Interfacial Properties of Suspended Particles are key in drug formulation, emulsions, and colloidal systems. It influences, aggregation, and dispersion in suspensions. At the interface between suspended particles and the surrounding liquid, several key properties affect the behavior and stability of the suspension: Interfacial Tension Exists between the solid particle surface and the liquid. Higher tension … Read more
Definition of Coarse Dispersion: A coarse dispersion is a type of dispersed system where the dispersed phase (particles) is relatively large in size (usually greater than 1 µm) and is distributed throughout a continuous phase (usually a liquid). Examples: Suspensions and emulsions. Contrast with: Colloidal dispersions (1 nm – 1 µm) True solutions (molecular size) … Read more
Definition of Suspensions: A suspension is a heterogeneous system in which insoluble solid particles (dispersed phase) are suspended in a liquid medium (dispersion medium). Applications in Pharmaceutics: Used to administer insoluble drugs orally, topically, or parenterally Examples: Antacids (e.g., aluminum hydroxide), antibiotics (e.g., amoxicillin suspension) Desirable Properties of Suspensions: Uniform particle size Stability (no rapid … Read more
Elastic Modulus (Young’s Modulus) helps assess strength in engineering and material science. Elastic Modulus (Young’s Modulus) measures material stiffness, showing stress–strain relationship. Definition: The ratio of stress to strain in the elastic region of the stress-strain curve. Measured in Pascals (Pa or N/m²). High E = stiff material (resists elastic deformation). Low E = more … Read more
Stress and Strain help study elasticity, plasticity, and strength of engineering materials. Stress and Strain explain material response—stress is force per area; strains is deformation ratio. Stress (σ) Definition: Stress is the internal force per unit area exerted by a material when an external force is applied. Formula: $\sigma = \frac{F}{A}$ Where: σ = stress … Read more
Purpose of Heckel Equation: The Heckel equation is used to study the compressibility and deformation behavior of powders during tableting. It relates porosity reduction to applied pressure and helps identify whether a material deforms plastically or elastically under compression. Equation: $\ln\!\left(\tfrac{1}{1-D}\right) = KP + A$ Where: D = relative density of the powder (i.e., density … Read more
Elastic and Plastic Deformation explains temporary vs permanent shape changes in materials under stress. Elastic and Plastic Deformation is key in material science for strength, durability, and design. When an external force is applied to a solid, it may change shape or size. This is called deformation. It can be elastic or plastic depending on … Read more
Rotational Viscometer (Brookfield Viscometer) works by measuring torque on a spindle rotating in fluid. Rotational Viscometer (Brookfield Viscometer) measures viscosity of liquids in pharmaceuticals and industries. Principle: Measures the torque required to rotate a spindle at constant speed in the sample. The resistance to rotation is a function of the sample’s viscosity. $\eta \propto \frac{\text{Torque}}{\text{Angular … Read more
Falling Sphere Viscometer (Stoke’s Law Viscometer) is used in labs for accurate fluid viscosity analysis. Falling Sphere Viscometer (Stoke’s Law Viscometer) measures viscosity by tracking a sphere’s fall through liquid. Principle: A ball (usually steel or glass) falls through the test liquid under gravity. The terminal velocity of the ball is used to calculate viscosity, … Read more
Capillary Viscometer (Ostwald Viscometer) measures viscosity by timing liquid flow through a narrow tube. Capillary Viscometer (Ostwald Viscometer) is widely used in labs for comparing fluid viscosities. Principle: Based on Poiseuille’s Law, which describes the laminar flow of liquid through a capillary. Time taken for a fixed volume of liquid to flow between two marks … Read more
