Citing FDA and Clinical Trials search

I would like to reference the results of my search using 

FDA- Search Orphan Drug Designations and Approvals


Basically what I did was search for a drug, for example trehalose. Then I used the data from the FDA to state in my text which diseases the drug has been approved as an orphan drug for, and from clinical trials to state if there are clinical trials ongoing.

How would I cite these searches?

You should check the style guidelines for your particular discipline. However, it seems referencing search methodology is best handled as a footnote (unless a description can be interwoven with the current text in a relevant and concise manner).