Dextran sodium salts

Fig. 2 Sensorgrams and calibration curve for different IL-8 concentrations in saliva supernatant premixed with lOmgmL of CM dextran sodium salt, a Sensorgrams corresponding to enhanced detection by secondary antibody for different IL-8 concentrations (5nM, 2nM, 1 nM, 500 pM, 250 pM, and OpM labeled as A, B, C, D, E, and F, respectively), b Calibration curve covering the IL-8 concentration range from 0 to 2 nM [26]...

The sodium salts of sulphuric acid esters of dextran are used as anticoagulants for the same purposes as heparin. 

Iron dextran injection contains a complex of iron hydroxide with dextrans of average molecular weight between 5000 and 7000, and is used for the treatment of iron-defieiency anaemia in situations where oral therapy is ineffeetive or impractical. The sodium salt of sulphurie aeid esters of dextran, i.e. dextran sodium sulphate, has anti-eoagulant properties eomparable with heparin and is formulated as an injection for intravenous use. 

The presence of three hydroxyl groups per glucose unit was shown by the preparation of a triacetate and a tribenzoate. Six or seven methyla-tions (using dimethyl sulfate and concentrated alkali) of dextran did not raise the methoxyl content above 41% (theoretical maximum 45.6%). Also, Purdie methylations (using methyl iodide and silver oxide) and methylation with thallium ethoxide and methyl iodide were ineffective in raising the methoxyl content of methylated dextran above 43.5%. The maximum theoretical methoxyl content was eventually attained by modified Muskat methylations. 6 Partially methylated dextran suspended in anisole solution was treated with sodium in liquid ammonia, and the sodium salt of methylated dextran thus formed was allowed to react with methyl iodide. The methoxyl content of the partially methylated dextran was raised by three such methylations from 42% to 45.5% and by five such methylations from 30% to 45.4%. 

Kokufuta, Zhang and Tanaka developed a gel system that undergoes reversible swelling and collapsing changes in response to saccharides, sodium salt of dextran sulfate (DSS) and a-methyl-D-mannopyranoside (MP) [126]. The gel consists of a covalently cross-linked polymer network of W-isopropylacrylamide into which concanavalin A (ConA) is immobilized. As shown in Fig. 31, at a certain temperature the gel swells five times when DSS ions bind to ConA due to the excess ionic pressure created by DSS. The replacement of the DSS by non-ionic MP brings about collapse of the gel. The transition can be repeated with excellent reproducibility. 

In contrast to dextran phosphate, which is only of scientific interest up to now, the dextran sulfuric acid half ester and its sodium salt, usually simple referred to as dextran sulfate, is a commercially available product today. Its high purity, water solubility and reproducible quality commend it for many applications in molecular biology and the health care sector. 

There is a limited number of polymers for which narrow MWD standards are commercially available polystyrene, poly(methyl methacrylate), poly(a-methyl styrene), polyisoprene, polybutadiene, polyethylene, poly(dimethyl siloxane), polyethyleneoxide, pullulan, dextran, polystyrene sulfonate sodium salt, and globular proteins. In some cases, the standards available cover a limited molecular weight range, so it may be impossible to construct the calibration curve over the complete column pore volume. 

Hie stability of amoxicillin sodium salt in various intravenous infusion fluids has been studied [33-35], Degradation was faster at the higher amoxicillin concentrations [33] and particularly in fluids containing dextrose, dextran or sorbitol [33-35], Other studies also showed a deleterious effect of carbohydrates and alcohols on the stability of amoxicillin in solution [36,37],... 

Amiel et al. [85, 86] investigated the formation of ternary complexes of a water soluble epichlorohydrin-linked f-CD polymer, cationic surfactant dodecyltrimethy-lammonium bromide (DTAB), and a polyanion sodium salt dextran sulfate (NaDxS) by viscometry and small angle neutron scattering. They proposed a structure of polyion complexes between NaDxS and the supramolecular polycation formed from fi-CD polymer and DTAB. More recently, Amiel et al. [87] have characterized in detail the supramolecular polycation. 

Equations are derived from the Manning theory of polyelectrolyte solutions that permit the calculation of the charge fraction of ionic polysaccharides using experimental counterion and coion diffusion coefficients. Results are reported for the sodium salts of heparin, dextran sulfate, alginate and the calcium salt of heparin. 

Amino-oxybutyl-dextran has been prepared by alkylation of a sodium salt of dextran followed by treatment with hydrochloric acid. Amino-oxybutyl-Sephadex was similarly prepared. 

More recently, camptothecin (CPT) was conjugated to poly(l-hydroxymethylethylene hydroxymethylformyl) (PHF or Eleximer ) and the conjugate 11 (XMT-1001) is currently in clinical development [72,73]. The polyacetal is derived from the exhaustive oxidation of dextran [74]. CPT is poorly soluble and prone to rapid inactivation through lactone ring hydrolysis in vivo [75]. As a cytotoxic compound, CPT has been used in many efforts to develop other CPT-polymer conjugates [45,76,77]. The sodium salt of CPT has also been examined in phase I trials, but only modest responses were observed while severe toxicities remain. 

Dextran, hydrogen sulfate, sodium salt. See Dextran sulfate sodium Dextrans. See Dextrin Dextran sulfate CAS 9042-14-2... 

Definition Sodium salt of the sulfuric acid ester of dextran... 

Figure 4 shows the of lyophilized formulations containing various polymer excipients as a function of relative humidity [26], As relative hymidity increased, for each formulation decreased. Formulations containing a, S-poly (vV-hydroxyethyl)-L-aspartamide (PHEA), methylcellu-lose (MC), and hydroxypropylmethylcellulose (HPMC) exhibited comparable r io values at lower humidities than formulations with dextran and carboxymethylcellulose sodium salt (CMC-Na). This indieates that the formulations containing PHEA, MC, and HPMC contain highly mobile protons at a lower temperature than the formulations containing dextran and CMC-Na at the same humidity. 

Cationic samples can be adsorbed on the resin by electrostatic interaction. If the polymer is strongly cationic, a fairly high salt concentration is required to prevent ionic interactions. Figure 4.18 demonstrates the effect of increasing sodium nitrate concentration on peak shapes for a cationic polymer, DEAE-dextran. A mobile phase of 0.5 M acetic acid with 0.3 M Na2S04 can also be used. 

Morimoto et al. [33] demonstrated that the ocular absorption of hydrophilic compounds over a wide range of molecular weights could be increased by 2 and 10 mM sodium taurocholate and sodium taurodeoxycholate in a dose-dependent manner. The compounds were glutathione (307 Da), 6-carboxyfluorescein (376 Da), FTTC-dextran (4 kDa), and insulin (5.7 kDa). Of the two bile salts, sodium taurodeoxycholate was more effective. At 10 mM, this bile salt increased the permeability of 6-carboxyfluorescein from 0.02% to 11%, glutathione from 0.08% to 6%, FITC-dextran from 0% to 0.07%, and insulin from 0.06% to 3.8%. Sodium taurocholate, on the other hand, increased the permeability to 0.13%, 0.38%, 0.0011%, and 0.14%, respectively. Taurodeoxycholate was more effective than taurocholate in the nasal epithelium as well [202], This difference in activities can possibly be attributed to their micelle-forming capability, which is higher for taurodeoxycholate, a dihydroxy bile salt [190],... 

High temperatures can break native S-S bonds and form new S-S bonds which can lock the protein into a denatured eonfiguration [89]. Low pH, sodium dodecyl sulfate. Tween 80, chaotropie salts, and exogenous proteins have been used to protect proteins from thermal inaetivation [90]. Ethylene glycol at 30-50% was used to protect the antiviral activity of P-interferon preparations [91]. Human serum albumin was used in recombinant human interferon-Psei-n which resulted in increased thermal stability [62]. Water-soluble polysaeeharides sueh as dextrans and amylose [92], as well as point-specific (site-directed) mutagenesis [93] have also been used to increase thermal stability of therapeutie proteins and peptides. 

Under biphase conditons (in dry dioxane) the activity of 46 for the reaction of 1-bromo-heptane with sodium phenoxide decreased with an increase in the length of aliphatic chains. Under triphase conditions, however, only catalyst 46 with n-octyl groups was active for chloride displacement reactions, and catalysts with groups smaller than n-butyl showed no activity 165). Polyacrylamides 46 with short aliphatic chains are too hydrophilic to act as catalysts under triphase conditions. Similar behavior has been observed for ammonium salts supported on dextran 95). 

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