They use PG as a carrier in Albuterol inhalers... So, no, I would say it isn't corrosive to lung tissue.
Albuterol for asthma and PG!? | E-Cigarette Forum
"Albuterol Sulfate Syrup for oral administration contains 2 mg of albuterol as 2.4 mg of albuterol sulfate in each teaspoonful (5 mL). Albuterol Sulfate Syrup also contains the inactive ingredients citric acid, FD&C Yellow #6, flavor enhancer, hypromellose,
propylene glycol, purified water, sodium benzoate, sodium citrate, strawberry flavor. Sodium hydroxide may be added to adjust pH."
Source:
ALBUTEROL SULFATE SYRUPFORM NO. 0825