Cationic polymer precipitation for enhanced impurity removal in downstream processing.

Area of Science:

• Biopharmaceutical Manufacturing
• Downstream Process Development
• Protein Purification

Background:

• Impurities like host cell proteins (HCPs) and DNA can compromise biologic product quality and stability.
• Early-stage impurity removal is crucial for efficient downstream purification processes.
• Polysorbate excipient stability is vital for maintaining drug efficacy and shelf life.

Purpose of the Study:

• To evaluate polyallylamine (PAA) precipitation for enhanced host cell protein (HCP) removal in biologic purification.
• To assess the impact of PAA precipitation on polysorbate excipient stability and product shelf life.
• To optimize PAA precipitation conditions using high-throughput screening and process analytical tools (PATs).

Main Methods:

• High-throughput screening of PAA precipitation conditions (pH, conductivity, concentration).
• Utilized process analytical tools (PATs) for particle size analysis.
• Scaled up precipitation to 20L and characterized impurity removal using ELISA, mass spectrometry, and DNA assays.
• Analyzed residual PAA and product quality attributes.

Main Results:

• Achieved >75% reduction in HCP concentration, >90% reduction in HCP species, and >99.8% reduction in DNA.
• Improved polysorbate-containing formulation buffer stability by at least 25% for three monoclonal antibodies (mAbs).
• Observed minimal impact on product quality with <5% yield loss and residual PAA <9 ppm.

Conclusions:

• PAA precipitation is a valuable tool for enhancing HCP and DNA clearance in biologic downstream purification.
• This method improves excipient stability, enabling longer product shelf life.
• PAA precipitation integrates effectively with existing purification platforms, offering solutions for challenging purification programs.