On a computer that is not connected to internet we use the Intelligent updater to update the defntion.
The IU is not capable to update the PTP and NTP defintion. This is by design.
Symantec cannot post the defntion for PTP and NTP for public because if they ( signatures / Certificate ) are hacked this will be a big threat .
So PTP and NTP only get updated when LiveUpdate runs on the particular computer.