My veterinary pharmacist tells me it has a 1 month shelf life and cannot be frozen.
This seems to conflict with some literature that James dug up that suggests 6 months.
However, I did stumble upon this technical document about parenteral preparations of metoclopromide. It claimed that it's okay to freeze saline mixtures for 4 weeks, but that dextrose formulations will degrade metocloprmide. Contrairly, it clamined that unfrozen, any mixture should be good for 24 hrs unprotected from light or 48 hrs if protected from light.
Nevertheles, this research paper casts some doubt on about those clams. Hor et. al found no apparent differenced between metaclopramide's stability at room temperature over a 48 hr time frame in either saline or dextrose solutions, or dark vs light conditions.
In-contrast, during my attempt at purchaseing the solution my self, the pharmacy assured me that their solution was good for greater than 6 months.
The discrepancies can best be attributed to formulation, and the addition of stabilizers to some products.