Dear Justin,

This is a general question. It depends on the type and nature of the drug. If methanol does not react with the drug I expect that the stability of the drug at temperatures of 2-8 C will be relatively high.

I suggest that you do a TLC of the solution stored every 2 days to check if there is any degradation.

Generally, relatively stable drugs can be stored in solution for at lease a month at 2-8 C without being undergo any degradation.

Hoping this will be helpful,

Rafik

I'm just curious why do you store a drug in methanol, which is toxic? Why not in ethanol?

Dear all, thank you for your kind responses. I am handling some steroidal drugs, which have very poor solubility in water. So methanol seems to be one of the better organic solvent for their dissolution.

To have a rough estimate, you should consider that 1 mg/ml methanol solution of prednisone  is stable for 1 week keeping it at room temperature 21 ± 2°C and for 4 weeks keeping it into freezer at -5 ± 2 °C.

Dear sirs,

Thank you for your answers. Greatly appreciated.

Warmest regards,

Justin