When there is a text which contains the & and ; together with out any space this & is not parsed as & instead it throws error.

It sounds like content expects XML, but what you are passing isn't valid XML. A simple way to convert plain text to XML is

for ($text) {
   s/&/&/g;
   s/'/'/g;
   s/"/"/g;
   s/</&lt;/g;
   s/>/&gt;/g;
}
[download]

However, I'd recommend avoiding content completely. The whole point of the module is to provide much better means of accessing and changing data than low-level functions like content.

Also there are some binary data in my text.

That may be a problem.
XML/1.0 doesn't allow many characters.
XML/1.1 doesn't allow the NUL character (chr(0)).
You might have to alter your scheme to allow the binary bits to be base64-encoded.

use XML::SMART;

That should be use XML::Smart;. Case *is* important, even if what you have *appears* to work.