Aaron Taylor, Stephen Stein, Benjamin Nottleson
Kindeva Drug Delivery, 11200 Hudson Road, Woodbury, Minnesota, 55129, USA
Summary
Spray pattern (SP) measurements are widely used to characterize metered dose inhaler (MDI) plumes and are commonly used as a quality control test for pressurized metered dose inhaler (pMDI) actuators. Kindeva conducted SP testing on six lots of pMDI actuators used for a suspension product. A minimum of ten SP measurements at a distance of 60 mm were conducted on each lot. There was an observed increase in the mean and standard deviation of SP Area and Ovality with successive lots over time. By swapping canisters and actuators, it was demonstrated that the SP Area and Ovality results were dictated by the actuator used and that the canister used had minimal impact on the SP results. Microscope evaluation of the actuators with elevated SP Area and Ovality demonstrated these actuators had irregular orifice shapes. The results demonstrate that SP testing can be a sensitive diagnostic method for identifying irregular actuator orifices and a sensitive SP method may be used as part of release testing of pMDI actuator batches.