Derived properties of Powders are not directly measurable like particle size but are calculated or observed based on fundamental measurements. They help understand handling, processing, and formulation behavior of powders in pharmaceutical manufacturing. Main derived properties include: Porosity Packing arrangement Densities (true, bulk, tapped) Bulkiness Flow properties

Methods For Determining Surface Area explain techniques to measure particle surface in powders and solids. Methods For Determining Surface Area is a critical parameter in pharmaceutics because it affects dissolution, adsorption, chemical reactivity, and bioavailability. It is especially important for fine powders and porous materials. BET (Brunauer–Emmett–Teller) Adsorption Method Principle: Based on physical adsorption of … Read more

Specific Surface Area refers to the total surface area per unit mass of a material or powder. Specific Surface Area influences solubility, dissolution, reactivity, and pharmaceutical formulations. Definition: Total surface area per unit mass or volume of a material $\text{Specific Surface Area (SSA)} = \frac{\text{Surface Area}}{\text{Mass}}$ Units: m²/g (area per mass) cm²/cm³ (area per volume) … Read more

Particle Shape influences surface area, flow, and packing of powders in pharmaceutical formulations. Particle Shape affects dissolution, stability, bioavailability, and product performance. While most techniques assume spherical particles, real particles often have irregular shapes (needle, plate, cube, etc.). Shape Descriptors: Aspect Ratio = Length / Width Sphericity = Surface area of a sphere with same … Read more

Principle of Andreasen Pipette Method The Andreasen Pipette Method is based on Stokes’ Law, which states that particles settle at a velocity proportional to their size in a fluid. Larger particles settle faster than smaller ones, allowing particle size distribution to be determined by sampling the suspension at fixed depths and times. The method is … Read more

Separation Methods are vital in pharmaceuticals, chemistry, food, and environmental analysis. Separation Methods involve techniques to isolate and purify components from mixtures efficiently. These are based on the physical separation of particles by size, using external forces. Sieving Applicable to coarse particles (>50 µm). A stack of sieves with decreasing mesh size is used. The … Read more

Counting Methods aid in micromeritics, ensuring accuracy in particle size analysis. These are the techniques to determine particle numbers in dispersions and powders. These determine size by counting individual particles and measuring them directly. Microscopy Optical Microscopy: Suitable for particles in the 1–100 µm range. A small amount of sample is spread on a slide, … Read more

Methods For Determining Particle Size explain techniques like microscopy, sieving, and sedimentation. Methods For Determining Particle Size helps in quality control of pharmaceuticals, food, and materials. Particle size can be measured using different principles and instruments. These methods can be broadly classified as: Category Examples of Techniques Counting Methods Optical microscopy, electron microscopy Separation Methods … Read more

Number and Weight Distribution explains particle size analysis based on count and mass of particles. It is the key in micromeritics for drug formulation and quality control. Number Distribution Based on counting the number of particles in each size range. Sensitive to smaller particles. Determined by methods like microscopy or Coulter counter. Weight or Volume … Read more