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Dr.-Ing. Andreas Danzer

Dr.-Ing. Andreas Danzer Foto von Dr.-Ing. Andreas Danzer

Telefon
+49(231)755-3212

Adresse

Fakultät Bio- und Chemieingenieurwesen
Emil-Figge-Str. 70
44227 Dortmund

Raum G2-518

Working Group „Kinetics and Transport Properties”

Research Fields:

The group focuses on theoretical and experimental investigation of kinetics in pharmaceutical formulations, especially in Amorphous Solid Dispersions (ASDs). In ASDs, the active pharmaceutical ingredient (API) is molecularly dispersed in a polymer matrix, which decelerates the recrystallization of the API. While the amorphous state of the API is more desirable due to higher solubility and dissolution rate in water, the crystalline state is the stable one from the thermodynamic point of view. However, the API crystallization at moderate temperatures can be kinetically inhibited due to the high glass transition temperature Tg of the ASD.         
Unfortunately, when exposed to relative humidity, the ASD will absorb water in regard of the vapor-liquid equilibrium (VLE). The absorbed water then acts as a plasticizer, increasing the molecular mobility, dramatically decreasing Tg and therefore accelerating the crystallization kinetics of the API. The research focuses on the thermodynamic modelling of the diffusional mass transport kinetics of water from the surrounding atmosphere into the ASD and its experimental validation. Thereby, the PC-SAFT equation of state is combined with the Maxwell-Stefan formalism, whereas the Fickian diffusion coefficients are determined experimentally via Dynamic Vapor Sorption (DVS) analysis. (Read more: Dominik Böttcher)
When the ASD is orally administered by the patient, the dissolution kinetics of the API and the polymer becomes important. The dissolution often leads to states of API supersaturation in the aqueous medium, followed by recrystallization or demixing, regarding the solid-liquid equilibrium (SLE) and the liquid-liquid equilibrium (LLE), respectively. The polymer influences both, the kinetics (dissolution, recrystallization and demixing) and the equilibrium solubility (SLE and LLE). The investigation focuses on the thermodynamic modelling of the dissolution- and recrystallization/demixing kinetics and their experimental validation. Thereby, the PC-SAFT equation of state is combined with the Statistical Rate Theory, whereas the kinetic rate constants of dissolution, crystallization and demixing are determined experimentally. (Read more: Adrian Krummnow)        
Mass transfer kinetics as well as crystallization kinetics are strongly influenced by the viscosity of ASD´s, which exhibit viscoelastic properties due to the presence of the polymer. The viscoelastic properties, like storage modulus, loss modulus or zero-shear viscosity, are influenced by the amount of water absorbed by the ASD. This investigation focuses on the modelling of the viscosity of ASD´s as a function of temperature, API/Polymer content ratio and relative humidity. Considering the viscosity as the main factor affecting molecular mobility, the influence on the crystallization velocity is determined within a new theoretical framework. Additionally, the change on the viscoelastic properties at the glass transition is investigated. (Read more: Birte Grönniger)

danzer_europa

Supervision TU Dortmund University      
Early Stage Researcher 3 (Amabille Kloc, Brasil)         
Early Stage Researcher 4 (Fatima Anjum, Pakistan)

Supercritical CO2 (scCO2) anti-solvent assisted spray drying may produce ASD´s in which the amorphous API exhibits particle diameters in the nanometer range embedded within the polymeric matrix. For process design reasons, the solubility of the API in scCO2 and scCO2 + organic solvent mixtures becomes relevant. This investigation focuses on the experimental determination of the API-solubility in scCO2 via a high-pressure apparatus and the theoretical modelling of the corresponding phase diagrams using the thermodynamic model PC-SAFT. 
After production and isolation of the nano-particles from scCO2-assisted spray drying into injectable nano-suspensions, the solubility enhancement of particles in the nanometer range will be investigated by incorporating interface effects. (Read more: Amabille Kloc)

This investigations focuses on the development of a membrane-based process to produce long acting suspensions and  remove any unwanted solvents from the final injectable long acting nano-suspensions which will be administered to the patient.  Thereby, crystal formation and solvent/anti-solvent switch is intended to be integrated in one apparatus. The optimal membrane will be identified and membrane performance will be investigated via determination of permeation rates and selectivites under different process conditions. Based on the membrane characterization, the process will be designed with respect to flux, feed rates and flow directions. Additionally, the influence of polymeric excipients and nano-crystals on the membrane performance will be investigated. (Read more: Fatima Anjum)

Curriculum Vitae

Personal Information:   
Date of Birth:                January 13th, 1988       
Place of Birth:               Hamburg

Career:

1994-2007:                    School time                 
2007-2009:                    Military Service
2009-2012:                    Studies of Chemical Engineering, TU Berlin (Germany), Degree: B.Sc. 
                                         Thesis: The calculation of phase equilibria and interfacial properties of sulfurous pure components.       
                                         Final grade: 1.0
2012-2014                     Studies of Chemical Engineering, TU Berlin (Germany), Degree: M.Sc. 
                                         Thesis: Calculation of gas solubilities in semi-crystalline polymers.        
                                         Final grade: 1.0
2015-2019:                    PhD-student, Karlsruhe Institute for Technology (KIT) Germany, Degree: Dr.-Ing.          
                                         Thesis: The Modelling of Liquid-Liquid Equilibria and Interfacial Properties in Reactive Mixtures.
                                         Final grade: summa cum laude 
2019-now:                     Group Leader “Kinetics and Transport Properties”        
                                         Laboratory of Thermodynamics, Prof. Sadowski, TU Dortmund 

Teaching

Pflichtveranstaltungen

PEP - Projektarbeit Einführung in die verfahrenstechnische Produktion

Transportprozesse

Vertiefungsveranstaltungen

Polymerthermodynamik

  

Publications and conference contributions:

Publications:

C. Bühl, A. Danzer, S. Enders, Prediction of surface properties of binary, sulfur containing mixtures. Fluid Phase Equilibria 416 (2016) 94-103.

T. Goetsch, A. Danzer, P. Zimmermann, A. Koehler, K. Kissing, S. Enders, T. Zeiner, Liquid-Liquid Equilibrium and Interfacial Tension of Hexane Isomers – Methanol Systems. Ind. Eng. Chem. Res. 56 (34) (2017) 9743-9752.

A. Danzer, S. Enders, Comparison of two modelling approaches for the interfacial tension of binary aqueous mixtures. J. Mol. Liq. 266 (2018) 309-320.

A. Danzer, S. Enders, Theoretical and experimental investigation of the interfacial properties in the ternary mixture Water + 1-Hexanol + Acetic Acid and Water + Hexylacetate + Acetic Acid using Density Gradient Theory and Spinning-Drop Tensiometry. J. Mol. Liq. 283 (2019) 482-490.

A. Danzer, S. Enders, Liquid-Liquid equilibrium and interfacial properties of the system Water + Hexylacetate + 1-Hexanol. Chemie Ingenieur Technik 91 (11) (2019) 1597-1605.

A. Danzer, S. Enders, Prediction of phase equilibrium and interfacial properties in the quaternary system Water + 1-Hexanol + Hexylacetate + Acetic Acid. Fluid Phase Equilibria 493 (2019) 50-57.

N. Haarmann, A. Reinhardt, A. Danzer, G. Sadowski, S. Enders, Modelling of Interfacial Tensions of Long-Chain Molecules and Related Mixtures Using PC-SAFT and the Density Gradient Theory. J. Chem. Eng. Data 65(3) (2020) 1005-1018.

A. Danzer, S. Enders, The Modelling of the Time-Dependency of Interfacial Properties due to Chemical Equilibrium Reactions in Demixed Fluid Systems. Fluid Phase Equilibria 499 (2019) 112240.

A. Danzer, S. Enders, Thermodynamic modelling of time-dependent interfacial properties in reactive liquid-liquid systems close to the critical point. J. Chem. Eng. Data 65 (2020) 312-318.

M. Fischlschweiger, A. Danzer, S. Enders, Predicting gas solubility in semi-crystalline polymer solvent systems by consistent coupling of Sanchez-Lacombe EOS with a continuum mechanics approach. Fluid Phase Equilibria 506 (2020) 112379.           

 

Conference contributions:

Oral:

2016: A. Danzer, S. Enders, Grenzflächeneigenschaften im ternären System Wasser + Hexanol + Essigsäure und Wasser + Hexylacetat + Essigsäure. Dechema Process Net Extraktion und Grenzflächenbestimmte Systeme Weimar.

2016: A. Danzer, S. Enders, The Solubility of Gases in Semicrystalline and Amorphous Polymers at High Pressures. European Meeting on Supercritical Fluids Essen.

2016: A. Danzer, S. Enders, Grenzflächeneigenschaften im ternären System Wasser + Hexanol + Essigsäure und Wasser + Hexylacetat + Essigsäure. Process Net Jahrestagung und 32. Dechema Jahrestagung der Biotechnologie Aachen.

2016: M. Fischlschweiger, A. Danzer, S. Enders, K. Langenbach, Einfluss der Semikristallinität auf die Gaslöslichkeit von Polymeren. Thermodynamik Kolloquium Kaiserslautern.

2017: A. Danzer, S. Enders, Die Berechnung der Grenzflächeneigenschaften von quaternären Flüssig-Flüssig Gleichgewichten mittels Dichtegradiententheorie. Jahrestreffen der Process Net Fachgruppen Mechanische Flüssigkeitsabscheidung, Kristallisation, Phytoextrakte, Adsorption, Extraktion, Fluidverfahrenstechnik und Membrantechnik Köln.

2017: A. Danzer, S. Enders, Modelling of Liquid-Liquid and Vapor-Liquid Interfacial Properties of Binary Water-Alcohol Mixtures using PC-SAFT EOS and Density Gradient Theory. SAFT Conference Heidelberg.

2017: M. Fischlschweiger, A. Danzer, S. Enders, Solubility of Gases in Glassy and Semicrystalline Polymers. 29th European Symposium on Applied Thermodynamics ESAT Bucharest, Romania.

2017: A. Danzer, S. Enders, Flüssig-Flüssig Grenzflächeneigenschaften von quaternären Mischungen. Thermodynamik Kolloqium Dresden.

2017: A. Danzer, S. Enders, Modelling of Time-Dependent Interfacial Properties due to Chemical Equilibrium Reactions in Demixed Fluid Systems. AIChe Annual Meeting Minneapolis, USA.

2018: A. Danzer, S. Enders, Grenzflächeneigenschaften chemisch reagierender Systeme. Dechema Process Net Extraktion und Rohstoffe Frankfurt am Main.

2018: A. Danzer, S. Enders, The Modelling of Interfacial Properties in Liquid-Liquid Systems superpositioned by Chemical Equilibrium. 30th European Symposium on Applied Thermodynamics ESAT Prague, Czech Republic.

2018: A. Danzer, S. Enders, Die Modellierung der zeitabhängigen Grenzflächeneigenschaften in Reaktivsystemen mit Flüssig-Flüssig Entmischung. Thermodynamik Kolloquium Kassel.

2019: A. Danzer, S. Enders, Die zeitabhängige Beschreibung des inhomogenen Zustandsgebietes in Flüssig-Flüssig Systemen mit chemischer Gleichgewichtsreaktion. Gemeinsame Jahrestagung Fachgruppen Extraktion und Phytoextraktion Muttenz, Switzerland.   

 

Posters: 

2013: A. Danzer, S. Enders, Phasengleichgewichte und Grenzflächenspannungen von schwefelhaltigen Stoffen. Thermodynamik Kolloquium Hamburg.

2014: C. Bühl, A. Danzer, G. O. Nino-Amezquita, S. Enders, Vorausberechnung der Oberflächeneigenschaften binärer und ternärer schwefelhaltiger Mischungen. Thermodynamik Kolloquium Stuttgart.

2015: C. Bühl, A. Danzer, S. Enders, Prediction of interfacial properties of binary, sulfur containing mixtures. SAFT Conference Houston, USA.

2015: A. Danzer, S. Enders, Die Berechnung der Gaslöslichkeit in semi-kristalline Polymere bei hohen Drücken. Thermodynamik Kolloquium Bochum.

2016: A. Danzer, S. Enders, Einfluss der Kompressibilität von Flüssig-Flüssig Grenzflächen. Thermodynamik Kolloquium Kaiserslautern.

2019: A. Danzer, S. Enders, Interfacial Properties for Reacting Liquid Mixtures, International Conference on Properties and Phase Equilibria for Product and Process Design (PPEPPD) Vancouver, Kanada.