Imanidis, Georgios
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Georgios
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Imanidis, Georgios
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Publikation Formulation and dermal delivery of a new active pharmaceutical ingredient in an in vitro wound model for the treatment of chronic ulcers(Elsevier, 09/2024) Thormann, Ursula; Marti, Selina; Lensmith, Elizabeth; Lanz, Michael; Herzig, Susanne; Naef, Reto; Imanidis, GeorgiosThe aim of this study was to investigate dermal delivery of the new active pharmaceutical ingredient (API) TOP-N53 into diabetic foot ulcer using an in vitro wound model consisting of pig ear dermis and elucidate the impact of drug formulation and wound dressing taking into consideration clinical relevance in the home care setting and possible bacterial infection. Different formulation approaches for the poorly water-soluble API including colloidal solubilization, drug micro-suspension and cosolvent addition were investigated; moreover, the effect of (micro-)viscosity of hydrogels used as primary wound dressing on delivery was assessed. Addition of Transcutol® P as cosolvent to water improved solubility and was significantly superior to all other approaches providing a sustained three-day delivery that reached therapeutic drug levels in the tissue. Solubilization in micelles or liposomes, on the contrary, did not boost delivery while micro-suspensions exhibited sedimentation on the tissue surface. Microbial contamination was responsible for considerable metabolism of the drug leading to tissue penetration of metabolites which may be relevant for therapeutic effect. Use of hydrogels under semi-occlusive conditions significantly reduced drug delivery in a viscosity-dependent fashion. Micro-rheologic analysis of the gels using diffusive wave spectroscopy confirmed the restricted diffusion of drug particles in the gel lattice which correlated with the obtained tissue delivery results. Hence, the advantages of hydrogel dressings from the applicatory characteristic point of view must be weighed against their adverse effect on drug delivery. The employed in vitro wound model was useful for the assessment of drug delivery and the development of a drug therapy concept for chronic diabetic foot ulcer. Mechanistic insights about formulation and dressing performance may be applied to drug delivery in other skin conditions such as digital ulcer.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation 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, Georgios01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Tablet formulation with dual control concept for efficient colonic drug delivery(Elsevier, 25.01.2023) Doggwiler, Viviane; Lanz, Michael; Paredes, Valeria; Lipps, Georg; Imanidis, Georgios01A - Beitrag in wissenschaftlicher ZeitschriftPublikation 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, ChristosA 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 ZeitschriftPublikation 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, Joerg3D-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 ZeitschriftPublikation Biphasic drug release testing coupled with diffusing wave spectroscopy for mechanistic understanding of solid dispersion performance(Elsevier, 2019) Jankovic, Sandra; Imanidis, Georgios; Kuentz, Martin01A - Beitrag in wissenschaftlicher ZeitschriftPublikation On production of fast-dissolving low-density powders for deep lung deposition by spray drying of a nanosuspension(31.08.2016) Simkova, Katerina; Joost, Berndt; Imanidis, Georgios06 - PräsentationPublikation On production of fast‑dissolving low-density powders for deep lung deposition by spray drying of a nanosuspension(2016) Simkova, Katerina; Joost, Berndt; Imanidis, Georgios06 - Präsentation