1. (General Engineering) tungsten-electrode inert gas welding: a method of welding in which the arc is maintained by a tungsten electrode and shielded from the access of air by an inert gas. Compare MIG welding.
A prescription for a controlled drug is valid for 28 days from the date given on the prescription. usually six months unless it's a controlled i.e. morphine, pethidine and methadone. These medicines are often misused, so have stricter legal controls on their supply to prevent them being obtained illegally. A prescription for a controlled drug is valid for 28 days from the date given on the prescription.
Prescriptions of control three through five (C III, IV, V) are valid for SIX months or FIVE refills, whichever comes first, and C III are subjected to a limit of a thirty day supply per dispense. Narcotic prescriptions of control two (C II) are valid for ONE month from the date they are written.