Investigation on magnetic and microwave behavior of magnetite nanoparticles coated carbon fibers composite

Radar absorbing materials, i.e. magnetite (Fe3O4) coated carbon fibers (MCCFs) were fabricated by electro-deposition technique. Black-colored single spinel phase Fe3O4 nanoparticles was easily synthesized by hydrothermal method using reduction of a Fe (III) - Triethanolamine complex in an aqueous alkaline solution at 60-80 ◦C. Uniform and compact Fe3O4 films were fabricated on nitric acid treated carbon fibers. A correlation between magnetic and absorption properties of specimens was made. It was found that the deposition time, and the sequences of the coating process have a significant effect on the reflection loss characteristics of the MCCFs. On the other hand, the temperature of the coating process affects strongly the composition of the thin film. MCCFs prepared at 80 ◦C possesses a much higher loss factor than the one prepared at 60 ◦C. The morphology, phases in the coating layer, magnetic properties and absorption behaviors of the MCCFs were examined using FESEM, XRD, permagraph, vector network analyzer (VNA), respectively. The highest reflection loss that is −10 dB at 12.27 GHz was observed in the sample deposited for four minutes. It was also found out that a uniform deposition layer can be observed in the sample deposited in three steps in which each step takes four minimums

Dissolution rate enhancement of ketoconazole by liquisolid technique

The study was conducted to enhance the dissolution rate of ketoconazole (KCZ) (a poorly water-soluble drug) using the liquisolid technique. Microcrystalline cellulose, colloidal silica, PEG400 and polyvinyl pyrrolidone (PVP) were employed as a carrier, coating substance, nonvolatile solvent and additive in the KCZ liquisolid compact formulation, respectively. The drug-to-PEG400 and carrier-to-coating ratio variations, PVP concentration and aging effects on the in vitro release behavior were assessed. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) data revealed no alterations in the crystalline form of the drug and the KCZ-excipient interactions within the process. The load factor and the drug release rate were significantly enhanced compared to directly compressed tablets in the presence of the additive. Increasing the PEG400-to-drug ratio in liquid medications enhanced the dissolution rate remarkably. The dissolution profile and hardness of liquisolid compacts were not significantly altered by keeping the tablets at 40 °C and relative humidity of 75 % for 6 months. With the proposed modification of the liquisolid process, it is possible to obtain flowable, compactible liquisolid powders of high-dose poorly-water soluble drugs with an enhanced dissolution rate

Microfluidic manufacture of lipid-based nanomedicines

Nanoparticulate technologies have revolutionised drug delivery allowing for passive and active targeting, altered biodistribution, control drug release (temporospatial or triggered), enhanced sta-bility, improved solubilisation capacity, reduction of dose and adverse effects. However, their manufacture remains immature, and challenges exist in industrial scale due to high batch-to-batch variability hindering their clinical translation. Lipid-based nanomedicines remain the most-widely approved nanomedicines and their current manufacturing methods remain discontinuous and face several problems such as high batch-to-batch variability affecting the critical quality attributes (CQAs) of the product, laborious multi-step processes, need for an expert workforce and are not easily amenable to industrial scale-up involving typically a complex process control. Several tech-niques have emerged in recent years for nanomedicine manufacture, but a paradigm shift occurred when microfluidic strategies able to mix fluids in channels with dimensions of tens of micrometers and small volumes of liquid reagents in a highly controlled manner to form nanoparticles with tunable and reproducible structure are employed. In this review, we summarize the recent ad-vancements in the manufacturing of lipid-based nanomedicines using microfluidics with particular emphasis on the parameters that govern the control of CQAs of final nanomedicines. The impact of microfluidic environments on formation dynamics of nanomaterials, and the application of mi-crodevices as platforms for nanomaterial screening were also discussed

Multiple dental anomalies accompany unilateral disturbances in abducens and facial nerves : a case report

This article describes the oral rehabilitation of an 8-year-old girl with extensively affected primary and permanent dentition. This report is unique in which distinct dental anomalies including enamel hypoplasia, irregular dentin formation, taurodontism, hpodontia and dens in dente accompany unilateral disturbance of abducens and facial nerves which control the lateral eye movement, and facial expression, respectively

Multiple dental anomalies accompany unilateral disturbances in abducens and facial nerves: A case report

This article describes the oral rehabilitation of an 8-year-old girl with extensively affected primary and permanent dentition. This report is unique in which distinct dental anomalies including enamel hypoplasia, irregular dentin formation, taurodontism, hpodontia and dens in dente accompany unilateral disturbance of abducens and facial nerves which control the lateral eye movement, and facial expression, respectively. Keywords: enamel hypoplasia; irregular dentin formation; taurodontism; hypodontia; dens in dente; abducens and facial nerves

Made-on-demand, complex and personalized 3D-printed drug products

Layer-by-layer fabrication of three dimensional (3D) objects from digital models is called 3D printing. This technology established just about three decades ago at the confluence of materials science, chemistry, robotics, and optics researches to ease the fabrication of UV-cured resin prototypes. The 3D technology was rapidly considered as a standard instrument in the aerospace, automotive, and consumer goods production factories. Nowadays, research interests in the 3D printed products have been raised and achieved ever-increasing traction in the pharmaceutical industry; so that, the first 3D printed drug product was approved by FDA in August 2015. This editorial summarizes the competitive advantages of the 3D printing for the made-on-demand, personalized and complex products, manufacturing of which establish opportunities for enhancing the accessibility, effectiveness, and safety of drugs

Nanomedicines for delivery across the blood-brain barrier

Central nervous system (CNS) disorders affect one in three worldwide and represent a large unmet medical need involving chronic conditions such as Alzheimer’s and Parkinson’s disease, stroke, brain tumours, migraine, pain, and mental diseases. CNS drug development is hampered by the restricted drug and biological transport across an anatomical barrier, the blood-brain barrier. Many brain tumours and neurological diseases can greatly benefit from the use of emerging nanotechnologies based on targeted nanomedicines that are able to noninvasively transport highly potent and specific pharmaceuticals across the blood–brain barrier. In this chapter, we will discuss blood-to-brain drug delivery strategies using nanocarriers such as polymeric and lipid-based strategies with a focus on the mechanism of permeation, pharmaceutical, pharmacokinetic/pharmacodynamic and regulatory and clinical aspects of their development. Although it remains unrealistic to expect a magic bullet for brain central nervous system delivery, nanomedicines are the only technologies to date to have shown considerable promise for these patients with chronic and devastating brain diseases

Risk assessment of electrofusion joints in commissioning of polyethylene natural gas networks

The application of polyethylene pipes and equipment in the natural gas networks is continuously increasing due to their competitive weight and cost compared to metallic materials. Electrofusion welding is an effective and fast approach for the production of polyethylene joints with high safety and endurance. However, recently intermittent failures have reported in underground polyethylene piping networks. Although the failure frequencies are low, but disasters could happen due to the failure in gas pipelines as they usually buried in populated areas. In this study a combination of Failure Mode and Effects Analysis (FMEA), and empirical methods were used to identify main damage mechanisms incorporated to intermittent failures of polyethylene natural gas networks. After performing the FMEA process, based on the obtained risk ranking, three most critical damage mechanisms, including improper scraping, lipid contaminations, and humidity existence in weld zones were investigated experimentally to determine their practical severity. According to empirical evaluations, improper scraping was the most severe damage mechanism, followed by the contaminated welding surfaces during the weld construction

Electrosprayed polymeric nanobeads and nanofibers of modafinil : preparation, characterization, and drug release studies

Introduction: Modafinil (MDF) is used orally for the treatment of attention-deficit/hyperactivity disorder and narcolepsy. It holds low solubility and high permeability; therefore, improving its dissolution properties by preparing nanoformulations can be a promising approach to enhance its oral absorption. Our aims were to prepare and characterize MDF-Eudragit® RS100 (MDF-ERS) nanoparticles by electrospray technique. Methods: Electrosprayed nanoparticles were fabricated by varying MDF to ERS ratios and concentrations. The formulations were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier-transform infrared spectroscopy (FTIR). Release studies were performed on nanoparticles, physical mixtures, and raw MDF. The release data were fitted to different models to understand the mechanism of the drug release. Results: Electrospraying of MDF and ERS solution resulted in the preparation of nonobeads or nanofibers, and the particulate characteristics of the obtained products were largely controlled by the polymer amount in the solution. PXRD and thermal analyses showed that MDF was an amorphous phase in the structures of nanoparticles. Using FTIR, no interaction was observed between MDF and ERS in nanoparticles. Nanoparticles showed biphasic release profiles and the order of dissolution rates was: nanofibers>MDF>nanobeads. The well-fitted model was Weibull model, indicating a Fickian diffusion as the main mechanism of release. Conclusion: The results suggest that by optimization of variables such as solution concentration of MDF-ERS nanofibers and nanobeads with higher dissolution rates can be made by electrospray. Electrospray deposition as a simple, continuous, and surfactant free method is an excellent choice for preparation of drug loaded polymeric nanoparticles

Enhancement of ketoconazole dissolution rate by the liquisolid technique

The study was conducted to enhance the dissolution rate of ketoconazole (KCZ) (a poorly water-soluble drug) using the liquisolid technique. Microcrystalline cellulose, colloidal silica, PEG400 and polyvinyl pyrrolidone (PVP) were employed as a carrier, coating substance, nonvolatile solvent and additive in the KCZ liquisolid compact formulation, respectively. The drug-to-PEG400 and carrier-to-coating ratio variations, PVP concentration and aging effects on the in vitro release behavior were assessed. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) data revealed no alterations in the crystalline form of the drug and the KCZ-excipient interactions within the process. The load factor and the drug release rate were significantly enhanced compared to directly compressed tablets in the presence of the additive. Increasing the PEG400-to-drug ratio in liquid medications enhanced the dissolution rate remarkably. The dissolution profile and hardness of liquisolid compacts were not significantly altered by keeping the tablets at 40 °C and relative humidity of 75 % for 6 months. With the proposed modification of the liquisolid process, it is possible to obtain flowable, compactible liquisolid powders of high-dose poorly-water soluble drugs with an enhanced dissolution rate