Development of ciprofloxacin-loaded poly(vinyl alcohol) dry powder formulations for lung delivery

Polymeric microparticles are micro carriers for the sustained drug delivery of drugs in the lungs, used as alternatives to the use of established excipients. This study aims to develop and characterize inhalable ciprofloxacin (CPx)-loaded poly(vinyl alcohol) (PVA) microparticles by a single-step spray-drying procedure. The optimization of the processing parameters was achieved by an orthogonal design of the most relevant processing parameters (polymer concentration, feed rate and inlet temperature). The obtained spray-dried particles showed a drug encapsulation efficiency higher than 90%. Furthermore, PVA-CPx formulations, with drug contents up to 10 wt%, showed a morphology and size suitable for inhalation, with a sustained release profile over 24 h. Data from Fourier transformed infra-red spectroscopy and differential scanning calorimetry indicated absence of interaction between the polymer matrix and the drug. Aerodynamic assessment of PVA CPx 10wt% was determined by the next generation impactor (NGI), using spray-dried CPx as a control. The results showed improved values of mass median aerodynamic diameter (5.06 +/- 0.10 mu m) and a fine particle fraction (39.78 +/- 0.98%) when comparing with the CPx alone (5.33 +/- 0.39 mu m and 30.43 +/- 1.38%). This study highlights the potential of spray-dried PVA microparticles as drug carriers for lung local delivery of antibiotics.