question about edible drug in plants

[ardalan]

Dears

I want to produce drug in plants (Molecular farming) by expression my gene in lettuce.
i have a challenge, it is enzymatic degradation in the stomach. my question is " Are there any amino acid sequences that protect
my drug in stomach?" can i attached this peptide to my protein?

Best regards

[JorgeLobo]

What drug and for what indication?