Polyvinylpyrrolidone properties

PROPERTIES AND USE IN ANALYSIS OF WATER-SOLUBLE POLYMER - POLYVINYLPYRROLIDONE... 

Last years the polymeric surface - active substances began to use as modifiers of organic reagent properties. In our work the behavior of synthetic polymers (polysulphonilpiperidinilmethylenhydroxide (PSPMH), polyvinylpyrrolidone (PVP), polyamines - polyguanidine and metacide) and natural polymers (starch, gelatin) for various molecular masses are investigated. 

The alternative noncovalent functionalization does not rely on chemical bonds but on weaker Coulomb, van der Waals or n-n interactions to connect CNTs to surface-active molecules such as surfactants, aromatics, biomolecules (e.g. DNA), polyelectrolytes and polymers. In most cases, this approach is used to improve the dispersion properties of CNTs [116], for example via charge repulsion between micelles of sodium dodecylsulfate [65] adsorbed on the CNT surface or a large solvation shell formed by neutral molecule (e.g. polyvinylpyrrolidone) [117] around the CNTs. 

Hida Y, Kozuka H (2005) Photo anodic properties of sol-gel-derived iron oxide thin films with embedded gold nanoparticles Effects of polyvinylpyrrolidone in coating solutions. Thin Solid Films 476 264-271... 

Tantishaiyakul V, Kaewnopparat N, Ingkatawomwong S. Properties of solid dispersions of piroxicam in polyvinylpyrrolidone K-30. Int J Pharm 1996 143 59-66. 

Synthetic polymers were generally preferred to the natural ones in protein conjugation because they are particularly efficient in modifying the biopharmaceutical, stability and immunological properties of insulin. Among the polymers used were polyvinylpyrrolidone, N-(2-hydroxypropyl) methacrylamides, and PEGs [12, 13]. 

Oechsner, M., and Keipert, S. (1999), Folyacrylic acid/polyvinylpyrrolidone bipolymeric systems. I. Rheological and mucoadhesive properties of formulations potentially useful for the treatment of dry-eye-syndrome, Eur. J. Pharm. Biopharm., 47(2), 113-118. 

The experimental results may be represented both by the titration curves or property-composition dependences. The extremums or bends on the titration curves indicate the formation of complexes and their composition. Thus, investigating the-possi-bility of complex formation in polyelectrolyte - nonionic polymer systems, one can use the methods of conductometric and potentiometric titration. The formation of interpolymer complexes in these systems, as some authors suggest18,211, is caused by a co-operative formation of hydrogen bonds between carboxy groups of the polyacid and oxygen atoms of nonionic polyvinylpyrrolidone or poly(ethylene glycol) and is therefore accompanied by an increase of pH of the solution. The typical titration curves for the system polyvinylpyrrolidone - copolymer maleic anhydride and acrylic add are shown in Fig. 1. The inflection points of the titration curves indicate the ratio at which the macromolecular components react with each other, i.e. the composition of the formed complexes. 

Glass transitions of polyvinylpyrrolidones of different molecular weight may be used as identityJ Water depresses the glass transitions and effects the physical properties of polyvinylpyrrolidone, as demonstrated by Tan and ChallaJ ... 

Iwata M, Ueda H. Dissolution properties of glibenclamide in combinations with polyvinylpyrrolidone. Drug Dev Ind Pharm 1996 22 1161-1165. 

Velocity gradients in blood vessels are reduced in cases of retarded peripheral circulation, especially in shock. Under these conditions erythrocytes may aggregate and the discovery of agents that are capable of reducing this stmctural viscosity is thus of great clinical value. Dextrans and polyvinylpyrrolidones diminish attraction between individual cells in blood and improve flow properties. 

Soluble polyvinylpyrrolidone was first used during World War II as a blood-plasma substitute. Although it has excellent properties for this purpose, it has no longer been used for a number of decades. The organism does not metabolize the polymer, with the result that after parenteral administration, small quantities of high-molecular components may remain within the body. This problem does not exist with oral administration. 

The ability to form complexes with such a large number of substances is a special feature of polyvinylpyrrolidone (Section 2.2.7). The complexes formed are almost always soluble and are stable only in an acid medium. This property can be used to increase the solubility of drugs in liquid dosage forms, as in the case of povidone-iodine. In solid dosage forms, the ability to form complexes is used to increase bioavailability. A reduction in the local toxicity of certain drugs can also be achieved by complexation with povidone. A special use for the complexation properties lies in the stabilization of proteins and enzymes in diagnostics. 

The following summary of toxicological properties is taken from the book A Critical Review of the Kinetics and Toxicology of Polyvinylpyrrolidone [225] ... 

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