particle size analysis
DESCRIPTION
Particle Size Analysis. Kausar Ahmad Kulliyyah of Pharmacy. http://staff.iiu.edu.my/akausar. Contents. Types of methods Factors influencing selection of methods. Fundamental knowledge. molecules become particles particles become granules granules become tablets etc. - PowerPoint PPT PresentationTRANSCRIPT
KAUSAR AHMADKULLIYYAH OF PHARMACY
PHM3133 Dosage Design 1 2010/11
1
Particle Size Analysis
http://staff.iiu.edu.my/akausar
Contents
PHM3133 Dosage Design 1 2010/11
2
Types of methods
Factors influencing selection of methods
Fundamental knowledge
PHM3133 Dosage Design 1 2010/11
3
molecules become particles
particles become granules
granules become tablets etc
Process requirements
PHM3133 Dosage Design 1 2010/11
4
From crystallization to formulation formation of particles drying granulation mixing compression dissolution
Specific operations dehydration/impregnation, spherical crystallization and the series of operations involved in micro-encapsulation.
Examples of particle-related advances
PHM3133 Dosage Design 1 2010/11
5
use of cholesteric liquid crystals and custom microencapsulation technologies in the personal care industry… www.hallcrest.com/about
microencapsulation technology to deliver omega-3 oils and other ingredients into functional foods.... www.ocean-nutrition.com/inside.asp?cmPageID
PHM3133 Dosage Design 1 2010/11
6
http://www.swri.org/3pubs/brochure/d01/microen/microen.htm
Interactions between materials and processes
PHM3133 Dosage Design 1 2010/11
7
Influenced by particle size
Need to choose correct scale of observation
e.g.right sizing method appropriate parameters
e.g. right aperture, lens, medium right measurements
e.g. calibrated, good quality standards to prepare the right material for the expected
function
Example
PHM3133 Dosage Design 1 2010/11
8
After size reduction, lots of fines were generated because of bad process condition.
To separate fines from product, a series of cyclones were used.
Eventually, the fines must be trapped using a dust filter.
WHAT IS THE SPECIFICATION of the filter cloth?
How to determine spec of cloth?
PHM3133 Dosage Design 1 2010/11
9
Filter cloth is used to trap dustPore size of cloth must be smaller than dust
Hence, must know size of fines!! To control processes IN manufacturing, need to
knowsize of raw materials, in-process materials and finished goods.
Size distribution of products & fines
PHM3133 Dosage Design 1 2010/11
10
How to detect the size of a sample that contains
Products? ………………. normal distribution
Fines?....................................normal distribution
Products + fines?..............SKEWED
What method to choose?
PHM3133 Dosage Design 1 2010/11
11
Can sieving be used? Must consider screen size….
Coulter counter? Size range for a particular aperture?
Microscopy? Magnification? Limitation?
Sample with wide size distribution
PHM3133 Dosage Design 1 2010/11
12
Not desirable as a product Rate of dissolution differs Processing problem
Fines tend to agglomerate Fines may affect flow
Measurements must be carried out more than once Coulter counter - at least two apertures Exercise: how about laser diffraction?
What to analyse?
PHM3133 Dosage Design 1 2010/11
13
Powders Granules Liquids Emulsions Creams Suspensions/dispersions
Powder samples
PHM3133 Dosage Design 1 2010/11
14
Flowability/dispersibility Poor if too fine. Why? Exercise: how to counter this problem when
using Coulter?
Shape Crystalline – geometric shape Acicular – needle-shape Granular equidimensional irregular shape Spherical
Emulsion samples
PHM3133 Dosage Design 1 2010/11
15
Will the size change upon dilution?
Can you use Coulter principle to measure size of fine sugar?
Will there be changes in zeta potential that may affect stability?
Can the technique employed analyse neat sample?
Dimensions
PHM3133 Dosage Design 1 2010/11
16
Diameter Most of the time not actual diameter BUT
equivalent diameter Mean Mode
Size distribution Normal Skewed
PolydispersityParticle shapeStatistics
Availability and cost
PHM3133 Dosage Design 1 2010/11
17
Cheap
Sieves
Moderate
Light microscopy
Coulter counter
Laser diffraction
Sedimentation
Expensive
Electron microscopy
Light scattering
Laser microscopy
Sieves
PHM3133 Dosage Design 1 2010/11
18
Suitable for:
Powder
Slurry
Dispersion
Right sieves with appropriate size interval
Laser diffraction
PHM3133 Dosage Design 1 2010/11
19
Suitable for:
Powder
Diluted liquid
Concentrated liquid?
Right lens and parameters e.g. density
Microscopy
PHM3133 Dosage Design 1 2010/11
20
Almost all types of samples
Depends on type of microscopy
Depends on magnification
Sample preparation is important
Salicylic acid 10X Salicylic acid 40X
PHM3133 Dosage Design 1 2010/11
21
Light microscope
O/W emulsion 10X O/W emulsion 40X
PHM3133 Dosage Design 1 2010/11
22
Light microscope
Salicylic acid 100X
PHM3133 Dosage Design 1 2010/11
23
coalescence
Selecting instrument
PHM3133 Dosage Design 1 2010/11
24
Need to consider:
allowable range of sizes
width & shape of the particle size distribution of sample
Sample Technique
Silica gel: 5-300 um Light microscopy: mag?
Granules: ave. 200 um SEM: mag?
Aspirin, grounded TEM: mag?
Eye cream Sieves: size?
Calamine-ZnO lotion Laser diffraction: lens?
Polystyrene dispersion Viscosity
Microemulsion of cod oil Photon correlation
Colloidal sulfur Coulter counter: aperture?
Bentonite clay dispersion
Polarised light microscopy: mag?
Surfactant Atomic Force Microscopy
PHM3133 Dosage Design 1 2010/11
25
Sizing technique for sulfur?
PHM3133 Dosage Design 1 2010/11
26
Hint: How many types of sulfur preparation available?
References
PHM3133 Dosage Design 1 2010/11
27
Aulton, M. E. (1988). Pharmaceutics: The Science of
dosage form design. London: Churchill
Livingstone.
Llachman, L, Lieberman, H. A. and Kanig, J. L.
(1986). The theory and practice of industrial
pharmacy (3rd ed.). Philadelphia: Lea & Febiger.