Facebook Meta Tag - og:description for database value with strip_tags() and substr()

HTML Code:
[PHP][CODE]$descpp = substr($fetchForumData[0]['descp'], 0, 300)."...";
// echo $descrp    {As it shows correctly as the description data from database limit to 300 words via echo}
<meta property="og:description" content="<?php echo strip_tags($descpp); ?>" />  [/CODE][/PHP]
The following script not working and shows result on facebook as '....' rather than '$descpp + .....'

And I already debug via http://developers.fa...com/tools/debug also.

And for
HTML Code:
[PHP][CODE]<meta property="og:description" content="<?php echo $fetchForumData[0]['descp']; ?>" />[/CODE][/PHP]
... its shows complete content on the top of the article page and after comment via facebook comment plugin it shows blank space on facebook timeline.

What is missing? Kindly advice as soon as possible.