Download presentation
Presentation is loading. Please wait.
Published byKeyon Ketchem Modified over 3 years ago
1
PARTICLE SIZE ANALYSIS
2
Why measure particle size of pharmaceuticals??? Since particle size can affect micromeritics of specimen substance,,,, like 1- “Processability” of powder 2-Final formulation
3
Methods for Determining Particle Size 1-Microscopy 2-Sieving 3-Sedimentation
4
Microscopy In this method, small sample size is mounted on the stage of microscope and the particle size is measured using the MICROMETER joined to it…….
5
Advantages : Relatively inexpensive Each particle individually examined Detect aggregates Permanent record – photograph Small sample sizes required For submicron particles, Electron microscopy can be performed.
6
DISADVANTAGES : Time consuming High operator fatigue No information about 3D,, just 2D info about specimen particles In case of electron microscopy, materials such as emulsions difficult/impossible to prepare.
7
SIEVING It is based upon WEIGHT DISTRIBUTION. Sieve analysis is performed using a nest or stack of sieves where each lower sieve has a smaller aperture size than that of the sieve above it. Approx. size range : 5μm - ~3mm
8
METHOD Sieving may be performed wet or dry, by machine or by hand, for a fixed time or until powder passes through the sieve at a constant low rate -Machines: – Shaking – Vibration – Use a jet of air to clear the sieves – Ultrasonics (wet sieving)
10
ADVANTAGES : Easy to perform Wide size range Inexpensive
11
DISADVANTAGES : Known problems of reproducibility Wear/damage in use or cleaning Irregular/agglomerated particles Rod-like particles : overestimate of under-size Labour intensive
12
Sedimentation Techniques: It is based upon WEIGHT DISTRIBUTION. These methods depend on the fact that the terminal velocity of a particle in a fluid increases with size. It follows Stoke’s Law,, states;
13
METHOD:
14
ADVANTAGES: Equipment required can be relatively simple. Inexpensive Can measure a wide range of sizes with accuracy and reproducibility.
15
DISADVANTAGES: Large particles create turbulence, are slowed and are recorded undersize. Particle re-aggregation during extended measurements. Particles have to be completely insoluble in the suspending liquid.
Similar presentations
© 2018 SlidePlayer.com Inc.
All rights reserved.
Ppt on pi in maths what is pi Ppt on environmental pollution and control Ppt on l&t finance limited Ppt on computer network security Ppt on nonverbal communication body language Ppt on job evaluation template Mba presentation ppt on functions of management Ppt on different solid figures Ppt on event handling in java Ppt on statistics in maths sign