Lower respiratory infections were the leading cause of sickness and mortality in 2013.1 The treatment of such infections relies on antibiotic therapy. However, antibiotic resistance to human pathogens and the prevalence of new cancer types continues to increase, so it is imperative not only to discover new lead-like drugs agents, but also develop new drug delivery systems for pulmonary diseases.2,3 In order to achieve such goal, it was isolated and elucidated antibacterial compounds from a marine-sediment-derived Actinobacteria, collected along Madeira archipelago. These bioactive compounds were obtained from Streptomyces aculeolatus, PTM-029, belonging to the MAR4 group. The structures of these compounds were elucidated by 1D and 2D NMR, HR-MS and other spectroscopic data. The antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium EF82 (VRE) were determined for the most promising compound isolated from PTM-029, with a minimum inhibitory concentration (MIC) of 1,95 μg/mL for both bacterial pathogens. Subsequently, chitosan and cholesterol-based dry powder formulations were manufactured, containing encapsulated POxylated polymer, efficiently synthesized using a supercritical-assisted polymerization in carbon dioxide (CO2), end-capped to a model drug ibuprofen (IBP) and a marine bioactive compound, PTM-029, F4, F39. The dry powder formulations (DPF) were then synthesized through the Supercritical Assisted Spray-Drying (SASD) technique. All the produced DPFs were characterized in detail in relation to their morphology, physical-chemical properties and aerodynamic performance. The resulting particles showed good aerodynamic diameters between the 1 and 7 μm, yields up to 45% and FPF percentages rounding the 71%, as well as the required morphology to make them suitable for pulmonary delivery
