A study by researchers from King’s College London, the University of Parma, and inhalation testing specialist Intertek evaluating the interdependence of DPI formulation and device factors has been published in the International Journal of Pharmaceutics. The article, titled “Formulating powder–device combinations for salmeterol xinafoate dry powder inhalers,” appeared in the July issue of the journal.
The team tested dry powder formulations of salmeterol using three types of lactose, varying concentrations of fine lactose, and three different capsule-based inhalers to determine what combinations would produce successful aerosolization, with “successful” defined as an emitted dose of >80% and an MMAD of 1–5 µm.
Of the three devices used in the testing, the Aerolizer was found to produce the best aerosolization performance across the entire range of formulations tested, but the team was able to create successful formulations for delivery by the Handihaler and Rotahaler as well. Of those devices, the Rotahaler exhibits the least resistance and the Handihaler the greatest resistance.
While the article concludes that it is “paramount to optimise the formulation and the device together in order to achieve an efficient deposition of micronized drug particles deep into the lungs,” Ben Forbes of King’s College London points out that DPI developers may not have the opportunity to co-develop a device with a formulation, instead having to tailor a formulation to a platform device, and the study also demonstrates ways to match formulations with existing devices having widely varying resistance.
Intertek Pharmaceutical Services Leader Mark Hammond commented, “Conducting studies such this is vital to pushing forward the evolution of inhalation technology as a means of delivering drug products and expanding the pharmaceutical industry’s understanding of how to develop more effective medicines.”
Read the Intertek press release.
Read the Journal of Pharmaceutics abstract.
