the spl characters were appended due to output format (by default it was locale) in lr_xml_extract()
I just entered optional parameter in the lr_xml_extract() and soap request went through.
lr_xml_extract("XML={response_1}",
"Query=/Envelope/Body/getOrderDetailList/orderActionHeader",
"XMLFragmentParam=ParamXml_OrderActionHeader",
"OutputFormat=utf-8",
LAST);