A review of emerging technologies enabling improved solid oral dosage form manufacturing and processing

Tablets are the most widely utilized solid oral dosage forms because of the advantages of self-administration, stability, ease of handling, transportation, and good patient compliance. Over time, extensive advances have been made in tableting technology. This review aims to provide an insight about the advances in tablet excipients, manufacturing, analytical techniques and deployment of Quality by Design (QbD). Various excipients offering novel functionalities such as solubility enhancement, super-disintegration, taste masking and drug release modifications have been developed. Furthermore, co-processed multifunctional ready-to-use excipients, particularly for tablet dosage forms, have benefitted manufacturing with shorter processing times. Advances in granulation methods, including moist, thermal adhesion, steam, melt, freeze, foam, reverse wet and pneumatic dry granulation, have been proposed to improve product and process performance. Furthermore, methods for particle engineering including hot melt extrusion, extrusion-spheronization, injection molding, spray drying / congealing, co-precipitation and nanotechnology-based approaches have been employed to produce robust tablet formulations. A wide range of tableting technologies including rapidly disintegrating, matrix, tablet-in-tablet, tablet-in-capsule, multilayer tablets and multiparticulate systems have been developed to achieve customized formulation performance. In addition to conventional invasive characterization methods, novel techniques based on laser, tomography, fluorescence, spectroscopy and acoustic approaches have been developed to assess the physical-mechanical attributes of tablet formulations in a non- or minimally invasive manner. Conventional UV-Visible spectroscopy method has been improved (e.g., fiber-optic probes and UV imaging-based approaches) to efficiently record the dissolution profile of tablet formulations. Numerous modifications in tableting presses have also been made to aid machine product changeover, cleaning, and enhance efficiency and productivity. Various process analytical technologies have been employed to track the formulation properties and critical process parameters. These advances will contribute to a strategy for robust tablet dosage forms with excellent performance attributes

Configuring electrochemical 3D printer for PCB production

In this document I look at an electrochemical 3D printer and compare it to a more established machine for the making of printing printed circuit board

Modeling, Simulation and Data Processing for Additive Manufacturing

Additive manufacturing (AM) or, more commonly, 3D printing is one of the fundamental elements of Industry 4.0. and the fourth industrial revolution. It has shown its potential example in the medical, automotive, aerospace, and spare part sectors. Personal manufacturing, complex and optimized parts, short series manufacturing and local on-demand manufacturing are some of the current benefits. Businesses based on AM have experienced double-digit growth in recent years. Accordingly, we have witnessed considerable efforts in developing processes and materials in terms of speed, costs, and availability. These open up new applications and business case possibilities all the time, which were not previously in existence. Most research has focused on material and AM process development or effort to utilize existing materials and processes for industrial applications. However, improving the understanding and simulation of materials and AM process and understanding the effect of different steps in the AM workflow can increase the performance even more. The best way of benefit of AM is to understand all the steps related to that—from the design and simulation to additive manufacturing and post-processing ending the actual application.The objective of this Special Issue was to provide a forum for researchers and practitioners to exchange their latest achievements and identify critical issues and challenges for future investigations on “Modeling, Simulation and Data Processing for Additive Manufacturing”. The Special Issue consists of 10 original full-length articles on the topic

Thermophysical and Thermochemical Property Measurement and Prediction of Liquid Metal Titanium Alloys with Applications in Additive Manufacturing

Accurate high-temperature thermophysical property data for liquid metals and alloys are important for simulation of laser-based 3D printing processes. To understand and better control such additive manufacturing processes, knowledge of density, viscosity, and surface tension of liquid metals and alloys versus composition and temperature is needed. Likewise, thermochemical property data information regarding alloys, including chemical activities and free energies relative to composition and temperature, aid in the understanding and development of phase data important in the material design process. Vacuum electrostatic levitation (ESL) is an important technique through which both thermophysical and thermochemical property measurements can be accomplished without physical contact with the liquid. We performed ESL measurements on molten Ti-based alloys, including elemental Ti, Ti-xAl binaries (x = 0-10 percent weight), Ti-6Al-4V, and Ti-6Al-4V-10Mo, through a container-less oscillating drop technique at the NASA Marshall Space Flight Center. Ti-Al-V-Mo quaternary alloy was studied for laser-based 3D printing, and showed improved mechanical properties over traditional β Ti alloys. Results for elemental Ti, Ti-xAl, and Ti-6Al-4V are compared with previously published results, while those for Ti-6Al-4V-10Mo are reported here for the first time. Additional thermodynamic data are generated for binary Ti-Al, and compared to CALPHAD results while viscosity and density values of liquid titanium were calculated via molecular dynamics and compared to experimental values. The test and simulation procedure developed provides a framework for the development of new and higher-order alloys in the high temperature regime and in the liquid phase

Multiple beam laser diode additive manufacturing for metal parts

MULTIPLE BEAM LASER DIODE ADDITIVE MANUFACTURING FOR METAL PARTS Andrew Payne Abstract Fibre laser based powder bed fusion has become the dominant commercial additive manufacturing technology for producing fully dense metal parts. This technology is difficult to scale up for build volume and build rate. Continuing advances in semiconductor technology have produced single emitter laser diodes with outputs of many tens of Watts and diode stacks that can output hundreds of Watts. These powers now make laser diodes effective for metal based additive manufacturing which when configured in a raster scanned multi beam array allow for scaling of build volume and rate. A multiple laser diode powder bed fusion additive manufacturing platform has been developed along with the firmware and software to enable the automated building of multiple layer objects. An ‘expose-move-expose’ strategy was employed for energy delivery; the multiple beam array is stationary whilst the diodes are on. The influence of powder layer thickness, exposure power, exposure time and the temporal and spatial positioning of exposures were investigated by the use of custom software analysis tools. Five scanning strategies were developed and characterised for the creation of layered objects. The higher absorptivity and lower thermal conductivity of powders when compared to bulk material produced an independence of melt volume from power for a given pulse energy in deep powder. Conversely the melt volume produced for a given pulse energy in a substrate without powder was proportional to the power used. The melt volume produced from a thin layer of powder on a substrate was also found to be proportional to power but the extent of powder denudation, whilst proportional to pulse energy, was independent from power. For a given pulse energy per exposure when creating lines of melt balls the greatest line sharpness and a lowest surface roughness were achieved with a small powder layer thickness, a high exposure power, a low spot pitch, a temporal delay of 400 ms and a square exposure profile. Single layers build in deep powder using the vertical scanning strategies (numbers one and two) showed the greatest consolidation but as layer thicknesses were between 400 and 1000 microns the relative density was no better than that of the un-fused powder. It is concluded that the intensity of the diode lasers used in this research, 2400 W/mm2 from 42 W focussed into a 150 μm diameter spot, is insufficient for building high density parts. This intensity did not produce sufficient melting of the substrate to enable efficient wetting of the melted powder. Consequently, the tendency for balling within the melt produced features within the re-solidified material that were hundreds of microns high. These features required commensurate powder layer thickness to allow uninterrupted passage of the powder wiper. The density of parts was compromised by the large layer thickness needed with 61% being the highest density achieved. Further study would benefit from using laser diodes with an output power greater than 40W.EPSR