Bi-layered hydroxypropylmethylcellulose and Eudragit based films were formulated as potential ocular drug delivery systems using chloramphenicol as a model antibiotic. Films were plasticized with polyethylene glycol 400 present in the Eudragit layer or both Eudragit and hydroxypropylmethylcellulose layers, and loaded with chloramphenicol (0.5% w/v in solution) in the hydroxypropylmethylcellulose layer. The weight, thickness and folding endurance of the optimized formulations were measured and further characterised for transparency, tensile, mucoadhesive, swelling and in vitro drug dissolution properties. The physical form of chloramphenicol within the films was evaluated using differential scanning calorimetry (DSC), and X-ray diffraction (XRD), complimented with scanning electron microscopy and energy dispersive X-ray spectroscopy. Fourier transform infrared spectroscopy was used to assess the interactions between the drug and the film components and confirm chloramphenicol's presence within the sample. Optimum films showed high transparency (≥80% transmittance), ease of peeling from Petri dish and folding endurance above 250. Average thickness was lower than contact lenses (0.4-1mm), confirming them as thin ocular films. The tensile properties showed a good balance between toughness and flexibility, and mucoadhesivity showed that they could potentially adhere to the ocular surface for prolonged periods. The drug loaded films showed swelling capacity that was greater than 300% of their original weight. The physical form of chloramphenicol within the films was amorphous (DSC and XRD) whilst in vitro drug dissolution showed sustained drug release from the films for four hours, before complete erosion. The chloramphenicol loaded films represent a potential means of treating common eye infections.
The studies presented in this article are based on the variation of some constructive parameters on various types of materials for a prehension system jaws. The pneumatic actuation prehension system is part of the structure of a manipulator integrated within a teaching platform for installation. In the tests, the varied parameters were the following: the type of plastic material, the way of printing on the 3D printer bed, the degree of fill (the density) and the geometric shape. The experimental tests have resulted in an optimal version of the prehension system jaws.
There is an increased interest in the use of the deep eutectic solvents (DESs) as electrolytic media for electrochemical synthesis of conducting polymers, which could influence their characteristics. Moreover, the polypyrrole layers represent an attractive route for pharmaceutical drug release. The paper presents several experimental results regarding the electrodeposition of polypyrrole and of polypyrrole-indomethacin coatings on nickel-chromium NiCr alloy substrates widely used in dentistry, involving DES-based electrolytes, namely eutectic mixtures of choline chloride and malonic acid. This type of electrolyte also allowed an enhanced dissolution of indomethacin as compared to aqueous ones. The electropolymerization process has been investigated by cyclic voltammetry and chronoamperometry. The obtained indomethacin containing polymeric coatings have been thoroughly characterized involving scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, contact angle measurements in simulated body fluid (SBF) and indomethacin release studies. Adherent and uniform polypyrrole-indomethacin layers have been obtained on NiCr alloy substrates. The release tests showed that the polypyrrole coatings containing indomethacin may deliver the drug molecules for longer periods of at least 17 days. The maximum released amount was around 99.6% suggesting these layers may act as an active reservoir for indomethacin. Kinetics analysis based on the Korsmeyer–Peppas model suggested the diffusion of the drug out of the polymer layer as the most probable mechanism governing the release.
The present paper is an investigation of two commercial Co‐Cr dental alloys, named Wirobond 280 and Wirobond C. The two alloys have similar composition; the difference is made by the small amount of Ga and Mn existing in Wirobond 280. The electrochemical behavior of the alloys was tested in the artificial Erikson saliva at different temperatures between 25 and 55 °C. The electrochemical methods used have been the potentiodynamic polarization and the electrochemical impedance spectroscopy. The investigation have been performed in the presence of two different fluoride ions concentrations and permitted to compute corrosion rate and the energy activation. In order to complete the tests the cell response has been studied in vitro. The stability of Wirobond 280 alloy is correlated with the greater cell viability and with a smaller level of ROS in comparison with the Wirobond C alloy. Regarding fluoride doping effect, based on the experimental data, we can conclude that NaF increases the corrosion rate of the Wirobond 280 and decrease the corrosion rate in the case of the Wirobond C. The study established that the Wirobond 280 alloy is the one with best properties.
Considering the strong need for improvement of security and multimedia systems in the automotive industry, wiring harness production is becoming more and more important. Adapting to the integration of new technologies on the vehicle is a challenge for wiring harnesses manufacturers. Now the production of wiring harnesses is still quite dependent on human resources, the way of distributing the workload on the workstations having a large share in increasing productivity. Components such as terminals, connectors and seals are getting smaller and smaller, making the manual handling more difficult. A solution to this problem could be increasing the automation degree in wiring harness production. The objective of the research topic approached in this article is to identify solutions for optimizing the wiring assembly flow by partially automating the production flow. The concern for the application of automated processes in the production of car wiring is not new, but so far, the wiring manufacturers have been more focused on automating the prefabrication of the elements that compose the harness and not the wiring harness assembly line. From an economic point of view, the automation of the assembly flow would increase productivity by reducing fabrication time and the uncertainty given by the human resource dependence.
Abstract.One of the problems identified in waste collection integrated systems is the storage space. The design process of an automated system for the storage of collected waste includes finding solutions for the optimal exploitation of the limited storage space, seen that the equipment for the loading, identification, transport and transfer of the waste covers most of the available space inside the integrated collection system. In the present paper a three-dimensional model of an automated storage system designed by the authors for a business partner is presented. The storage system can be used for the following types of waste: plastic and glass recipients, aluminium cans, paper, cardboard and WEEE (waste electrical and electronic equipment). Special attention has been given to the transfer subsystem, specific for the storage system, which should be able to transfer different types and shapes of waste. The described virtual model of the automated system for the storage of collected waste will be part of the virtual model of the entire integrated waste collection system as requested by the beneficiary.
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