$re = '/(?:\'(\w+)|\G(?<!^))(?:;(\w+)=(\w+))?(?::([^\']*)\'.*$)?/m';
$str = '$subject = \'name:content\' ;
$subject = \'name;param1=value1:content\' ;
$subject = \'name;param11=value11;param21=value21:content\' ;';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php