Alginate microparticles for Polymyxin B Peyer's patches uptake: microparticles for antibiotic oral administration

Area of Science:

• Pharmaceutics and Drug Delivery
• Biomaterials Science
• Microbiology

Background:

• Oral administration of drugs like Polymyxin B (PMB) is often limited by poor bioavailability.
• The Gut Associated Limphoid Tissue (GALT) is a key target for localized drug delivery within the intestine.
• M cells in Peyer's patches offer a pathway for targeted uptake into the GALT.

Purpose of the Study:

• To develop microparticles for improved oral delivery of Polymyxin B (PMB).
• To enhance PMB's oral bioavailability by protecting it within the gastrointestinal tract.
• To facilitate drug delivery to the Gut Associated Limphoid Tissue (GALT) via M cell uptake.

Main Methods:

• Preparation of sub-3-micrometer alginate microparticles using spray-drying.
• Cross-linking of microparticles with calcium ions and chitosan to ensure gastrointestinal resistance.
• Evaluation of PMB loading, alginate/PMB interaction, cross-linking degree, and PMB activity using spectrophotometry, rheology, EDS, and microbiological assays.

Main Results:

• Optimized cross-linking of alginate microparticles enabled effective loading and retention of cationic PMB in gastric conditions.
• Sustained release of PMB was achieved in intestinal fluid.
• The developed microparticle system preserved the biological activity of Polymyxin B.

Conclusions:

• Sub-3-micrometer alginate-chitosan microparticles are a promising system for oral delivery of Polymyxin B.
• This formulation enhances PMB's oral bioavailability and enables targeted delivery to the GALT.
• The method ensures the preservation of the antibiotic's therapeutic efficacy.