Addition Of Water-soluble Polymers Research Articles

Probucol-Ursodeoxycholic Acid Otic Formulations: Stability and In Vitro Assessments for Hearing Loss Treatment

Targeted drug delivery is an ongoing aspect of scientific research that is expanding through the design of micro- and nanoparticles. In this paper, we focus on spray dried microparticles as carriers for a repurposed lipophilic antioxidant (probucol). We characterise the microparticles and quantify probucol prior to assessing cytotoxicity on both control and cisplatin treated hair cells (known as House Ear Institute-Organ of Corti 1; HEI-OC1). The addition of water-soluble polymers to 2% β-cyclodextrin resulted in a stable probucol formulation. Ursodeoxycholic acid (UDCA) used as formulation excipient increases probucol miscibility and microparticle drug content. Formulation characterisations reveals spray drying results in spherical UDCA-drug microparticles with a mean size distribution of ∼5-12 μm. Probucol microparticles show stable short-term storage conditions accounting for only ∼10% loss over seven days. By mimicking cell culture conditions, both UDCA-probucol (67%) and probucol only (82%) microparticles show drug release in the initial two hours. Furthermore, probucol formulations with or without UDCA preserve cell viability and reduce cisplatin-induced oxidative stress. Mitochondrial bioenergetics results in lower basal respiration and non-mitochondrial respiration, with higher maximal respiration, spare capacity, ATP production and proton leak within cisplatin challenged UDCA-probucol groups. Overall, we present a facile method for incorporating lipophilic antioxidant carriers in polymer-based particles that are tolerated by HEI-OC1 cells and show stable drug release, sufficient in reducing cisplatin-induced reactive oxygen species accumulation.

Dynamic Interfacial Tensions of Surfactant and Polymer Solutions Related to High-Temperature and High-Salinity Reservoir.

Betaine is a new surfactant with good application prospects in high-temperature and high-salinity reservoirs. The interfacial properties of two kinds of betaine mixtures with a good synergistic effect were evaluated in this paper. On this basis, the effects of temperature-resistant, salt-resistant polymers with different contents of 2-acrylamide-2-methylpropanesulfonic acid (AMPS) on dynamic interfacial tensions (IFTs) against n-alkanes and crude oil were studied. The experimental results show that the IFTs between betaine ASB and n-alkanes can be reduced to ultra-low values by compounding with anionic surfactant petroleum sulfonate (PS) and extended anionic surfactant alkoxyethylene carboxylate (AEC), respectively. ASB@AEC is very oil-soluble with nmin value ≥14, and ASB@PS is relatively water-soluble with nmin value of 10. The water solubility of both ASB@PS and ASB@AEC is enhanced by the addition of water-soluble polymers. The HLB of the ASB@AEC solution becomes better against crude oil after the addition of polymers, and the IFT decreases to an ultra-low value as a result. On the contrary, the antagonistic effect in reducing the IFT can be observed for ASB@PS in the same case. In a word, polymers affect the IFTs of surfactant solutions by regulating the HLB.

Characteristics investigation of composite electrochromic films based on Ni(Oh)2, polyvinyl alcohol, and polyvinylpyrrolidone

The cost of electrochromic “smart” windows ranges from 200–800 USD/m2. The high cost is determined by the small volume of production and the high cost of vacuum methods for applying device layers. The development of other methods could lead to lower costs and further mass use of “smart” windows. The paper presents the work on improving the electrochemical method of deposition of electrochromic films based on Ni(OH)2. Composite electrochromic films were deposited from Ni(NO3)2 solutions with the addition of water-soluble polymers – polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and mixtures thereof. Two PVA grades and one PVP grade were used in the experiments. As a result, six films were obtained from solutions of different compositions and concentrations of polymers. An investigation of the optical properties of the films in the initial state showed that there is no intense absorption of light in the entire visible spectrum and the transmission corresponds to a glass substrate. Thus, the formed electrochromic films will not produce tints and visible light absorption in the finished electrochromic element. The electrochemical and electrochromic characteristics of the films differed significantly depending on the amount and specific polymers used. The film obtained from a solution containing PVA grade 24-99 was the most electrochemically active, while the best electrochromic characteristics were in the film deposited from a solution of a mixture of PVP grade 24-99 and PVP. Moreover, the films obtained in solutions containing separately PVA grade 24-99 and PVP had worse electrochromic characteristics, and the electrochemical characteristics were the same or worse relative to the film obtained in a mixture of polymers. The results of the method of electrochemical impedance spectroscopy showed compliance with the found electrochromic and electrochemical characteristics of the formed films.

Impregnating Compound for Cement-Concrete Road Pavement

The paper proposes an impregnation composition for cement concrete roads used as an ice-phobic coating. The composition has been made based on keratin-containing components derived from animal waste with the addition of water-soluble polymers. The main parameter of serviceability of the coating impregnated with the developed composition was assessing the adhesion resistance of ice crust to concrete under the influence of mechanical loads. For this purpose, tests of big specimens (surface area 1925 cm2) in laboratory conditions with application of vibration and impact loads and modelling of thermal stresses were conducted. The test results showed the effectiveness of the ice-coating, as in all experiments, the uncoated specimens showed a greater resistance of the ice crust to mechanical stresses. An additional evaluation parameter was comparing the water absorption capacity of coated and uncoated concrete. The test results showed a significant difference in the water absorption capacity of the uncoated specimens, exceeding the coated specimens by 47%. Due to the results obtained, it will be possible to use the impregnation compound effectively to improve the ice resistance of cement concrete coatings.

Mechanical enhancement of cellulose nanofibril (CNF) films through the addition of water-soluble polymers

In this work, water-soluble polymers were screened through solution casting and polyvinyl alcohol (PVA) and poly(2-ethyl-2-oxazoline) (PEOX) were found as reinforcement agents for cellulose nanofibril (CNF) films. Mechanical property increases of 99% in elastic modulus, 93% in the ultimate tensile strength (UTS) and 134% in the work of failure (WOF) were reported for TEMPO-oxidized cellulose nanofibrils (TOCNFs) with 0.44 mmol/g carboxylate groups and 15 wt% PVA. PEOX had a higher elastic modulus increase of 113%, yet lower UTS and WOF increases were found at 63% and 28%, respectively. Additionally, increases in UTS and elastic modulus were also seen in mechanically fibrillated CNFs and TOCNFs with higher carboxylate contents (1.5 mmol/g). The toughening mechanism was attributed to the formation of strong hydrogen bonding between the CNFs and the hydrophilic polymers added. The presence of such mechanisms was indirectly confirmed by tensile testing, zeta potential and rheology.

Пропиточный состав для цементно-бетонного покрытия дорог для улучшения ледофобных свойств

The article proposes an impregnation composition for cement concrete roads used to improve the ice-phobic properties of the pavement. The composition is based on the keratin production technology. The distinctive component of the composition is the addition of water-soluble polymers. One of the study criteria was to evaluate the performance of the impregnation composition, its adhesion resistance to mechanical impact. Tests were conducted for large samples (surface area 1925 cm2) in laboratory conditions with the application of vibration and shock loads. The test results showed the effectiveness of the ice-resistant coating, as in all experiments the uncoated specimens showed greater resistance of the ice crust to mechanical stress.

Antifungal drug solubilizing activity and self-aggregation ability of cationic aminocalix[4]arene in comparison to SBEβCD: effect of addition of water-soluble polymer

Ionized calixarene derivatives often possess properties of typical surfactants, aggregating in aqueous solutions. Their solubilizing properties, in this case, are often greater than conventional excipients, cyclodextrins. This in addition to their reported low toxicity makes these compounds promising pharmaceutical excipients. In this study we investigate the solubilizing ability of a cationic aminocalix[4]arene (CALIX), towards antifungal drugs, alone and with addition of HPMC. Next, the compound’s self-aggregation properties in the presence of drug alone or in conjunction with polymer were studied using DLS, and compared to that for SBEβCD. Twenty percent (w/v) CALIX solution solubilizes antifungal drugs more efficiently than SBEβCD, improving for example the solubility of clotrimazole more than 21,000 times compared to its intrinsic solubility, and addition of 0.25 % HPMC into complexation media increases this effect further. Introduction of drug alone or in combination with the polymer into the complexation media significantly changes the microenvironment of excipient’s aqueous solution, resulting either in smaller or larger aggregates depending on the drug chosen, presence of the polymer or the excipient used. Growth of the aggregates is observed to a greater extent upon introduction of clotrimazole into the media than with econazole nitrate and in some cases the particles were large enough to be observed by conventional light microscopy.

Characterization of Bulk Fluid and Transport Properties for Simulating Polymer-Improved Aquifer Remediation

AbstractIn situ mobility reduction resulting from the addition of water-soluble polymers to subsurface remedial fluid formulations has the potential to significantly improve the delivery and subsurface distribution of remediation agents within heterogeneous contaminated aquifer systems. However, the increased viscosity, non-Newtonian rheology, competing retention and acceleration mechanisms, and the potential for these fluids to reduce media permeability because of mechanical filtration of these large polymer molecules complicate treatment design calculations and often necessitate numerical simulation for purposeful evaluation and application of this technology. In this paper, laboratory and computational methods are presented that were used to characterize bulk fluid and porous media transport properties of xanthan gum biopolymer-amended fluids for the purpose of facilitating numerical simulation. A detailed discussion of polymerized fluid transport mechanisms and input parameters for simulating polymer ...

Formation of Dynamic Duolayer Systems at the Air/Water Interface by using Non-ionic Hydrophilic Polymers

The inclusion of a water-soluble polymer, poly(vinyl pyrrolidone) (PVP), into a surface active film composition before application to the water surface leads to the formation of a dynamic duolayer; a novel surface film system. This duolayer shows improved surface viscosity over the monolayer compound alone, while the addition of polymer maintains other film properties such as evaporation control and equilibrium spreading pressure. Brewster Angle Microscopy shows that the duolayer film undergoes a different formation mechanism upon film compression, and the resultant surface pressure/area isotherm is different at lower surface pressures indicating the PVP is present on the water surface at these pressures and squeezed out to the water subphase at higher pressures. The addition of water-soluble polymers to form a dynamic duolayer provides a unique way to produce defect-free and tightly packed films while polymer is associated with the film. This finding provides new knowledge for the design of surface films with improved properties with potential applications in many areas.

Green Processing of Nanofibers for Regenerative Medicine

AbstractElectrospinning of polymer scaffolds is mostly carried out using organic solvents, but the drawbacks are: solvent costs, environmental hazards, and presence of traces of solvent impurities. The use of water‐soluble polymers (WSPs), water or aqueous solutions as an electrospinning medium (green processing) is a very attractive method to avoid such issues. However, a few WSP such as polyelectrolytes are not spinnable as such, but have been electrospun by addition of WSPs, additives, and salts. This paper covers solution properties, polyelectrolyte nanofibrous scaffolds (polysaccharides, biopolymers, etc.), fabrication through green processing, and their regenerative medical applications such as wound dressing, drug delivery, and tissue engineering. This is the first review to cover the above issues, the drawbacks of current methods, and future challenges.

Effect of water soluble polymer additives on the phase composition and size of zirconia particles during precipitation from salt solutions

The effect of water soluble polymer additives on the phase composition and particle sizes of zirconia stabilized with yttria during precipitation from water-alcohol salt solutions has been studied by the methods of X-ray structural analysis, Raman spectroscopy, thermal nitrogen desorption, and sedimentation analysis using an ultracentrifuge DC-24000. It has been demonstrated that agar-agar and PVA additives are most effective.

Zinc removal from wastewater by complexation-microfiltration process

As a result of its wide industrial applications, zinc has become an important contaminant in aquatic environment since it is a toxic heavy metal and some of its compounds such as zinc arsenate and zinc cyanide, may be extremely hazardous. Therefore, there is a growing need for developing simple methods capable of separating and recovering trace zinc from environmental waters. Nowadays, the ultra and microfiltration method for trace metals removal from waters by the addition of water-soluble polymers into the aqueous solutions has become a significant research area. The choice of watersoluble macroligands remains important for developing this technology. Sodium carboxymethyl cellulose (Na-CMC) was selected as complexing agent. The microfiltration experiments were carried out in stirred dead-end cell. To separate formed polymer-metal complex Versapor membranes were used. The concentration of heavy metal ions after microfiltration in aqueous solution was determined using atomic absorption spectroscopy (AAS). Effects of amount of complexing agent, pH value, type of anion, ionic strength and operating pressure on the flux (J) and rejection coefficient (R) were investigated. Experimental results indicate a considerable influence of the pH, ionic strength and type of anion on the rejection coefficient, while effect of amount of complexing agent is relatively insignificant. The Na-CMC used in the research proved to be very effective, which may be supported by the high rejection coefficients obtained (99%).

Lyotropic Lipid Phases Confined in Cylindrical Pores: Structure and Permeability

A model membrane system based on lipid lyotropic phases confined inside the pores of a well-defined scaffold membrane, thereby forming a double-porous membrane structure, is described. The model membrane system is characterized with regard to lipid structure, lipid location, and phase transitions, using small-angle X-ray scattering, differential scanning calorimetry, and confocal microscopy. The system enables studies of transport across oriented lipid bilayers as well as of lipids in confinement. The lipids are shown to be located inside the membrane pores, and the effect of confinement on lipid structure is shown to be small, although dependent on the surface properties of the scaffold membrane. For transport studies, Franz diffusion cells and different types of drugs/dyes are used, and the transport studies are complemented with theoretical modeling. Lipids investigated include monoolein, dioleoyl phosphatidylcholine, dimyristoyl phosphatidylcholine, and E. coli total lipid extract. In the case of monoolein, the lipid structure can be changed from a bicontinuous cubic Ia3d phase to a liquid crystalline lamellar phase, by controlling the osmotic pressure of the surrounding solution through addition of water-soluble polymer. The osmotic pressure can thereby be used as a switch, changing the permeability of the lipid phase up to 100-fold, depending on the properties of the diffusing substance. The large effect of changing the structure implies an alignment of the lamellar phase inside the pores.

Effect of water-soluble polymers on the physical stability of aqueous polymeric dispersions and their implications on the drug release from coated pellets

Purpose: To investigate the physical stability and drug release-related properties of the aqueous polymer dispersions Kollicoat® SR 30 D and Aquacoat® ECD (an ethylcellulose-based dispersion) in the presence water-soluble polymers (pore formers) with special attention to the potential flocculation of the polymer dispersions. Methods: A precise characterization of the flocculation phenomena in undiluted samples was monitored with turbidimetric measurements using the Turbiscan Lab-Expert. Theophylline or propranolol HCl drug-layered pellets were coated with Kollicoat® SR 30 D and Aquacoat® ECD by the addition of water-soluble polymers polyvinyl pyrrolidone (Kollidon® 30 and 90 F), polyvinyl alcohol–polyethylene glycol graft copolymer (Kollicoat® IR), and hydroxypropyl methylcellulose (Pharmacoat® 603 or 606) in a fluidized bed coater Glatt GPCG-1 and drug release was performed according to UPS paddle method. Results: Stable dispersions were obtained with both Kollicoat® SR 30 D (a polyvinyl acetate-based dispersion) and Aquacoat® ECD with up to 50% hydrophilic pore formers polyvinyl alcohol-polyethylene glycol graft copolymer (Kollicoat® IR) and polyvinyl pyrrolidone (Kollidon® 30). In general, Kollicoat® SR 30 D was more stable against flocculation than Aquacoat® ECD. Stable dispersions were also obtained with higher amounts of water-soluble polymer or by reducing the concentration of the polymer dispersion. Flocculated dispersions resulted in porous films and, thus, in a sharp increase in drug release. Conclusions: Kollicoat® SR 30 D was more resistant to flocculation upon addition of water-soluble polymers than Aquacoat® ECD. The continuous adjustment of drug release from Kollicoat® SR 30-coated pellets was possible with Kollicoat® IR amounts over a broad range.

Studies on the effect of water-soluble polymers on drug-cyclodextrin complex solubility.

The effect of complexation of irbesartan (IRB), a practically water-insoluble drug, with cyclodextrins in presence of different concentrations of water-soluble polymers (PEG 4000 and PVP K-90) on the dissolution rate of the drug has been investigated. Phase solubility studies were carried out to evaluate the solubilizing power of betaCD in association with water-soluble polymers towards IRB and to determine the apparent stability constant (K (S)) of the complexes. Improvement in K(S) value for ternary complexes (IRB-betaCD-polymers) clearly proved the benefit on the addition of water-soluble polymer to increase complexation efficiency. The dissolution rate of the drug from ternary systems containing PEG 4000 and PVP K-90 was higher as compared to the binary system. An optimum increase in the dissolution rate of the drug was observed at a polymer concentration of 5% w/w for PVP K-90 and 10% w/w for PEG 4000. DSC, FTIR, SEM, and XRD studies were carried out to characterize the complexes.

Effects of additives on the cloud points of selected nonionic linear ethoxylated alcohol surfactants

Effects of various additives including inorganic salts, nonionic and ionic surfactants, water-soluble polymers and alcohols on the cloud points of three linear nonionic surfactants, Tergitol 15-S-7, Tergitol 15-S-9 and Neodol 25-7, were investigated. These surfactants are readily biodegradable and either linear primary or secondary ethoxylated alcohols. Cloud points of these surfactants were functions of their concentrations and concentrations of additives. The cloud points of nonionic surfactant mixtures lay in between the cloud points of individual component surfactants. Presence of two ionic surfactants, sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB), increased the cloud point of 1 wt% Tergitol 15-S-7 micellar solution dramatically when concentrations of ionic surfactants approaching their critical micelle concentration. Addition of water-soluble polymers decreased the cloud point, while addition of inorganic salts can either increase or decrease the cloud points. However, the effect of an alcohol additive on cloud point was dependent on its chain length or its water solubility. Interestingly, synergistic effects between sulfate or phosphate and pentanol on depression of cloud points of Tergitol 15-S-9 were discovered. A linear model predicting cloud points of Tergitol 15-S- X ( X = 7, 9 and 12) surfactants and Neodol 25- X ( X = 7, 9 and 12) surfactants were proposed with a correlation to logarithm of their ethylene oxide numbers.

The effects of water-soluble polymers on hydroxypropyl-β-cyclodextrin solubilization of oleanolic acid and ursolic acid

The objective of this study was to investigate the influence of water-soluble polymers on the complex formation of hydroxypropyl-β-cyclodextrin (HP-β-CD) with oleanolic acid (OA) and ursolic acid (UA), two insoluble isomeric triterpenic acids. The interactions of OA and UA with HP-β-CD in water-soluble polymer solutions were studied by ultraviolet (UV) spectrophotometry. Phase-solubility studies were carried out to evaluate the solubilizing power of HP-β-CD, in association with water-soluble polymers, towards OA and UA. UV spectra indicated that the absorption intensity decreased upon the addition of HP-β-CD both in the absence and presence of water-soluble polymers. Stability constants were also calculated from the UV spectra. When water-soluble polymers were added, both the solubilization effect and the complexation efficiency (CE) of HP-β-CD with the isomers decreased. The experimental results suggested that the addition of water-soluble polymers inhibit the solubilization effect of HP-β-CD with OA and UA.

On the frictional contribution to the viscosity of cement and silica pastes in the presence of adsorbing and non adsorbing polymers

This paper is devoted to the role of hydrodynamic lubrication in the flow of dense suspensions of non-Brownian cement or silica particles. The role of hydrodynamic lubrication is ambiguous since it is primarily a source of viscous dissipation but, by preventing direct contact between particles and friction, it may facilitate flow. We show that in the concentration and shear rate regimes investigated here direct contact friction between cement or silica particles is contributing to the overall energy dissipation. Addition of water-soluble polymers, either adsorbing or not adsorbing, was used as a mean to control friction. We show that, independently of the adsorption capacity of the polymer, it is the non adsorbed polymer which, thanks to hydrodynamic lubrication, prevents direct contacts and reduces the overall energy dissipation. This leads to the counterintuitive situation where by increasing the interstitial fluid viscosity, the suspension viscosity is decreased. When hydrodynamic lubrication is no longer able to avoid direct frictional contact, dilatant and shear-thickening behaviors set in.

Nanofibrous membranes from aqueous electrospinning of carboxymethyl chitosan

Carboxymethyl chitosan (CMCS) with varying molecular weights(Mv = 40–405 kDa) and degreesof substitution (DS = 0.25–1.19) has been synthesized by alkalization of chitosan, followed bycarboxymethylation with monochloroacetic acid. At DS up to 1.19, the locationswhere carboxymethylation took place were influenced by the alkalizationtemperature, i.e., both C2 and C6 substitution at ambient temperature(N,O-carboxymethylated) and mainly C6 substitution at the lower temperature,−15 °C (O-carboxymethylated). Generally, carboxymethylation was more favorable at the primary C6 hydroxylthan the C2 position with increasing DS. CMCS synthesized from 405 kDa CS was soluble in waterat DS≥0.73 whereas those from 40 and 89 kDa became water-soluble at lower DS of 0.25 and0.36, respectively. Electrospinning of aqueous solutions of CMCS was facilitatedwith the addition of water-soluble polymers, including PEO, PAA, PAAm andPVA. The optimal fiber formation was observed at equal mass composition ofO-CMCS (89 kDa at 0.36 DS) and PVA, producing nanofibers withan average diameter of 130 nm. Heat-induced esterification (at140 °C for 30 min) produced inter-molecular covalent cross-links within and among fibers, renderingthe fibrous membrane water-insoluble. Membranes containing higher CMCS carboxyl toPVA hydroxyl ratio retained better fiber morphology upon extended water exposure,indicating more favorable inter-molecular cross-links. The fibrous membranes generatedwith less substituted CMCS were more hydrophilic and retained a greater extent of thedesirable amine functionality.

Ultrasonic Studies on Lamivudine: β-Cyclodextrin and Polymer Inclusion Complexes

The aim of the present study is to enhance the solubility and stability of drugs in addition of water-soluble polymer and carbohydrate complexes. The data show that the polymer polyvinyl alcohol (PVA) interacts with the free Lamivudine and with the Lamivudine; beta-cyclodextrin (beta-CD) inclusion complex, in both cases with particular intermolecular interaction was studied using ultrasonic technique under different concentrations at a temperature 303 K. Consequently, the reason of this study was to improve the biological performance of the drug through enhancing its solubility and stability. The binary and ternary mixtures prepared inclusion complexes of Lamivudine in beta-CD and PVA. The presence of PVA, changes the drug: beta-CD interaction, a Lamivudine: beta-CD: PVA complex was formed. In addition, the presence of PVA produces a strong increase in the binding constant at a particular concentration (1.25%). In the ternary complex, the Lamivudine is wrapped at both ends for the beta-CD. In this complex, the polymer seems to act as a bridge between both beta-CD molecules that bind the Lamivudine.