Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Martin Feth is active.

Publication


Featured researches published by Martin Feth.


European Journal of Pharmaceutical Sciences | 2011

Challenges in the development of hydrate phases as active pharmaceutical ingredients--an example.

Martin Feth; Norbert Nagel; Bruno Baumgartner; Martin Bröckelmann; David Rigal; Bernhard Otto; Michael Spitzenberg; Markus Schulz; Bernd Becker; Franceska Fischer; Christine Petzoldt

The challenges during pilot plant scale-up of the SAR474832 API (active pharmaceutical ingredient) production in view of crystallization, isolation, drying and micronization are reported. A variety of different solid-state analytical and spectroscopic techniques (also coupled methods) were applied in order to understand the complex phase transition behaviour of the crystallographic phase (form 1) chosen for development: a partially non-stoichiometric channel-hydrate (x (1+1.25) H(2)O) crystallizing from pure water in the crystal habit of fine needles, which tend to agglomerate upon isolation and drying. Processes have been developed for drying, sieving and micronization by jetmilling to avoid non-desired phase transitions (overdrying effects) into other hydrate forms. Special methods have been established to minimize, monitor and control the formation of amorphous content during the particle size reduction steps. By optimizing all production parameters it was possible to produce API batches in 10 kg scale with physical quality suitable for oral formulations (e.g. particle size d 90 value<20 μm, water content and crystallographic phase corresponding to desired form 1 of SAR474832).


Journal of Pharmaceutical Sciences | 2011

New Technology for the Investigation of Water Vapor Sorption–Induced Crystallographic Form Transformations of Chemical Compounds: A Water Vapor Sorption Gravimetry–Dispersive Raman Spectroscopy Coupling

Martin Feth; Jörg Jurascheck; Michael Spitzenberg; Jürgen Dillenz; Günter Bertele; Herbert Stark

In this study, a new dynamic water vapor sorption gravimetry (DWVSG)-Raman spectroscopy coupled system is presented and described for the investigation of water (de)sorption-induced solid-phase transition of active pharmaceutical ingredients (APIs). The innovative characteristic of the system is the possibility to measure up to 23 samples gravimetrically and spectroscopically in one sorption/desorption experiment. The used dispersive RXN1 Raman system with a 6-mm laser spot P(h) AT probe head is ideal for this kind of coupled technology, as the energy density at the point of measurement of the sample is low, which grants that gravimetrical data and the state of the sample (phase transformations or even degradation) are not influenced by the laser beam. The capabilities of the system were tested by the investigation of a crystalline, nonstoichiometric hydrate form (form 1) and the corresponding X-ray amorphous form of an API (SAR474832). For the crystalline hydrate form, it was possible to correlate the weight loss at low humidities to a crystallographic phase transition (form 2). Furthermore, it was possible to show that the phase transition is reversible upon water uptake (sorption cycle); however, a further intermediate crystal form (form 3) is involved in the rehydration process. By multivariate curve resolution analysis of the Raman spectra, the form distribution diagrams of the desorption/sorption cycle could be constructed. For the amorphous material, the recrystallization process was monitored by the changes in the Raman spectra. The recrystallization point was detected at high humidities (>90% relative humidity), the crystal phase formed was identified (form 1), and the time needed for the conversion into the crystalline state was determined. The form transformation processes were visualized by contour plots (time/humidity vs. wavenumber vs. Raman intensity). In summary, it was concluded that the presented water sorption gravimetry-Raman spectroscopy coupling is a powerful tool to study solid-state transitions of pharmaceutical compounds or galenic formulations. The information obtained can, for example, be used to optimize drying, conditioning, or rerystallization processes of chemical products or to determine their optimal storage conditions. This is especially interesting for physically and chemically labile hydrate phases.


European Journal of Pharmaceutics and Biopharmaceutics | 2014

An example of how to handle amorphous fractions in API during early pharmaceutical development: SAR114137 – A successful approach

Christine Petzoldt; Oliver Bley; Stephen J. Byard; Doris Andert; Bruno Baumgartner; Norbert Nagel; Christoph Tappertzhofen; Martin Feth

The so-called pharmaceutical solid chain, which encompasses drug substance micronisation to the final tablet production, at pilot plant scale is presented as a case study for a novel, highly potent, pharmaceutical compound: SAR114137. Various solid-state analytical methods, such as solid-state Nuclear Magnetic Resonance (ssNMR), Differential Scanning Calorimetry (DSC), Dynamic Water Vapour Sorption Gravimetry (DWVSG), hot-stage Raman spectroscopy and X-ray Powder Diffraction (XRPD) were applied and evaluated to characterise and quantify amorphous content during the course of the physical treatment of crystalline active pharmaceutical ingredient (API). DSC was successfully used to monitor the changes in amorphous content during micronisation of the API, as well as during stability studies. (19)F solid-state NMR was found to be the method of choice for the detection and quantification of low levels of amorphous API, even in the final drug product (DP), since compaction during tablet manufacture was identified as a further source for the formation of amorphous API. The application of different jet milling techniques was a critical factor with respect to amorphous content formation. In the present case, the change from spiral jet milling to loop jet milling led to a decrease in amorphous API content from 20-30 w/w% to nearly 0 w/w% respectively. The use of loop jet milling also improved the processability of the API. Stability investigations on both the milled API and the DP showed a marked tendency for recrystallisation of the amorphous API content on exposure to elevated levels of relative humidity. No significant impact of amorphous API on either the chemical stability or the dissolution rate of the API in drug formulation was observed. Therefore, the presence of amorphous content in the oral formulation was of no consequence for the clinical trial phases I and II.


Journal of Medicinal Chemistry | 2007

Synthesis and evaluation of 7H-8,9-dihydropyrano[2,3-c]imidazo[1,2-a]pyridines as potassium-competitive acid blockers.

Andreas Palmer; Burkhard Grobbel; Cornelia Jecke; Christof Brehm; Peter Jan Zimmermann; Wilm Buhr; Martin Feth; Wolfgang-Alexander Simon; Wolfgang Kromer


Bioorganic & Medicinal Chemistry | 2008

5-Substituted 1H-pyrrolo[3,2-b]pyridines as inhibitors of gastric acid secretion☆

Andreas Palmer; Gabriela Münch; Christof Brehm; Peter Jan Zimmermann; Wilm Buhr; Martin Feth; Wolfgang Alexander Simon


Bioorganic & Medicinal Chemistry | 2007

Preparation of tetrahydroimidazo[2,1-a]isoquinolines and their use as inhibitors of gastric acid secretion

Andreas Palmer; Burkhard Grobbel; Christof Brehm; Peter Jan Zimmermann; Wilm Buhr; Martin Feth; Hans Christof Holst; Wolfgang Alexander Simon


Bioorganic & Medicinal Chemistry Letters | 2007

Novel indanyl-substituted imidazo[1,2-a]pyridines as potent reversible inhibitors of the gastric H+/K+-ATPase ☆

Peter Jan Zimmermann; Wilm Buhr; Christof Brehm; Andreas Palmer; Martin Feth; Joerg Senn-Bilfinger; Wolfgang-Alexander Simon


Journal of Pharmaceutical Sciences | 2008

Physicochemical, Crystallographic, Thermal, and Spectroscopic Behavior of Crystalline and X-ray Amorphous Ciclesonide

Martin Feth; Jürgen Volz; Ursula Hess; Ernst Sturm; Rolf-Peter Hummel


Bioorganic & Medicinal Chemistry | 2009

Spiro(imidazo[1,2-a]pyrano[2,3-c]pyridine-9-indenes) as inhibitors of gastric acid secretion

Andreas Palmer; Sandra Chrismann; Gabriela Münch; Christof Brehm; Peter Jan Zimmermann; Wilm Buhr; Jörg Senn-Bilfinger; Martin Feth; Wolfgang Alexander Simon


Archive | 2006

Novel Sulphonylpyrroles as Inhibitors of Hdac S Novel Sulphonylpyrroles

Thomas Maier; Thomas Beckers; Rolf-Peter Hummel; Martin Feth; Matthias Müller; Thomas Bär; Jürgen Volz

Collaboration


Dive into the Martin Feth's collaboration.

Researchain Logo
Decentralizing Knowledge