scholarly journals Selective Laser Sintering of a Photosensitive Drug: Impact of Processing and Formulation Parameters on Degradation, Solid State, and Quality of 3D-Printed Dosage Forms

2021 ◽  
Vol 18 (10) ◽  
pp. 3894-3908
Author(s):  
Rishi Thakkar ◽  
Daniel A. Davis ◽  
Robert O. Williams ◽  
Mohammed Maniruzzaman
Keyword(s):  
Solid State ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Dosage Forms ◽  
3D Printed ◽  
Formulation Parameters

scholarly journals Selective Laser Sintering of a Photosensitive Drug: Impact of Processing and Formulation Parameters on Degradation, Solid-State, and Quality of 3D Printed Dosage Forms

2021 ◽  
Author(s):  
Rishi Thakkar ◽  
Daniel Alan Davis ◽  
Robert O Williams ◽  
Mohammed Maniruzzaman
Keyword(s):  
Solid State ◽  
Selective Laser Sintering ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Dosage Forms ◽  
Disintegration Time ◽  
Drug Degradation ◽  
Independent Variables ◽  
3D Printed ◽  
The Impact

This research study utilized a light-sensitive drug, nifedipine (NFD), to understand the impact of processing parameters, and formulation composition on drug degradation, crystallinity, and quality attributes (dimensions, hardness, disintegration time) of selective laser sintering (SLS) based 3D printed dosage forms. Selective laser sintering (SLS), in most cases, uses an ultraviolet laser source, and drugs tend to absorb radiation at varying intensities around this wavelength (455 nm). This phenomenon may lead to chemical degradation, and solid-state transformation, which was assessed for nifedipine in formulations with varying amounts of vinyl pyrrolidone-vinyl acetate copolymer (Kollidon® VA 64) and potassium aluminum silicate-based pearlescent pigment (Candurin®), processed under different SLS conditions in the presented work. After preliminary screening Candurin®, surface temperature (ST), and laser speed (LS) were identified as the significant independent variables. Further, using the identified independent variables a 17-run, randomized, Box-Behnken design was developed to understand the correlation trends and quantify the impact on degradation (%), crystallinity, quality attributes (dimensions, hardness, disintegration time) employing qualitative and quantitative analytical tools. The design of experiments (DoE) and statistical analysis observed that LS and Candurin® (%wt) had a strong negative correlation on drug degradation, hardness, and weight, whereas ST had a strong positive correlation with, drug degradation, amorphous conversion, and hardness of the 3D printed dosage form. From this study, it can be concluded that formulation and processing parameters have a critical impact on stability and performance; hence these parameters should be evaluated and optimized before exposing light-sensitive drugs to the SLS processes.

Evolution of Direct Selective Laser Sintering of Metals

2011 ◽  
Vol 383-390 ◽  
pp. 6252-6257
Author(s):  
Francesco Cardaropoli ◽  
Fabrizia Caiazzo ◽  
Vincenzo Sergi
Keyword(s):  
Complex Geometry ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Layer By Layer ◽  
Metal Powders ◽  
Additive Process ◽  
Operator Experience ◽  
Critical Phases ◽  
Time Required

Direct Metal Selective Laser Sintering (DMSLS) is a layer-by-layer additive process for metal powders, which allows quick production of complex geometry parts. The aim of this study is to analyse the improvement of DMSLS with “EOSINT M270”, the new laser sintering machine developed by EOS. Tests were made on sintered parts of Direct Metal 20 (DM20), a bronze based powder with a mean grain dimension of 20 μm. Different properties and accuracy were evaluated for samples manufactured with three different exposure strategies. Besides mechanical properties, the manufacturing process was also examined in order to evaluate its characteristics. The quality of laser sintered parts is too affected by operator experience and skill. Furthermore, critical phases are not automatic and this causes an extension of time required for the production. Due to these limitations, DMSLS can be used for Rapid Manufacturing, but it is especially suitable to few sample series.

The Impact of Employing Different Quality PA2200 Powder Grades to Shrinkage on Sintered Part in Selective Laser Sintering Process

2015 ◽  
Vol 789-790 ◽  
pp. 126-130
Author(s):  
W.A.Y. Yusoff ◽  
D.T. Pham ◽  
K.D. Dotchev
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Sintering Process ◽  
Melt Flow Rate ◽  
Input Material ◽  
Low Degree ◽  
Powder Properties ◽  
Plastic Parts ◽  
The Impact

One of the challenges which Laser Sintering faces is the Rapid Manufacturing of plastic parts with good consistent quality. This is due to the fact that plastic powder properties deteriorate during the long periods of time through the LS building and cooling cycles. This paper presents an experimental study of the deterioration or ageing of PA12 powder properties in the LS process. The influences of different grades of recycled PA12 powders are investigated. The main aim of this research is to develop a methodology of controlling the input material properties that will ensure consistent and good quality of the fabricated parts. From the experiment it was found that PA12 powder with high melt flow rate, low melting temperature, low glass transition temperature and low degree of crystallization temperature could improve the sintering process to produce a good Laser Sintering (LS) parts with lower shrinkage rate.

Research on Surface Quality Enhancement of Wood-Plastic Composite Powder SLS Parts by Post Processing

2010 ◽  
Vol 113-116 ◽  
pp. 508-511 ◽  
Author(s):  
Wei Liang Zeng ◽  
Yan Ling Guo
Keyword(s):  
Surface Quality ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Wood Plastic Composite ◽  
Post Processing ◽  
Plastic Composite ◽  
Rp Process ◽  
Sintering Properties

According to its advantages, such as low-cost and green biological etc., Wood-Plastic Composite(WPC) is more suitable for make parts by Selective Laser Sintering(SLS) rapid prototyping (RP) process. With optimal design of components, the parts made by WPC have good mechanical properties as well as with good laser sintering properties. In order to further improve the surface quality of the parts, the post-processing–infiltrating with wax–is introduced. After post-processing, the void fraction is decreased from 51% to 7%, surface quality has been greatly improved, Ra belows 13µm on average, after polishing the surface is more smooth and Ra belows 5µm averagely，compared to those without post processing, surface roughness decrease 22% and 73% respectively.

scholarly journals Preparation of 3D printed silver nanocomposites and their antibacterial properties

2021 ◽  
Vol 267 ◽  
pp. 02003
Author(s):  
Chunli Zhu ◽  
Xiaofen Fu ◽  
Xing Gao ◽  
Haotian Kan
Keyword(s):  
Slow Release ◽  
Preparation Method ◽  
Selective Laser Sintering ◽  
Antibacterial Properties ◽  
Polypropylene Composite ◽  
Nano Silver ◽  
Preparation Period ◽  
3D Printed ◽  
Composite Engineering

The 3D printed antibacterial polymer products were rapidly sintered to obtain by selective laser sintering with highly dispersed Nano-silver modified Kaolin powder and polyamide/polypropylene composite engineering material. The preparation method of polymer products not only shortens the preparation period, but also guarantees the precision and quality of the product as well as the slow-release function of the Nano-silver.

scholarly journals Selective Laser Sintering 3D Printing of Orally Disintegrating Printlets Containing Ondansetron

Pharmaceutics ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 110 ◽  
Author(s):  
Nour Allahham ◽  
Fabrizio Fina ◽  
Carmen Marcuta ◽  
Lilia Kraschew ◽  
Wolfgang Mohr ◽  
...  
Keyword(s):  
3D Printing ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Manufacturing Technology ◽  
Commercial Product ◽  
Cyclodextrin Complexes ◽  
Orally Disintegrating Tablet ◽  
3D Printed ◽  
Added Benefit ◽  
Different Levels

The aim of this work was to explore the feasibility of using selective laser sintering (SLS) 3D printing (3DP) to fabricate orodispersable printlets (ODPs) containing ondansetron. Ondansetron was first incorporated into drug-cyclodextrin complexes and then combined with the filler mannitol. Two 3D printed formulations with different levels of mannitol were prepared and tested, and a commercial ondansetron orally disintegrating tablet (ODT) product (Vonau® Flash) was also investigated for comparison. Both 3D printed formulations disintegrated at ~15 s and released more than 90% of the drug within 5 min independent of the mannitol content; these results were comparable to those obtained with the commercial product. This work demonstrates the potential of SLS 3DP to fabricate orodispersible printlets with characteristics similar to a commercial ODT, but with the added benefit of using a manufacturing technology able to prepare medicines individualized to the patient.

3D printed chemically and mechanically robust membrane by selective laser sintering for separation of oil/water and immiscible organic mixtures

2020 ◽  
Vol 385 ◽  
pp. 123816 ◽  
Author(s):  
Shushan Yuan ◽  
Dieter Strobbe ◽  
Xin Li ◽  
Jean-Pierre Kruth ◽  
Peter Van Puyvelde ◽  
...  
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Organic Mixtures ◽  
3D Printed ◽  
Oil Water

Systematic Dimensional Calibration Process for 3D Printed Parts in Selective Laser Sintering (SLS)

2015 ◽  
Author(s):  
Sangho Ha ◽  
Hweeyoung Han ◽  
Daeil Kwon ◽  
Namhun Kim ◽  
Hyeonnam Kim ◽  
...  
Keyword(s):  
Regression Model ◽  
Polynomial Regression ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Engineering Properties ◽  
Calibration Process ◽  
Order Polynomial ◽  
3D Printed ◽  
Deformation Patterns ◽  
Polynomial Regression Model

The selective laser sintering (SLS) processes, known for enhancing engineering properties and durability of products, are widely used in auto part development processes. The dimensional displacements of the 3D printed parts, however, hinder utilizing the technology directly to enhance their development process. In general, the SLS process causes curved shapes (convex) due to thermal deformation (thermal expansion and thermal contraction) in the powder sintering and cooling processes, which accompanies multi-phase changes of the raw materials (polymer powders). In this research, we aim to present a systematic dimensional calibration process by investigating and analyzing the dimensional deformation patterns of 3D printed samples in SLS platform (using 3D Systems’ sPro60 SD). Firstly, the test samples with complex features are produced to check the reference dimensional deviation of the SLS process. Secondly, the deformation patterns are measured and analyzed as a form of a 2nd order polynomial regression model in the global Cartesian coordinates of the platform. Lastly, the dimensional calibration methods to minimize the process errors are presented by the pre-processing of the original CAD file (.stl) with inverse transformation of the features using the 2nd order polynomial regression model. At the end of the paper, we will propose an algorithm that predicts the deformation and calibrates point-based 3D CAD STL files of samples in order to mitigate the dimensional deformation, along with test samples for illustrative purposes.

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