Stability study of sodium colistimethate-loaded lipid nanoparticles

Area of Science:

• Pharmaceutical Nanotechnology
• Drug Delivery Systems
• Infectious Disease Therapeutics

Background:

• Antibiotic encapsulation in nanoparticulate carriers is crucial for treating infections.
• Pulmonary infections in cystic fibrosis patients often involve Pseudomonas aeruginosa.
• Sodium colistimethate is a key antibiotic for treating multidrug-resistant Gram-negative bacteria.

Purpose of the Study:

• To develop and evaluate the stability of sodium colistimethate-loaded solid lipid nanoparticles (Colist-SLNs) and nanostructured lipid carriers (Colist-NLCs).
• To assess the suitability of these nanoparticles for treating pulmonary infections in cystic fibrosis patients.
• To compare the long-term stability and antimicrobial efficacy of Colist-SLNs and Colist-NLCs.

Main Methods:

• Design and preparation of Colist-SLNs and Colist-NLCs using trehalose as a cryoprotectant.
• Stability analysis over one year following International Conference on Harmonisation (ICH) guidelines.
• Determination of minimum inhibitory concentration (MIC) against Pseudomonas aeruginosa.
• Assessment of physico-chemical characteristics at various storage conditions.

Main Results:

• Colist-SLNs lost antimicrobial activity within three months.
• Colist-NLCs maintained adequate antibacterial activity (MIC ≤16 μg/mL) throughout the one-year study.
• Colist-NLCs exhibited stable physico-chemical properties at 5°C and 25°C/60% relative humidity for one year.
• Colist-NLCs demonstrated significantly better stability compared to Colist-SLNs.

Conclusions:

• Colist-NLCs represent a more stable and effective nanoparticulate system for colistimethate delivery compared to Colist-SLNs.
• The enhanced stability of Colist-NLCs supports their potential as a therapeutic option for cystic fibrosis-related pulmonary infections.
• Further research into Colist-NLCs could lead to improved treatment strategies for challenging bacterial infections.