Polyvinylpyrrolidone, additives

Minerals, particularly Bentonite, are used to remove proteins that tend to cause haze in white wines. The natural tannin of red wines usually removes unstable proteins from them. Excess tannin and related phenols can be removed and haze from them prevented by addition of proteins or adsorbents such as polyvinylpyrrolidone. Addition of protein such as gelatin along with tannic acid can even be used to remove other proteins from white wines. Egg whites or albumen are often used to fine red wines. Casein can be used for either process, because it becomes insoluble in acidic solutions like wines. 

No. 18, Sept.2002, p.3787-97 RELEASE OF GENTAMICIN SULPHATE FROM A MODIFIED COMMERCIAL BONE CEMENT. EFFECT OF H YDROXYETHYL METHACRYLATE COMONOMER AND POLYVINYLPYRROLIDONE ADDITIVE ON RELEASE MECHANISM AND KINETICS Frutos P Diez-Pena E Frutos G Barrales-Rienda J M CSIC Madrid,Universidad Complutense The influence of hydroxyethyl methacrylate monomer addition to a PMMA bone cement liquid component and of a polyvinyl pyrrolidone to the solid component on the release of gentamicin sulphate is discussed. The possibility of calculating the desired released amount and composition of devices to achieve very defined drug release profiles were investigated. 42 refs. 

A wide range of additives can also be introduced into the sol-gel matrices in order to modulate the hydrophobicity of the materials and to improve enzyme stability, activity and accessibility, leading to hybrid or even composite sol-gel matrices. Polymers [157,179,180] such as polyethyleneglycol, polyvinylpyrrolidone, polyvinylalcohol, polyglycidol, polyethyleneimine, polyacrylate have been simultaneously entrapped with enzymes in a siloxane matrix, as well as organic additives (sugar, amino add)... 

As required by Directive 89/107/EEC, criteria of purity have been drawn up for all the listed food additives (with a couple of exceptions). Purity criteria for all the permitted sweeteners have been prescribed in Directive 95/31/EC,6 as amended, and criteria for all the permitted colours are contained in Directive 95/ 45/EC,7 as amended. Directives that prescribe purity criteria for all the additives authorised under Directive 95/2/EC have been drawn up in stages. Directive 96/ 77/EC8 containing purity criteria for antioxidants and preservatives is amended by Directives 98/86/EC which lays down purity criteria for emulsifiers, stabilisers and thickeners and 2000/63/EC which contains purity criteria for most additives numbered E 500 and above, and for certain other additives not covered in the earlier directives. Purity criteria for most of the few remaining permitted miscellaneous additives are contained in Directive 2001/30/EC however, purity criteria for E 1201 polyvinylpyrrolidone and E 1202 polyvinylpolypyrrolidone are still being considered by the Scientific Committee on Food. Some methods of analysis for verifying prescribed purity criteria have been developed at EU level these are contained in Directive 81/712/EEC.9... 

The batch size ranged from 3.75 up to 60 kg. To obtain precise scale-up measurements, the excipients which were used belonged to identical lots of primary material [10% (W/W) corn starch, 4% (W/W) polyvinylpyrrolidone as binder, and 86% (W/W) lactose]. As can be seen from Figure 4, the amount of granulating liquid is linearly dependent on the batch size. During the scale-up exercise, the rate of addition of the granulation liquid was enhanced in proportion to the larger batch size. Thus the power profile, which was plotted... 

It is used in the manufacture of polyvinylpyrrolidone (PVP), in the manufacture of copolymers with, for example, aciv lic acid, acrylates, vinyl acetate and acrylonitrile and in the synthesis of phenolic resins. About 10-15% of the monomer is used in the pharmaceutical industry for the production of PVP-iodine complex used as a disinfectant. It is also used as a reactive solvent of ultraviolet-curable resins for the production of printing inks and paints as paper and textile auxiliaries, and as an additive in the cosmetics industry (Harreus, 1993). 

The irradiation of a mixture of two polymers A and Bn, either in the solid state or in solution, yields free radicals A and Z , which by recombination give the initial An and Bn polymers or by cross-addition a graft (or block) copolymer 4j,BQ. Although this method gives only very low yields of graft copolymers, it has nevertheless be applied by Hekg-lein in the system polyvinylpyrrolidone-polyacrylamide (102). 

Condensation of DNA induced by neutral polymer has been actively studied and is defined in terms of polymer-salt induced condensation, or (psai)-condensation (Lerman, 1971 Ubbink and Odijk, 1995 Evdokimov et al., 1976). Actually, in 1 1 salt solution, such as NaCl solution, DNA molecules are condensed by the addition of neutral hydrophilic polymers, such as polyethylene glycol (PEG) and polyvinylpyrrolidone. It was suggested that the collapse of the DNA coil was caused by the osmotic... 

Blots are prehybridized to block all nonspecific binding (which causes background). To do this, one first wets the nitrocellulose in 3 X SSC, then in 50% formamide, 3X SSC, 0.1% sodium dodecyl sulfate (SDS), 1 mM EDTA (pH 8.0), 10 mM Tris (pH 7.5), 10X Denhardt s solution [1X Denhardt s is 0.02% Ficoll, 0.02% bovine serum albumin (BSA), and 0.02% polyvinylpyrrolidone 360], 0.05% sodium pyrophosphate, and 100 /ig/ml denatured DNA. Denatured DNA is sheared herring or salmon sperm DNA that has been boiled for 10 min before addition to the prehybridization mix. Blots are sealed within plastic bags, placed between two glass plates to give uniform distribution of prehybridization solution over the blot, and incubated in a water bath at 37° for at least 1 hr. 

If pH extremes cannot be utilized, then either a coated capillary or buffer additives can be used. Without either of these, proteins might adsorb to the inner capillary wall. Adsorption will affect the separation and in some circumstances this may be beneficial. Additives that are often added to CE buffer systems include surfactants, zwitterionic salts, ethylene glycol, methyl-cellulose, organic modifiers, and quaternary amines. Capillary coatings include polyacrylamide, polyethyleneglycol, polyvinylpyrrolidone, and methyl-cellulose. Mazzeo and Krull65 discuss capillary coatings and buffer additives further. 

Nakano and Fujishige prepared a colloidal nickel boride catalyst by reducing nickel chloride with sodium borohydride in ethanol in the presence of polyvinylpyrrolidone) as a protective colloid.83 Catalytic activity of the colloidal catalyst was higher than P-2 Ni boride for the hydrogenation of acrylamide and markedly enhanced by the addition of sodium hydroxide in the hydrogenation of acetone.84... 

The features of initiation of free radical reactions in polymers by dimers of nitrogen dioxide are considered. The conversion of planar dimers into nitrosyl nitrate in the presence of amide groups of macromolecules has been revealed. Nitrosyl nitrate initiates radical reactions in oxidative primary process of electron transfer with formation of intermediate radical cations and nitric oxide. As a result of subsequent reactions, nitrogen-containing radicals are produced. The dimer conversion has been exhibited by estimation of the oxyaminoxyl radical yield in characteristic reaction of p-benzoquinone with nitrogen dioxide on addition of aromatic polyamide and polyvinylpyrrolidone to reacting system. The isomerisation of planar dimers is efficient in their complexes with amide groups, as confirmed by ab initio calculations. 

Most research into the study of dispersion polymerization involves common vinyl monomers such as styrene, (meth)acrylates, and their copolymers with stabilizers like polyvinylpyrrolidone (PVP) [33-40], poly(acrylic acid) (PAA) [18,41],poly(methacrylicacid) [42],or hydroxypropylcellulose (HPC) [43,44] in polar media (usually alcohols). However, dispersion polymerization is also used widely to prepare functional microspheres in different media [45, 46]. Some recent examples of these preparations include the (co-)polymerization of 2-hydroxyethyl methacrylate (HEMA) [47,48],4-vinylpyridine (4VP) [49], glycidyl methacrylate (GMA) [50-53], acrylamide (AAm) [54, 55], chloro-methylstyrene (CMS) [56, 57], vinylpyrrolidone (VPy) [58], Boc-p-amino-styrene (Boc-AMST) [59],andAT-vinylcarbazole (NVC) [60] (Table 1). Dispersion polymerization is usually carried out in organic liquids such as alcohols and cyclohexane, or mixed solvent-nonsolvents such as 2-butanol-toluene, alcohol-toluene, DMF-toluene, DMF-methanol, and ethanol-DMSO. In addition to conventional PVP, PAA, and PHC as dispersant, poly(vinyl methyl ether) (PVME) [54], partially hydrolyzed poly(vinyl alcohol) (hydrolysis=35%) [61], and poly(2-(dimethylamino)ethyl methacrylate-fo-butyl methacrylate)... 

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