What are FaSSIF, FeSSIF and FaSSGF and why are they so useful?
FaSSIF/FeSSIF/FaSSGF are ‘Biorelevant’ dissolution media and you can make all three from our
FaSSIF: Fasted State Simulated Intestinal Fluid
FeSSIF: Fed State Simulated Intestinal Fluid
FaSSGF: Fasted State Simulated Gastric Fluid
These media contain natural surfactants (bile salts and phospholipids) present in the gut to simulate
gastrointestinal fluids much more accurately than conventional dissolution media. Importantly they
also take food into account: drugs in Fasted State media (before a meal) often behave very
differently from those in the Fed State (after a meal). These are incredibly useful tools when
developing an oral drug because simple laboratory experiments in them can help predict how the
drug is likely to perform in the gut.
We’ve been selling FaSSIF/FeSSIF/FaSSGF (originally known as ‘SIF Powder’) for more than 10 years,
it’s referenced in hundreds of publications and used by the 10 biggest pharmaceutical companies in
Speed and Convenience
The method for making these Biorelevant Media from our product is incredibly quick and simple;
add powder to buffer and you’re ready to go. We’ve recently introduced a range of Buffer
Concentrates (sold separately) that enable you to make the three different media faster and more
reproducibly than ever before.
We manufacture from a dedicated factory in London and apply strict production protocols and
analytical procedures to ensure you get product of the highest quality and reproducibility.
All raw ingredients are sourced from quality certified companies and chemically tested by a 3rd party
laboratory before manufacturing even begins.
We’ve invested heavily in production equipment with considerable capacity. In conjunction with our
‘Just in Time’ approach to manufacturing, this ensures you’ll receive the freshest product possible
with the confidence that we’ll always have supply available for you. In the previous 10 years, we’ve
not been out of stock for even one week!
Every batch we make is analysed by a GLP certified and FDA approved independent laboratory to
make sure you get the best media possible. This is reflected in the Certificates of Analysis supplied
with each bottle. Finally, our products are tested thoroughly in the biorelevant.com laboratories to
ensure they are working perfectly.
Buying from us
Purchasing our products could not be any easier!
Flexible Payment Methods: order direct from this web page and choose to pay by credit card,
PayPal or Bank Transfer
Instant Quotes: select the product(s) you want, then get your Quote from the Mini Cart (top right of
24 Hour Dispatch: we aim to dispatch all orders (unless proforma) within 1 day of receipt
Free Shipping: we use FedEx or DHL international priority services and shipping on all orders is free
The range of powders from biorelevant.com is the fastest way to obtain reliable results for biorelevant solubility and dissolution testing.