Microsphere delivery of Risperidone as an alternative to combination therapy

Area of Science:

• Pharmacology
• Materials Science
• Drug Delivery Systems

Background:

• Parenteral Risperidone delivery aims to improve patient compliance by reducing oral medication needs.
• Achieving both initial and sustained release is crucial for effective antipsychotic therapy.

Purpose of the Study:

• To develop a novel parenteral Risperidone delivery system using poly (D,L-lactide-co-glycolide) (PLGA) microspheres.
• To optimize particle size and drug loading for controlled initial and extended Risperidone release in vivo.
• To evaluate the in vivo performance of the developed microspheres compared to a marketed product.

Main Methods:

• PLGA microspheres encapsulating Risperidone were prepared using solvent extraction/evaporation.
• Microspheres were characterized for drug content (HPLC), particle size (laser diffractometry), and morphology (SEM).
• In vivo studies in rats assessed Risperidone and 9-hydroxyrisperidone levels following administration of different microsphere formulations.

Main Results:

• In vivo release profiles were significantly influenced by microsphere particle size and drug loading.
• Larger particles and higher drug loading (Formulation C) resulted in a smaller initial burst and prolonged drug release.
• Formulation C demonstrated faster achievement of steady-state drug levels compared to the marketed Risperdal Consta®.

Conclusions:

• Optimized Risperidone-loaded PLGA microspheres can provide both initial and sustained therapeutic levels.
• The developed parenteral system has the potential to eliminate the need for oral co-administration, improving patient compliance.
• Formulation C offers a promising alternative to existing parenteral Risperidone treatments, with faster attainment of steady-state concentrations.