Don't consolidate into just any bottle. You need the actual prescription bottle, i. e. If you need two or three bottles of one particular medication and each bottle is about 1/4 full (which is typical), open all the bottles of the same medication and put all the pills into only one of the bottles. You have the prescription info on the bottle but you only have one bottle of that particular medication with enough pills for a couple months rather than three bottles of the same med.
You need to have all your prescriptions anyway. Be sure you have the generic names since they are sold under different names in different countries.
I still think you should talk to your doctor and see if he can consolidate our just cut some of your meds. You might also ask your pharmacist if he can put them in smaller bottles. I have no idea why they use such large bottles. It's a complete waste.
I'm also not sure why a dozen bottles is taking up too much luggage space. You may want to rethink the amount of stuff you are packing. I take a carry-on that I check, a back pack and my purse that holds all my things for 4 to 6 weeks plus my painting supplies. Remember, you have to lug all that stuff around. Keep it light.