Dissolution properties of praziquantel--PVP systems

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Praziquantel (PZQ) is a poorly water-soluble drug used to treat schistosomiasis.
• Improving PZQ's dissolution and bioavailability is crucial for effective treatment.

Purpose of the Study:

• To characterize the dissolution behavior of PZQ from physical mixtures and coprecipitates with polyvinylpyrrolidone (PVP).
• To compare the release kinetics of PZQ from different PZQ-PVP systems.
• To investigate the potential formation of a PZQ-PVP complex and its effect on drug release.

Main Methods:

• Preparation of PZQ-PVP physical mixtures and coprecipitates at various drug loadings (10-100% w/w).
• Dissolution testing of prepared systems.
• Analysis of release kinetics using established models and percolation theory.

Main Results:

• Coprecipitates showed increased PZQ release compared to intact PZQ, but less than physical mixtures.
• Distinct release behaviors were observed between coprecipitates and physical mixtures.
• PVP presence in coprecipitates led to near zero-order release, supporting PZQ-PVP complex formation.

Conclusions:

• PVP significantly influences PZQ dissolution, with physical mixtures yielding higher release rates than coprecipitates.
• The formation of a PZQ-PVP complex is hypothesized to explain the observed dissolution profiles, particularly the near zero-order release from coprecipitates.
• Percolation theory provides a framework for interpreting the release kinetics of these PZQ-PVP systems.