Determining local residence time distributions in twin-screw extruder elements via smoothed particle hydrodynamics

Bauer, Hannes; Matić, Josip; Evans, Rachel C.; Gryczke, Andreas; Ketterhagen, William R.; Sinha, Kushal; Khinast, Johannes

doi:10.1016/j.ces.2021.117029

Cited by 14 publications

(7 citation statements)

References 45 publications

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“…The screw speed is known to influence mean residence time (MRT) of the material in the barrel. 26 The flow pattern of material that determines the degree of mixing was found to approach a plug flow with the increase in feed rate, while low feed rates promoted axial mixing. 48 On the other hand, low feed rates of volumetric feeders cause a pulsing flow of the ingredients that is prone to affect the product composition.…”

Section: Processing Parametersmentioning

confidence: 96%

“…29 The other variable of the HME process is the screw speed that invariably affects the mass transport and mixing process. 26,49 The screw speed was also found to affect the flow pattern of the material processed in a twin shell extruder. It was observed that as the screw speed decreased the flow of the material approached a plug flow, whereas high screw speed promoted axial dispersion.…”

Section: Processing Parametersmentioning

confidence: 99%

“…To resolve this issue, PAT monitored residence time distribution (RTD), which represents the time taken by the material to traverse the unit operation has been employed to ensure content uniformity . It is typically measured by injecting a tracer into the system followed by measuring its concentration profile over time . However, there is an acute shortage of equipment that could be used for CM of pharmaceutical DPs.…”

Section: Challenges/barriers For Implementation Of CMmentioning

confidence: 99%

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Can Continuous Manufacturing of Topical Semisolids by Hot Melt Extrusion Soon Be a Reality?

Matadh,

Echanur,

Suresh

et al. 2023

Mol. Pharmaceutics

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For more than five decades, pharmaceutical manufacturers have been relying heavily on batch manufacturing that is a sequential, multistep, laborious, and time-consuming process. However, late advances in manufacturing technologies have prompted manufacturers to consider continuous manufacturing (CM) is a feasible manufacturing process that encompasses fewer steps and is less tedious and quick. Global regulatory agencies are taking a proactive role to facilitate pharmaceutical industries to adopt CM that assures product quality by employing robust manufacturing technologies encountering fewer interruptions, thereby substantially reducing product failures and recalls. However, adopting innovative CM is known to pose technical and regulatory challenges. Hot melt extrusion (HME) is one such state-of-the-art enabling technology that facilitates CM of diverse pharmaceutical dosage forms, including topical semisolids. Efforts have been made to continuously manufacture semisolids by HME integrating the principles of Quality by Design (QbD) and Quality Risk Management (QRM) and deploying Process Analytical Technologies (PAT) tools. Attempts have been made to systematically elucidate the effect of critical material attributes (CMA) and critical process parameters (CPP) on product critical quality attributes (CQA) and Quality Target Product Profiles (QTPP) deploying PAT tools. The article critically reviews the feasibility of one of the enabling technologies such as HME in CM of topical semisolids. The review highlights the benefits of the CM process and challenges ahead to implement the technology to topical semisolids. Once the CM of semisolids adopting melt extrusion integrated with PAT tools becomes a reality, the process can be extended to manufacture sterile semisolids that usually involve more critical processing steps.

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Section: Processing Parametersmentioning

confidence: 96%

Section: Processing Parametersmentioning

confidence: 99%

Section: Challenges/barriers For Implementation Of CMmentioning

confidence: 99%

See 1 more Smart Citation

Can Continuous Manufacturing of Topical Semisolids by Hot Melt Extrusion Soon Be a Reality?

Matadh,

Echanur,

Suresh

et al. 2023

Mol. Pharmaceutics

View full text Add to dashboard Cite

show abstract

“…The twin‐screw extruder is widely used to provide homogeneous mixing of different ingredients such as additives, fillers, and liquids, and it is the heart of continuous production lines for food, cellulose pulp, polymer compounds, chemical compounds, and energetic materials. [ 1–3 ] Extrusion is a continuous process consisting in shaping or transforming a material within a screw/barrel system, and the involved mechanisms are mostly thermo‐mechanical. [ 4 ] The length‐to‐diameter (L/D) ratio is a very important factor concerning product quality and the rheological properties of the material during extrusion.…”

Section: Introductionmentioning

confidence: 99%

Gel‐spinning of ultra‐high molecular weight polyethylene by a twin‐screw extruder with an ultra‐large length‐to‐diameter ratio

Jian

Liu

et al. 2022

Polymer Engineering & Sci

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A twin‐screw extruder with an ultra‐large length‐to‐diameter (L/D) ratio of 136 was developed and applied in the gel‐spinning process of ultra‐high molecular weight polyethylene (UHMWPE). UHMWPE gel fibers with concentrations of 6–18 wt% were produced at barrel temperatures of 150–180°C and screw speeds of 10–40 rpm. The residence time of the UHMWPE gel solution in the extruder increased with the increase of solution concentration and barrel temperature and decreased with the increase of screw speed. The tensile properties and crystallinity of the UHMWPE gel fibers decreased with the increase of solution concentration. Due to the great shear effect of the ultra‐large L/D ratio, the barrel temperature and screw speed could be lower to optimize the structure and tensile properties of UHMWPE fibers. Compared to the extruder with the L/D ratio of 36, the tensile strength, modulus, and elongation at break of the gel fibers prepared by the extruder with the L/D ratio of 136 were increased by 148.8%, 117.6%, and 54.2%, respectively. The crystallinity of the gel fibers was increased by 50.6%. The fiber had a dense and smooth surface with oriented fibrils, which indicates the great ability of the ultra‐large L/D ratio for disentanglement of molecular chains.

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“…Although this might seem easily accomplishable, every aspect is affected by various variables and some of them are interlinked (5)(6)(7). For instance, the feed rate directly determines the residence time of the product in the extruder, but the residence time is also influenced by the screw design, where restrictive elements cause a longer residence time (8)(9)(10). Moreover, restrictive elements can induce different shear forces, leading to different energy inputs into the melt and consequently to possible temperature peaks, so called hot spots, within the extrusion process (11,12).…”

Section: Introductionmentioning

confidence: 99%

ASD Formation Prior to Material Characterization as Key Parameter for Accurate Measurements and Subsequent Process Simulation for Hot-Melt Extrusion

2022

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Process simulation facilitates scale-up of hot-melt extrusion (HME) and enhances proper understanding of the underlying critical process parameters. However, performing numeric simulations requires profound knowledge of the employed materials’ properties. For example, an accurate description of the compounds’ melt rheology is paramount for proper simulations. Hence, sample preparation needs to be optimized to yield results as predictive as possible. To identify the optimal preparation method for small amplitude oscillatory shear (SAOS) rheological measurements, binary mixtures of hydroxypropylmethylcellulose acetate succinate or methacrylic acid ethyl acrylate copolymer (Eudragit L100-55) together with the model drugs celecoxib and ketoconazole were prepared. The physical powder mixtures were introduced into the SAOS as a compressed tablet or a disk prepared via vacuum compression molding (VCM). Simulations with the derived parameters were conducted and compared to lab-scale extrusion trials. VCM was identified as the ideal preparation method resulting in the highest similarity between simulated and experimental values, while simulation based on conventional powder-based methods insufficiently described the HME process.

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Determining local residence time distributions in twin-screw extruder elements via smoothed particle hydrodynamics

Cited by 14 publications

References 45 publications

Can Continuous Manufacturing of Topical Semisolids by Hot Melt Extrusion Soon Be a Reality?

Can Continuous Manufacturing of Topical Semisolids by Hot Melt Extrusion Soon Be a Reality?

Gel‐spinning of ultra‐high molecular weight polyethylene by a twin‐screw extruder with an ultra‐large length‐to‐diameter ratio

ASD Formation Prior to Material Characterization as Key Parameter for Accurate Measurements and Subsequent Process Simulation for Hot-Melt Extrusion

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