Sirius SDIThe Sirius SDI (Surface Dissolution Imager) provides the ability to look directly at the solid-liquid interface as a sample is dissolving. Real-time ultra-violet (UV) movies of the dissolution process can be gained microns from the drug surface. Typical experiments last 30 minutes and require 2mg of sample and 20mL of dissolution medium. The Sirius SDI includes ActiPix™ UV area imaging technology, a flow cell and sample holder, an integrated syringe pump and software.

Data can be recorded and reviewed in real time. The flow cell provides a constant velocity of laminar flow. This creates steady-state conditions so that reliable images can be recorded for each moment of flow. A 2-D array of pixels collects images once per second at pre-chosen wavelengths to provide absorbance data over a 2-D area. When combined with specialized software analysis tools, the data provides a unique and time-saving insight into a compound’s behaviour. Physical changes and dissolution can be visualized simultaneously. The instrument can also be used to measure intrinsic dissolution rates, which are obtained in a fraction of time it takes when using conventional dissolution systems.

Our applications:

  • Real time observation of compressed API or tablet dissolution
  • Observations at static and under-flow conditions
  • Comparing data obtained from other imaging methods – MRI, Raman imaging, FT-IR imaging
  • Observation of precipitation during dissolution

See manufacturer’s overview of this product for more details.

Examples of our application:


Observation of dissolution of aprepitant from a polymer matrix (either PVP or soluplus) at two different pH values. Red indicates high absorbance, blue indicates zero absorbance.