Side effects of albuterol (salbutamol)are directly related to the dose delivered and absorbed into blood stream. By controlling aerosol delivery, dose delivered, site of deposition, amount of drug absorption can be determined and thus the magnitude of the side effects. Delivery and deposition of aerosols are determined by both aerosol characteristics (size and timing of delivery) and breathing characteristics (breath size, flow rate and breathholding). Data supports the theory that if a high dose of albuterol can be deposited in the larger airway generations and prevented from entering the pulmonary circulation from the lung periphery, that this will result in the largest magnitude of bronchodilator response with the lowest circulatory absorbance.