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.
All prescriptions do have a Use by date on them, and this is generally 1 year from when the prescription is issued, or the expiration on the bottle, whatever is sooner. NJPharmacist: The use by date isn't necessarily an expiration date. For a drug such as Benzonatate capsules, the date would be 1 year. However, for a drug such as a controlled substance such as Vicodin, a prescription would only be valid for 6 months. The use by date isn't necessarily an expiration date. For a drug such as Benzonatate capsules, the date would be 1 year.