FaSSIF, FeSSIF and FaSSGF are types of Biorelevant Media that simulate human gut fluids.
FaSSIF: Fasted State Simulated Intestinal Fluid
FeSSIF: Fed State Simulated Intestinal Fluid
FaSSGF: Fasted Stated Simulated Gastric Fluid
These in vitro tools can indicate how a drug product will dissolve when it enters the gastrointestinal tract. All three media can be made from the same powder.
The media are usable for 48 hours from preparation.
For reasons of practicality and precision, we do not recommend making less than the following volumes:
FaSSIF: 250 mL
FeSSIF: 50 mL
FaSSGF: 1 L
You can select any of the three hydrate forms for preparing your phosphate buffer, it makes no difference to the final results. Simply use the one that is most convenient for you.
Degassing the buffer is entirely optional. If you are using the media for dissolution testing, degassing can potentially affect how the dosage form disintegrates so you may wish to do so. However, we generally do not recommend it because degassed media reabsorb atmospheric gases rapidly and re-equilibrate quickly after degassing.