CREATE OR REPLACE FUNCTION GET_TEXT_FOR_XML1(P_VALUE VARCHAR2) RETURN VARCHAR2 
   IS
      v_result VARCHAR2(2000);
   BEGIN
      SELECT REGEXP_REPLACE(XMLELEMENT(Q1, P_VALUE).getclobval(), '</*Q1>', '')
        INTO v_result FROM dual;
      RETURN v_result;
   END;

   CREATE OR REPLACE FUNCTION GET_TEXT_FOR_XML2(P_VALUE VARCHAR2) RETURN VARCHAR2 DETERMINISTIC
   IS
      v_result VARCHAR2(2000) := P_VALUE;
      v_search_char sys.odcivarchar2list := sys.odcivarchar2list('&', '"', '©', '®', '™', '?', 
                                                                 'Ј', '„', '“', '«', '»', 
                                                                 '>', '<', '&#8805;', '&#8804;', '&#8776;', 
                                                                 '&#8800;', '&#8801;', '§', '&#8734;');
      v_replace_char sys.odcivarchar2list := sys.odcivarchar2list('&',  '"', '©', '®',  '™', '€',
                                                                  '&#163;','„','“','«', '»',
                                                                  '>',   '<',   '&#8805;',   '&#8804;',    '&#8776;',
                                                                  '&#8800;',   '&#8801;','§', '&#8734;');
   BEGIN
      FOR g IN v_search_char.FIRST..v_search_char.LAST
      LOOP
         v_result := REPLACE(v_result, v_search_char(g), v_replace_char(g));
      END LOOP;      
      RETURN v_result;
   END;

dbms_output.put_line(dbms_xmlgen.convert('12312 '' " > <', dbms_xmlgen.ENTITY_DECODE));