f2 Similarity Calculator
Compare test and reference dissolution profiles with f2 and f1, using the FDA or EMA rules for which time points count.
- f2 and f1
- FDA or EMA rules
- %CV check
- No sign-up
Four steps, or fewer
- Choose FDA or EMA. They differ in which points after 85% dissolution may be used.
- Paste the mean % dissolved of 12 units per product at each time point. Add the %CV columns to check variability.
- Read f2 and f1. The table shows which time points were used.
Not sure what to enter? Press Load example to see the calculator with realistic data. Your inputs are saved in this browser, so they are still there when you come back.
How f2 is calculated
f1 = Σ |Rₜ − Tₜ| / Σ Rₜ × 100
f2 between 50 and 100 indicates similar profiles (an average difference of no more than about 10% at each point); f1 up to 15 supports similarity.
Conditions for using f2
- At least three time points, excluding zero, with 12 units of each product.
- FDA: only one time point after both products reach 85% dissolved. EMA: not more than one mean value above 85% for either product.
- %CV of no more than 20% at the earlier time points and no more than 10% at the others.
- If both products dissolve 85% or more within 15 minutes, the profiles are considered similar without f2.
If variability is too high, consider a bootstrap f2 or a multivariate model-independent method.
References
- FDA Guidance: Dissolution testing of immediate release solid oral dosage forms (1997)
- EMA Guideline on the investigation of bioequivalence (CPMP/EWP/QWP/1401/98 Rev. 1)
- ICH M9 Biopharmaceutics classification system-based biowaivers
These calculators are decision support for orientation and training. They are not validated GMP software, and results must be checked against your approved method, SOP and the current pharmacopoeia or guideline before use in GMP records. Your data is processed in your browser and is not sent to Molgenium.