Ok so I got another version of this based on the above answers but taking more things in account(utf-8, \n and   ; ), also a line stripping the wordpress shortcodes commented if used with wp.
function neatest_trim($content, $chars)
if (strlen($content) > $chars)
{
$content = str_replace(' ', ' ', $content);
$content = str_replace("\n", '', $content);
// use with wordpress
//$content = strip_tags(strip_shortcodes(trim($content)));
$content = strip_tags(trim($content));
$content = preg_replace('/\s+?(\S+)?$/', '', mb_substr($content, 0, $chars));
$content = trim($content) . '...';
return $content;
}