Split a string at a certain number of characters but not in the middle of a word

[shortysbest]

How could I split a string in half but not in the middle of a word?

 

$information = "This is the string of text, however at some point in the sentence a word may get split in half.";
$cut = round(strlen($information)/2); ///where to cut (50%)
$split1 = substr($information, 0, $cut); //first half
$split2 = substr($information, $cut); // second half

[ignace]

$estimatedSplit=2;
$string='foo bar';
echo substr($string, 0, strpos($string, ' ', $estimatedSplit));