PLGA, chitosan or chitosan-coated PLGA microparticles for alveolar delivery? A comparative study of particle stability during nebulization

Colloids Surf B Biointerfaces. 2008 Apr 1;62(2):220-31. doi: 10.1016/j.colsurfb.2007.10.005. Epub 2007 Oct 11.

Abstract

Various types of rifampicin (RIF)-loaded microparticles were compared for their stability during nebulization. Poly(lactide-co-glycolide) (PLGA), chitosan (CHT) and PLGA/CHT microparticles (MPs) were prepared by emulsion or precipitation techniques. MPs ability to be nebulized (NE%) as well as stability during freeze-drying or/and nebulization (NEED%), were evaluated after RIF extraction from MPs and determination by light spectroscopy. MP mean diameters and zeta-potential values were measured by dynamic light scattering, morphology was assessed by SEM, cytotoxicity by MTT method and mucoadhesive properties by mucin association. In all cases, freeze-drying prior to nebulization did not affect EE%, NE or NEED%. In CHT, MPs RIF encapsulation efficiency (EE%) decreased with increasing CHT concentration (viscosity) and CHT-MP NEED% was higher when the polymer was crosslinked by glutaraldehyde. PLGA MPs, exhibited both higher RIF EE% and also higher nebulization ability and NEED%, compared to CHT ones, but also higher cytotoxicity. However, when the two polymers were combined in the PLGA/CHT MPs, EE%, NE% and NEED% increased with increasing MP CHT-content. PLGA/CHT MPs with 0.50% or 0.75% CHT exhibited highest EE% for RIF and also best nebulization ability and stability, compared to all other MP formulations studied. Additionally they had good mucoadhesive properties and comparably low cytotoxicity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adhesiveness
  • Administration, Inhalation
  • Antibiotics, Antitubercular / administration & dosage*
  • Antibiotics, Antitubercular / pharmacokinetics
  • Cell Line
  • Chemical Phenomena
  • Chemistry, Physical
  • Chitosan / pharmacology*
  • Chitosan / toxicity
  • Diffusion
  • Drug Compounding / methods
  • Drug Delivery Systems
  • Drug Stability
  • Electrochemistry
  • Emulsions
  • Humans
  • Lactic Acid / pharmacology*
  • Lactic Acid / toxicity
  • Microscopy, Electron, Scanning
  • Microspheres*
  • Molecular Weight
  • Mucins / chemistry
  • Mucous Membrane / metabolism
  • Nebulizers and Vaporizers
  • Particle Size
  • Polyglycolic Acid / pharmacology*
  • Polyglycolic Acid / toxicity
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polymers / pharmacology*
  • Polymers / toxicity
  • Pulmonary Alveoli / metabolism*
  • Rifampin / administration & dosage*
  • Rifampin / pharmacokinetics
  • Solvents
  • Tetrazolium Salts
  • Thiazoles

Substances

  • Antibiotics, Antitubercular
  • Emulsions
  • Mucins
  • Polymers
  • Solvents
  • Tetrazolium Salts
  • Thiazoles
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid
  • Chitosan
  • thiazolyl blue
  • Rifampin