You can type drug names into www.rxlist.com
then check the clinical pharmacology section for rates of absorption.
Not really sure but it appears canasa might have just as high a rate of absorption as apriso. The various 5asa pills test differently. Canasa tests mention hairloss in users. Apriso doesn't.
Diagnosed with proctosigmoiditis as my 50th birthday present Dec 2009
4.8 grams Asacol HD plus 1000mg canasa daily for 8 weeks
Now on 1.6 gr Asacol HD daily,fish oil, homemade yogurt(VSL#3/Mountain high cultures), pscillium husk,glucosamine sulfate,turmeric and Mutaflor(e. coli nissle).
Will begin fazing in boswellia,s. boulardii, and bromelain for both UC and/or back/joint inflammation soon.