Corticosteroids and bioavailability.

This presentation has attempted to provide a brief view of the importance of bioavailability and bioequivalence to those physicians who use corticosteroids. In particular it emphasizes that in vitro tests may not be reliable for predicting variability between formulations and, more importantly, cannot take the place of a bioavailability study. The implication would seen clear: namely, that a manufacturer who wishes to market a formulation similar to that already available and found to be acceptable clinically cannot rely on merely matching the standard formulation with in vitro tests but should substantiate that his formulation is, indeed, bioequivalent to the standard. In addition, data have been presented that clearly suggest the importance of bioavailability methodology as a new and useful pharmacological tool. In conclusion, as far as the bioavailability of corticosteroids in the marketplace is concerned, an old adage may be paraphrased: "If you don't know your bioavailability, know your manufacturer."