Welcome to the Q&A Forum

It does take some time for Google to remove pages from the index.  You can speed it along a little by using the "Remove URL" link under Optimization in Google's Webmaster tools. You should also disallow the url in your robots.txt file as well, to be on the safe side if you don't want the page to show up in searches. And there is also Google's page about removal: https://support.google.com/webmasters/bin/answer.py?hl=en&answer=59819