MDRS provides data that complements information gathered using routinely applied analytical techniques in the development of nasal sprays, including high pressure liquid chromatography (HPLC) and laser diffraction, and has some advantages compared to alternative Raman-based techniques, such as Raman mapping. The table below draws out the key features of MDRS relative to such techniques.
| Comparing MDRS with: | Key features for comparison | Benefits of MDRS |
| HPLC | Unlike HPLC, MDRS is non-destructive, so it can deliver microstructural information – particle size and shape data – as well as chemical identification. | Measuring particle size and shape data for the API by MDRS helps to identify/rationalize differences in likely bioavailability. |
| Raman mapping | In contrast to traditional Raman mapping techniques, MDRS applies an initial sample classification based on particle size and shape parameter to identify formulation components. The application of Raman spectroscopy is then targeted to regions of the sample where simple classification based on size and shape is not possible. This workflow reduces the time of measurement compared to Raman mapping. | Shorter measurement times for MDRS mean greater analytical productivity and reduced costs. |
| Laser diffraction | Unlike laser diffraction, MDRS offers chemical specificity, delivering component-specific data rather than results for the formulation in its entirety. Furthermore, laser diffraction can only infer the presence of agglomerates through pre- and post-dispersion measurements, rather than robustly confirm this via combined size and shape measurements. | Being able to generate information specifically for the API means that MDRS provides crucial insight into factors affecting bioavailability. Specific identification of agglomerates, and their subsequent chemical analysis by MDRS, supports systematic investigation of the stability and dispersion of the dose. |
