Enhanced nasal retention of hydrophobically modified polyelectrolytes

Area of Science:

• Polymer Science
• Biomaterials Science
• Drug Delivery

Background:

• Hydrophobically modified polyelectrolytes (HMP) integrate ionizable and hydrophobic groups.
• Pluronic-poly(acrylic acid) copolymers are a class of HMP with temperature-dependent solubility and bioadhesive properties.
• These copolymers exhibit sol-gel transitions at body temperature, suggesting potential for in-situ gelling formulations.

Purpose of the Study:

• To evaluate the hypothesis that Pluronic-poly(acrylic acid) copolymers enhance nasal retention.
• To compare the nasal retention of these HMP with conventional bioadhesive and thermogelling polymers.
• To investigate the combined bioadhesive and thermogelling effects on drug delivery in the nasal cavity.

Main Methods:

• Utilized a rat model to assess nasal clearance of fluorescent labels.
• Compared Pluronic-poly(acrylic acid) copolymers with Carbomer 934P (bioadhesive) and Pluronic F127 (thermogelling).
• Quantified the enhancement in residence time of fluorescent labels in the nasal cavity for each polymer formulation.

Main Results:

• Pluronic-poly(acrylic acid) copolymers demonstrated a 5-8 fold enhancement in residence time compared to Carbomer 934P.
• These HMP showed a 3-6 fold greater residence time enhancement than Pluronic F127.
• The combined bioadhesive and thermogelling properties of HMP led to superior nasal retention.

Conclusions:

• Pluronic-poly(acrylic acid) copolymers exhibit significantly enhanced nasal retention compared to purely bioadhesive or thermogelling polymers.
• The combination of bioadhesive and thermogelling characteristics is key to superior retention.
• These HMP represent a promising platform for improved nasal drug delivery systems.