Karl Gerhard Wagner

Pós-doutorado

Idiomas

Áreas de atuação

Produções bibliográficas

• BOCHMANN, ESTHER ; GRYCZKE, ANDREAS ; WAGNER, KARL . Validation of Model-Based Melt Viscosity in Hot-Melt Extrusion Numerical Simulation. PHARMACEUTICS , v. 10, p. 132, 2018.

• HAGELSTEIN, VERONIKA ; GERHART, MARKUS ; WAGNER, KARL G. . Tricalcium citrate - a new brittle tableting excipient for direct compression and dry granulation with enormous hardness yield. DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY , v. 44, p. 1631-1641, 2018.

• EVANS, RACHEL C. ; KYEREMATENG, SAMUEL O. ; ASMUS, LUTZ ; DEGENHARDT, MATTHIAS ; ROSENBERG, JOERG ; WAGNER, KARL G. . Development and Performance of a Highly Sensitive Model Formulation Based on Torasemide to Enhance Hot-Melt Extrusion Process Understanding and Process Development. AAPS PHARMSCITECH , v. 19, p. 1592-1605, 2018.

• BOCHMANN, ESTHER S. ; STEFFENS, KRISTINA E. ; GRYCZKE, ANDREAS ; WAGNER, KARL G. . Numerical simulation of hot-melt extrusion processes for amorphous solid dispersions using model-based melt viscosity. EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS , v. 124, p. 34-42, 2018.

• BOCHMANN, ESTHER S. ; ÜSTÜNER, ELGIN E. ; GRYCZKE, ANDREAS ; WAGNER, KARL G. . Predicting melt rheology for hot-melt extrusion by means of a simple T-measurement. EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS , v. 119, p. 47-55, 2017.

• BOCHMANN, ESTHER S. ; NEUMANN, DIRK ; GRYCZKE, ANDREAS ; WAGNER, KARL G. . Micro-scale prediction method for API-solubility in polymeric matrices and process model for forming amorphous solid dispersion by hot-melt extrusion. EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS , v. 107, p. 40-48, 2016.

• ZECEVIC, DAMIR E. ; WAGNER, KARL G. . Rational Development of Solid Dispersions via Hot-Melt Extrusion Using Screening, Material Characterization, and Numeric Simulation Tools. JOURNAL OF PHARMACEUTICAL SCIENCES , v. 102, p. 2297-2310, 2013.

Projetos de pesquisa

• 2001 - 2005

  Pulsatile-Drug-Release, Descrição: The objective of this study was to investigate the anion-controlled drug release mechanism through the cationic coating polymer Eudragit RS 30 D as a function of the anion attraction toward the polymer's quarternary ammonium group (QAG), anion valence, and film composition. The mechanism was investigated by dissolution testing, determination of chloride ion exchange using ion chromatography, plasticizer leaching by means of differential scanning calorimetry, and water uptake by Karl Fischer titration. All experiments were performed on coated theophylline micro tablets or isolated films of various compositions using 0.01 M sodium nitrate, sodium sulfate, disodium succinate, sodium acetate, and succinic acid as dissolution media. The mechanism of drug release involved an immediate penetration of dissolution medium into the polymer followed by an instant exchange of chloride against the medium's anion species at completely different rates compared with the drug release. Dependent on the attraction of the anion toward the QAGs, a water flux was induced by back and forth exchanging anions. Strong attraction (nitrate, sulfate) resulted in a low water flux while weak attraction resulted in a high flux (acetate, succinic acid). The water flux increased at increasing number of QAGs. Plasticizer acted as a diluent in respect of the number of QAGs, thus higher plasticizer concentrations led to lower drug release.. , Situação: Concluído; Natureza: Pesquisa. , Alunos envolvidos: Doutorado: (1) . , Integrantes: Karl Gerhard Wagner - Coordenador / Karl G Wagner - Integrante.