避免在XML保存上进行双重编码

I'm creating a XML file with SimpleXMLElement like this :

 $xml = new SimpleXMLElement('<?xml version="1.0" encoding="UTF-8"?><DonneesDepot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></DonneesDepot>');

I insert some data and I save with:

$xml->asXML($path);

When I save, this automatically encode &, >, <, but I need to encode the quotes, so when I insert my data I use htmlspecialchars() :

htmlspecialchars($some_data, ENT_XML1 | ENT_QUOTES, 'UTF-8') 

This encode the quotes with &apos; but then because of the encoding on saving this encode as &amp;apos;,

How can I do to save the file and encoding also the quotes or save the file without any encoding and then I could use htmlspecialchars() when I insert my data?