Mytelase is old but it is fully approved and has been kept current, just like Mestinon. Prostigmin was grandfathered because it came to market before the FDA was founded. The FDA has a mandate to remove grandfathered drugs or have them go through the current approval process. This is why Prostigmin is no longer approved. It would cost more to go through the approval process than they would ever make back in sales.

Actually in the case of Guaifenesin, the original formula was approved, but the time-release version was not and faced removal. The first company that filed for it's approval got the exclusive rights to make it.

My housemate did talk to the Office of the Deputy CMO at Sanofi this morning. She is hoping for a call back from the Deputy CMO. She also found a Canadian Pharmacy that regularly imports from France. They are checking on Mytelase.