This book presents work on nanocarrier systems for pulmonary drug delivery for use in the treatment of asthma. Using sucrose as a carrier, liposomes were generated or dispersed in situ from proliposomes within the medical nebulisers investigated. The Pari (air-jet) and the Omron (vibrating-mesh) nebulisers produced large mass and lipid outputs with a large lipid fraction deposited in the lower stage of a two-stage impinger. The Liberty (Ultrasonic) nebuliser failed to deliver more than 6% of the lipid employed.Multilamellar liposomes were generated from ethanol-based proliposomes. The resultant vesicles entrapped 62% of the available salbutamol sulphate compared to only 1.23% entrapped by liposomes made by the thin film method. Aeroneb Pro or Aeroneb Go vibrating-mesh nebulisers generated aerosol droplets of larger volume median diameter and narrower size distribution than the Pari (air-jet) nebuliser. Unlike the vibrating-mesh nebulisers, the performance of the jet nebuliser was independent of formulation. A nebuliser-dependent significant loss of the originally entrapped drug was demonstrated. A customised large mesh Aeroneb Pro reduced the drug losses during nebulisation.