Particle Surface Charge Determination

Accurate determination of particle surface charge is a critical step in the physical and chemical analysis of pharmaceutical formulations. Surface charge, typically measured as zeta potential, plays a significant role in the stability, bioavailability, and overall efficacy of pharmaceutical products. Protheragen-ING Lab offers comprehensive particle surface charge determination services to support the development and optimization of your pharmaceutical formulations.

Importance of particle surface charge

• Stability: The surface charge affects the colloidal stability of suspensions. A high zeta potential indicates strong repulsive forces between particles, preventing aggregation and sedimentation, which is critical for maintaining the homogeneity and stability of liquid formulations.
• Bioavailability: The surface charge can influence the interaction of particles with biological membranes, impacting the drug's absorption and bioavailability. Understanding and optimizing this parameter ensures effective drug delivery.
• Efficacy: Surface charge affects the distribution and release profile of active pharmaceutical ingredients (APIs). By controlling the surface charge, we can enhance the therapeutic efficacy of the drug.

Fig. 1 Cationic nanoparticles are more prone to enter the cells by electrostatic attraction of negatively charged cell membrane^[1].

Our particle surface charge determination services

Our laboratories are equipped with state-of-the-art instrumentation and experienced scientists to provide reliable particle surface charge determination services. Our team is experienced in handling a wide range of drug product samples, ensuring that formulation integrity is maintained throughout the analytical process. We provide comprehensive reports, including detailed data interpretation and recommendations for optimizing formulations based on surface charge analysis.

Zeta Potential Analysis

The electrostatic potential of the sliding plane of particles suspended in a liquid medium is measured to provide a quantitative assessment of surface charge. We employ advanced techniques such as electrophoretic light scattering (ELS) and laser Doppler electrophoresis to measure the potential of particles in a wide range of formulations.

Fig. 2 The origin of zeta potential^[2].

Isoelectric Point Determination

Determines the pH at which the net surface charge of particles is zero, a key parameter for understanding colloidal stability.

Electrophoretic Mobility Measurements

Characterizes the motion of charged particles in an applied electric field, allowing the calculation of potential.

These analyses are performed according to established pharmacopeia methods and industry best practices to ensure accurate and reproducible results.

Applications

Our particle surface charge determination services are applicable to various pharmaceutical formulations, including:

• Suspensions: Ensuring stability and preventing aggregation of APIs in liquid form.
• Emulsions: Enhancing the stability and uniformity of oil-in-water or water-in-oil emulsions.
• Nanoparticles: Optimizing the surface properties of nanoparticles for targeted drug delivery.
• Powders: Understanding the flow and compaction properties of powdered formulations.

For more information about our particle surface charge determination services or to discuss your specific project requirements, please contact us.