Biomedical subjects

M Dathe

Publications and source records attributed to M Dathe.

3 recordsLinked to original sources

PubMed1992

[Potential cardiotonics. 15. Crystal modifications of 3-cyano-2-morpholino-5-(4-pyridinyl)pyridine (AWD 122-14)].

The preparation and X-ray crystallographic characterisation of 10 polymorphic or pseudo-polymorphic forms of the novel cardiotonic AWD 122-14 are described. Thermic transformations of some polymorphic forms into the alpha-form was proved by thermogravimetric analysis and powder diffraction pattern. In dissolution behaviour no significant differences were found between the crystalline modifications but with regard to galenic processing compact alpha-, gamma- and epsilon-forms show advantages.

Cardiotonic Agents↗

PubMed1990

Insulin aggregation in solution.

The process of insulin aggregation in neutral solutions was studied by dynamic light scattering. Solutions of different concentrations were subjected to thermal and mechanical stress (37 degrees, rotation) for a period of 4 weeks. The starting solutions contained exclusively one particle distribution of insulin in the association equilibrium with hexamers as the largest structures. After a lag period of about 8 days the solutions showed continuously increasing scattering intensities but did not evolve perceptible turbidity within the experimental period. A more rapid increase in scattering intensity was observed in diluted than in concentrated solutions. The analysis of scattering data unexpectedly revealed that insulin species did not grow continuously. After the lag period one additional relatively restricted size distribution with particles of a mean radius of about 100 nm was found, the amount of which increased continuously with time. The occurrence of these particles seems to be related to adsorption phenomena of insulin to the solid interface. We assume the 100 nm-class of aggregates to be a transient state in the physical destabilization process of insulin solutions.

Humans↗

PubMed1988

[Crystal modifications of 3-cyan-6-methyl-5-(pyrid-4-yl)-1,2-dihydropyrid-2-one (milrinone)].

The preparation and characterisation of crystalline alpha-, beta- and gamma modifications of 3-cyan-6-methyl-5-(4-pyrid-4-yl)-1,2-dihydropyrid-2-on e are described. The thermic transformation of alpha- and beta-modification into gamma-modification was proved by thermogravimetric analysis (t.g.a.), differential scanning calorimetry (d.s.c.), IR and powder diffraction pattern. In dissolution behaviour no significant differences were found between the modifications.

Chemical Phenomena↗