The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
Roland Bodmeier - One of the best experts on this subject based on the ideXlab platform.
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floating Matrix tablets based on low density foam powder effects of formulation and processing parameters on drug release
European Journal of Pharmaceutical Sciences, 2003Co-Authors: A Streubel, Juergen Siepmann, Roland BodmeierAbstract:Abstract The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i) polypropylene foam powder, (Ii) Matrix-forming polymer(s), (Iii) drug, and (iv) filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 °C. Different types of Matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of Matrix former. The release rate could effectively be modified by varying the “Matrix-forming polymer/foam powder” ratio, the initial drug loading, the tablet geometry (radius and height), the type of Matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.
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floating Matrix tablets based on low density foam powder effects of formulation and processing parameters on drug release
European Journal of Pharmaceutical Sciences, 2003Co-Authors: A Streubel, Juergen Siepmann, Roland BodmeierAbstract:The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i). polypropylene foam powder, (Ii). Matrix-forming polymer(s), (Iii). drug, and (iv). filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 degrees C. Different types of Matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of Matrix former. The release rate could effectively be modified by varying the "Matrix-forming polymer/foam powder" ratio, the initial drug loading, the tablet geometry (radius and height), the type of Matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.
Julian R. Jones - One of the best experts on this subject based on the ideXlab platform.
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scaffold channel size influences stem cell differentiation pathway in 3 d printed silica hybrid scaffolds for cartilage regeneration
Biomaterials Science, 2020Co-Authors: Siwei Li, Francesca Tallia, Ali Mohammed, Molly M Stevens, Julian R. JonesAbstract:We report that 3-D printed scaffold channel size can direct bone marrow derived stem cell differentiation. Treatment of articular cartilage trauma injuries, such as microfracture surgery, have limited success because durability is limited as fibrocartilage forms. A scaffold-assisted approach, combining microfracture with biomaterials has potential if the scaffold can promote articular cartilage production and share load with cartilage. Here, we investigated human bone marrow derived stromal cell (hBMSC) differentiation in vitro in 3-D printed silica/poly(tetrahydrofuran)/poly(e-caprolactone) hybrid scaffolds with specific channel sizes. Channel widths of ∼230 μm (210 ± 22 μm mean strut size, 42.4 ± 3.9% porosity) provoked hBMSC differentiation down a chondrogenic path, with collagen Type Ii Matrix prevalent, indicative of hyaline cartilage. When pores were larger (∼500 μm, 229 ± 29 μm mean strut size, 63.8 ± 1.6% porosity) collagen Type I was dominant, indicating fibrocartilage. There was less Matrix and voids in smaller channels (∼100 μm, 218 ± 28 μm mean strut size, 31.2 ± 2.9% porosity). Our findings suggest that a 200–250 μm pore channel width, in combination with the surface chemistry and stiffness of the scaffold, is optimal for cell–cell interactions to promote chondrogenic differentiation and enable the chondrocytes to maintain their phenotype.
A Streubel - One of the best experts on this subject based on the ideXlab platform.
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floating Matrix tablets based on low density foam powder effects of formulation and processing parameters on drug release
European Journal of Pharmaceutical Sciences, 2003Co-Authors: A Streubel, Juergen Siepmann, Roland BodmeierAbstract:Abstract The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i) polypropylene foam powder, (Ii) Matrix-forming polymer(s), (Iii) drug, and (iv) filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 °C. Different types of Matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of Matrix former. The release rate could effectively be modified by varying the “Matrix-forming polymer/foam powder” ratio, the initial drug loading, the tablet geometry (radius and height), the type of Matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.
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floating Matrix tablets based on low density foam powder effects of formulation and processing parameters on drug release
European Journal of Pharmaceutical Sciences, 2003Co-Authors: A Streubel, Juergen Siepmann, Roland BodmeierAbstract:The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i). polypropylene foam powder, (Ii). Matrix-forming polymer(s), (Iii). drug, and (iv). filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 degrees C. Different types of Matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of Matrix former. The release rate could effectively be modified by varying the "Matrix-forming polymer/foam powder" ratio, the initial drug loading, the tablet geometry (radius and height), the type of Matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.
Siwei Li - One of the best experts on this subject based on the ideXlab platform.
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scaffold channel size influences stem cell differentiation pathway in 3 d printed silica hybrid scaffolds for cartilage regeneration
Biomaterials Science, 2020Co-Authors: Siwei Li, Francesca Tallia, Ali Mohammed, Molly M Stevens, Julian R. JonesAbstract:We report that 3-D printed scaffold channel size can direct bone marrow derived stem cell differentiation. Treatment of articular cartilage trauma injuries, such as microfracture surgery, have limited success because durability is limited as fibrocartilage forms. A scaffold-assisted approach, combining microfracture with biomaterials has potential if the scaffold can promote articular cartilage production and share load with cartilage. Here, we investigated human bone marrow derived stromal cell (hBMSC) differentiation in vitro in 3-D printed silica/poly(tetrahydrofuran)/poly(e-caprolactone) hybrid scaffolds with specific channel sizes. Channel widths of ∼230 μm (210 ± 22 μm mean strut size, 42.4 ± 3.9% porosity) provoked hBMSC differentiation down a chondrogenic path, with collagen Type Ii Matrix prevalent, indicative of hyaline cartilage. When pores were larger (∼500 μm, 229 ± 29 μm mean strut size, 63.8 ± 1.6% porosity) collagen Type I was dominant, indicating fibrocartilage. There was less Matrix and voids in smaller channels (∼100 μm, 218 ± 28 μm mean strut size, 31.2 ± 2.9% porosity). Our findings suggest that a 200–250 μm pore channel width, in combination with the surface chemistry and stiffness of the scaffold, is optimal for cell–cell interactions to promote chondrogenic differentiation and enable the chondrocytes to maintain their phenotype.
Juergen Siepmann - One of the best experts on this subject based on the ideXlab platform.
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floating Matrix tablets based on low density foam powder effects of formulation and processing parameters on drug release
European Journal of Pharmaceutical Sciences, 2003Co-Authors: A Streubel, Juergen Siepmann, Roland BodmeierAbstract:Abstract The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i) polypropylene foam powder, (Ii) Matrix-forming polymer(s), (Iii) drug, and (iv) filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 °C. Different types of Matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of Matrix former. The release rate could effectively be modified by varying the “Matrix-forming polymer/foam powder” ratio, the initial drug loading, the tablet geometry (radius and height), the type of Matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.
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floating Matrix tablets based on low density foam powder effects of formulation and processing parameters on drug release
European Journal of Pharmaceutical Sciences, 2003Co-Authors: A Streubel, Juergen Siepmann, Roland BodmeierAbstract:The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i). polypropylene foam powder, (Ii). Matrix-forming polymer(s), (Iii). drug, and (iv). filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 degrees C. Different types of Matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of Matrix former. The release rate could effectively be modified by varying the "Matrix-forming polymer/foam powder" ratio, the initial drug loading, the tablet geometry (radius and height), the type of Matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.
