I'm related to an RA sufferer on humira so I have been investigating storge when travelling.
I believe I have a method of storage that will keep the drug within permitted temperature limits for 90 hours without attention.
I use Lyan Packaging items (also bearing the name "Icer Tech"). Other products may be just as good.
THe packaging is a cardboard box 350 by 350 by 250 mm. with some cool packs of 0.5 and 1 litre capacity. Note that these are coolpacks not isce packs.
I have found it necessary to increase pack insulation either to 50 mm. of polystyrene or 35 mm. of polyurethane foam. I use a Maplin electronic thermometer for temperature measurement.
The major problem I have found is the low initial temperature of the cool packs when removed from the freezer. You could leave them out in the room for a while. I use 2 off 1 litre frozen packs with one 0.5 litre already warm pack to provide additional temperature buffering.
This gives a cool time of 90 hours with external temperature of 19 degrees C.
Caution:- be careful handling part frozen packs as the cooling produces sharp crystals that can pierce the polythene bag of the pack.
Clearly it is possible to extend the period by taking along extra packs and getting a hotel or other business to freeze down a pack or two.
Lyan packaging is reasonably priced less than 2 pound sterling for a 1 litre cool pack.