SN-38 loading capacity of hydrophobic polymer blend nanoparticles: formulation, optimization and efficacy evaluation

Area of Science:

• * Pharmaceutical Nanotechnology
• * Polymer Science
• * Drug Delivery Systems

Background:

• * Poor drug loading of hydrophobic drugs is a major challenge in nanoencapsulation, often exacerbated by rapid crystallization.
• * Existing methods using FDA-approved polymers like PLGA and PCL in nanoprecipitation can worsen drug loading issues.
• * 7-Ethyl-10-hydroxy-camptothecin (SN-38) is a potent anticancer drug with poor solubility, necessitating advanced delivery systems.

Purpose of the Study:

• * To investigate if a dual-hydrophobic polymer nanoparticle core enhances drug loading of SN-38 compared to single-polymer systems.
• * To optimize the Poly(lactic-co-glycolic acid) (PLGA)/Polycaprolactone (PCL) ratio and Lutrol®F127 addition for maximizing SN-38 loading.
• * To achieve nanoparticle formulations with suitable size for passive tumor targeting and assess their biocompatibility and efficacy.

Main Methods:

• * Utilized nanoprecipitation with a D-optimal design to optimize the PLGA/PCL ratio and Lutrol®F127 concentration.
• * Analyzed drug/polymer and polymer/polymer interactions to confirm miscibility and compatibility.
• * Conducted in vitro toxicity and efficacy studies using SW-480 cell line and evaluated blood circulation profiles.

Main Results:

• * The dual-polymer core demonstrated significantly higher SN-38 loading capacity due to polymer miscibility and compatibility.
• * Optimized nanoparticles exhibited acceptable size for passive tumor targeting.
• * Blank nanoparticles showed good biocompatibility, while drug-loaded nanoparticles displayed enhanced in vitro efficacy compared to free SN-38.
• * The optimized formulation achieved a promising blood circulation profile with an elimination half-time of 7.4 hours.

Conclusions:

• * A dual-polymer nanoparticle core strategy effectively overcomes the poor drug loading limitations of hydrophobic drugs like SN-38.
• * The optimized formulation offers a promising platform for improved cancer therapy with enhanced efficacy and pharmacokinetics.
• * This approach holds potential for developing advanced nano-drug delivery systems for poorly soluble therapeutics.