Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “POLYVINYLPYRROLIDONE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2001

The Adsorption of Polyvinylpyrrolidone on Kaolinite Saturated with Sodium Chloride.

The adsorption of two different molecular weights of polyvinylpyrrolidone (PVP) (M(w)=44,000 and M(w)=360,000 g mol(-1)) from water on kaolinite saturated with sodium chloride has been studied. The adsorption of PVP increases slowly as temperature increases. The adsorption of PVP on the kaolinite was studied by considering Fourier transform infrared (FTIR) spectra, X-ray diffraction patterns, and dielectric constants. During the adsorption process, PVP interacts with saturating sodium cations and possibly forces some of them onto the edges of the kaolinite; thus, the dielectric constant of saturated kaolinite is reduced after PVP adsorption. Copyright 2001 Academic Press.

Journal Article↗
PubMed2002

Polyvinylpyrrolidone adsorption and structural studies on homoionic Li-, Na-, K-, and Cs-montmorillonite colloidal suspensions.

Structural aspects of dilute homoionic Li-, Na-, K-, and Cs-montmorillonite (M-montmorillonite) particle suspension (1 g/L) under low-electrolyte-concentration (0.1 mM MCl) conditions were characterized by static (absorbance or turbidity) and dynamic (photon correlation spectroscopy) light-scattering methods as well as by the adsorption behaviors of nonionic polyvinylpyrrolidone (PVP) mol wt 5,000 g/mol (LMW PVP) and mol wt 400,000 g/mol (HMW PVP). Taking Li-montmorillonite as a reference for a single plate particle, a particle size increase and a surface accessibility decrease to polymer adsorptions were measured along the Li, Na, K, and Cs series. The results are related to the existence of montmorillonite quasicrystals or tactoids in diluted suspension, whose stability increases along the same cation series. Molecular weight effects on the PVP surface accessibility are discussed in terms of permeation properties of the different M-montmorillonite particles. Modeling the results calculates an average number of plates in montmorillonite quasi-crystals and the surface area distribution of ultramicropores <0.7 nm and pores >0.7 nm in M-montmorillonite particles. It can also be demonstrated by applying hydrodynamic and electrokinetic methods that the measured high absorbance or turbidity increase of PVP-loaded montmorillonite particles is not due to aggregation phenomena but to a PVP contribution in the light-scattering intensity.

Journal Article↗
PubMed2002

Affinity extraction of dye- and metal ion-binding proteins in polyvinylpyrrolidone-based aqueous two-phase system.

Affinity extraction of dye- and metal ion-binding proteins, respectively, in a polyvinylpyrrolidone (PVP40)-Reppal PES 100 two-phase system was investigated. Due to the ability of PVP to complex azo dyes and inorganic ions, covalent coupling of the ligands was not essential. Cibacron Blue F3GA was used as the ligand for extraction of lactate dehydrogenase (LDH) from porcine muscle, while copper ions were used for extraction of B. stearothermophilus LDH with a fusion tag of six histidine residues (His6-LDH) from recombinant Escherichia coli homogenate. The binding strength of the enzymes to their respective ligands was only slightly reduced in the presence of PVP. The partition coefficient of Cibacron Blue and Cu2+ ions in the two-phase systems composed of different concentrations of PVP and Reppal was in the range of 20-30, with maximal partitioning being observed in the 17% (w/w) PVP40-10% Reppal PES100 system. Only a minor leakage of the ligands to the bottom phase was observed with time. The partitioning of porcine LDH to the PVP phase was increased 100-fold, and a maximal recovery of 89% was obtained in the two-phase system loaded with 0.2% (w/w) Cibacron Blue. The enzyme was quantitatively recovered with further purification from the PVP-dye phase using a secondary extraction step with 170 mM phosphate or alternatively with 100 mM phosphate containing NADH or NaCl. A more than 10-fold increase in the partition coefficient of His6-LDH was achieved in the two-phase system loaded with 0.4% (w/w) copper sulfate compared to the system lacking the metal ions. The enzyme was also back-extracted into phosphate phase in the presence of imidazole.

Animals↗
PubMed1985

Scanning electron microscopic findings on the rabbit meninges after local lavage with Polyvinylpyrrolidon-Jod-Komplex.

The microbicide Polyvinylpyrrolidon-Jod-Komplex (P.J.K.) was experimentally evaluated for its use in local lavage of the epidural space. In 20 rabbits a lumbar laminectomy was performed followed either by local lavage with P.J.K. or with NaCl. After one month the meningeal covering of the operated spinal cords revealed no signs of fibrosis or arachnoid adhesions when studied macroscopically or by scanning electron microscopy (SEM).

Animals↗
PubMed1977

Movement of 125I albumin and 125I polyvinylpyrrolidone through bone tissue fluid.

The passage of tissue fluid through cortical bone has been investigated using radioactively labelled macromolecules as markers. The results suggest that in the cortex of young rabbit femur the movement of tissue fluid is in the same net direction as blood, mainly from the endosteal to the periosteal surface. Some albumin is incorporated from extravascular tissue fluid into calcified matrix at sites of bone formation. Polyvinylpyrrolidone, average molecular weight 35,000, is able to pass through extravascular tissue fluid in bone but is not incorporated into calcified matrix. In rabbits made vitamin D deficient, much less alblmin is retained in regions of bone formation than is the case with controls. Albumin adsorbs to the surface of calcium phosphate precipitates and it is suggested that this mechanism may be mainly responsible for its incorporation into bone.

Albumins↗
PubMed1985

Is prophylactic abdominal irrigation with polyvinylpyrrolidone iodine (PVPI) safe?

In order to investigate the safety of abdominal irrigation with polyvinylpyrrolidone iodine (PVPI), the abdominal cavities of normal rats were irrigated with the highest nonlethal dose. Samples of the peritoneal fluid were taken before and 1, 2, and 4 hours after irrigations. Control studies were done with saline. After irrigation with PVPI, the protein concentration in the peritoneal fluid showed a 40-fold increase, compared with only a doubling after saline irrigations. Irrigation with PVPI causes serious peritoneal damage, and should therefore not be performed as a prophylactic procedure.

Abdomen↗
PubMed1986

The effect of doxycycline on polyvinylpyrrolidone-induced granuloma formation in the rat liver.

The tetracyclines specifically inhibit mitochondrial protein synthesis when present at the same low concentrations as used for their antibacterial action. Inhibition of mitochondrial protein synthesis leads to decrease in the oxidative energy-generating capacity of cells. Therefore, the presence of tetracyclines may result in proliferation arrest. In the present study we show that continuous intravenous administration of polyvinylpyrrolidone (PVP) induces the formation of granulomas in the normal rat liver; the rats usually die within 2 weeks of continuous PVP treatment. Athymic (nude) rats appear to be more resistent to the deleterious effects of PVP as they survive the treatment for at least 5 weeks. Although the livers of the PVP-treated nude rats are heavily infiltrated with phagocytic cells, they seldom show granulomas. Reconstitution of nude rats with syngenic thymocytes leads, on the other hand, to extensive granuloma formation. Normal rats treated continuously with PVP plus doxycycline, however, all survive, their livers showing only a few very small granulomas and the normal low number of phagocytic cells. We conclude that the formation of granulomas induced by PVP is a process which is mediated by T-lymphocytes. Because doxycycline prevents this kind of granuloma formation it seems likely that doxycycline not only impairs the proliferation and differentiation of T-lymphocytes but also of monocytes and macrophages.

Animals↗
PubMed1999

[Polyvinylpyrrolidone deposits in the pleura].

We report on the case of a 45-years old woman with repeated pleural effusions lasting for 2 years. She had a history of breast carcinoma 6 years ago, which was treated by breast amputation and radiation. After repeated histological and cytological examinations no tumorous compromise of the pleura or other cause for the effusions could be found. A pleural resection was performed. On the histological and electron microscopical examination deposits of a foreign substance were found, which was identified as polyvinylpyrrolidone. This substance was obviously introduced in the pleural cavity by the attempts to treat the effusions by pleurodesis with Diclofenac and Tetracycline (Vibravenös). The diagnosis is suggested by the histological findings, but it must be confirmed by anamnesis, also for PVP deposits in other organs.

Breast Neoplasms↗
PubMed2005

Functionality of cross-linked polyvinylpyrrolidone as a spheronization aid: a promising alternative to microcrystalline cellulose.

PURPOSE: This work seeks to explore and demonstrate the functionality of cross-linked polyvinylpyrrolidone (crospovidone) as a spheronization aid and a promising alternative to microcrystalline cellulose (MCC). METHODS: Pellets were prepared with various grades of crospovidone using both small- and large-scale extrusion-spheronization. A Box-Behnken experimental design was employed to elucidate the effects of operating variables on the quality of the pellets. Size and shape analyses of these pellets were conducted and compared to those prepared using MCC. RESULTS: Crospovidone was believed to behave like a liquid repository in its interaction with water during extrusion-spheronization, although its binding ability was weaker than that of MCC. Spherical pellets of narrow size distribution could be made from the finer crospovidone grades with different lactose grades. However, crospovidone-based formulations required higher water levels than weight-equivalent MCC-based formulations. Crospovidone pellets were of equivalent quality to those prepared with MCC, especially in the shape, size, and yield. CONCLUSIONS: Crospovidone can be successfully employed as a spheronization aid to produce good pellets without the need of a binder, unlike most of the previously proposed materials. This study exemplified the enormous potential of crospovidone to serve as a competent alternative to MCC in the production of pellets by extrusion-spheronization.

Cellulose↗
PubMed2006

Kinetics and mechanism for the reaction of cysteine with hydrogen peroxide in amorphous polyvinylpyrrolidone lyophiles.

PURPOSE: Peroxide impurities play a critical role in drug oxidation. In metal-free aqueous solutions, hydrogen peroxide (H(2)O(2)) induced thiol oxidation involves a bimolecular nucleophilic reaction to form a reactive sulfenic acid intermediate (RSOH), which reacts with a second thiol to form a disulfide (RSSR). This study examines the reaction of cysteine (CSH) and H(2)O(2) in amorphous polyvinylpyrrolidone (PVP) lyophiles to explore the possible relevance of the solution mechanism to reactivity in an amorphous glass. MATERIALS AND METHODS: Amorphous PVP lyophiles containing CSH and H(2)O(2) at varying initial 'pH' and reactant concentrations were prepared by methods designed to minimize reaction during lyophilization. Kinetic studies were conducted anaerobically at 25 degrees C and reactants and products were monitored by HPLC. Products were characterized and the kinetic data were fit to models adapted from the solution mechanism. RESULTS: Key differences in the reactions in aqueous solution and amorphous PVP are: (1) while only cystine (CSSC) forms in solution, three degradants-cysteine sulfinic acid (CSO(2)H), cysteine sulfonic acid (CSO(3)H) and cystine (CSSC)--form in amorphous PVP; (2) simple bimolecular kinetics govern the solution reaction while initial rates in amorphous PVP suggested more complex kinetics (i.e., non-unity values for reaction order); and (3) heterogeneous (i.e., biphasic) reaction dynamics are evident in amorphous PVP. The differences in product formation and apparent reaction orders in the solid-state could be rationalized by partitioning of the same reactive intermediate to multiple products in the solid-state due to the restricted mobility of CSH. Beyond the initial rate region, the kinetics in amorphous PVP could be described by the Kohlrausch-Williams-Watts (KWW) stretched-exponential equation or by assuming two populations of reactant molecules having different reactivities. CONCLUSIONS: When reactive intermediates are involved, differences in degradant profiles and other characteristics (e.g., rate constants, apparent reaction order) in the amorphous-state may simply reflect altered rates for individual reaction steps due to glass-induced changes in relative reactant mobilities rather than a change in overall mechanism.

Algorithms↗
PubMed1984

125I-wheat germ agglutinin blotting: increased sensitivity with polyvinylpyrrolidone quenching and periodate oxidation/reductive phenylamination.

Two substantial improvements in sensitivity in the identification of 125I-wheat germ agglutinin-binding glycoproteins on nitrocellulose blots of sodium dodecyl sulfate-polyacrylamide gels are reported. The major improvement in sensitivity (about 30-fold) derives from the use of 2% (w/v) polyvinylpyrrolidone (average Mr 40,000) instead of bovine serum albumin or denatured hemoglobin as the quenching agent (or carrier) during incubation with 125I-wheat germ agglutinin in detergent-free, phosphate-buffered saline. Under these conditions, specific labeling with 125I-wheat germ agglutinin is observed for orosomucoid derivatives that display N-acetylglucosamine or sialic acid residues at the nonreducing termini of their oligosaccharides, as well as for a number of glycoprotein components of a rat hepatocyte plasma membrane fraction. An additional improvement in sensitivity (up to 10-fold) results from an increase in the binding of 125I-wheat germ agglutinin to sialic acid-containing glycoproteins after treatment of the blots with 5 mM sodium metaperiodate followed by 5 mM aniline in the presence of 30 mM sodium cyanoborohydride. This treatment appears to cause the sequential oxidation and reductive phenylamination of the side chain of glycoprotein sialic acid residues.

Amination↗
PubMed1984

The effect of cytochalasin B on the release of lysosomal enzymes and intra-lysosomally-stored polyvinylpyrrolidone in the isolated perfused rat liver.

The uptake and subcellular distribution in vivo and release in vitro of 125I-polyvinylpyrrolidone (125I-PVP) has been studied in rat liver. Using the techniques of sucrose-density-gradient sedimentation and isopycnic centrifugation, it was shown that 4-15 days after injection of 125I-PVP the majority of the radioactivity was still in a high-molecular-weight form and associated with the lysosomes of the liver, the size and density properties of which were not significantly altered. Practically all of the 125I-PVP found in the lysosomes was free in the lumen and not associated with the lysosomal membrane, its intra-lysosomal distribution being much more similar to that of beta-galactosidase than arylsulphatase or beta-N-acetylglucosaminidase. In an isolated recirculating perfusion system the liver released all the enzymes studied (arylsulphatase, beta-galactosidase and lactate dehydrogenase) and, when previously loaded, 125I-PVP was also released into the perfusate. The magnitude of the release was always in the order 125I-PVP greater than beta-galactosidase greater than arylsulphatase. Preloading the lysosomes in vivo appeared to bring about an increase in the mean levels of release of all the enzymes, but the wide spread of data made this statistically significant only for lactate dehydrogenase. The microfilament poison cytochalasin B increased the release of arylsulphatase and beta-galactosidase, but not lactate dehydrogenase, in the perfused non-loaded livers, but failed to augment the release of any of the enzymes or 125I-PVP in the loaded livers. After perfusion, subcellular fractionation of the liver showed that the lysosomes had become enlarged and more fragile, especially so with those rich in 125I-PVP and beta-galactosidase rather than those rich in arylsulphatase and beta-N-acetylglucosaminidase.

Animals↗
PubMed1987

Suppression of IgG memory responses by T cells activated with the type 2 antigen polyvinylpyrrolidone (PVP).

Although type 2 antigens, such as polyvinylpyrrolidone (PVP), generally do not prime for IgG memory responses or activate specific helper T cells (TH), previous studies have established that low doses of PVP (0.0025 microgram) can prime for IgG memory and induce TH in vivo. Doses of PVP that are optimally immunogenic for IgM antibody production (0.25-25 micrograms) do not prime for IgG memory responses and preferentially activate PVP-specific suppressor T cells (TS) which suppress IgG antibody production. The studies reported here further characterize PVP-specific TS and begin to investigate the mode of action of these TS. TS induced with high doses of PVP have a typical suppressor cell surface phenotype in that they are Lyt 2+, I-J+, L3T4-, I-A- T cells. PVP-specific TS are inducible in mice expressing the X-linked immune defect and are Igh restricted in their actions. These TS suppress PVP-specific IgG responses of PVP-HRBC (horse red blood cells)-primed B cells when the TH population is from low-dose PVP-primed mice but not when the TH population is from PVP-HRBC-primed mice. Thus the TS do not apparently directly suppress the B-cell responses but act indirectly to suppress IgG responses by preventing the expression of PVP-specific TH function. The TS induced by 0.25 microgram PVP also prevent the generation of PVP-specific memory B cells apparently by preventing the expression of functional TH which are required for induction of memory B cells. Elimination of TS activation by pretreatment of mice with cyclophosphamide at the time of priming with 0.25 microgram PVP results in the expression of TH function and priming of memory B cells.

Animals↗
PubMed1996

Comparative spermicidal performance of iodinated and non-iodinated contraceptive formulations of nonoxynol-9 co-precipitated with polyvinylpyrrolidone.

The objective of this study was to evaluate the spermicidal qualities of various combinations of nonoxynol-9 (N-9; whole molecule = oligomers 1-18) and its isolated fractions (oligomers 8-10, 4-6 and 1-3), co-precipitated with non-iodinated and/or iodinated (Io) polyvinylpyrrolidone (PVP) as possible vaginal contraceptives. Spermicidal qualities of known equimolar concentrations of various combinations of PVP/N-9 and PVP-Io/N-9 were tested via a modified Sander-Cramer test (SCT) using human spermatozoa. Spermicidal agents and semen samples were mixed 1:1 (v/v) and evaluated for sperm viability. Spermicidal activity was reported as the minimal concentration (microgram/mL) of spermicide capable of killing all spermatozoa within 20 sec after exposure to the spermicide. The spermicidal activity of PVP/N-9 and PVP-Io/N-9 preparations containing N-9 oligomers 1-18 and/or 8-10 was similar, and these preparations were more efficient in killing the spermatozoa than the ones containing N-9 oligomers 4-6 and 1-3. Polyvinyl-pyrrolidone proved to be an effective vehicle for PVP/N-9 and PVP-Io/N-9 preparations, especially those containing N-9 oligomers 4-6 and 1-3. Incorporation of Io into the spermicidal preparations brought about additional efficacy. The current findings could be of clinical significance in future studies when preparing and delivering those selected co-precipitates vaginally.

Cell Survival↗
PubMed1994

Polyvinylpyrrolidone-coated silica packings for chromatography of proteins and peptides.

Polyvinylpyrrolidone (PVP)-coated silica sorbents were synthesized by interaction of a copolymer of vinyl-methyldiethoxysilane and vinylpyrrolidone with LiChrospher Si 300 and LiChrospher Si 500 silicas. The coating procedure retains the wide-pore structure of the starting silicas, as was shown by nitrogen adsorption, mercury porosimetry and inverse size-exclusion chromatographic measurements. Good selectivity and separation ability of the synthesized packings toward proteins and peptides were demonstrated in the hydrophobic interaction chromatographic mode of separation. Aromatic compounds undergo a specific interaction with bonded PVP chains which can be used for the preconcentration or selective recovery of polycyclic aromatic hydrocarbons.

Amino Acid Sequence↗
PubMed1988

Responses in Xenopus to the thymus independent antigen polyvinylpyrrolidone (PVP) and its haptenated derivative, trinitrophenylated PVP (TNP-PVP).

Xenopus laevis (the South African clawed toad) can respond to thymus dependent (TD) and thymus independent (TI) antigens. However, the response to trinitrophenylated Ficoll (TNP-Ficoll), a TI-2 antigen in mammals, is thymus dependent in Xenopus. Polyvinylpyrrolidone (PVP), classed as a TI antigen in mammals, is also a TI antigen in Xenopus, but responses to PVP and TNP-PVP are thymus regulated. As with TNP-Ficoll, capacity to respond to TNP-PVP diminishes during metamorphosis, and tolerance can be induced via the stimulation of TD suppression with trinitrobenzene sulphonic acid. Animals treated with N-methyl-N-nitrosourea and adult-thymectomised Xenopus, which lack certain TD responses, can nevertheless respond to TNP-PVP. Based on this and other information, it is concluded that TNP-PVP should be classed as a TI-2 antigen in Xenopus.

Aging↗
PubMed1994

Superovulation in the cow with a single intramuscular injection of FSH dissolved in polyvinylpyrrolidone.

It is desirable to reduce the number of treatments required to induce superovulation in cows. In this study we examined whether dissolving FSH in polyvinylpyrrolidone(PVP) would reduce the rate of absorption of FSH and allow it to be administered in a single dose for superovulation. In Experiment 1, 10 cows each received a single dose of FSH which contains 0.6% luteinizing hormone (FSH-R; 30 mg i.m.) dissolved in 30% PVP (10 ml) or in saline. In Experiment 2, a single injection of 30 mg FSH-R dissolved in 30% PVP was given to 25 cows, and 32 cows were injected twice daily in declining doses to receive a total of 28 mg FSH-R dissolved in saline. Prostaglandin F2alpha was given to all the cows 48 h after the first FSH treatment. Embryos were collected on Day 7 or 8 post insemination. In Experiment 1, the effect of FSH dissolved in PVP was compared with that dissolved in saline (number of recovered ova and embryos; 9.4+/-4.1 vs. 0). In Experiment 2, the rate of transferable embryos by single injection of FSH-R in PVP were significantly higher (P<0.05) than that of treatment of multiple injection groups. Progesterone concentration measured in serum collected 4 times from estrus (Day-0) to the day of embryo collection, indicated similar patterns in the 2 treatment groups. These findings suggest that PVP is a suitable solvent for prolonging the absorption of FSH given in a single injection thus providing a more practical approach of FSH administration.

Journal Article↗
PubMed1994

Superovulatory response and quality of embryos recovered from anestrus ewes after a single injection of porcine FSH dissolved in polyvinylpyrrolidone.

The effects of a single injection of porcine FSH (pFSH) administered in long acting vehicle on the superovulatory response of milk (Sarda breed) sheep were determined during the anestrous season. The sheep (n=42), synchronized with intravaginal sponges (40 mg fluorogestone acetate -FGA- for 14 d) were submitted 24 h before sponge removal to three different superovulatory treatments. Group 1 (n=16) was treated with a single intramuscular (im) injection of 16 mg of pFHS dissolved in 30 % polyvinylpyrrolidone (PVP); Group 2 (n=12) was injected im with 6, 5, 3 and 2 mg of pFSH every 12 h over 2 d; Group 3 (n=14) was given 800 IU of PMSG and 12 mg of pFSH. All sheep were mated with a fertile ram. Embryos were recovered surgically at Day 7 of sponge removal and graded for the quality according to their morphology. The percentage of good quality embryos recovered was 84% in Group 1, 68% in Group 2 and 77% in Group 3. Data for the onset of estrus, number of corpora lutea (CL), number of unovulated follicles, embryo recovery rate, embryo quality and fertilization rate were recorded for the 3 groups. The onset of estrus, number of CL, number of unovulated follicles, fertilization rate and number of good quality embryos did not differ significantly among the 3 groups. The embryo recovery rate was significantly lower in the group treated with PMSG-FSH (Group 3) than in the 2 other groups. It is concluded that during the anestrous season a single injection im of pFSH results on average in a superovulatory response as good as the more traditional treatments like multiple injections of pFSH and PMSG-pFSH combined.

Journal Article↗