0907_GF_ONdrugDelivery November 2012 Pulmonary and Nasal.indd

Copyright © 2012 Frederick Furness Publishing 14 Nasal sprays that deliver active ingredients using droplets are well-established drug delivery vehicles, both for locally acting and systemic therapies. More recently, though, the pharmaceutical industry has started to turn its attention to delivering dry powders via the nasal route, a step that parallels the introduction of dry powder inhalers (DPIs) for pulmonary drug delivery. The current high levels of research activity in the area of dry nasal powder development reflect the potential rewards, which include high patient compliance, good product stability and sterility, and closely targeted drug delivery. The traditional analytical tools for nasal sprays include laser diffraction particle size analysis, spray pattern and plume geometry measurement. With dry nasal powder technology in its infancy and no regulatory guidance specific to it, it is timely to question how well these techniques support further development and to review any requirements for additional analyses. Moreover, should these powder-based systems be tested following inhalation or aqueous nasal spray guidelines? An optimised analytical toolkit will not only promote the development of efficacious products, but also accelerate their commercialisation within the constraints of the regulatory framework. The case studies presented here help in understanding the applicability of laser diffraction and plume geometry measurement for characterising dry powder nasal sprays. WHY USE NASAL SPRAYS?