FaSSGF 101

What is FaSSGF?

FaSSGF (Fasted State Simulated Gastric Fluid) is a biorelevant test medium that replicates gastric fluid after drinking a glass of water. In vitro tests in it can help reveal how your oral drug is likely to behave in the stomach after drinking a glass of water. Although drugs are not generally absorbed in the stomach, the interaction with stomach fluid can influence the solubility and dissolution of many drugs greatly and impact on the subsequent absorption; this is especially true of bases. Though it can be useful to test release of Test Formulations against the Reference to ensure release profiles in the stomach are the same, this medium is rarely discriminatory for BCS 2 drugs. In these cases, it's important to test in a medium replicating a small intestinal fluid from which absorption occurs.

What’s in FaSSGF?

Gastric fluid in vivo in the fasted state contains low levels of physiological surfactants refluxed back into the stomach from the upper section of the small intestine. FaSSGF contains the same type and low level of these physiological surfactants. These components can contribute to the wetting of a dosage form and drug. FaSSGF has the average acidic pH of fasted gastric fluid and similar osmolarity too. These are also important parameters to control when testing drugs or formulations sensitive to pH and salt content.

How do I make FaSSGF?

FaSSGF can be made in less than two minutes with 3F Powder and diluted FaSSGF Buffer Concentrate. 

For more product details download the FaSSGF Technical Data Sheet (TDS) here.

Download our Biorelevant Dissolution Guides here.