Prediction of the composition of prolonged release tablets based on 4,4'-(propandiamido) sodium dibenzoate using the SeDeM method

Introduction. Direct compression technology is one of the most common tablet technologies. As known, many active pharmaceutical ingredients are not suitable for this technology without the addition of special excipients. A useful tool for determining the suitability of powdered materials for direct compression technology is the Sediment Delivery Model (SeDeM) method, based on the concept of Quality by Design. The presented method allows not only to assess the suitability of a material for direct compression, but also helps to predict the composition of a solid dosage form in the form of a tablet, which, in turn, leads to a significant reduction in experimental work carried out in the development of a new drug.Aim. Prediction of the compositions of matrix tablets based on sodium 4,4'-(propanediamido)dibenzoate with prolonged release, obtained by direct compression using the method of mathematical modeling SeDeM.Materials and methods. The objects of the study were the original substance sodium 4,4'-(propanediamido)dibenzoate, as well as a number of auxiliary substances, which included polymers used for dosage forms with prolonged release, a dusting component – magnesium stearate, and a filler – lactose monohydrate. Physicochemical and technological properties of APIs, explosives, obtained tablet mixtures and tablets were studied in accordance with the requirements of the State Pharmacopoeia of the Russian Federation XIV ed. and EP 9th ed.Results and discussion. The properties of the substance and excipients were assessed in accordance with the SeDeM method. It was found that the substance 4,4'-(propanediamido) sodium dibenzoate is not suitable for direct pressing due to poor flowability and low compressibility. Hypromellose Methocel K4M had good compressibility, but it did not have sufficient flowability. The other tested polymers had satisfactory properties for the direct compression technology. The composition of the tablet mixtures was calculated using the SeDeM method, the obtained tablet mixtures had satisfactory technological characteristics for obtaining tablets by direct compression. The tablets obtained as a result of the experiment also met the pharmacopoeial requirements.Conclusion. Prediction of the composition of sustained-release tablets based on the original substance sodium 4,4'-(propanediamido)dibenzoate was carried out using the SeDeM method. It was found that this method is suitable for the development of the composition of tablets based on sodium 4,4'-(propanediamido)dibenzoate.

Nanomodified Epoxy Materials with Improved Operating Characteristics

The purpose of the work is to develop new polymer composite nanomodified materials for the restoration of hull parts of agricultural machinery.As a result of research, a comparative analysis of the properties of composites based on epoxy resin ED-20 with the addition of 0.1-1.5 mass parts of carbon nanotubes “Taunit-M” obtained by free casting and direct pressing was carried out. The effectiveness of the developed compositions is proved when using them as binders in the production of fiber-reinforced composites.It was found that the introduction of 0.5 to 1 mass. parts CNT "Taunit" allows you to increase the strength characteristics of the resin ED-20 1.5-4 times with uniaxial tension, 2-2.5 times with three-point bending and reduce weight wear by 5-10 times.

Investigation of Different Joining by Forming Strategies when Connecting Different Metals without Auxiliary Elements

Lightweight constructions become more and more important, especially in the mobility sector. In this industry, the increasingly strict regulations regarding the emissions of carbon dioxide can be achieved to a certain extent by reducing the vehicle weight. Thus, multi-material systems are used. Conventional joining techniques reach their limits when joining different materials due to different thermal expansion, unequal stiffness or chemical incompatibilities. This is why additional joining elements or adhesives are used. These must be viewed critically regarding a lightweight and resource-efficient production, since they add weight or complicate the recycling process of these components. Consequently, there is a great and growing need for new versatile joining technologies in order to overcome these challenges and to be able to react to changing process parameters and boundary conditions. Joining without an auxiliary element using pin structures formed directly from the sheet metal plane is one approach to meet these challenges. These pin structures are then joined by direct pressing into the joining partner. This is possible with a variety of material combinations, but is advantageous with regard to continuous fibre-reinforced thermoplastic composites (CFRTP), as the fibres do not have to be cut when joining CFRTP using pin structures. In this paper, the formability of pin structures made of a dual-phase steel DP600 (HCT590X + Z) is investigated. The extruded pin structures are joined by direct pin pressing with an EN AW-6014 to form tensile shear specimens. Different joining strategies are investigated to compare their influence on the joint strength. The results have shown that it is feasible to form suitable pins from a DP600 dual-phase steel to produce reliable connections with an aluminium sheet joined by direct pin pressing.

Computer Simulation of the Direct Pressing Process Through Various Matrix Funnel Profiles

The stressed and deformed state of the metal and the dimensions of the center of deformation during pressing depend significantly on the design of the tool and, in particular, on the shape of the matrix funnel. However, there is still no single point of view on the influence of the geometry of the deformation center on the energy forces of the metal pressing process. Based on the analysis of the field of slip lines of the steady-state stage of pressing through a symmetric single-point matrix, it is proposed to use the profile of the matrix funnel made along the slip line separating the elastic and plastic zones. The following types of matrix funnel profiles were investigated using computer simulation of direct extrusion of lead samples with a drawing value 81 at a speed of 1 mm/s: cycloid concave; convex; the second convex, which is built on the logarithmic dependence; conical and concave, which is built along a sliding line that separates the elastic zones from the plastic in the pressing process. The results of theoretical studies, computer simulations of the direct pressing process using the Deform 2D/3D software package, and experimental experiments have shown that optimal energy-power conditions are achieved by pressing through a matrix that has a profile made along the slip line. The results of the experimental study of the kinetics of the flow of the discrete medium showed that the shape of the matrix funnel influences the size of the deformation center and the distribution of the resulting deformation in the molding. From the analysis of deformation of the granules, it is determined that the concave funnel, built along the slip line, is characterized by a curvature of the axisymmetric particles in the direction of deformation. These curvatures decrease as the granules move to the axis of symmetry of the matrix. It is noted that for a convex funnel, the length of the deformation center is greatest; for a conical metal flow is close to the radial in the direction of the truncated cones.

The influence of technological parameters for the production of plasticized polyvinylbutyral films on their optical and physico-mechanical properties

The effect of pressure, temperature and time during direct pressing on the strength and optical characteristics of adhesive plasticized polyvinyl butyral films is studied. A mathematical analysis of the results of a full factorial experiment is carried out and the regression equations are derived.

Study on the Solid Welding Conditions of Hollow Extrusion of 7075 Aluminum Alloy

Direct extrusion by port hole–bridge die configuration has been successfully used to fabricate products with hollow cross sections for 6000 series aluminum alloys. When these aluminum alloys flow through the upper die (with bridge and port hole) material flows separately. These separate materials contact together when they flow through the lower die (with welding chamber). The contacting and welding processes occurs naturally if the material temperature and contact pressure are suitable; then the product with hollow and complicated cross section will be obtained when the material flow through bearing regions in lower die. This solid welding process for 6000 series aluminum alloys is without any problem. However, if for 7000 series aluminum alloys this situation alerts since different alloy compositions such as Zn and Cu causing welding process in lower die failed. It will impede the success of industry application with light and high strength aluminum alloys. In order to determine the solid welding conditions during hollow extrusion with port-hole die structure for high strength aluminum alloy such as 7000 series, an easy tooling configuration has been designed. Based on this approach, two split and half die components with taper angle feature were inserted into an outer steel ring. In the beginning, some clearances happen between inner die and outer ring result from design in purpose. When the upper punch continues to press the testing billet, the clearance disappears gradually due to the designed taper angle of inner die and outer ring. However, when the pushing pressure from upper punch is over 350 Mpa and billet temperature is maintained at about 480C below melting temperature, small gaps between the two split half die components occur automatically. During this situation, two small flashes can flow into the opening gaps both from the upper and lower billets which then can weld together. However, these two upper and lower billets in direct pressing zone did not weld together. Several experiments at different pressure have been conducted and the best solid welding condition has been obtained. The proposed method (die configuration) is easy and cheap because there is no necessary to conduct experiment in controlled environment such as in vacuum chamber of Gleeble test or in a protective atmosphere. The grain size and grain structure as well as grain flow have been discussed in the proposed paper for testing parts in direct pressing zone and in flash zone. Some SEM photos and EDS analysis have been prepared and will be presented in this paper.