Application of spectroscopic imaging for characterizing API: polymer systems as a screening tool for the development of potential amorphous solid dispersions
Abstract
Raman and infrared mapping techniques were employed in this study for the characterization of drug-polymer films cast on glass plates and for finding good amorphous solid dispersion formulation candidates containing dabigatran etexilate. To verify the results obtained from this approach, two common solvent evaporation-based solid dispersion processes were used for the preparation of samples and those samples were analyzed conventionally, with solid state NMR and modulated DSC.
Solid solutions containing amorphous dabigatran etexilate with a low probability of crystallization were identified, using mapping techniques in samples with 75% of drug dissolved in Kollidon K30 and in 50% of drug dissolved in Kollidon VA64 and Soluplus. On the contrary, all samples prepared by spray drying were characterized as solid solutions which may lead to crystallization of the API in certain concentrations.
This was shown to be valid in materials containing Kollidon VA64 and Soluplus, respectively, and more than 50% of the API when prepared by solvent evaporation. The experimental data obtained in this study proved that spectral mapping-based screening methods are able to identify potential candidates for amorphous solid dispersion formulations which are less prone to crystallization.