Continuously producible aztreonam-loaded inhalable lipid nanoparticles for cystic fibrosis-associated Pseudomonas aeruginosa infections - Development and in-vitro characterization

Biomater Adv. 2025 Jan:166:214027. doi: 10.1016/j.bioadv.2024.214027. Epub 2024 Sep 3.

Abstract

Cystic fibrosis (CF) is a genetic disorder affecting nearly 105,000 patients worldwide and is characterized by poor respiratory function due to accumulation of thick mucus in the lungs, which not just acts as a physical barrier, but also provides a breeding ground for bacterial infections. These infections can be controlled with the help of antibiotics which can be delivered directly into the lungs for amplifying the local anti-bacterial effect. More than 50 % of CF patients are associated with Pseudomonas aeruginosa infection in their lungs which requires antibiotics such as Aztreonam (AZT). In this study, we prepared inhalable AZT-loaded lipid nanoparticles using Hot-melt extrusion (HME) coupled with probe sonication to target Pseudomonas aeruginosa infection in the lungs. The optimized nanoparticles were tested for physicochemical properties, stability profile, in-vitro aerosolization, and antimicrobial activity against Pseudomonas aeruginosa. The optimized nanoparticles with a PEI concentration of 0.1 % demonstrated a uniform particle size of <50 nm, a spherical shape observed under a transmission electron microscope, and >70 % drug entrapment. Incorporating cationic polymer, PEI, resulted in sustained drug release from the lipid nanoparticles. The in-vitro aerosolization studies exhibited a mass median aerodynamic diameter (MMAD) of <4.3 μm, suggesting deposition of the nanoparticles in the respirable airway. The antimicrobial activity against Pseudomonas aeruginosa showed the minimum inhibitory concentration of the formulation is 2-fold lower than plain AZT. Stability profile showed the formulations are stable after exposure to accelerated conditions. In conclusion, hot-melt extrusion in combination with probe sonication can be used as a potential method for the continuous production of AZT-loaded lipid nanoparticles with enhanced anti-bacterial activity.

Keywords: Aztreonam; Cystic fibrosis; Hot-melt extrusion; Inhalation; LBF's (lipid based formulations); Nanoparticles; Polyethyleneimine; Scalable production.

MeSH terms

  • Administration, Inhalation
  • Anti-Bacterial Agents* / administration & dosage
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Aztreonam* / administration & dosage
  • Aztreonam* / chemistry
  • Aztreonam* / pharmacology
  • Cystic Fibrosis* / drug therapy
  • Cystic Fibrosis* / microbiology
  • Humans
  • Lipids / chemistry
  • Liposomes
  • Microbial Sensitivity Tests
  • Nanoparticles* / chemistry
  • Particle Size
  • Pseudomonas Infections* / drug therapy
  • Pseudomonas Infections* / microbiology
  • Pseudomonas aeruginosa* / drug effects

Substances

  • Aztreonam
  • Anti-Bacterial Agents
  • Lipids
  • Lipid Nanoparticles
  • Liposomes