Co-sprayed dried antibiotics for dry powder inhalation delivery

Inhaled antiobiotics can potentially be delivered in high concentrations to the site of infection in the airways, with low systemic bioavailability, thus reducing toxicity. Currently antibiotic inhalation therapy is limited to nebulizers (1) which are cumbersome, expensive and require routine maintenance (2). Furthermore, these nebulizer delivery systems have, in general, low efficiency and poor reproductibility of delivery. Dry powder antibiotic inhalation may provide a suitable alternative to drug nebulization for high dose delivery. To the authors knowledge, no combination dry powder antibiotic inhalation product exists, and few studies exist, and few studies report inhalation of micronized antibiotics (3-6). The aim of this study was to assess the in vitro aerosolization suitability of a combination antibiotic product comprimising of doxycycline and ciprofloxacin, as a dry powder (DPI) formulation.