Bioequivalence and Bioavailability Forum

Some hints [RSABE / ABEL]

posted by Helmut  – Vienna, Austria, 2014-05-23 19:11 (4418 d 21:58 ago) – Posting: # 12998
Views: 7,230

Dear Khaoula,

❝ […] The test formulation is judged to be SABE with the reference product if the upper 95% confidence limit is <0 and after applie the TOST for the new limits or no

The general model (both for RSABE and ABEL) is

(I)     –θ_s ≤ (μ_T–μ_R)/σ_W ≤ θ_s.

We can rearrange this inequation to

(II)   –θ_sσ_W ≤ μ_T–μ_R ≤ θ_sσ_W.

That’s the model used by the EMA. The conventional 90% confidence interval should lie within the scaled (i.e., widended) acceptance limits. Therefore, the name of the method is Average Bioequivalence with Expanding Limits (ABEL).

The FDA went another path. Start from (II) and square all sides in order to obtain:

(III)  θ_s²σ_W² ≤ (μ_T–μ_R)² ≤ θ_s²σ_W².

Homework:

• The algebra to get (μ_T–μ_R)² – θ_s²σ_W² ≤ 0 from (III).
  
• Find out why the FDA requires the upper 95% confidence limit to be ≤0.

For some references see this post. The paper by the two Lászlós is free.

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


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Complete thread:

• HVDP RSABE (FDA) and ABEL (EMA) khaoula 2014-05-20 19:18 
  • HVDP RSABE (FDA) and ABEL (EMA) d_labes 2014-05-22 14:24
    • HVDP RSABE (FDA) and ABEL (EMA) khaoula 2014-05-23 15:37
      • Some hintsHelmut 2014-05-23 17:11
        • Some hints ElMaestro 2014-05-23 18:34
          • Maths dummy Helmut 2014-05-23 23:44
        • Some hints khaoula 2014-05-23 20:56