Snowwhite2 paper: Selective laser sintering of distinct drug and polymer layers

In this installment of our series showcasing the impact of the Snowwhite SLS 3D printer on scientific advancement, we’re focusing on the paper “Selective laser sintering of distinct drug and polymer layers as a novel manufacturing strategy for individually dosed tablets“. We’ll kick things off by breaking down the study’s purpose and its key outcomes in plain language, ensuring everyone can grasp the significance of the research. Then, for those interested in the technical details, we’ll present the original abstract and any associated references.

Understanding the study and its main result

This study looked into a new way to make personalized medicine using our Sharebot Snowwhite2 SLS printer. Instead of mixing drug powder and other ingredients together, they used separate containers for the drug (indomethacin, or IND) and another material (polyvinyl alcohol, or PVA). This allowed them to print alternating layers of pure drug and pure excipient in one go.

They successfully made tablets with different doses of IND just by changing the number of drug layers. A big achievement was being able to print pure IND, which is usually hard to print by itself. They also found that the printing process changed the drug slightly, which might help it dissolve and work better in the body. Tests showed that the printed tablets dissolved faster than regular IND powder.

Main result

The main discovery is a simplified and effective method for creating personalized, multi-layered drug tablets using Selective Laser Sintering (SLS) without needing to pre-mix powders. This approach allows for direct printing of distinct drug and excipient layers, enabling precise dose control and potentially improving drug absorption. A key part of this discovery was successfully printing pure crystalline indomethacin, which was previously thought to be very difficult with SLS technology.

Selective laser sintering of distinct drug and polymer layers as a novel manufacturing strategy for individually dosed tablets

Jonas Autenrieth (a), Daniel Hedbom (b), Maria Strømme (b), Thomas Kipping (c), Jonas Lindh (b), Julian Quodbach (d)
a) Division of Molecular Pharmaceutics, Department of Pharmacy, Uppsala University, Uppsala Biomedical Center, P.O Box 580, SE-751 23 Uppsala, Sweden
b) Division of Nanotechnology and Functional Materials, Department of Materials Science and Engineering, Uppsala University, Ångström Laboratory, Regementsvägen 1, Uppsala 751 03, Sweden
c) Merck Life Science KGaA, Frankfurter Str. 250, Postcode: D033/001, DE-642 93 Darmstadt, Germany
d) Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, the Netherlands

Ref.: https://www.sciencedirect.com/science/article/pii/S2590156725000234

Abstract

Selective Laser Sintering (SLS) is an emerging additive manufacturing technology with potential for the production of personalized pharmaceuticals. In this study, we investigated a novel simplified formulation approach in SLS-based manufacturing of individually dosed, multi-layered tablets with distinct layers of pure active pharmaceutical ingredient (API) and excipient. Indomethacin (IND) was chosen as the model API, and polyvinyl alcohol (PVA) served as the excipient. Unlike conventional methods requiring powder blending, this approach utilizes separate powder tanks for IND and PVA, enabling direct printing of alternating layers in a single-step procedure.
We successfully fabricated tablets with controlled IND doses by varying the number of IND layers, maintaining consistent printing parameters across different compositions and confirming the API’s chemical stability in the product. Since SLS is conventionally used for thermoplastic substances, the successful sintering of pure IND layers was a key achievement in the study, as this crystalline API is typically not printable separately. Energy dispersive X-ray spectroscopy (EDS) demonstrated the successful formation of distinct API and excipient layers. Differential scanning calorimetry (DSC) characterization revealed that the sintering process partially amorphized IND, which may enhance dissolution and bioavailability. Dissolution testing indicated that the printed tablets exhibited improved dissolution rates compared to raw IND powder.
The study successfully demonstrated the possibility of SLS-based production for personalized dosing by omitting powder blending steps. The ability to create individualized dosages with minimal excipients and simplified processing represents a step toward further investigation of SLS for clinical settings, including hospital and pharmacy-based drug production.

Sharebot Snowwhite2 paper on dual material medical pills

Snowwhite2 paper: Selective laser sintering for printing bilayer tablets

Our journey through scientific discoveries enabled by the Snowwhite SLS 3D printer continues with an examination of the paper titled “Selective laser sintering for printing bilayer tablets“. We’ll start by making the research accessible, explaining the central question the study addressed and the primary findings. Afterwards, we’ll include the original abstract and any cited sources for those wishing to explore the finer points of the work.

Understanding the study and its main result

This research used a our Snowwhite2 to make special two-layer tablets. These tablets contained two different medicines: rosuvastatin and acetylsalicylic acid.

First, the researchers made single-layer tablets of each medicine separately. They used different laser strengths to see how that affected the tablets’ properties like how well they dissolved, how easily they broke (friability), and how hard they were.

After figuring out the best settings, they created the two-layer tablets. They used a new technique that involved a 3D-printed case to hold the different medicine powders in the right places during printing.

The results showed that stronger lasers made the tablets denser, harder, less likely to break, and released the medicine more slowly. Also, the new method successfully created perfectly aligned two-layer tablets, and combining the two medicines didn’t significantly change how they dissolved.

Main result

The main discovery here is that it’s possible to use Selective Laser Sintering (SLS) 3D printing to create multi-material drug delivery systems. In simpler terms, they figured out a way to 3D print pills with different medications in separate layers, and they developed a new method to make sure those layers are perfectly aligned. This opens the door for making more complex and customized medicine combinations in a single tablet.

Selective laser sintering for printing bilayer tablets

Laura Andrade Junqueira (a), Atabak Ghanizadeh Tabriz (a), Vivek Garg (b), Siva Satyanarayana Kolipaka (c), Ho-Wah Hui d, Nathan Boersen (d), Sandra Roberts (d), John Jones (e), Dennis Douroumis (a) (c)
a) Delta Pharmaceutics Ltd., Chatham, Kent ME4 4TB, UK
b) Wolfson Centre for Bulk Solids Handling Technology, Faculty of Engineering & Science, University of Greenwich, Central Avenue, Chatham ME4 4TB, UK
c) Centre for Research Innovation (CRI), University of Greenwich, Chatham ME4 4TB, UK
d) Drug Product Development, Bristol Myers Squibb, 556 Morris Avenue, Summit, NJ 07901, USA
e) Bristol Myers Squibb, Reeds Lane, Moreton, Wirral, UK

Ref.: https://doi.org/10.1016/j.ijpharm.2024.125116

Abstract

In this study Selective Laser Sintering (SLS) was used to produce bilayer tablets containing rosuvastatin and acetylsalicylic acid. Initially, monolithic tablets of each drug were manufactured using different laser intensities in order to identify their impact on the tablet’s dissolution, friability and hardness. After the optimization, the final bilayer tablet was fabricated using a new method, that allowed the printing using different powder blends. For that, a 3D-printed casing was employed to maintain the compartments of the tablet in the correct position during the printing process. The results demonstrated that the increased laser intensities led to denser inner cores, enhanced hardness, decreased friability, and slower drug release. Moreover, the new method was able to produce bilayer tablets completely aligned, showing a minor impact on dissolution when the two compartments were printed together in a single tablet. The work demonstrated the feasibility of using SLS in the production of multi-material drug delivery systems.

Snowwhite2 paper: Understanding the mechanisms of gold(III) adsorption

In this installment of our series showcasing the impact of the Snowwhite SLS 3D printer on scientific advancement, we’re focusing on the paper “Understanding the mechanisms of gold(III) adsorption onto additively manufactured polyamide adsorbent, AM-N12“. We’ll kick things off by breaking down the study’s purpose and its key outcomes in plain language, ensuring everyone can grasp the significance of the research. Then, for those interested in the technical details, we’ll present the original abstract and any associated references.

Understanding the study and its main result

This scientific paper looks at how well a special type of plastic material, made using our Snowwhite2, can grab gold (specifically, gold with a +3 charge, written as gold(III)) from solutions that contain many different metals. The researchers found that the plastic works best at a very acidic condition (pH 0) for capturing the most gold. Even when other metals like platinum, palladium, copper, and others were present in the solution, the plastic was very good at picking out only the gold.

The way the gold sticks to the plastic seems to be mainly in a single layer. The speed at which the gold attaches to the plastic follows common patterns. Computer modeling suggests that the gold(III) might stick to the plastic through different forces, including negative charges repelling each other (anion-anion interaction), positive and negative charges attracting (electrostatic attraction), and a weaker type of bond called hydrogen bonding.

When they looked closely at the plastic after it had captured gold, they found that some of the gold(III) had changed into gold with a +1 charge (gold(I)), and even some pure gold metal (gold(0)). This means a chemical reaction happened where the gold was reduced. Lastly, they were able to remove about half of the captured gold from the plastic using a mixture of chemicals, and they could reuse the plastic again.

Main result

The main discovery is that this specifically designed 3D-printed plastic material (AM-N12) is highly selective for capturing gold(III) from complex mixtures of metals. Importantly, the researchers also found that during the capture process, some of the gold(III) is converted into lower forms of gold (gold(I) and gold(0)) on the surface of the plastic. This suggests that the plastic not only adsorbs the gold but also plays a role in a chemical reduction reaction. They also showed that the gold can be partially removed and the plastic can be reused.

Understanding the mechanisms of gold(III) adsorption onto additively manufactured polyamide adsorbent, AM-N12

Asiia Hurskainen (a), John Kwame Bediako (a), Youssef El Ouardi (a), Morad Lamsayah (b), Janne Frimodig (c), Eveliina Repo (a)
a) Department of Separation Science, School of Engineering Science, Lappeenranta-Lahti University of Technology (LUT), FI-53850 Lappeenranta, Finland
b) Laboratory of Applied and Environmental Chemistry (LCAE), Faculty of Science, University Mohammed First, 60 000 Oujda, Morocco
c) Department of Chemistry, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland

Ref.: https://www.sciencedirect.com/science/article/pii/S0009250924014301

Abstract

The focus of this paper is to study the adsorption behavior and mechanisms of gold(III) onto additively manufactured polyamide adsorbent, AM-N12 from synthetic multimetal leached solutions. Study of the effect of pH revealed that pH 0 was the optimum condition for reaching maximum gold(III) adsorption. In competitive mixtures containing Au(III) and other metal ions, i.e., Pt, Pd, Cu, Al, Fe, Pb, Sn, Ni, and Zn, extremely high selectivity towards Au ions was observed. Fitting of the adsorption isotherm data showed the order of Freundlich < Langmuir < Sips model, depicting likely monolayer adsorption process. Moreover, the kinetics data fitted well to the pseudo-first-order and pseudo-second-order models. Density Functional Theory (DFT) molecular modelling suggested anion–anion interaction, electrostatic attraction, and hydrogen bonding as possible adsorption mechanisms of gold(III). Furthermore, characterization and X-ray photoelectron spectroscopy (XPS) analysis indicated that after adsorption, portions of Au(III) were reduced to Au(I) and some portions were further reduced to Au(0), thus signifying reduction reaction. Finally, approximately 50 % of the adsorbed gold(III) was desorbed in 24h which was appro and the adsorbent regenerated using a mixture of 0.5 M thiourea and 1 M Hcl.

Snowwhite2 paper: Recovery of rare elements from mining wastewater

Welcome back to our series highlighting the exciting ways the Snowwhite SLS 3D printing technology is contributing to scientific discovery. Today, we’re diving into the research presented in the paper “Recovery of rare earth elements from mining wastewater with aminomethylphosphonic acid functionalized 3D-printed filters“. We’ll start by explaining the core of this study and its main findings in simple terms, making it easy to understand. After that, we’ll take a look at the original abstract and any relevant references for those who want to delve deeper into the specifics of the research.

Understanding the study and its main result

This scientific paper talks about a new way to get valuable metals called Yttrium (Y), Neodymium (Nd), and Dysprosium (Dy) from waste left over from mining. This waste also has other metals like Aluminum (Al), Potassium (K), Calcium (Ca), Scandium (Sc), Iron (Fe), Cobalt (Co), Copper (Cu), Zinc (Zn), and Uranium (U).

The scientists made special filters using a our Snowwhite2 and Nylon-12. They added another chemical, α-aminomethylphosphonic acid, to these filters to help grab the metals. They chose Nylon-12 because it doesn’t react with the metals they were studying. They used powerful microscopes and X-rays to see the tiny structure of the filters, like how many holes they had and how the special chemical was spread inside. They also used another technique called FTIR to see how the filters changed after they were made and after they soaked up the metals. The scientists tested how well the filters could grab the metals at different levels of acidity (pH). They found that Scandium (Sc) was grabbed the most, followed by Iron (Fe) and Uranium (U), and then Y, Nd, and Dy. Aluminum, Copper, Zinc, Potassium, Calcium, and Cobalt were grabbed the least. They then tried to take the valuable metals back out of the filters using a strong acid. They found that they could get most of the Y, Nd, and Dy back out, but Scandium, Iron, and Uranium stayed stuck in the filters.

Main result

The main discovery is that these specially designed 3D-printed filters can effectively separate and recover the valuable rare earth elements Yttrium (Y), Neodymium (Nd), and Dysprosium (Dy) from complex mining waste, while leaving behind unwanted metals like Scandium, Iron, and Uranium. This method could be useful for cleaning up mining waste and getting valuable resources at the same time.

Recovery of rare earth elements from mining wastewater with aminomethylphosphonic acid functionalized 3D-printed filters

Emilia J. Virtanen (a) (c), Esa Kukkonen (a) (c), Janne Yliharju (b) (c) (d) , Minnea Tuomisto (e), Janne Frimodig (a), Kimmo Kinnunen (b) (c), Elmeri Lahtinen (a), Mikko M. Hänninen (a), Ari Väisänen (a), Matti Haukka (a), Jani O. Moilanen (a) (c)

a) Department of Chemistry, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
b) Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
c) Nanoscience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
d) School of Resource Wisdom, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
e) Department of Chemistry, University of Turku, FI-20014 Turku, Finland

Ref: https://www.sciencedirect.com/science/article/pii/S1383586624023384#f0045

Abstract

Herein we report the use of nylon-12-based 3D-printed filters incorporating α-aminomethylphosphonic acid as an active additive for the recovery of Y, Nd, and Dy from the mining waste solution containing Al, K, Ca, Sc, Fe, Co, Cu, Zn, Y, Nd, Dy, and U. Nylon-12 was chosen for the polymer matrix of the filter due to its inactivity towards the studied metals. The micrometer-level structure of the filters was studied with a scanning helium ion microscope and X-ray tomography to reveal the porosity, pore size, and active additive distribution in the filters. Furthermore, FTIR spectroscopy was used to analyze the compositional changes in the 3D-printed filters after the printing and adsorption processes. Adsorption of the metals was studied at a pH range of 1–4, and the following adsorption trend Sc > Fe > U > Y, Nd, Dy > Al, Cu, Zn > K, Ca, Co was observed in each of the studied pH values. The sequential recovery process for metals was studied at pH 2, and desorption of the metals from the filters was performed with 6 M HNO3. 100 % adsorption of REEs, Fe, and U was achieved during the recovery process, and on average, over 88 % of the adsorbed Y, Nd, and Dy were desorbed from the filters. In contrast to Y, Nd, and Dy, the desorption of Sc, Fe, and U was minimal (Fe and U) or negligible (Sc) with 6 M HNO3 due to their strong coordination to the active additive. Maximum adsorption capacities for Y, Nd, Dy, and U were determined by using linear Langmuir adsorption isotherm. The best maximum adsorption capacity was determined for Sc, Qmax = 0.51 mmol/g followed by U, Nd, Dy, and Y with capacities of 0.47, 0.24, 0.23, and 0.17 mmol/g, respectively. Overall, this study achieved a complete removal of Sc, Fe, and U from the simulated mining waste solution leaving a final eluate that mainly contained Y (320 μg), Nd (350 μg), Dy (330 μg), and Al (710 μg) demonstrating the applicability of the 3D-printed filters in the recovery of Y, Nd, and Dy from the multimetal solution.