Pulmonary Delivery Systems

Pulmonary Delivery Systems

        Pharmaceutical aerosols have been employed to deliver drugs for both localised and systematic effects. The performance of aerosolized drugs is determined by many physico-chemical and biological factors, of which the design of aerosol devices, morphology and crystal forms of drugs and excipients are the key areas of interest. Thus, characterisation of the inhaler device, engineering of drug and carrier crystals and formulation of dry powder for inhalation are essential elements. Dry powder inhalers have become established as delivery devices for drugs such as bronchodilators and steroids in the treatment of diseases of the respiratory tract. A particular advantage of this type of device is that it is breath-actuated, so most patients can easily be trained in its use. However, from fraction of the formulated dose that is delivered to the respiratory airways from commercially available devices is seldom greater than 10-15 %. Although this does not represent a problem with inexpensive drugs, it will not be the case with biotechnology. The formulation is often based upon the adherence of the micronised drug particles to the surface of an inert carrier such as lactose, the particle size of which is too large to penetrate the airways. It is therefore essential that, upon inspiration, sufficient turbulence be created by the device to dislodge the drug particles from the carrier.
        Pulmonary delivery of antibiotics has attracted much attention in recent years but formulation and aerosolization of these agents has remained to be a challenge since many drugs are susceptible to chemical and/or physical degradation. Therefore, the formulation and aerosolisation of aerosols containing antibiotics are also being investigated with a view to maintaining the biological activities, improving pulmonary deposition and absorption of these drugs. New biotechnology developments challenge pharmaceutical manufacturers, as many new drugs deteriorate when swallowed. An appealing delivery alternative is “breathing in” or inhaling medications. However, aerosol inhalers must be improved to meet environmental and economic challenges, and at the same time, they should deliver the correct amount of medicine to the appropriate lung tissue.
In order to use the lung to deliver drugs into the systemic circulation there are two basic requirements. The first is that the macromolecule must possess a natural ability to be absorbed through the lung epithelium. The second is that a technology capable of delivering the molecule to the peripheral airways efficiently and reproducibly is available.

 

Research staff
• Assoc. Prof. Dr. Teerapol Srichana, Department of Pharmaceutical Technology
• Dr. Somchai Sawatdee

©2016 Drug Delivery System Excellence Center

Faculty of Pharmaceutical Sciences, Prince of Songkla University
Tel. +66(0) 7428 8979 Fax. +66(0) 7428 8979
Contact Us