Hollow fiber membranes, characterized by their unique porous structure, high separation efficiency, and low shear stress properties, are widely employed in pharmaceutical production and serve as key materials in drug separation and purification processes.

During operation, hollow fiber membranes are susceptible to contamination and fouling, which can result in diminished membrane flux and separation efficiency. Physical or chemical cleaning methods can be utilized to remove contaminants from the membrane surface and pores, thereby restoring their initial filtration performance.

It can also effectively prevent cross-contamination between batches, eliminate contaminants and residual residues, prevent microbial and pyrogenic contamination, maintain process flux and production efficiency, ensure stable yield and product quality, and maximize service life through thorough cleaning.

Figure 1. Hollow Fiber Usage Process

Recommended Cleaning Agents and Temperature Parameters

Cleaning agents must:

• Be compatible with hollow fiber modules and hardware systems
• Be fully removable post-cleaning
• Have verifiable removal efficacy
• Utilize commonly available chemical types

The following table contains common contaminants and corresponding cleaning protocols.

Table 1. Commonly Used Cleaning Agents and Temperature Recommendations

Cleaning Process Development Methodology

Cleaning efficacy evaluation: Measure water flux recovery rate pre- and post-cleaning using the formula:

Recommended Ceaning Strategies:

• Implement NaClO treatment followed by acidic cleaning agents, with post-storage testing
• Evaluate comprehensively through process flux, product quality, and NWP recovery metrics
• Cleaning efficacy enhancement hierarchy: Temperature elevation > Extended cleaning duration > Increased tangential flow velocity
• For initial use, develop CIP methods achieving ≥70% NWP recovery
• Conduct pre-/post-use NWP comparisons under identical test parameters (tangential flow velocity, TMP)
• Monitor post-storage NWP for slow-release contaminants

Table 2. Recommendations for Cleaning Process Development

Cleaning Sequence Schematic

Tips:

Keep cleaning records and record relevant test processes and parameters

Cleaning Efficacy Demonstration

Typical NWP recovery rates: 70-80% post-cleaning

Process flux averages: ~30 LMH for first 4 cycles, ~23 LMH for subsequent 6 cycles (varies with material batches)

Case Study

Optimized cleaning protocols significantly improved yield retention during second reuse cycle.
For nucleic acid-based contaminants resistant to alkaline cleaning, acid washing is recommended.

Post-Cleaning Storage Recommendations

Tips:

• Never store dried or frozen
• Maintain storage solution sealed within hollow fiber cartridges
• Optimal storage: 4°C refrigeration (≤25°C maximum), protected from direct sunlight
• Replace storage solution monthly initially; adjust replacement frequency based on validation studies