Aerosol Delivery Devices Research Articles

New devices for asthma

The major antiasthma drugs currently are prescribed most often in aerosol form, with the use of a variety of inhaled-drug delivery devices. The 20th century has seen the evolution of ever more sophisticated aerosol delivery devices from the crude, medicated mist generators of questionable efficacy developed in the 19th century, to small-volume nebulizers, to the latest generation of metered-dose inhalers (MDIs) and dry-powder inhalers (DPIs).1 It is hoped that further refinements in these devices will occur in the 21st century to make aerosol drug delivery even more efficient and convenient, as well as environmentally friendly. MDIs are currently the most widely used aerosol delivery devices. Over the last two decades, auxilliary devices for MDIs have been developed, such as spacers or aerosol holding chambers, to overcome problems associated with press-andbreathe MDI use. In addition, a growing interest has emerged in microelectronic monitoring devices to help physicians and patients monitor their own inhaler use, to assess and improve compliance, and, at least with one device, to optimize drug delivery from MDIs. The purpose of this review is to provide a broad overview of both current and experimental devices for use in asthma and a brief discussion of what improvements are needed in such devices as we enter the new century.

Controlled dosing of nicotine via an Intranasal Nicotine Aerosol Delivery Device (INADD).

The present report describes an Intranasal Nicotine Aerosol Delivery Device (INADD) employing an artist's airbrush as aerosolizer and precise, electromechanical control of spray duration. It was designed for the administration of controlled doses of nicotine in a laboratory setting and has been used successfully in over 30 smokers and nonsmokers of both genders. In the present study, nicotine was administered to 12 male smokers at three different doses (0.05 mg, 1.00 mg, and 2.00 mg), and at the same dose (1 mg) on three different occasions. The low dose produced a minimal change in plasma nicotine, while the high dose produced a peak increment of around 16 ng/ml. The medium dose reliably produced a peak increment of around 8-9 ng/ml on all three occasions. Nicotine in plasma showed a sharp rise followed by a slower decline, mimicking the pattern associated with cigarette smoking. Physiological and biochemical responses showed significant dose-response relationships. Subjective reports suggested that aerosol dosing was somewhat aversive, but it is unclear whether this effect is intrinsic to the method or due to other factors. The device described in this report answers the need for a safe and easy means of controlling nicotine dose. Moreover, since nicotine administration via aerosol is novel for both smokers and non-smokers, minimizing the contributions of behavioral tolerance and habituation to the dosing vehicle, it lends itself to the comparison of the pharmacological effects of nicotine between experienced and naive subjects.

Apparatus and method for measuring regional distribution of therapeutic aerosols and comparing delivery systems

An apparatus has been designed to estimate the respiratory tract distribution of therapeutic aerosols. It consists of an accurate life size model of the human oral passage extending from lips to mid-trachea, a Y branch for flow adjustment and a cascade impactor. Aerosol delivery devices are positioned to introduce the generated aerosol into the oral entrance, simulating their in vivo delivery. The aerosol which penetrates the oral airway model cast passes to the cascade impactor for aerodynamic size classification to estimate regional delivery to the bronchial and pulmonary zones. The apparatus has been tested using a metered dose inhaler (MDI) at a range of inspiratory flow rates.