Bioequivalence and Bioavailability Forum

Dear Samaya,

May I add a point, the choice of the model will depend of your data.

First you have to understand your data and not only to press a "wizard" and to wait for results. Phoenix is a great software but if you input wrong information/incorect setting at the begining results are going to be nonsense.

If you use a time scaling that means for example that in vivo is slower than in vitro but with a similar shape/kinetic. In this case time scaling is simple. If the shape of the curve in vitro and in vivo is different that means that you do not reflect the same type of kinetics ... that is more problematic except if you know why.

Some key points:

• which model used for fitting the data before time scaling.
  
• what is the number of points that you have in vitro and in vivo. If you have only 3 points in vitro (close to 20, 50 and 80% dissolved) forget it, you cannot have a good estimation of the shape of the dissolution curve.
  
• Do not over-parametrize your time scaling equation even if you have the impression that fit is better => if you have 3 points and 3 parameters fit is perfect but not informative.

As stated by Simon you have a lot of information on Phoenix forum.

Best regards,

JM