More than 10 people can be seen holding up a life net to catch the animal as they waited for the drugs to take effect.
Dr Ainsley said the panda was found to be malnourished after 48 hours on the run, eating nothing but unripe figs.
It is unknown how the animal escaped, with zoo staff launching a review - including rewatching CCTV footage - to determine how he got out.
The panda's adventure was the first mammal escape from the zoo in recent years, with the species enclosure being rebuilt only a couple of months ago.
"He's now just being transferred back into the zoo where he'll spend the next couple of days in our animal health department just getting a check-up and making sure he's Okay," Dr Ainsley said.