The solution I'm thinking of is to buy whole flaxseed and then extract the oil. It should be extracted using the cold pressed method and used within a week or two at most. It should be stored in dark bottles to keep the light away from it and it should also be kept inside the refrigerator.
The criteria for choosing the best flaxseed oil are:
1. Organic as much as possible.
2. It should be as fresh as possible. (specially if organic flaxseed oil
is not available)
3. Should be stored in dark bottles and kept under refrigeration.
4. Should be cold pressed as the alpha-linolenic acid could be destroyed by heat.
5. It should be hygenically prepared.
I hope that helps.
disclaimer: pic is not mine. imported it from http://barbaramendeznutrition.com/wp-content/uploads/2011/11/flax-seed-oil.jpg.