Developing Methods for Automated Delivered Dose Uniformity (DDU) Testing for Nasal Sprays

Adam Smith & Mark Copley

Copley Scientific Ltd, Colwick Quays Business Park, Road No 2, Nottingham, NG4 2JY, UK


Studies were carried out to assess strategies for automating delivered dose uniformity (DDU) testing for nasal sprays. DDU was determined by two alternative methods. With the first a novel accessory was used to ensure complete dose collection in a vertical/near vertical orientation and subsequent chemical assay, as required for regulatory nasal spray testing. This method was trialled using two commercially available suspension-based formulations Beclometasone Dipropionate (BDP) and Fluticasone Propionate (FP) and in each case excellent drug recovery and high repeatability was observed; 99 ± 4% and 96 ± 5% relative to label dose, respectively. The second method was based on the measurement of shot weight, by difference, an alternative compendial method for solution-based formulations. Water was used as a placebo formulation and again, excellent repeatability was observed; an RSD of between 0.45% and 0.8% over 150 deliveries, in each of 5 runs. The shot weight method was also used for ‘Number of deliveries per container testing’. Testing was highly efficient, taking ~100 mins with no manual intervention required post set-up, a substantial gain in analyst time. Together, the results illustrate how DDU test set-ups for nasal sprays can be implemented to achieve high productivity and high repeatability.

Key Message

Automated test set-ups enable high repeatability in DDU testing for nasal sprays and release analysts for higher value work. Effective, accessible solutions are demonstrated for both dose collection and shot weight measurement, a particularly fast and efficient approach for solution-based formulations.