"Kryptonite"
see if they laugh.
I dont think what the answer you give is as important as how you give it. I think the intent is not really to see what your weaknesses are, but to gauge how you see yourself and see that you arent someone who sees themselves as perfect.
What if you said something like "I tend to overeat when I get stressed, so I make sure to have plenty of mini-carrots around when Im busy." Would they think that was trite? What if that IS your big weakness?
Shyness is OK to use, but Pharmacy is still a very public oriented field, so unless you plan on working in mail-order or in a hospital where your sure they wont send you out around the patients this is an iffy weakness. Although truth be told I did address a lot about my struggles through social anxiety in my personal statement.
You are correct, do not use anything related to time management or organization or accuracy as weaknesses.