Permeation of Therapeutic Drugs in Different Formulations across the Airway Epithelium In Vitro.

BACKGROUND: Pulmonary drug delivery is characterized by short onset times of the effects and an increased therapeutic ratio compared to oral drug delivery. This delivery route can be used for local as well as for systemic absorption applying drugs as single substance or as a fixed dose combination. Drugs can be delivered as nebulized aerosols or as dry powders. A screening system able to mimic delivery by the different devices might help to assess the drug effect in the different formulations and to identify potential interference between drugs in fixed dose combinations. The present study evaluates manual devices used in animal studies for their suitability for cellular studies. METHODS: Calu-3 cells were cultured submersed and in air-liquid interface culture and characterized regarding mucus production and transepithelial electrical resistance. The influence of pore size and material of the transwell membranes and of the duration of air-liquid interface culture was assessed. Compounds were applied in solution and as aerosols generated by MicroSprayer IA-1C Aerosolizer or by DP-4 Dry Powder Insufflator using fluorescein and rhodamine 123 as model compounds. Budesonide and formoterol, singly and in combination, served as examples for drugs relevant in pulmonary delivery. RESULTS AND CONCLUSIONS: Membrane material and duration of air-liquid interface culture had no marked effect on mucus production and tightness of the cell monolayer. Co-application of budesonide and formoterol, applied in solution or as aerosol, increased permeation of formoterol across cells in air-liquid interface culture. Problems with the DP-4 Dry Powder Insufflator included compound-specific delivery rates and influence on the tightness of the cell monolayer. These problems were not encountered with the MicroSprayer IA-1C Aerosolizer. The combination of Calu-3 cells and manual aerosol generation devices appears suitable to identify interactions of drugs in fixed drug combination products on permeation.

Aclidinium/formoterol fixed-dose combination for the treatment of chronic obstructive pulmonary disease.

This review will be focused on the development of aclidinium bromide/formoterol fumarate (ACLI/FORM) fixed-dose combinations (FDC) that have been granted marketing authorization by the European Commission to be used as a maintenance bronchodilator treatment to relieve symptoms in adult patients with chronic obstructive pulmonary disease (COPD). ACLI/FORM FDC has been studied in 2 pivotal trials involving over 3,400 patients with COPD, in which it was compared with ACLI alone, FORM alone and placebo. The addition of FORM to ACLI resulted in greater bronchodilation than FORM or ACLI alone. ACLI/FORM FDC was also shown to increase the percentage of patients who had an improvement in symptoms and health-related quality of life compared with monotherapies. The frequency of side effects reported with ACLI/FORM FDC was low and their nature did not raise any major safety concern.