If we are talking about ibuprofen, here the usual dose for adults is 400 mg, instead of the 200 mg usual in the US. There are different brands with different prices. The process to sell medicines here is quite different than in other countries. For instance in Buenos Aires a pharmacy can buy the ibuprofen with a huge discount (40-80% off) so the pharmacy decides how much is going to charge the medicine to the public.
The other medicine mentioned above, I think it was naproxeno, is available without a prescription, just asking over the counter.
I dont know if ANMAT has enought financial resources to perform quality controls in samples of medicines or visiting laboratories like its counterpart in the US (FDA) but the argentinian laboratories dont want to get involved in any scandal, or get products out of the market, or get closed to manufacture medicines. So, the argentinian industry works pretty well. ANMAT is very strict regarding the approval of a new medicine, generic or not. It follows international standards, the US or UK pharmacopeia, for instance.
Personally, I had allergic reections to an excipient while living in the US, so that is not exclusive of this country.