Imanidis, Georgios

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Imanidis
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Georgios
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Imanidis, Georgios

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Now showing 1 - 7 of 7
  • Publication
    Efficient colonic drug delivery in domestic pigs employing a tablet formulation with dual control concept
    (Elsevier, 06/2023) Doggwiler, Viviane; Puorger, Chasper; Paredes, Valeria; Lanz, Michael; Nuss, Katja M.; Lipps, Georg; Imanidis, Georgios [in: Journal of Controlled Release]
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publication
    Tablet formulation with dual control concept for efficient colonic drug delivery
    (Elsevier, 25.01.2023) Doggwiler, Viviane; Lanz, Michael; Paredes, Valeria; Lipps, Georg; Imanidis, Georgios [in: International Journal of Pharmaceutics]
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publication
    On the usefulness of four in vitro methods in assessing the intraluminal performance of poorly soluble, ionisable compounds in the fasted state
    (Elsevier, 2022) O'Dwyer, Patrick J.; Box, Karl J.; Imanidis, Georgios; Vertzoni, Maria; Reppas, Christos [in: European Journal of Pharmaceutical Sciences]
    A small-scale two-stage biphasic system, a small-scale two-stage dissolution-permeation system, the Erweka mini-paddle apparatus, and the BioGIT system were evaluated for their usefulness in assessing the intraluminal performance of two low solubility drugs in the fasted state, one with weakly acidic properties (tested in a salt form, diclofenac potassium) and one with weakly alkaline properties [ritonavir, tested as an amorphous solid dispersion (ASD) formulation]. In all in vitro methods, an immediate-release tablet and a powder formulation of diclofenac potassium were both rapidly dissolved in Level II biorelevant media simulating the conditions in the upper small intestine. Physiologically based biopharmaceutics (PBB) modelling for the tablet formulation resulted in a successful simulation of the average plasma profile in adults, whereas for the powder formulation modelling indicated that gastric emptying and transport through the intestinal epithelium limit the absorption rates. Detailed information on the behaviour of the ritonavir ASD formulation under both simulated gastric and upper small intestinal conditions were crucial for understanding the luminal performance. PBB modelling showed that the dissolution and precipitation parameters, estimated from the Erweka mini-paddle apparatus data and the small-scale two-stage biphasic system data, respectively, were necessary to adequately simulate the average plasma profile after administration of the ritonavir ASD formulation. Simulation of the gastrointestinal transfer process from the stomach to the small intestine was necessary to evaluate the effects of hypochlorhydric conditions on the luminal performance of the ritonavir ASD formulation.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publication
    Development of immediate release 3D-printed dosage forms for a poorly water-soluble drug by fused deposition modeling. Study of morphology, solid state and dissolution
    (Elsevier, 15.04.2021) Imanidis, Georgios; Fanous, Marina; Bitar, Malak; Gold, Sarah; Sobczuk, Adam; Hirsch, Adam; Ogorka, Joerg [in: International Journal of Pharmaceutics]
    3D-printing technologies such as Fused Deposition Modeling (FDM) bring a unique opportunity for personalized and flexible near-patient production of pharmaceuticals, potentially improving safety and efficacy for some medications. However, FDM-printed tablets often exhibit tendency for slow dissolution due to polymer erosion-based dissolution mechanisms. Development of immediate release (IR) 3D-printed dosage with poorly water-soluble compounds is even more challenging but necessary to ensure wide applicability of the technology within pharmaceutical development portfolios. In this work, process and morphology were considered to achieve IR of BCS class IV compound lumefantrine as model active pharmaceutical ingredient (API) using basic butylated methacrylate copolymer (Eudragit EPO) as matrix former, as well as hydrophilic plasticizer xylitol and pore former maltodextrin. Grid-designed tablets with size acceptable for children from 6 years old and varying programmed infill density were successfully 3D-printed with 5% lumefantrine while higher drug load led to increased brittleness which is incompatible with 3D-printing. Lumefantrine assay was 92 to 97.5% of theoretical content depending on drug load and process parameters. 3D-printed tablets with 65% infill density met rapid release criteria, while 80% and 100% showed slower dissolution. Structural characteristics of 3D-printed tablets with non-continuous surface such as accessible porosity and specific surface area by weight and by volume were quantified by a non-destructive automated µCT-based methodology and were found to correlate with dissolution rate. Increase in accessible porosity, total surface area, specific surface area and decrease in relative density were statistically significant critical factors for modification of lumefantrine dissolution rate. Crystallinity in manufactured tablets and filaments was explored by highly sensitive Raman mapping technique. Lumefantrine was present in the fully amorphous state in the tablets exhibiting adequate stability for on-site manufacturing. The study demonstrates feasibility of immediate release FDM-3D-printed tablets with BCS class IV API and illustrates the correlation of FDM design parameters with morphological and dissolution characteristics of manufactured tablets.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publication
    Biphasic drug release testing coupled with diffusing wave spectroscopy for mechanistic understanding of solid dispersion performance
    (Elsevier, 2019) Jankovic, Sandra; Imanidis, Georgios; Kuentz, Martin [in: European Journal of Pharmaceutical Sciences]
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publication
    06 - Präsentation
  • Publication
    06 - Präsentation