Bioequivalence and Bioavailability Forum

Dear Helmut, I've read the two articles above and have a question.
FDA stated: "Active and inactive ingredients are not in exactly the same proportion between different strengths as stated above, but the ratios of inactive ingredients to total weight of the dosage form are within the limits defined by the SUPAC-IR and SUPAC-MR guidances (up to Level II)."
I'm confusing by the words. Could the proportion of the active ingredient change?
For example: Drug Y is formulated as a IR tablets of 4 and 16 mg strengths with total mass of 204 and 101 mg, respectively. The same inactive ingredients are used for both strength with same propotions out of the total weight, except for filler ingredient (to account for the change of the active subtance).
Could biowaiver be applied for 4-mg strength in this case? The articles above don't have example like this.
I'm a newbie in this field, so please excuse for my little knowledge. And my English is not so good too. Thanks!

---

Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post #5! [Helmut]