![]() ![]() The scattering angle is small (30° or less).The particle size is relatively large (at least, 10 times the laser wavelength).This approximate expression can be used only when the following two conditions are satisfied: In a word, the Fraunhofer diffraction theory is one of the approximate expressions of the Mie scattering theory. Let's take a look at the relationship between the Fraunhofer diffraction theory and Mie scattering theory. However, in actual measurement of particle size distribution, the measurement time is not affected at all since there are parameter tables already calculated and stored in computer memory. That is, these theories are used to calculate what kind of light intensity distribution patterns are produced by particles of various sizes, and this data is stored beforehand on a computer as a parameter table (numerical table) containing a vast amount of information.Ī considerable amount of time is required for calculating this parameter table. The Fraunhofer diffraction theory and Mie scattering theory are used to obtain this relationship. For this, the correspondence relationship between particle size and light intensity distribution pattern must be known in advance. Philadelphia: Lea & Febiger.With the laser diffraction/scattering method, particle size is specified from the light intensity distribution pattern. The theory and practice of industrial pharmacy (3rd ed.). Pharmaceutics: The Science of dosage form design. Sizing technique for sulfur? Hint: How many types of sulfur preparation available? PHM3133 Dosage Design 1 2010/11 Selecting instrument Need to consider: allowable range of sizes width & shape of the particle size distribution of sample PHM3133 Dosage Design 1 2010/11 Salicylic acid 100X coalescence PHM3133 Dosage Design 1 2010/11 Light microscope O/W emulsion 10X O/W emulsion 40X PHM3133 Dosage Design 1 2010/11 Light microscope Salicylic acid 10X Salicylic acid 40X PHM3133 Dosage Design 1 2010/11 Microscopy Almost all types of samples Depends on type of microscopy Depends on magnification Sample preparation is important PHM3133 Dosage Design 1 2010/11 ![]() Laser diffraction Suitable for: Powder Diluted liquid Concentrated liquid? Right lens and parameters e.g. Sieves Suitable for: Powder Slurry Dispersion Right sieves with appropriate size interval PHM3133 Dosage Design 1 2010/11 Laser microscopy PHM3133 Dosage Design 1 2010/11.Statistics PHM3133 Dosage Design 1 2010/11.Most of the time not actual diameter BUT equivalent diameter.Can the technique employed analyseneat sample? PHM3133 Dosage Design 1 2010/11.Will there be changes in zeta potential that may affect stability?.Can you use Coulter principle to measure size of fine sugar?.Spherical PHM3133 Dosage Design 1 2010/11.Granular equidimensional irregular shape.Exercise: how to counter this problem when using Coulter?.Suspensions/dispersions PHM3133 Dosage Design 1 2010/11.Exercise: how about laser diffraction? PHM3133 Dosage Design 1 2010/11.Coulter counter - at least two apertures.Measurements must be carried out more than once.Magnification? Limitation? PHM3133 Dosage Design 1 2010/11.Products + fines?.SKEWED PHM3133 Dosage Design 1 2010/11.How to detect the size of a sample that contains.To control processes IN manufacturing, need to knowsize of raw materials, in-process materials and finished goods.Pore size of cloth must be smaller than dust.WHAT IS THE SPECIFICATION of the filter cloth? PHM3133 Dosage Design 1 2010/11 Eventually, the fines must be trapped using a dust filter. To separate fines from product, a series of cyclones were used. to prepare the right material for the expected function PHM3133 Dosage Design 1 2010/11Įxample After size reduction, lots of fines were generated because of bad process condition.correct scale of observation e.g.right sizing method.Interactions between materials and processes PHM3133 Dosage Design 1 2010/11Įxamples of particle-related advances 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. Specific operations dehydration/impregnation, spherical crystallization and the series of operations involved in micro-encapsulation.granules become tablets etc PHM3133 Dosage Design 1 2010/11.Particle Size Analysis Kausar Ahmad Kulliyyah of Pharmacy PHM3133 Dosage Design 1 2010/11Ĭontents Types of methods Factors influencing selection of methods PHM3133 Dosage Design 1 2010/11 ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |