Julie D. Suman

Inhalation therapy: technological milestones in asthma treatment.

The humble origins of the propellant driven metered dose inhaler, as a response to a childs enquiry, initiated an industry which supplies approximately a half billion inhalers globally for the treatment of asthma. These inhalers fall into three major groups: nebulizers; propellant driven metered dose inhalers and dry powder inhalers. Each requires drug formulation, metering and device technology to be successful. In recent years there have been several new developments in the field including auxiliary systems to improve drug delivery from the device to the patient and new categories of device, notably single breath aqueous systems. As device technology improves and our understanding of the disease leads to new drugs the only barrier to therapy is the patient. Patient training and compliance will continue to be important factors in the success, or failure, of inhaled therapy and the role of health care professionals will depend on who sponsors their intervention.

Characterization of stability and nasal delivery systems for immunization with nanoemulsion-based vaccines

BACKGROUND Many infectious diseases that cause significant morbidity and mortality, especially in the developing world, could be preventable through vaccination. The effort to produce safe, thermally stable, and needle-free mucosal vaccines has become increasingly important for global health considerations. We have previously demonstrated that a thermally stable nanoemulsion, a mucosal adjuvant for needle-free nasal immunization, is safe and induces protective immunity with a variety of antigens, including recombinant protein. The successful use of nanoemulsion-based vaccines, however, poses numerous challenges. Among the challenges is optimization of the formulation to maintain thermal stability and potency and another is accuracy and efficiency of dispensing the vaccines to the nasal mucosa in the anterior and turbinate region of the nasal cavity or potentially to the nasopharynx-associated lymphoid tissue. METHODS We have examined the effects of different diluents [phosphate-buffered saline (PBS) and 0.9% NaCl] on the stability and potency of nanoemulsion-based vaccines. In addition, we have determined the efficiency of delivering them using commercially available nasal spray devices (Pfeiffer SAP-62602 multidose pump and the BD Hypak SCF 0.5 ml unit dose Accuspray(TM)). RESULTS We report the stability and potency of PBS-diluted ovalbumin-nanomeulsion mixtures for up to 8 months and NaCl-diluted mixtures up to 6 months when stored at room temperature. Significant differences in spray characteristics including droplet size, spray angle, plume width, and ovality ratios were observed between the two pumps. Further, we have demonstrated that the nanoemulsion-based vaccines are not physically or chemically altered and retain potency following actuation with nasal spray devices. Using either device, the measured spray characteristics suggest deposition of nanoemulsion-based vaccines in inductive tissues located in the anterior region of the nasal cavity. CONCLUSIONS The results of this study suggest that nanoemulsion-based vaccines do not require specially engineered delivery devices and support their potential use as nasopharyngeal vaccine adjuvants.