4835 Unable to parse xml data for some records

4835 Unable to parse xml data for some records

I am using ZOHO CRM API insert records for my website . Some records show 4835 error code
$xml  = '<Leads>';
$xml .= '<row no="1">';
$xml .= '<FL val="Last Name">'.htmlspecialchars($name).'</FL>';
$xml .= '<FL val="Email">'.htmlspecialchars($email).'</FL>';
$xml .= '<FL val="Phone">'.htmlspecialchars($phone).'</FL>';
 $xml .= '<FL val="Lead Source">'.htmlspecialchars($traffic_source).'</FL>';
 $xml .= '<FL val="Description">'.substr(htmlspecialchars($email_subject.' -'.$email_message),0,32000).'</FL>';
 $xml .= '</row>';
 $xml .= '</Leads>';

Values for above xml are :
Email : abc@domain.com
Subject : HodafeDync
Phone : 123456
Email Message : amlodipine cialis interact  http://pharm-ol.com - generic cialis  cialis and mania  <a href="http://pharm-ol.com ">generic cialis</a> - cialis erections  vendita on line cialis generico

Response is : <?xml version="1.0" encoding="UTF-8" ?>
<response uri="/crm/private/xml/Leads/insertRecords"><error><code>4835</code><message>Unable to parse XML data</message></error></response>

Any suggestions on what could be the problem? Thanks in advance