Presentation on theme: "KAUSAR AHMAD KULLIYYAH OF PHARMACY PHM3133 Dosage Design 1 2010/11 1 Particle Size Analysis"— Presentation transcript:
KAUSAR AHMAD KULLIYYAH OF PHARMACY PHM3133 Dosage Design /11 1 Particle Size Analysis
Contents PHM3133 Dosage Design /11 2 Types of methods Factors influencing selection of methods
Fundamental knowledge PHM3133 Dosage Design /11 3 molecules become particles particles become granules granules become tablets etc
Process requirements PHM3133 Dosage Design /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 /11 5 use of cholesteric liquid crystals and custom microencapsulation technologies in the personal care industry… microencapsulation technology to deliver omega-3 oils and other ingredients into functional foods....
PHM3133 Dosage Design /11 6
Interactions between materials and processes PHM3133 Dosage Design /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 /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 /11 9 Filter cloth is used to trap dust Pore size of cloth must be smaller than dust Hence, must know size of fines!! To control processes IN manufacturing, need to know size of raw materials, in-process materials and finished goods.
Size distribution of products & fines PHM3133 Dosage Design /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 /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 /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 /11 13 Powders Granules Liquids Emulsions Creams Suspensions/dispersions
Powder samples PHM3133 Dosage Design /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 /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 /11 16 Diameter Most of the time not actual diameter BUT equivalent diameter Mean Mode Size distribution Normal Skewed Polydispersity Particle shape Statistics
Sizing technique for sulfur? PHM3133 Dosage Design /11 26 Hint: How many types of sulfur preparation available?
References PHM3133 Dosage Design /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 (3 rd ed.). Philadelphia: Lea & Febiger.