Powder Testing

Standardized Tapped Density Measurement

Tapped density is a fundamental technical parameter used to understand the packing behavior of powders. Pharma Test instruments utilize a controlled mechanical tapping motion to settle a powder sample within a graduated cylinder. The stroke height and the frequency of the taps are strictly regulated to ensure consistency. This process reduces the volume of the powder by eliminating air voids between particles, allowing the instrument to determine the final tapped density, which is critical for determining storage requirements and packaging dimensions.

Calculation of Hausner Ratio and Compressibility Index

The relationship between bulk density and tapped density provides a technical indication of a powder's flowability. Pharma Test systems automatically facilitate the calculation of the Hausner Ratio and the Carr's Compressibility Index. A high ratio indicates significant inter-particulate friction and poor flow, whereas a low ratio suggests a free-flowing powder. These indices are indispensable for quality control laboratories to validate the suitability of a raw material for high-speed tableting processes.

Powder Flow Rate Through an Orifice

To evaluate how a powder will discharge from a hopper or feeder, Pharma Test offers instruments that measure flow through an orifice. This technical procedure involves timing the passage of a standardized quantity of material through funnels with varying diameters. The result, expressed as mass per unit of time, allows for the characterization of the kinetic flow properties. This data is essential for setting up production machinery and ensuring that the die fill remains constant throughout the manufacturing run.

Angle of Repose and Internal Friction Analysis

The angle of repose is a technical measurement of the steepest angle of a stable powder heap. Pharma Test systems allow for the precise determination of this angle by measuring the height and radius of the cone formed by the falling powder. A smaller angle indicates a free-flowing material, while a larger angle suggests cohesive forces. This measurement is a key indicator of the internal friction between particles and is used to predict the behavior of powders during mixing and transport.

Sieve Analysis and Particle Size Distribution

Particle size distribution significantly affects both flow and density. Pharma Test provides sieve shaking instruments designed for the dry separation of powders into different size fractions. By using a stack of standardized sieves with decreasing mesh sizes, the instrument uses electromagnetic or mechanical vibration to sort particles. This technical analysis ensures that the particle size remains within the specified range to prevent segregation and ensure that the dissolution profile of the final dosage form is not compromised.

Mechanical Stroke and Frequency Precision

In tapped density testing, the precision of the mechanical stroke is vital for compliance with EP and USP standards. Pharma Test instruments are engineered to maintain a constant stroke height (typically 3mm or 14mm) and a consistent tapping frequency. This level of mechanical precision ensures that the energy imparted to the powder sample is identical across different laboratories, facilitating method transfer and global standardization of quality control protocols.

Modular Design for Different Cylinder Volumes

To accommodate varying sample availability and density ranges, Pharma Test instruments feature a modular design that supports different sizes of graduated cylinders. Whether using 10ml, 100ml, or 250ml cylinders, the system maintains the same technical tapping parameters. This flexibility allows researchers to perform accurate density measurements even when dealing with expensive active pharmaceutical ingredients (APIs) available only in limited quantities.

Data Integration and Reporting Excellence

Modern powder testing requires documented proof of compliance. Pharma Test galenic instruments can be connected to printers or computer systems to generate detailed reports. These reports include all primary data such as initial volume, final volume, number of taps, and the calculated density values. This technical documentation provides a clear audit trail, ensuring that the physical characteristics of every batch are recorded and stored for regulatory review and manufacturing optimization.

Read more about Pharma Test Powder Testing