Hydrophilic Solution Research Articles

Dry state microcrystals stabilized by an HPMC film to improve the bioavailability of andrographolide

ObjectiveThe main purpose of this study was to improve the in-vitro dissolution and the in-vivo bioavailability of a poorly water-soluble drug, andrographolide (ADG). MethodsA wet-milled suspension was prepared using a Lab basket mill in the presence of a hydrophilic carrier solution and then it was layered on to MCC beads with a fluidized bed coater to obtain solidified pellets. Optical microscopy, particle size distribution investigation, differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) were used to characterize the wet-milled suspension. In addition, the ADG pellets were subjected to investigations involving scanning electron microscopy (SEM), as well as dissolution, accelerated stability and bioavailability measurements. ResultsThe particle size was significantly reduced (from 31.6μm to 2.17μm), however, the ADG in suspension retained its crystallinity as shown by the results of the DSC and PXRD investigations. The dissolution of the new pellets and commercial dripping pills was 95.6% and 48%, respectively, in pure water over 60min. After a 6 month accelerated test (40°C and RH 75%), although the initial dissolution rate declined slightly, the overall dissolution of the new pellets within 60min was almost as high as the freshly prepared pellets. In the in-vivo evaluation, the Cmax (87.54±54.82μg/L) and AUC(0−t) of the new pellets (495.86±281.05μg/Lh) were clearly higher than those of the dripping pills (30.88±12.02μg/L, 301.07±133.85μg/Lh), while the Tmax of the test preparation was shorter than that of the reference (1.38h vs 3.29h). ConclusionThese results showed that the new core–shell structured pellets consisting of ADG microcrystalline particles and stabilized by HPMC alone, markedly improved the dissolution and bioavailability of andrographolide.

Controlled antiseptic/eosin release from chitosan-based hydrogel modified fibrous substrates

Fibers of cellulose networks were stably coated with N-methacrylate glycol chitosan (MGC) shells using subsequent steps of dip coating and photo-curing. The photo-crosslinked MGC-coated cellulose networks preserved their fibrous structure. A model hydrophilic antiseptic solution containing eosin, chloroxylenol and propylene glycol was incorporated into the shells to study the drug release dynamics. Detailed drug release mechanism into phosphate buffered saline (PBS) solutions from coated and pristine fibers loaded with the antiseptic was investigated. The results show that the MGC-coated cellulose fibers enable the controlled gradual release of the drug for four days, as opposed to fast, instantaneous release from eosin coated pristine fibers. This release behavior was found to affect the antibacterial efficiency of the fibrous cellulose sheets significantly against Staphylococcus aureus and Candida albicans. In the case of the MGC–eosin functionalized system the antibacterial efficiency was as high as 85% and 90%, respectively, while for the eosin coated pristine cellulose system the efficiency was negative, indicating bacterial proliferation. Furthermore, the MGC–eosin system was shown to be efficacious in a model of wound healing in mice, reducing the levels of various pro-inflammatory cytokines that modulate early inflammatory phase responses. The results demonstrate good potential of these coated fibers for wound dressing and healing applications. Due to its easy application on common passive commercial fibrous dressings such as gauzes and cotton fibers, the method can render them active dressings in a cost effective way.

Hydrophilic Carbon Nano-Particles; Preparation and Applications

The hydrophilic carbon nanoparticles have been produced from synthetic graphite blocks by the electrochemical oxidation method in pure water. The resulting electrolyzed solution contains colloidal carbon nanoparticles (mean diameter is ca. 400 nm) and shows the pH value of around 2.5. The colloidal state of the solution is maintained more than a several years. After evaporation of water from the solution, carbon powders are obtained, which show a high solubility to water, namely the powder is hydrophilic. The electrolyzed solution containing carbon nanoparticles directly used as the electrical conductivity enhancer for the restoring the deteriorated lead-acid batteries by electrochemical method. The hydrophilic carbon nanoparticles were used as the environmental friendly solid-lubricant for the mechanical cutting coolants. In the case of aqueous coolants, the oily substances are used in the emulsion state in usual. By using the hydrophilic carbon nanoparticle suspension, no surfactants and no oily substances are required to maintain the suspension state. However, the cutting coolants are used in the pH values of alkaline state near 10, so the hydrophilic carbon nanoparticle solution has been neutralized by alkaline substances such as alkanolamines. In the case of oily cutting fluids for heavy duties, carbon mamo-particle powders are used after neutralized by basic barium dinonylnaphthalenesulfonate. The aqueous solutions of hydrophilic carbon nanoparticles exhibit the ability of sanitization effects to the cutting fluids and prolong the life times of them.

Comparative Phenolic Fingerprint and LC-ESI+QTOF-MS Composition of Oregano and Rosemary Hydrophilic Extracts in Relation to their Antibacterial Effect

Rosemary ( Rosmarinus officinalis ) and oregano ( Origanum vulgare ) are known aromatic plants used as spice, with good flavoring, preservative, antioxidant and antibacterial activity. Beside their known terpenoid content responsible for the antibacterial activity, the water-soluble compounds (phenolic derivatives) are of high interest not only for their antioxidant activity but as a good alternative or as a hydrophilic new antibacterial solution. Two hydrophilic extracts from each plant were obtained (15% plant in hot water) and the phytochemicals were fingerprinted by UV-Vis and FTIR spectrometry and quantified. The total phenolic content was higher in case of oregano (54.2 mg GAE/g DW) comparing to rosemary (54.25 vs 15.35 mg GAE/g dry matter). By LC-ESI + QTOF-MS analysis there were identified mainly, in both extracts, flavonoid and diterpene derivatives, mainly carnosol, carnosic acid, rosmarinic acid, kaempferol 3-O-glucuronide. Other flavonoid glucuronides were more specific to one or the other plant, e.g. Luteolin 3'-(4''-acetylglucuronide) for rosemary and Apigenin 7-O-glucuronide for oregano. Water favorized increased extraction of flavonoid derivatives and soluble diterpenes, but not non-soluble  terpenes. The antibacterial activity of both extracts was tested against B.cereus , L. monocytogenes , Salmonella , S. aureus and E.coli . Both oregano and rosemary extracts showed a slight antibacterial activity, which can be related to the low concentration of terpenoids, known to have the most important antibacterial activity in these plants. Nevertheless, the antibacterial activity seems to be strain dependent, Bacillus cereus being the most sensitive bacterial strain comparing with the other four bacteria, the oregano extract having a slightly superior activity comparing to the rosemary extract.

Silica aerogel/polyvinyl alcohol (PVA) insulation composites with preserved aerogel pores using interfaces between the superhydrophobic aerogel and hydrophilic PVA solution

A fabrication method was designed for thermal insulation composites by applying the thermal characteristics of silica aerogels with preservation of pores in the aerogel to achieve extremely low thermal conductivity of the composites. A new process was proposed to generate interfaces between superhydrophobic silica aerogels and a hydrophilic polyvinyl alcohol (PVA) solution and to fabricate the silica aerogel/PVA composite forcibly while PVA is precipitated over the interfaces by making the solvent vaporize at a slow rate during stirring. Well-preserved aerogel pores were observed in the PVA-coated composites using an electron microscope and a low thermal conductivity of 0.022W/mK was achieved, which is only 11% of the thermal conductivity of PVA. The measured thermal conductivity of the aerogel/PVA composite was lower than that predicted by the Mori–Tanaka method (MTM) with the perfect interface assumption due to the effect of phonon scattering at the incomplete interfaces.

내수성이 우수한 PET 필름용 친수성 코팅액의 제조

내수성이 우수한 PET 필름용 친수성 코팅액의 제조

Separation of Am and Cm by using TODGA and DOODA(C8) adsorbents with hydrophilic ligand-nitric acid solution

Extraction chromatographic separation of trivalent minor actinides (MA: Am and Cm) was investigated by using solid adsorbents impregnating the lipophilic diamide-type ligands, TODGA (N,N,N′,N′-tetraoctyl-3-oxapentane-1,5-diamide) and DOODA(C8) (N,N,N′,N′-tetraoctyl-3,6-dioxaoctane-1,8-diamide). In nitric acid eluents, hydrophilic diamide-type ligands, DOODA(C2) (N,N,N′,N′-tetraethyl-3,6-dioxaoctanediamide) and TEDGA (N,N,N’,N’-tetraethyl-diglycolamide) were included for the respective adsorbents as masking agents in order to produce a synergistic effect in mutual separation of Am and Cm. The adsorption tendency of Am and Cm for the adsorbents was opposite each other, that was similar to the case of lanthanides.

Development of a novel bi-coated combination capsule containing mosapride and probiotics for irritable bowel syndrome

The objective of this study was to develop a novel combination product containing mosapride and probiotics for the treatment of irritable bowel syndrome. Enteric-coated hard gelatin capsules containing probiotics were prepared to protect acid-labile probiotics from the stomach by spray coating with hydroxypropylmethylcellulose phthalate, and then coated with various hydrophilic polymer solutions containing mosapride. The influence of different hydrophilic polymers on the aqueous solubility and dissolution of sparingly soluble mosapride from the capsule was investigated to select the one which imparted highest solubility to mosapride in an aqueous solution. The physicochemical properties of the hydrophilic polymer coating were assessed using SEM and DSC. In addition, the bioavailability of the mosapride-coated capsule in beagle dog was evaluated and compared to that of conventional mosapride tablet (CMT). Based on DSC studies, the mosapride in polymer coating underwent amorphization or molecular dispersion. The enteric-capsule coated with mosapride/HPMC exhibited improved solubility of mosapride at acidic pH and showed significantly improved AUC (1.5-fold) and Cmax (1.6-fold) compared to the CMT. In conclusion, drug/polymer coated enteric gelatin capsule can be an alternative technique for co-delivery of sparingly water-soluble drug and acid-labile drug for enhanced solubility and bioavailability as well as for protection from acid degradation.

Control of corona composition and morphology in aggregates of mixtures of PS-b-PAA and PS-b-P4VP diblock copolymers: effects of pH and block length.

The corona compositions and morphologies in aggregates of mixtures of amphiphilic polystyrene-block-poly(acrylic acid) (PS-b-PAA) and polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) diblock copolymers are influenced by controllable assembly parameters such as the hydrophilic block length and solution pH. The morphologies and corona compositions of the aggregates were investigated by transmission electron microscopy and electrophoretic mobility, respectively. When mineral acids or bases are present during aggregate formation, they can exert a strong influence on the corona composition. Morphology changes were also seen with changing pH, as well as changes in corona composition, specifically for vesicles. Because of complications introduced by the presence of ions, the general hypothesis that the external corona of the vesicles is composed of the longer chains, while the shorter chains form the inner corona, which is valid only in mixtures containing only nonionic chains without any additives (no acids or bases) or within a well-defined narrow pH range. In addition to the numerical block lengths and the pH, the solubility of the hydrophilic blocks can also influence the morphology and as well as the interfacial composition of vesicles; as the numerically longer chains become less soluble, they can contract and move to the interior, while the numerically shorter but more soluble chains go to the external corona. A remarkable morphological feature of the pH continuum is that for some compositions vesicles are observed in four distinct pH regions, separated by pH ranges in which other morphologies dominate. The effect of pH and microion content on coil dimensions of the PVP and PAA chains in the block copolymers is most likely responsible for the observed behavior.

Preparation and drug delivery study of electrospun hollow PES ultrafine fibers with a multilayer wall

The focus of this work was the preparation of hollow ultrafine fibers with a multilayer wall via coaxial electrospinning technology in one step and then studied their drug delivery properties. In this paper, by choosing a suitable dilute hydrophilic polymer solution as the core solution, polyethersulfone (PES) hollow ultrafine fibers with two different layers wall (porous structure layer and dense smooth layer) were formed during coaxial electrospinning process in one step. They showed good drug delivery capacity when curcumin was used as the model drug. There were much larger delivery amounts, more stable release rate, and higher utilization rate of PES hollow ultrafine fibers with a multilayer wall to curcumin than that of PES porous ultrafine fibers. Compared with porous ultrafine fibers, hollow ultrafine fibers with two different layers wall were more suitable to be used as drug delivery materials. Besides, between the two hollow ultrafine fibers with two different layers wall mentioned in this paper, there was much better drug delivery capacity for the hollow fibers produced with the core solution of PVA/DMSO. These results showed that PES hollow ultrafine fibers with two different layers wall have the potential to be used as the drug delivery materials.

Micellization of sodium laurylethoxysulfate (SLES) and short chain imidazolium ionic liquids in aqueous solution

In the present study the interactions between an anionic surfactant sodium laurylethoxysulfate (SLES) and three short chain imidazolium (1-butyl-3-methylimidazolium) based ionic liquids (bmim-octyl SO4, bmim-methyl SO4 and bmim-BF4) in aqueous solution have been investigated. Generally when a surfactant is dissolved in a hydrophilic ionic liquid aqueous solution the critical micelle concentration (cmc) obtained is attributed to the surfactant because the ionic liquid (IL) is considered to be only a cosolvent. However, some short hydrophilic ionic liquids posses surface activity in aqueous solution and behave like a surfactant. In that case mixed aggregates between surfactant and ionic liquid can be formed. The three SLES/IL systems here studied have been treated as typical binary surfactant mixtures in aqueous solution. Surface tension measurements have revealed that mixed aggregates and monolayers of surfactant and ionic liquid instead of single surfactant are responsible for the surface active properties of these aqueous solutions. From the Regular Solution Theory, negative interaction parameters (β) for mixed aggregates and monolayers have been found for all SLES/IL mole ratios indicating synergism between the anionic surfactant and the ionic liquids.

Construction of PANI–cellulose composite fibers with good antistatic properties

Novel polyaniline (PANI)/cellulose filament fibers were spun from hydrophobic PANI and hydrophilic cellulose complex solution dissolved in aqueous solution containing 7 wt% NaOH/ 12 wt% urea as solvent by wet-spinning. At low PANI content, the composite fibers realized a transition from an insulator to semiconductor.

Low-temperature facile solution-processed gate dielectric for combustion derived oxide thin film transistors

An improved hydrophilic aluminum nitrate solution was designed to spin coat robust dielectric layers for thin film transistors.

Self-Healing Vesicles Deposit Lipid-Coated Janus Particles into Nanoscopic Trenches

Using dissipative particle dynamics (DPD) simulations, we model the interaction between nanoscopic lipid vesicles and Janus nanoparticles localized on an adhesive substrate in the presence of an imposed flow. The system is immersed in a hydrophilic solution, and the hydrophilic substrate contains nanoscopic trenches, which are either step- or wedge-shaped. The fluid-driven vesicle successfully picks up Janus particles on the substrate, transports these particles as cargo along the surface, and then drops off the particles into the trenches. For Janus particles with a relatively large hydrophobic region, lipids from the bilayer membrane become detached from the vesicle and bound to the hydrophobic domain of the deposited particle. While the detachment of these lipids rips the vesicle, it provides a coating that effectively shields the hydrophobic portion of the nanoparticle from the outer solution. After the particle has been dropped off, the torn vesicle undergoes structural rearrangement, reforming into a closed structure that resembles its original shape. In effect, the vesicle displays pronounced adaptive behavior, shedding lipids to form a protective coating around the particle and undergoing a self-healing process after the particle has been deposited. This responsive, adaptive behavior is observed in cases involving both the step- and wedge-shaped trenches, but the step trench is more effective at inducing particle drop off. The results reveal that the introduction of grooves or trenches into a hydrophilic surface can facilitate the targeted delivery of amphiphilic particles by self-healing vesicles, which could be used for successive delivery events.

Non-spherical particle formation induced by repulsive hydration forces during spray drying

Non-spherical particles were produced during a spray-drying process, but the exact mechanism of their formation was unknown. The non-spherical particles form when the strength of the colloidal droplets is exceeded by external stress stemming from drag in the velocity gradient. Here, we show that repulsive hydration forces reduce the mechanical strength of the droplets; this is critical to the formation of non-spherical particles. Toroidal or ellipsoidal particles were prepared from low-concentration hydrophilic SiO2, TiO2, and CuO colloidal solutions, but not from hydrophobic ZnO colloidal solutions. The surface properties of the solid particulates are crucial for the morphology of particles formed during spray drying.

A new method to prepare high performance perfluorinated sulfonic acid ionomer/porous expanded polytetrafluoroethylene composite membranes based on perfluorinated sulfonyl fluoride polymer solution

Perfluorinated sulfonyl fluoride (PFSF) resin, the precursor of perfluorinated sulfonic acid (PFSA) ionomer is successfully dissolved in perfluorinated solvents, and its hydrophobic nature is utilized to resolve the difficulty of impregnating hydrophilic PFSA solution into hydrophobic porous expanded polytetrafluoroethylene (ePTFE). The composite membrane fabricated through such simple but effective method is well impregnated, leading to better ionic conductivity and lower gas permeability. The fuel cell constructed with PFSF solution based membranes shows superior performance as compared to that of its aqueous PFSA solution based counterpart, which is comparable to that of commercial Nafion® 211.

Harnessing Fluid-Driven Vesicles To Pick Up and Drop Off Janus Particles

Using dissipative particle dynamics (DPD) simulations, we model the interaction between nanoscopic lipid vesicles and Janus nanoparticles in the presence of an imposed flow. Both the vesicle and Janus nanoparticles are localized on a hydrophilic substrate and immersed in a hydrophilic solution. The fluid-driven vesicle successfully picks up Janus particles on the substrate and transports these particles as cargo along the surface. The vesicle can carry up to four particles as its payload. Hence, the vesicles can act as nanoscopic "vacuum cleaners", collecting nanoscopic debris localized on the floors of the fluidic devices. Importantly, these studies reveal how an imposed flow can facilitate the incorporation of nanoparticles into nanoscale vesicles. With the introduction of a "sticky" domain on the substrate, the vesicles can also robustly drop off and deposit the particles on the surface. The controlled pickup and delivery of nanoparticles via lipid vesicles can play an important step in the bottom-up assembly of these nanoparticles within small-scale fluidic devices.

Mashed Potatoes and Maize

Mashed Potatoes and Maize

Microwave-assisted synthesis and up–down conversion luminescent properties of multicolor hydrophilic LaF3:Ln3+nanocrystals

Monodisperse water-soluble LaF(3):Ln(3+) nanocrystals (NCs) have been successfully fabricated via a fast, facile and environmentally-friendly microwave-assisted modified polyol process with polyvinylpyrrolidone (PVP) as an amphiphilic surfactant. The obtained NCs can be well dispersed in hydrophilic solutions with small sizes in the range of 9-12 nm. The LaF(3):Ln(3+) NCs (Ln = Eu, Nd, Ce, Tb, Yb, Er, Yb, Ho and Yb, Tm) have the unique feature of up-down conversion from visible to NIR emission owing to the ladder-like arranged energy levels of Ln(3+) and in particular, the high efficiency upconversion of the two-photon, obtained from excitation by a continuous 980 nm laser. This investigation focuses on both the up and down conversion fluorescence properties of water-soluble monodisperse crystalline LaF(3):Ln(3+) NCs in such a small size. Furthermore, the three-dimensional PDMS rod-like fluorescence displays and a silica surface modification by a core/shell structure on the obtained NCs can improve the biocompatibility, indicating potential applications in optical 3D devices and as bio-probes.

Quantitative High Performance Liquid Chromatography Determination of Alkanolamines in Ionic Liquid Absorbents

The development of modern absorption media suitable for CO2 scrubbing, such as ionic liquids and their mixtures, requires appropriate analytical protocols. In this paper, the application of high-performance liquid chromatography to the determination of alkanolamine at various concentrations in ionic liquid solutions was investigated. Both hydrophilic and hydrophobic commercial ionic liquids, such as 1-butyl-3-methylimidazolium acetate [bmim][OAc], 1-ethyl-3-methylimidazolium octylsulfate [emim][OcSO4], and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [bmim][NTf2], were studied in this paper and different sample preparation procedures were used for each class of solvent. A simple extraction step was necessary prior to HPLC analysis for hydrophobic ionic liquids. This step was performed using five times more 0.05 M KH2PO4 than needed for the ionic liquid sample. Hydrophilic ionic liquid solutions could be analyzed after diluting the sample with water. The general procedure involved separation at room temperature using a cation-exchange HPLC with 0.05 M KH2PO4 as the mobile phase and refractometric detection without derivatizing the amines. The influence of the temperature and mobile phase composition on alkanolamine retention was investigated. The relationship between the peak area and alkanolamine concentration was linear over 3 orders of magnitude (2–200 nmol). The detection limit (LOD) for monoethanolamine (MEA) and diethanolamine (DEA) was 1.5 and 2 nmol, respectively. For hydrophobic ionic liquids, which require extraction, it was possible to analyze a 0.004% MEA solution. The quantity of the sample required for analysis was 0.1 g, and the analysis time did not exceed 20 minutes.