What is the ruling on aspartame, used as a sweetener in foods and medicines, which breaks down into methanol, known to be from Khamr (wine/intoxicants)?

Some research has indicated that "Aspartame" is 200 times sweeter than sugar and contains no calories, and it has not been confirmed that it converts into an alcoholic substance. If this is proven true and it is used in medications, then medications containing alcohol are not permissible to use except out of necessity. It is also not permissible to add even a small percentage of alcohol to the food of diabetic patients.