PHP remove special character from string

You want str replace, because performance-wise it's much cheaper and still fits your needs!

$title = str_replace( array( '\'', '"', ',' , ';', '<', '>' ), ' ', $rawtitle);

(Unless this is all about security and sql injection, in that case, I'd rather to go with a POSITIVE list of ALLOWED characters... even better, stick with tested, proven routines.)

Btw, since the OP talked about title-setting: I wouldn't replace special chars with nothing, but with a space. A superficious space is less of a problem than two words glued together...

preg_replace('#[^\w()/.%\-&]#',"",$string);

Your dot is matching all characters. Escape it (and the other special characters), like this:

preg_replace('/[^a-zA-Z0-9_ %\[\]\.\(\)%&-]/s', '', $String);