A bit late answer, but...
$pdescription = substr(strip_tags(trim($row['content']), '<b><br>'), 0, 200);
or you can make it longer, but easier to read:
$pdescription = trim($row['content']);
$pdescription = strip_tags($pdescription, '<b><br>');
$pdescription = substr($pdescription, 0, 200);