Al:

"Throughout our extensive clinical and preclinical program for AFREZZA, we have seen no signals to raise any safety concerns about our formulation or our delivery. Both the insulin and the carrier quickly crossed into arterial blood, there is no accumulation in the lungs. Some patients do react with a tiny cough when first inheriting a powder, but we have seen no unusual adverse effect throughout the long series of more than 60 clinical trials. There are patients who have been using AFREZZA and enjoying this therapy for almost 5 years."

http://seekingalpha.com/article/971551-mannkind-management-discusses-q3-2012-results-earnings-call-transcript?find=lung%20&all=false