In practice, the active ingredient(s) are required to be the same, but there can be some variation in e.g. binders that can make differences. The characteristics of the generic (bioavailbility, onset time, etc) are only required to be within a certain range compared to the original, not be identical.
In practice, the active ingredient(s) are required to be the same, but there can be some variation in e.g. binders that can make differences. The characteristics of the generic (bioavailbility, onset time, etc) are only required to be within a certain range compared to the original, not be identical.
See this, for example: http://en.wikipedia.org/wiki/Generic_drug#Efficacy