature above the lower critical solution temperature (LCST) of the PNIPAM block in the absence of the Fe³⁺ ion. We have also found that the inversion from one type to the other is reversible. The transformation from the PAMPS-core micelle to the PNIPAM-core micelle was induced by removing Fe³⁺ ion using ethylenediaminetetraacetic acid followed by elevating the temperature above the LCST of the PNIPAM block, while the reverse transformation was triggered by adding Fe³⁺ ion at a lower temperature.     

Control of C.I. Basic Violet 10 aggregation in aqueous solution by the use of poly(sodium 4-styrenesulfonate)

The aggregation behavior of C.I. Basic Violet 10 in the presence of poly(sodium 4-styrenesulfonate) was modified, as a consequence of short-range interactions. In aqueous acidic media, the cationic dye forms hydrophobic ion pairs with polymeric benzene sulfonate groups which tend to aggregate in H-contacts, this tendency being readily influenced by the relative concentration of the macromolecule with respect to that of the dye. In the case of dilute aqueous dye solutions (≤10^?4 M), for which the probability of dye self-aggregation is small, C.I. Basic Violet 10 self-contacts are forced in the presence of a moderate excess of poly(sodium 4-styrenesulfonate). At dye concentrations >10^?4 M, for which the probability of dye self-aggregation increases, dye-dye contacts are minimized in the presence of a large excess of the polymer. Hence, the luminescence of dye solutions can be tuned insorar as, that of dilute dye solutions is quenched whilst that of concentrated dye solutions can be enhanced. This behavior was not observed for other polyelectrolytes such as poly(sodium vinylsulfonate), or the more hydrophobic poly(sodium 2-(N-acrylamido)-2-methyl-propanesulfonate).     

聚苯乙烯-马来酸钠SSMA制备及其分散性能研究

以苯乙烯和马来酸酐单体为原料、过氧化苯甲酰为引发剂,通过溶液聚合沉淀法制备了苯乙烯-马来酸酐共聚物SMA。采用NaOH将其水解得到苯乙烯-马来酸钠盐SSMA。采用FT-IR、1HNMR对其结构进行了确证,采用凝胶色谱(GPC)对其分子量进行了测定。将SSMA应用于颜料黑的分散,其粒径约为200 nm左右,分散指数(PDI)为0.2左右。与小分子分散剂对比实验表明,其具有良好的分散性能。     

Mechanical and thermal properties of poly(lactic acid)/starch blends with dioctyl maleate

Poly(lactic acid) (PLA)/starch blends were prepared blending with dioctyl maleate (DOM). DOM acted as a compatibilizer at low concentrations (below 5%), and markedly improved tensile strength of the blend. However, DOM functioned as a plasticizer at concentrations over 5%, significantly enhancing elongation. Compatibilization and plasticization took place simultaneously according to the analysis of, for example, mechanical properties and thermal behavior. With DOM as a polymeric plasticizer, thermal loss in the blends was not significant. Water absorption of PLA/starch blends increased with DOM concentration. DOM leaching in an aqueous environment was inhibited. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1697–1704, 2004     

Preparation and properties of poly(propylene carbonate maleate) microcapsules for controlled release of pazufloxacin mesilate

A novel biodegradable aliphatic polycarbonate, poly(propylene carbonate maleate) (PPCMA) was synthesized by terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride (MA), using a polymer supported bimetallic complex as catalyst. The utility of PPCMA to encapsulate and control the release of drug pazufloxacin mesilate (PZFX), via microcapsules, was investigated. PPCMA microcapsules containing PZFX were elaborated by solvent evaporation method based on the formation of double W/O/W emulsion. The manufacturing parameters such as the volume ratio of V(PPCMA) : V(PZFX), the concentration of stabilizer gelatin in outer aqueous phase played major roles on microcapsule characters, and were altered to optimize the process parameters. The PPCMA‐PZFX microcapsules were obtained with smooth and spherical surface under optimum condition, the mean diameter of microcapsules was ～ 2 μm, and the drug loading and drug encapsulation efficiency of the microcapsules were 22.9 ± 1.05% and 82.1 ± 2.03%, respectively. PZFX released from PPCMA microcapsules was found to reach 89.8 ± 2.89% after 36d in a pH 7.4 phosphate‐buffered solution, and the release profile obeyed the Higuchi equation. The results suggest that the new polymer PPCMA provides an alternative to degradable matrix polymers for long‐term sustained releasing drug delivery systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and properties of the water-soluble self-acid-doped polypyrrole: poly[4-(3-pyrrolyl)butanesulfonic acid]

The water-soluble polypyrrole, poly[4-(3-pyrrolyl)butanesulfonic acid] (P3PyBSH), in which the β-position of pyrrole ring is substituted with n-butanesulfonic acid group, is synthesized by oxidation polymerization of 3PyBSNa followed with an ion-exchange of Na⁺ with H⁺. It can be cast into free-standing film from its aqueous solution and has a conductivity of 4.0×10⁻⁴ S/cm, higher than that of its sodium salt (5.5× 10⁻⁶ S/cm) by about 2 orders. The increase in conductivity is attributed to the self-doping by the protons originally on the side chains as supported by the absence of the anion FeCl₄ ⁻ (which generates during the polymerization) and the presence of polaron and bipolaron characteristics in its UV-Vis and IR spectra.     

Polyelectrolyte complexes formed by hyperbranched poly(sulfone‐amine) hydrochlorate and poly(sodium acrylate)

A new type of polyelectrolyte complexes formed by hyperbranched poly(sulfone‐amine) hydrochlorate and poly(sodium acrylate) has been reported. It has been found that the stoichiometry between polycation and polyanion is 1.16, which means that hyperbranched polyelectrolyte can also form the compact complexes in spite of the ill‐defined structure. Moreover, the effect of various parameters, such as the architecture of poly(sulfone‐amine), molecular weight of polymer, concentration and low molecular salt, on the complexation is also discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2323–2329, 2007     

Water-soluble polyelectrolyte complexes formed by poly(diallyldimethylammonium chloride) and poly(sodium acrylate-co-sodium 2-acrylamido-2-methyl-1-propanesulphonate)-graft-poly(N,N-dimethylacrylamide) copolymers

The formation of polyelectrolyte complexes (PECs) between the cationic homopolymer poly(diallyldimethylammonium chloride) (PDADMAC) and the anionic graft copolymers poly(sodium acrylate-co-sodium 2-acrylamido-2-methyl-1-propanesulphonate)-graft-poly(N,N-dimethylacrylamide) (P(NaA-co-NaAMPS)-g-PDMAM) was studied in aqueous solution in comparison with the PECs formed between PDADMAC and the graft copolymer backbone poly(sodium acrylate-co-sodium 2-acrylamido-2-methyl-1-propanesulphonate). The turbidimetric study of the PECs formed revealed that associative phase separation is prevented when the anionic polyelectrolyte is grafted with the nonionic hydrophilic poly(N,N-dimethylacrylamide) side chains. The PECs are formed through a charge neutralisation process and they adopt a compact structure, as shown by conductivity and viscometry measurements respectively. The water-insoluble PEC core seems to be stabilised by a hydrophilic PDMAM corona, leading to the formation of nanoparticles with a hydrodynamic radius of some decades of nanometers as determined by quasi-elastic light scattering measurements.     

以低分子量聚乙烯基苯磺酸钠为模板的聚3,4-二氧乙烯噻吩水分散体的制备及性能

通过RAFT聚合,制备了低分子量的聚乙烯基苯磺酸钠（PSS）;其次以低分子量的聚乙烯基苯磺酸钠为模板制备了聚3,4-二氧乙烯噻吩（PEDOT）：聚乙烯基苯磺酸钠（PSS）水分散体,研究了作为模板的聚乙烯基苯磺酸钠的不同分子量对PEDOT：PSS水分散体结构和性能的影响。结果显示：通过核磁氢谱（¹H NMR）表征,证明成功制备了分子量为3900,4900,9600和18300的聚乙烯基苯磺酸钠。用荧光探针法发现低分子量PSS在水中能形成胶束,临界胶束浓度在10^-6g·ml^-1左右。用四探针表面电阻测试发现,低分子量PSS为模板可明显提高PEDOT薄膜的导电性,最大提高了近3倍。用紫外可见分光光度计（UV）研究发现,以低分子量PSS为模板使PEDOT的透明性有一定的下降,这主要是由于RAFT试剂部分和PEDOT：PSS的相分离造成的。热稳定性的测试表明,低分子量PSS为模板对PEDOT的热稳定性没有明显的影响。