Bioequivalence and Bioavailability Forum

Dear Nelson
first of all you need to get more information from the sponsor. Why did he develop a 300 mg formulation whereas the originator (and other generics) have a 500 mg solid oral formulation on the market (at least here in Germany). Does he have safety and efficacy data for the 300 mg formulation? Does he plan a hybrid application for the paediatric population? By definition your sponsors' formulation is not a pure generic and hence a bioequivalence study against the originator 500 mg formulation as you described is not applicable to get a marketing authorisation. I guess you could show bioequivalence against the oral solution of the originator (500 mg/ml => 300 mg/0.6 ml) as reference.
BTW, please keep in mind that a single dose of dipyrone should be 8-16 mg/kg body weight. If you administer 1500 mg you really need subjects with a high BMI.
I hope this helps.
Kind regards
Dan