Hot Melt Research Articles

Model-based real-time optimization in continuous pharmaceutical manufacturing

In this work, real-time optimization (RTO) schemes are proposed and applied on a continuous pharmaceutical manufacturing process which consists of three units: synthesis unit, hot melt extrusion unit and direct compaction line. The developed RTO strategies calculate the operating conditions by optimizing the considered objective functions while satisfying the specific constraints. Moreover, the RTO schemes can cope with intentional changes in the process and unintentional changes such as disturbances. Results from simulations and experiments are presented in this work. An advantageous performance is achieved when using the developed schemes.

Amorphous solid dispersions of amphiphilic polymer excipients and indomethacin prepared by hot melt extrusion

Improving the solubility of poorly water-soluble drugs is essential for enhancing bioavailability, formulation flexibility and reducing patient-to-patient variability. The preparation of amorphous solid dispersions (ASDs) is an attractive strategy to formulate such drugs, leading to higher apparent water solubility and therefore higher bioavailability. For such ASDs, water-soluble polymer excipients, such as poly(vinyl pyrrolidone) (PVP) or poly(vinyl pyrrolidone-co-vinyl acetate) (P(VP-co-VA)), are employed to solubilize and stabilize the drug against crystallization. We posit that polymers bearing tertiary amides are particularly well suited to stabilizing drugs containing H-bond donors, as they offer strong H-bonding potential between the polymer and drug. The aim of this study was to compare new and established polymers with tertiary amides as excipients for ASDs. Experimental amphiphilic ABA triblock copolymers comprising poly(2-methyl-2-oxazoline) (pMeOx), poly(2-butyl-2-oxazoline) (pBuOx) and poly(2-butyl-2-oxazine) (pBuOzi) blocks, were compared with the established excipients, PVP and P(VP-co-VA). ASDs with indomethacin as the model drug were prepared at high drug loadings via hot melt extrusion. The extrudates were studied with DSC and PXRD, revealing the ASDs to be fully amorphous up to 75wt% indomethacin, independent of the polymer used. 13C CPMAS NMR provided insights into intermolecular associations as a function of drug loading, and suggested the presence of drug dimers at 75wt% drug loading in pMeOx-pBuOzi-pMeOx and pMeOx-pBuOx-pMeOx, which could affect physical stability. Independent of the polymers, the solid-state form of the drug in the ASD was found to affect the dissolution profile of the samples, insofar as the samples containing crystalline indomethacin showed slower dissolution than the fully amorphous ones. This study shows that the polymers comprising poly(2-oxazoline) and poly(2-oxazine) are effective polymers for ASD preparation, similar to PVP and P(VP-co-VA) which merits further investigations into these novel polymers for formulating ASDs.

Crystallization modeling of two semi-crystalline polyamides during material extrusion additive manufacturing

In this work, a heat transfer model is developed for thermally-driven material extrusion additive manufacturing of semicrystalline polymers that considers the heat generated during crystallization by coupling crystallization kinetics with heat transfer. The materials used in this work are Technomelt PA 6910, a semicrystalline hot melt adhesive with sub-ambient glass transition temperature (Tg) and slow crystallization, and PA 6/66, a traditional semicrystalline polyamide with a higher Tg and fast crystallization. The coupled model shows that the released heat during crystallization depends on material selection, with Technomelt PA 6910 and PA 6/66’s temperatures increased by less than 1 °C and up to 6.3 °C, respectively, due to enthalpy of crystallization. Increasing the layer time decreases the layer temperature as well as the initial crystallinity. However, its effect on final crystallinity in Technomelt PA 6910 is negligible due to continued crystallization of the material after printing. Experimental validation shows good agreement for Technomelt PA 6910, but consistently underpredicts PA 6/66 crystallinity. Increasing modeled environmental temperature leads to better agreement with experimental results for PA 6/66, suggesting that higher temperatures may have been experienced. Shear-induced crystallization may also be contributing to crystallinity in this material. The results from this model highlight the importance of and interrelationships between material and processing parameter selection and can aid in achieving quality prints from semicrystalline thermoplastics.

Study on the mechanism of aluminum melt corrosion of Fe-SG series metals

This paper investigates the corrosion behavior of Fe-SG series metals with different graphite nodule counts to molten Al by using the ultrasonic vibration hot-dip aluminum experimental method. Fe-SG series metals to aluminum melt exhibited a much better corrosion resistance compared to H13 tool steel. As the graphite nodule count increases, the hot melting loss rate of Fe-SG series metals gradually decreases, indicating an improvement in corrosion resistance to aluminum melt. Scanning and EDS analysis of the samples after hot-dip aluminum testing revealed that the thickness of the product layer increased progressively with the extension of hot-dip aluminum time. Through the analysis of the structure and composition of the product layer, it was found that the corrosion products in H13 steel were composed of Fe2Al5 and FeAl3. In addition to the two phases, the product layer of the Fe-SG series metals also contained granularly distributed Fe-Al-Si intermetallic compounds within the Fe2Al5 phase. This resulted in a better corrosion resistance to aluminum melt.

Effect of Rheological on the Physical and Electrical Properties of Extruded Micro Carbon -LLDPE Composites

This study focuses on formulating and optimizing a conductive polymer composite (CPC) material tailored for electromechanical applications. Linear Low-Density Polyethylene (LLDPE) polymer and micro carbon particles derived from rice husk were compounded using a hot compaction process and melt blended through a single-screw extrusion machine. A mix of 50% loading of microcarbon particles was used in this research. It was determined that the experiment was successfully conducted, resulting in a stabilized density of approximately 1 g/cm³. The research demonstrates how the prototype Extruder Head effectively stabilizes the density of composites. Electrical conductivity demonstrated a notable increase in conductivity toward higher density. These findings underscore the successful development of a CPC material with improved electrical conductivity, making it a highly suitable tool for high carbon-loading composite material.

Toward Sustainable Adhesives with Biodegradability, Scalability, and Removability: Poly(butylene succinate)-Based Hot-Melt Adhesives

Toward Sustainable Adhesives with Biodegradability, Scalability, and Removability: Poly(butylene succinate)-Based Hot-Melt Adhesives

Water content drives distinct evolution trajectory of Early Cretaceous granitoids in inland and coastal southeast China

Water plays a crucial role in determining the crystallization sequence of magma, which subsequently influences the chemical compositions of magmatic rocks across different tectonic settings. In this study, we compared the evolutionary features of granitic rocks along the coast and inland areas of southeast China, aiming to identify the key factors influencing their evolution. Our work indicates that multiple granitic intrusions formed between 126 and 142 Ma in the coastal region of southeastern China, which is consistent with the formation ages of large-scale granitoids in the inland Gan-Hang Belt. Isotopic characteristics suggest that the granitic rocks in southern Fujian originated from the melting of juvenile crust, while those in northern Fujian and eastern Zhejiang were formed from the partial melting of ancient crustal rocks, incorporating mafic magma evolved from the mantle. Most of the granitoids from the coastal region of southeastern China exhibit low zircon saturation temperatures (680–800 °C) and Zr/Sr ratios (<1), suggesting their origin from a cold, wet magma reservoir. The porphyritic quartz diorite and porphyritic monzogranite represent the residual cumulate rocks of this hydrous magma reservoir, whereas the granitic porphyry and high-silica equigranular alkali feldspar granite evolved from the felsic melts extracted from the same reservoir. In contrast, most of the Early Cretaceous granitoids in the Gan-Hang Belt, located in the inland areas of southeast China, display high zircon saturation temperatures (800–900 °C) and Zr/Sr ratios (>1), indicating their origin from hot, water-poor magma reservoirs. The porphyritic granites in this region represent residual cumulate rocks formed in water-poor magma reservoirs, whereas the high-silica equigranular granites evolved from hot felsic melts extracted from similar magma reservoirs. In the Early Cretaceous, the coastal region of southeastern China was closer to the Late Mesozoic paleo-Pacific subduction zone, where crystal-melt segregation within cold, wet magma reservoirs predominantly influenced magma evolution. Conversely, the granitoids in the Gan-Hang Belt in the inland region, located farther from the Late Mesozoic paleo-Pacific subduction zone, were associated with a rift tectonic setting and formed through crystal-melt segregation within hot, water-poor magma reservoirs. Our study underscores the critical role of water content in magma reservoirs in shaping the chemical composition of granitic rocks through crystal-melt segregation, thereby deepening our understanding of crustal formation processes across diverse tectonic environments.

Self-healing and degradable functionalization of EVA hot-melt adhesives based on disulfide bonds and polymer free radical copolymerization

This study aims to provide a new approach for the industrialization of self-healing adhesive or membrane materials. EVA hot melt adhesive has a market share of over 50 %, and it needs to be cured during use. It is a thermosetting resin that is difficult to recycle and reuse. In response to the defects mentioned above, we developed a self-healing and degradable EVA-based hot-melt adhesives (EDS) based on disulfide bonds and polymer free radical copolymerization. Specifically, we used divinyl disulfide as a crosslinking agent. Under the action of a peroxide initiator, disulfide and EVA formed a cross-linked network through free radical copolymerization. In the study, we characterized the Functionality and comprehensive performance of EDS using various testing methods such as FT-IR, DSC, and SEM. The research results indicate that EDS achieves self-healing and degradation by utilizing the rearrangement reaction of disulfide bonds under ultraviolet light and its reducibility under strong alkaline conditions. While maintaining the same electrical insulation performance, the barrier performance, thermal conductivity, aging resistance, and mechanical properties of EDS have all been improved. Meanwhile, we discussed the self-healing mechanism, curing kinetics, degradation mechanism, and aging mechanism of EDS.

Melt-extruded formulations of fenofibrate with various grades of hydrogenated phospholipid exhibit promising in-vitro biopharmaceutical behavior

In the current study, it was demonstrated that three commercially available grades of hydrogenated phospholipids (HPL) differing in their content of phosphatidylcholine may be used as components for hot melt-extruded binary (HPL as sole excipient) or ternary (in combination with copovidone) solid dispersions of fenofibrate (FEN) at mass fractions between 0.5 and 20% (ternary) or 80% (binary). X-ray powder diffraction indicated complete conversion of crystalline fenofibrate into the amorphous state by hot melt extrusion for all ternary blends. In contrast, both the binary blends (HPL- and copovidone-based) contained minor remaining crystallites. Irrespectively, all solid dispersions induced during dissolution studies a supersaturated state of FEN, where the ternary ASDs showed enhanced and more complete release of FEN as compared to the binary blends and, even more pronounced, in comparison to the marketed micronized and nano-milled formulations. In terms of the cumulated amount permeated, there were marginal differences between the various formulations when combined dissolution/permeation was done using FeSSIF as donor medium; with FaSSIF as donor medium, the binary HPL-ASD containing the grade with the highest phosphatidylcholine fraction performed best in terms of permeation, even significantly better than the marketed nano-crystal formulation. Otherwise, no significant differences were seen between the various grades of HPL when FEN dissolution and permeation were analyzed for ternary solid dispersions. In conclusion, the in-vitro biopharmaceutical behaviour of hydrogenated phospholipid-containing blends manufactured by hot melt extrusion appears promising. They can be a viable formulation option for poorly water-soluble and lipophilic drug compounds like FEN.

Facile synthesis of polyester-polyether block copolyols for the sustainable high-performance polyurethane reactive hot melt adhesives

The presence of polyols with both polyester and polyether structures in polyurethane enhances bonding strength and facilitates easy curing. In this study, polyester-polyether block polyols with varying molecular weights (2500–3500) were synthesized through ring-opening polymerization (ROP) using l-lactide (LA) and ε-Caprolactone (CL). The chemical structure of the polyols was characterized using 1H nuclear magnetic resonance (1H NMR), Fourier transform infrared (FTIR), and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) were employed to examine the crystalline morphology of the polyols. Subsequently, the synthesized polyols were combined with 4,4′-diphenylmethane diisocyanate (MDI) and other additives to prepare polyurethane reactive hot melt adhesives. It was observed that, in PCL-based polyurethane reactive hot melt adhesives, increasing the molecular weight of the polyols resulted in improved crystalline morphology, increased lap shear strength and tensile strength, and enhanced thermal stability. On the other hand, PLA-based polyurethane reactive hot melt adhesives exhibited low bonding strength and lacked practical application value due to the poor toughness of PLA. Interestingly, the bonding strength and tensile strength of PLA-based polyurethane reactive hot melt adhesives improved when physically blended with PCL-based polyurethane reactive hot melt adhesives. These polyols offer a novel approach for utilizing LA and CL in adhesive applications.

Thermally stimulated bio-acrylate based detachable adhesives with sustainable bonding-debonding design

The electronics and automotive industries utilize acrylic adhesives extensively. Their exceptional mechanical strength, accompanied by their permanent nature, renders recycling impracticable. Present work has successfully synthesized acrylate biopolymer based detachable adhesive, which is both eco-friendly and sustainable. Glycerol, from mustard oil, was oxidatively-dehydrated to synthesize acrylic acid, which along with dimethyl glyoxime was chain polymerized to obtain an eco-friendly acrylic based hot melt detachable adhesive (AAHMDA). Mechanical strength of prepared adhesive was tested through thermo-mechanical bonding-debonding cycles on glass, wood, and metal. In three tests of 0.2 g adhesive against specific applied stress on all surfaces, metal (1494.49 N/m2) and wood (1851.17 N/m2) remained intact for 2 h and 30 min. Maximum cleavage stress (applied weight) on glass, wood, and metal slides, using 0.2 g adhesive, was found to be 26503.61 N/m2 (1200 g), 19824.71 N/m2 (950 g), and 26328.24 N/m2 (1300 g), respectively, when repeatedly tested for 15 cycles. Gel contents and water absorption capacity of sample were found at 99.79 % and 38.78 %, respectively. Prepared AAHMDA possesses the capability to create a robust mechanical bond that is readily detachable when heated, which makes it a cost effective adhesive. Owing to its strong bonding and simple detachment procedure, AAHMDA appears to have a promising future in materials research, sustainability initiatives, and changing industry demands.

Green synthesis of silver nanoparticles from mulberry leaf through hot melt extrusion: Enhanced antioxidant, antibacterial, anti-inflammatory, antidiabetic, and anticancer properties

Green synthesis of silver nanoparticles from mulberry leaf through hot melt extrusion: Enhanced antioxidant, antibacterial, anti-inflammatory, antidiabetic, and anticancer properties

Computational Support to Explore Ternary Solid Dispersions of Challenging Drugs Using Coformer and Hydroxypropyl Cellulose.

A majority of drugs marketed in amorphous formulations have a good glass-forming ability, while compounds less stable in the amorphous state still pose a formulation challenge. This work explores ternary solid dispersions of two model drugs with a polymer (i.e., hydroxypropyl cellulose) and a coformer as stabilizing excipients. The aim was to introduce a computational approach by preselecting additives using solubility parameter intervals (i.e., overlap range of solubility parameter, ORSP) followed by more advanced COSMO-RS theory modeling. Thus, a mapping of calculated mixing enthalpy and melting points is proposed for in silico evaluation prior to hot melt extrusion. Following experimental testing of process feasibility, the selected formulations were tested for their physical stability using conventional bulk analytics and by confocal laser scanning and atomic force microscopy imaging. In line with the in silico screening, dl-malic and l-tartaric acid (20%, w/w) in HPC formulations showed no signs of early drug crystallization after 3 months. However, l-tartaric acid formulations displayed few crystals on the surface, which was likely a humidity-induced surface phenomenon. Although more research is needed, the conclusion is that the proposed computational small-scale extrusion approach of ternary solid dispersion has great potential in the formulation development of challenging drugs.

Comparative Study of Polycaprolactone and Polylactic Acid as Matrices for Atorvastatin Release - Biomaterial Suppliers for Additive Manufacturing in Drug Delivery Systems using nanocomposites

The use of the polymer/drug combination in additive manufacturing involves filament production through hot melt extrusion (HME). Atorvastatin (ATV) has diverse effects, including bone anabolism and cardiovascular improvements. This study compares the addition of ATV to polycaprolactone (PCL) and polylactic acid (PLA). Filaments of PCL/ATV and PLA/ATV were produced through HME and characterized by Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Raman, Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and Small-Angle X-ray Scattering (SAXS). ATV release was assessed using UV-Vis. The EDS analysis confirmed the presence of ATV in the filament, despite it not being possible, based on surface morphology, to distinguish between polymer and drug, which indicates good dispersion of ATV in the polymeric matrix. FTIR, RAMAN, XRD, and SAXS analyses reveal ATV's distinct interactions with PLA and PCL. FTIR highlights ATV's stronger interaction with PLA, while Raman indicates changes in PLA, they are less pronounced than in PCL. The XRD shows PLA's amorphous nature compared to PCL semi crystallinity nature. XRD suggests potential ATV amorphization in PLA_ATVf (filaments), while PCL_ATVf shows a decrease in crystallinity compared to PCL. HME's effect on ATV is essential. Despite ATV's crystallinity in PCL-ATVf by XRD, its release resembles PLA_ATVf. At the eighth hour, ATV release from PCL_ATVf was 12% higher than from PLA_ATVf. The data fitted the Korsmeyer-Peppas model.

Biocompatible Natural Polymers and Cutting-Edge Fabrication Techniques in the Development of Next-Generation Oral Thin Films for Enhanced Drug Delivery Systems.

Oral thin films are changing the way drugs are delivered, making drug administration more convenient and patient-friendly. This review delves into the fascinating possibilities of natural polymers in thin film design. We consider the benefits of biocompatible polymers produced from chitosan, gelatin, and pullulan. Their intrinsic biodegradability and safety make them excellent for use with a wide range of patients. Additionally, the research investigates novel strategies for creating these distinctive drug delivery systems. We look beyond standard solvent casting techniques, hot melt extrusion methods, rolling methods, etc. These technologies provide exact control over film qualities, allowing for tailored medication delivery and increased patient compliance. This review seeks to bridge the gap between natural polymers and cutting-edge fabrication processes. By investigating this combination, we pave the road for the development of next-generation oral thin films that are more efficacious, patient-acceptable, and environmentally-friendly.

In-line NIR coupled with machine learning to predict mechanical properties and dissolution profile of PLA-Aspirin

In the production of polymeric drug delivery devices, dissolution profile and mechanical properties of the drug loaded polymeric matrix are considered important Critical Quality Attributes (CQA) for quality assurance. However, currently the industry relies on offline testing methods which are destructive, slow, labour intensive, and costly. In this work, a real-time method for predicting these CQAs in a Hot Melt Extrusion (HME) process is explored using in-line NIR and temperature sensors together with Machine Learning (ML) algorithms. The mechanical and drug dissolution properties were found to vary significantly with changes in processing conditions, highlighting that real-time methods to accurately predict product properties are highly desirable for process monitoring and optimisation. Nonlinear ML methods including Random Forest (RF), K-Nearest Neighbours (KNN) and Recursive Feature Elimination with RF (RFE-RF) outperformed commonly used linear machine learning methods. For the prediction of tensile strength RFE-RF and KNN achieved R2 values 98% and 99%, respectively. For the prediction of drug dissolution, two time points were considered with drug release at t = 6 h as a measure of the extent of burst release, and t = 96 h as a measure of sustained release. KNN and RFE-RF achieved R2 values of 97% and 96%, respectively in predicting the drug release at t = 96 h. This work for the first time reports the prediction of drug dissolution and mechanical properties of drug loaded polymer product from in-line data collected during the HME process.

Designing the regularity of biodegradable copolyester for sustainable hot-melt adhesives: Adhesion, removability, and biodegradability

Recent research has increased in eco-friendly hot-melt adhesives as alternatives to conventional commercial hot-melt adhesives. However, there have been limitations in terms of removability and biodegradability. This study addresses these issues by designing a novel molecular structure for a single polymer, resulting in a sustainable hot-melt adhesive that offers strong adhesion, clear removability, and high biodegradability without additional additives. By varying the ratio of alcohol monomers 1,4-butanediol (BD) and ethylene glycol (EG) during polymerization, we synthesized poly(butylene adipate-co-butylene terephthalate-co-ethylene adipate-co-ethylene terephthalate) (PBEAT) with four block segments. We increased the open time by reducing the regularity of the molecular structure, controlling crystallization behavior, and inhibiting polymer chain packing. This improvement in wettability with the adherend allowed us to achieve a lap shear adhesion strength of 3.18 MPa. Additionally, we proposed a debonding mechanism based on the correlation between the crystallization temperature (Tc) block copolymer's and shear adhesion failure temperature (SAFT), demonstrating the removability of the prepared hot-melt adhesive. Finally, analyses of hydrolysis, enzymatic degradation, and biodegradation in compost confirmed that reduced crystallinity enhances biodegradability. PBE30AT, exhibiting the strongest adhesion strength, achieves complete degradation in compost within 20 days, faster than neat poly(butylene adipate-co-terephthalate) (PBAT). This research offers a novel and practical approach to enhancing the potential and expandability of sustainable adhesives by tailoring the molecular structure of the polymer.

Formulation optimization of chitosan surface coated solid lipid nanoparticles of griseofulvin: A Box-Behnken design and in vivo pharmacokinetic study.

Solid lipid nanoparticles (SLNs) are becoming increasingly favored for their robust biocompatibility and their capacity to enhance drug solubility, particularly for drugs with limited water solubility. This study delves into the effectiveness of the hot melt sonication technique in fabricating SLNs with high drug loading capabilities and sustained release characteristics. Griseofulvin (GF), chosen as a representative drug due to its poor water solubility, was encapsulated into SLNs composed of stearic acid. Optimization of chitosan-coated GF-loaded SLNs (CS-GF-SLN) was conducted using a Box-Behnken design. Utilizing the desirability approach, optimal parameters were determined, including a lipid quantity of 450.593 mg, chitosan content of 268.67 mg, and sonication duration of 2.14 hours. These parameters resulted in a zeta potential of -34.8 mV and a particle size (PS) of 56.87 nm. Following optimization, the refined formulation underwent comprehensive assessment across various parameters. Notably, the drug encapsulated within SLNs exhibited sustained release over three days, as illustrated by the in-vitro drug release profile. The optimized formulation demonstrated a bioavailability enhancement by approximately 1.7 to 2.0 times compared to the conventional formulation. Furthermore, administration of drug-loaded SLNs to a macrophage cell line demonstrated no cytotoxicity, affirming their suitability as conventional drug delivery platforms for GF.

3D printing novel enteric capsule shells for personalized drug delivery

Individualized drug delivery presents a viable strategy for enhancing medication efficacy and patient safety. It involves producing small batches of custom dosages tailored to each patient’s individual needs. However, current pharmaceutical manufacturing processes are not designed for personalized dosage forms. Additive manufacturing processes have great potential in the pharmaceutical industry due to the customizable nature of 3D printing technologies and the increasing demand for customized pharmaceutics and drug delivery systems. Conventional enteric capsules are prepared by dip coating to achieve gastro-resistant release, but the manufacturing process is erratic and unreliable. This study aimed to investigate the feasibility of manufacturing enteric capsules from enteric polymers using the hot melt extrusion (HME) and fused filament fabrication (FFF) process. HME was utilized to prepare filaments using enteric polymers, Hypromellose acetate succinate (HPMC-AS), and Eudragit-L 100–55, with plasticizers, sorbitol, and polyethylene glycol 4000 (PEG-4000), and a thermoplastic polymer, polyvinyl alcohol (PVA). A computer-aided design program was utilized to design size 0 capsules. The prepared capsule design and filaments were used to fabricate capsules using the FFF process. Powdered red dye was used to simulate the drug and its release from FFF fabricated capsules was evaluated in simulated gastric and intestinal fluids, pH 1.2 and 6.8, respectively. Various combinations of enteric polymer, plasticizer, and thermoplastic polymer were examined. Thermogravimetric analysis (TGA) showed that the temperatures used for processing polymer blends were well below their thermal degradation temperatures, and dye release profiles were generated using image analysis software. This study demonstrates that capsules made with HPMCAS, PEG-4000, and PVA via the FFF process are suitable for controlling drug release and that the release profile can be modified by making small changes to the formulation.

An alternative filament fabrication method as the basis for 3D-printing personalized implants from elastic ethylene vinyl acetate copolymer

In this work, a novel tool for small-scale filament production is presented. Unlike traditional methods such as hot melt extrusion (HME), the device (i) allows filament manufacturing from small material amounts as low as three grams, (ii) ensures high diameter stability almost independent of the viscoelastic behavior of the polymer melt, and (iii) enables processing of materials with rheological profiles specifically tailored toward fused filament fabrication (FFF). Hence, novel materials, previously difficult to process due to HME limitations, become easily accessible for FFF for the first time. Here, we showcase the production of highly flexible drug-free, and drug-loaded filaments based on ethylene-vinyl acetate polymers with a vinyl acetate content of 28 w% (EVA28) and unprecedented high melt flow rates of up to 400 g/10 min. Owing to their low viscosity, FFF with low print nozzle sizes of 250 μm was achieved for the first time for EVA28. These small nozzle diameters facilitate 3D-printing of high-resolution structures in small-dimensional dosage forms such as subcutaneous implantable drug delivery systems, which can later be used for personalization. Consequently, the material portfolio for FFF is tremendously broadened, allowing material and formulation optimization toward FFF, independent of a preliminary extrusion process.