from this guidance. The first of the two bioavailability studies evaluated the in vivo performance against an oral solution. Two 300 microgram tablets, the test product, were compared to a 600 microgram oral solution in a single dose to a crossover study design. Pharmacokinetic parameters, AUC and Cmax, were evaluated without an endogenous baseline correction, and total thyroxine was used as the measure.
The second study was recommended to evaluate the dosage form proportionality within a particular product line. Three treatments were chosen to represent the low, middle and high ends of the product line and each treatment was administered as a single 600 microgram dose under fasting conditions. Pharmacokinetic analyses again, as with the other study, were conducted using total thyroxine without an endogenous baseline correction.
Finally, the issue of formulation which is, in my opinion, perhaps the most important aspect of this guidance. It's a small section in the guidance, but it has a very big impact. In order to be acceptable to the agency, a sponsor's products must target 100 percent of the label claim, something that had never been done