Swab recovery for active residue

I am validating for recovery factor in swab sampling for testing active residue in cleaning validation but I have some question in need of your assistance. Please help me clarify some following problems:

Which solvent using in swab sampling? Can I use the mobile phase of HPLC chromatography in swab sampling or only use water- ethanol - isopropanol?

Assumed that the acceptance value for active residue in my product is not more that 1.12 microgram per inch and the swab area is 100 inch. Anyone help me to experiment design for evaluate the swab recovery.

In my opinion, I performed swab recovery at 50%, 100%, 150% of acceptance value. It means I spiked 56 microgram, 112 microgram and 168 micrograp take swab sampling. Is this ok?

Thank you very much for your reply!

In an ideal case we must see that the solvent used in the swabs must aid to dissolve all the product under test when comes in to its contact.
In your case you used the ideal solvent and there is nothing wrong with the procedural aspect.

In my opinion, the solvent used in the swab recovery should be same as that of the cleanign agent.
If we use a different solvent, the recovery percent obtained in recovery study may not be the representative of acctual recovery.
Before initiating cleaning validation, you should establish the solubility profile of all possible contaminants and identify a ideal cleanign agent.