Pharmaceutical equivalence of the combination formulation of budesonide and formoterol in a single capsule with a dry powder inhaler.

Objective: To evaluate the pharmaceutical equivalence of a test formulation (fixed-dose combination of budesonide and formoterol fumarate in a single capsule dispensed in an Aerocaps® inhaler) in relation to a reference formulation (budesonide and formoterol fumarate in two separate capsules dispensed in an Aerolizer® inhaler).

Methods: This was an in vitro study in which we performed the identification/quantification of the active ingredients by HPLC and determined dose uniformity and aerodynamic particle size distribution in the test and reference formulations.

Results: In the test formulation, the content of budesonide and formoterol was 111.0% and 103.8%, respectively, compared with 110.5% and 104.5%, respectively, in the reference formulation. In the test formulation, dose uniformity regarding budesonide and formoterol was 293.2 µg and 10.2 µg, respectively, whereas it was 353.0 µg and 11.1 µg in the reference formulation. These values are within the recommended range for this type of formulation (75-125% of the labeled dose). The fine particle fraction (< 5 µm) for budesonide and formoterol was 45% and 56%, respectively, in the test formulation and 54% and 52%, respectively, in the reference formulation.

Conclusions: For both of the formulations tested, the levels of active ingredients, dose uniformity, and aerodynamic diameters were suitable for use with the respective dry powder inhalers.