Comparative in vitro performance evaluation of the Novopulmon 200 Novolizer and Budesonid-ratiopharm Jethaler: two novel budesonide dry powder inhalers.

A special single dose collector and a multi stage liquid impinger were used to assess the consistency of delivered dose and fine particle fraction respectively, of the Novopulmon 200 Novolizer (Viatris, Frankfurt, Germany) and Budesonid-ratiopharm Jethaler (Ratiopharm, Ulm, Germany). The obtained average delivered dose from the Jethaler at 4 kPa is 199 microg (99.5% of the label claim) versus 219 microg (109.6%) for the Novolizer (mean of 90 doses from the same device). The corresponding relative standard deviation (RSD) for the Jethaler is on average 14.05% (maximal and minimal dose are 289 and 148 microg respectively), versus an RSD of 5.56% for the Novolizer (max. is 240; min. is 187 microg). It can be shown that the rather extreme spread in the delivered dose from the Jethaler is caused by a variation in metered mass, and to less extent by a poor content uniformity of the drug-lactose compact. The fine particle fractions (FPFs, as percent of label claim, for particles <5.1 microm) of both devices show an increase with increasing pressure drop across the inhalers, although at 4 kPa already 62% (Jethaler), respectively 72% (Novolizer) of the 'maximal' value (at 8 kPa) is achieved. FPF from the Novolizer is highest at all pressure drops and varies between 23.2% (at 2 kPa) and 54.3% (at 8 kPa). The difference in FPF between both devices increases with decreasing upper class for the FPF: the ratio of FPF from Novolizer to that from Jethaler (at 4 kPa) is 1.42 for particles < 5.1 microm versus 2.14 for particles < 1.8 microm, suggesting that the aerosol produced by the Novolizer has much greater potential for deep lung deposition.