IVIVC from Long Acting Olanzapine Microspheres

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Biopharmaceutics

Background:

• Poly(lactic-co-glycolic) acid (PLGA) microspheres are widely used for long-acting injectable formulations.
• Establishing an in vitro-in vivo correlation (IVIVC) is critical for predicting drug performance and ensuring product quality.

Purpose of the Study:

• To characterize Olanzapine PLGA microsphere formulations.
• To establish a Level A IVIVC by correlating in vitro drug release with in vivo absorption.
• To evaluate alternative methods for in vivo data analysis.

Main Methods:

• Four Olanzapine PLGA microsphere formulations were prepared and characterized.
• In vitro drug release was assessed using a dialysis method at 37°C.
• In vivo drug release profiles were determined using deconvolution (Nelson-Wagner method) and fractional AUC.

Main Results:

• In vitro and in vivo release profiles showed the same rank order.
• Fractional AUC provided in vivo profiles comparable to the Nelson-Wagner method.
• A statistically significant Level A IVIVC (R² > 0.96) was established, demonstrating a strong correlation between in vitro release and in vivo absorption.

Conclusions:

• A Level A IVIVC can be successfully established for Olanzapine PLGA microspheres.
• Fractional AUC is a viable alternative to the Nelson-Wagner method for in vivo data analysis.
• Appropriate in vitro methods are essential for developing reliable IVIVCs for long-acting injectable products.