In-Situ Forming Polyester Implants for Sustained Intravesical Oxybutynin Release

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Urology

Background:

• Neurogenic detrusor overactivity (NDO) causes bladder dysfunction due to neurological conditions like spinal cord injury.
• Current treatments involve frequent catheterization and oral medications such as oxybutynin hydrochloride.
• There is a need for improved, less invasive treatment options for NDO patients.

Purpose of the Study:

• To investigate a novel in situ forming implant (ISFI) for sustained release of oxybutynin hydrochloride in the urinary bladder.
• To quantify drug release, polymer degradation, and solvent release in vitro for PLGA-based formulations.
• To identify formulation parameters influencing drug release and polymer degradation for NDO treatment.

Main Methods:

• Development and in vitro testing of PLGA-based ISFIs with varying drug loads and polymer terminations.
• Quantification of oxybutynin hydrochloride release profiles over time.
• Assessment of PLGA polymer degradation rates using different formulations and drug concentrations.
• Evaluation of solvent release characteristics.

Main Results:

• Drug load and PLGA termination significantly impacted drug release and polymer degradation.
• Increased drug load (1.5% to 7.5%) enhanced PLGA degradation.
• Oxybutynin base catalyzed polymer degradation; acid-terminated PLGA increased degradation compared to ester-terminated.
• Formulation parameters were identified to control drug release and polymer degradation.

Conclusions:

• A biodegradable ISFI is feasible for NDO treatment, potentially enabling single administration for up to one week.
• This novel implant could significantly improve the quality of life for NDO patients by reducing treatment burden.
• Understanding formulation parameters is key to optimizing drug release and polymer degradation for effective NDO therapy.