Virucidal filter materials were prepared by electrospinning a solution of 28 wt % poly(vinylidene difluoride) in N,N-dimethylacetamide without and with the addition of 0.25 wt %, 0.75 wt %, 2.
View Article and Find Full Text PDFAtmos Environ X
January 2023
Nanofibrous filter materials were prepared by electrospinning a solution of 28 wt% poly(vinylidene fluoride) in N,N-dimethylacetamide with and without the addition of 2 wt% AgNO, Cu(NO)·2.5HO or ZnCl. X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy, inductively coupled plasma mass spectroscopy, thermogravimetric analysis, contact angle measurement, nitrogen sorption, and mercury intrusion porosimetry methods were used for the characterization of physical structure as well as the chemical composition of the electrospun materials.
View Article and Find Full Text PDFCrystallinity in an amorphous solid dispersion (ASD) may negatively impact dissolution performance by causing lost solubility advantage and/or seeding crystal growth leading to desupersaturation. The goal of the study was to evaluate underlying dissolution and crystallization mechanisms resulting from residual crystallinity contained within bicalutamide (BCL)/polyvinylpyrrolidone vinyl acetate copolymer (PVPVA) ASDs produced by hot melt extrusion (HME). In-line Raman spectroscopy, polarized light microscopy, and scanning electron microscopy were used to characterize crystallization kinetics and mechanisms.
View Article and Find Full Text PDFA variety of sucrose replacers (SRs) are increasing in popularity for reducing sucrose usage in low moisture baked goods (cookies, biscuits, etc.). The goal of this study was to link SR physicochemical properties to their observed effects on starch thermal properties, including results from differential scanning calorimetry, rapid viscoanalysis, particle size analysis, and model wire-cut cookie baking performance.
View Article and Find Full Text PDFHaemanthamine (HAE) has been proven as a potential anticancer agent. However, the therapeutic use of this plant-origin alkaloid to date is limited due to the chemical instability and poorly water-soluble characteristics of the agent. To overcome these challenges, we developed novel amphiphilic electrospun nanofibers (NFs) loaded with HAE, phosphatidylcholine (PC) and polyvinylpyrrolidone (PVP), and intended for a stabilizing platform (template) of self-assembled liposomes of the active agent.
View Article and Find Full Text PDFWe investigated nozzleless ultrasound-enhanced electrospinning (USES) as means to generate nanofibrous drug delivery systems (DDSs) for pharmaceutical and biomedical applications. Traditional electrospinning (TES) equipped with a conventional spinneret was used as a reference method. High-molecular polyethylene oxide (PEO) and chitosan were used as carrier polymers and theophylline anhydrate as a water-soluble model drug.
View Article and Find Full Text PDFThe present study introduces a modified melt-electrospinning (MES) method for fabricating the melt-electrospun fibers (MSFs) of a poorly water-soluble drug and carrier polymer. The MES of poorly water-soluble model drug indomethacin (IND) and hydrophilic carrier polymer, Soluplus® (SOL) were prepared at a 1:3 drug-polymer weight ratio. Water was used as an external plasticizer to regulate a MES processing temperature and to improve fiber formation.
View Article and Find Full Text PDFSolid dispersions (SDs) hold a proven potential in formulating poorly water-soluble drugs. The present paper investigates the interfacial phenomena associated with the bulk powder flow, water sorption, wetting and dissolution of the SDs prepared by a modified melt and quench-cooling (QC) method. Poorly water-soluble indomethacin (IND) was QC molten with solubilizing graft copolymer (Soluplus®) or polyol sugar alcohol (xylitol, XYL).
View Article and Find Full Text PDFObjective: Artesunate (ART) is proven to have potential anti-proliferative activities, but its instability and poor aqueous solubility limit its application as an anti-cancer drug. The present study was undertaken to develop coaxial electrospraying as a novel technique for fabricating nanoscale drug delivery systems of ART as the core-shell nanostructures.
Methods: The core-shell nanoparticles (NPs) were fabricated with coaxial electrospraying and the formation mechanisms of NPs were examined.
The conversion of active pharmaceutical ingredient (API) from amorphous to crystalline form is the primary stability issue in formulating amorphous solid dispersions (SDs). The aim of the present study was to carry out qualitative and quantitative analysis of the physical solid-state stability of the SDs of poorly water-soluble piroxicam (PRX) and polyvinyl caprolactam-polyvinyl acetate-polyethylene-glycol graft copolymer (Soluplus(®)). The SDs were prepared by a solvent evaporation method and stored for six months at 0% RH/6 °C, 0% RH/25 °C, 40% RH/25 °C and 75% RH/25 °C.
View Article and Find Full Text PDFEndoprosthetic replacement of the elbow joint is comparatively rare with less than 100 cases per year in Germany. Patients with forms of rheumatism constitute the major proportion and they also show the significantly best results. The indications are assessed in a stage-adapted manner and depend mostly on the stability and the grade of bony destruction.
View Article and Find Full Text PDFElectrospinning was introduced as a novel technique for preparing controlled-release (CR) amorphous solid dispersions (SD) and polymeric nanofibers of a poorly water-soluble drug. Piroxicam (PRX) was used as a low-dose poorly-soluble drug and hydroxypropyl methylcellulose (HPMC) as an amorphous-state stabilising carrier polymer in nanofibers. Raman spectroscopy, X-ray powder diffraction (XPRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used in the physical characterisation of the CR-SD nanofibers.
View Article and Find Full Text PDFElectrospinning is an effective method in preparing polymeric nanofibrous drug delivery systems (DDSs) for topical wound healing and skin burn therapy applications. The aim of the present study was to investigate a new synthetic graft copolymer (Soluplus) as a hydrophilic carrier polymer in electrospinning of nanofibrous DDSs. Soluplus (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PCL-PVAc-PEG)) was applied in the nonwoven nanomats loaded with piroxicam (PRX) as a poorly water-soluble drug.
View Article and Find Full Text PDFDuring aqueous drug-layer coating, drug substance(s) are exposed to water and elevated temperatures which can lead to water-mediated process induced transformations (PITs). The effects of aqueous drug-layer coating of pellets (Cellets(®)) on the anhydrous piroxicam, PRX, were investigated in the miniaturized coating equipment and with free films. Hydroxypropyl methylcellulose (HPMC) was used as a carrier coating polymer.
View Article and Find Full Text PDFThe aim of this study was to gain understanding about the effects of different solid-state forms of a poorly water-soluble piroxicam on drug dissolution and oral bioavailability in rats. Three different solid-state forms of piroxicam were studied: anhydrate I (AH), monohydrate (MH), and amorphous form in solid dispersion (SD). In addition, the effect of a new polymeric excipient Soluplus® (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer) on oral bioavailability of piroxicam was investigated.
View Article and Find Full Text PDFThe aim of the present study was two-fold: (1) to investigate the effect of pH and presence of surfactant sodium lauryl sulphate (SLS) on the solubility and dissolution rate of two solid-state forms of piroxicam (PRX), anhydrate (PRXAH) and monohydrate (PRXMH), and (2) to quantitatively assess the solid-phase transformation of PRXAH to PRXMH in slurry with a special interest to the impact on the solubility and dissolution behavior of the drug. X-ray powder diffractometry (XRPD), Raman spectroscopy and scanning electron microscopy (SEM) were used for characterization of the solid-state forms. Phase transformation was monitored in slurry by means of in-line Raman spectroscopy, and the partial least squares (PLS) regression model was used for predicting the amount of PRXMH.
View Article and Find Full Text PDFThe aim of this study was to expand understanding of how baccalaureate-level nursing students engage in and transition through international health-care experiences (IHCEs). Using a qualitative, interpretative research design, the authors conducted in-depth, semi-structured interviews with 12 former nursing students. This article focuses on international nursing shock, one of the key themes that emerged from participants' narratives.
View Article and Find Full Text PDFA decrease in load-bearing activity, as experienced during spaceflight or immobilization, affects the musculoskeletal system in animals and humans, resulting in the loss of bone and connective tissue. It has been suggested that hypergravity (HG) can counteract the deleterious effects of microgravity-induced musculoskeletal resorption. However, little consensus information has been collected on the noninvasive measurement of collagen degradation products associated with enhanced load-bearing stress on the skeleton.
View Article and Find Full Text PDFSince the Eocene, the diversity of artiodactyls has increased while that of perissodactyls has decreased. Reasons given for this contrasting pattern are that the evolution of a ruminant digestive tract and improved locomotion in artiodactyls were adaptively advantageous in the highly seasonal post-Eocene climate. We suggest that evolution of a carotid rete, a structure highly developed in artiodactyls but absent in perissodactyls, was at least as important.
View Article and Find Full Text PDFThe aim of this study was to evaluate the effect of selective feticide (SF) compared to expectant management (EM) on perinatal outcome in dichorionic and monochorionic twins discordant for anencephaly. For this purpose, we conducted a systematic review of literature and added ten unpublished cases. As a result, we found that in dichorionic twins, mean gestational age (GA) at birth in the SF group was 38.
View Article and Find Full Text PDFConservation of energy is a prerequisite thermoregulatory strategy for survival in northern hemisphere winters. We have used thermistor/data logger assemblies to measure temperatures in the brain, carotid artery, jugular vein and abdominal cavity, in pronghorn antelope to determine their winter body temperature and to investigate whether the carotid rete has a survival role. Over the study period mean black globe and air temperature were -0.
View Article and Find Full Text PDFWe have used thermistor/data logger assemblies to measure temperatures in the brain, carotid artery, jugular vein and abdominal cavity, and subcutaneously, in five pronghorn antelope over a summer in Wyoming. Globe and air temperature varied by up to approximately 50 degrees C daily during the summer and maximum solar radiation was approximately 900 W m(-2). Brain temperature (38.
View Article and Find Full Text PDFRadiat Prot Dosimetry
April 2003
Stimulation spectra of several TLD materials in the short-wave spectral region are measured using the optically stimulated afterglow (OSA) method for determination of absorbed dose. Optical stimulation spectra are studied in the region of wavelengths lower than those of emission spectra. The effective optical stimulation hands have been found for examined materials in the regions of wavelengths which overlap with fluorescence excitation bands.
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