This document discusses in-process quality control of suspensions and emulsions. It outlines the importance of in-process quality control to minimize variability, ensure quality, and monitor process variables. Key in-process quality control tests for suspensions include appearance, particle size measurement, drug content uniformity, and redispersibility. Important tests for emulsions include appearance, particle size distribution, phase separation, creaming, coalescence, and breaking. Proper in-process quality control ensures a stable, uniform final product is produced.

1. IN PROCESS QUALITY CONTROL OF
SUSPENSIONS AND EMULSIONS
QUALITY CONTROL AND QUALITY ASSURANCE
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2. CONTENTS
IN PROCESS QUALITY CONTROL
PURPOSE
IMPORTANCE
USFDA -CGMP GUIDELINES
IPQC OF SUSPENSIONS
IPQC OF EMULSIONS
CONCLUSION
REFERENCES

3. IN PROCESS QUALITY CONTROL
▪ IPQC stands for IN PROCESS QUALITY CONTROL .
▪ These are checks that are carried out before the manufacturing process
is completed.
▪ IPQC means controlling the procedures involved in manufacturing of
the dosage form starting from raw material purchase to dispatch of the
quality product in ideal packaging.
▪ Evaluates & monitors products flaws for quality.
▪ Activity performed between QA/QC .
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4. PURPOSE
▪ To ensure detectable and significant human errors.
▪ To minimize inter batch and intra batch variability.
▪ To ensure quality of final product.
▪ To ensure continuous monitoring of process variables which are going
to affect the quality of product.
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5. IMPORTANCE
▪ Provide accurate, specific and definite description of the procedure to
be employed.
▪ It is a planned system to identify the materials, equipment, processes,
and operators.
▪ It is to detect the errors if and when it does occurs.
▪ Is to enforce the flow of manufacturing and packing operation
according to established rules and practice.
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6. USFDA-CGMP GUIDELINES
▪ To assure batch uniformity and integrity of drug product, written
procedures shall be established and followed.
▪ Valid in process specification for such characteristics shall be
constituent with drug product.
▪ In process material shall be tested for identity, strength, quality and
purity.
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7. SUSPENSIONS
▪ It is a biphasic type of system.
▪ Pharmaceutical suspension can be defined as class of dispersed system
in which a finely divided solid is dispersed uniformly in a liquid
dispersion medium.
▪ The insoluble solid may have size range from 10 to 1000 µm.
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8. IPQC TESTS OF SUSPENSIONS
▪ Appearance
▪ Photo microscopic examination
▪ Colour, odour and taste
▪ Density
▪ pH value
▪ Clarity testing
▪ Pourability
▪ Viscosity
▪ Rheology
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9. ▪ Zeta potential measurement
▪ Drug content uniformity
▪ Particle size measurement
▪ Sedimentation rate and sedimentation volume
▪ Redispersibility
▪ Potency test
▪ Preservative effectiveness
▪ Compatibility with primary container-closure system
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10. APPEARANCE
▪ It must appear uniform and elegant .
▪ Particles of suspension should be well distributed.
▪ No hard cake formation of particles
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11. PHOTO MICROSCOPIC EXAMINATION
▪ The suspension is examined for particles size distribution and crystal
habit under the microscope with camera.
▪ It is mainly used for distinguish between flocculated and non-
flocculated particles and to determine changes in the physical
properties.
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12. COLOUR, ODOUR AND TASTE
▪ Features like these especially important in orally administered
suspensions. Variation in colour often indicates poor distribution and/or
differences in particle size. Variation in taste, especially of active
constituents can often be attributed to changes in particle size, crystal
habit and subsequent particle dissolution.
▪ Change in colour, odour and taste can also indicates chemical instability.
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13. DENSITY
▪ Density of the suspension is an important parameter. Decrease in
density indicates the presence of entrapped air with in the structure of
the suspension.
▪ Hydrometers are used to measure the density
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14. PH VALUE
▪ pH of the phases of suspension also contribute to stability and
characteristics of formulations. So pH of the different vehicles, phases
of suspension before mixing and after mixing are monitored and
recorded time to time to ensure optimum pH environment being
maintained.
▪ Different types of methods are used in the measurement of pH.
a)Dip a piece of pH paper into the sample.
b)pH meter
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15. CLARITY TESTING
▪ Clarity testing is carried out to check the particulate matter in the
sample.
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16. POURABILITY
▪ This test is carried out on the phases of suspension after mixing to
ensure that the final preparation is pourable and will not cause any
problem during filling and during handling by patient
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17. VISCOSITY
▪ Stability of a suspension is solely dependant on the sedimentation rate
of dispersed phase which is dependant on the viscosity of the
dispersion medium. So this test is carried out to ensure optimum
viscosity of the medium so a stable, redispersible suspension can be
formed.
▪ The viscosity of the dispersion medium is measured before mixing with
dispersed phase and also viscosity after mixing is determined using
Brook field viscometer.
▪ The calculated values are compared with standard values and if any
difference is found necessary corrective action is taken to get optimized
viscosity.
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18. VISCOSITY MEASUREMENT
▪ The viscosity can be measured by;
a)cup and bob viscometer
b)cone and plate viscometer
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20. PARTICLE SIZE
▪ As the particle size is reduced they tend to exhibit Brownian movement.
▪ So it is necessary to choose the optimum particle size for maximum
stability.
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21. DRUG CONTENT UNIFORMITY
▪ For proper dosing of the dosage form it is necessary that the active
ingredient is uniformly distributed throughout the dosage form.so
samples are withdrawn from the dispersed phase after micronization
and after mixing with dispersion medium, assayed to find out degree of
homogeneity.
▪ If any discrepancy is found out it is suitably corrected by monitoring the
mixing step to ensure a reliable dosage formulation.
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22. EMULSIONS
▪ It is also a type of biphasic system.
▪ Emulsions can be defined as a dispersion of at least two immiscible
liquids, one of which is dispersed as droplets in the other liquid, and
stabilized by an emulsifying agent.
▪ The globule diameter may range from 0.1 to 100 µm.
▪ Emulsions are thermodynamically unstable systems.
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23. IPQC TESTS FOR EMULSIONS
▪ Appearance
▪ Clarity testing
▪ pH value
▪ Viscosity
▪ Rheology
▪ Drug content uniformity
▪ Particle size distribution
▪ Densities of phases
▪ Phase volume ratio
▪ Charge of electrical double layer
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24. ▪ Physical properties of interface
▪ Temperature fluctuations
▪ Quality control of water
▪ Breaking or cracking
▪ Compatibility of product with container-closure system
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25. CREAMING
▪ Creaming is the concentration of globules at the top or bottom of the
emulsion.
▪ The floccules move either upward or downward leading to creaming.
▪ It can be observed by a difference in colour shade of the layers.
▪ Creaming is influenced by
a)globule size
b)viscosity of the dispersion medium
c)differences in the densities of dispersed phase and dispersion medium
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26. COALESCENCE
▪ Coalescence is followed by creaming stage.
▪ In this process the emulsifier film around the globules is destroyed to a
certain extent.
▪ This step can be recognised by increased globule size and reduced
number of globules.
▪ Coalescence is observed due to
a)insufficient amount of the emulsifying agent
b)altered partitioning of the emulsifying agent
c)incompatibilities between emulsifying agents
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27. BREAKING
▪ This is indicated by complete separation of oil and aqueous phases.
▪ It is an irreversible process that is simple mixing fails to resuspend the
globules into an uniform emulsion.
▪ In breaking the protective sheath around the globules is completely
destroyed.
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28. PHASE INVERSION
▪ This involves the change of emulsion type from o/w to w/o or vice
versa.
▪ When we intend to prepare one type of emulsion say o/w and if the
final emulsion turns out to be w/o it can be termed as a sign of
instability
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29. Fig; instability in emulsion29

30. PARTICLE SIZE DISTRIBUTION
▪ Globules of uniform size impart maximum stability.
▪ In such emulsions globules pack loosely and globule to globule contact
is less.
▪ Globule distribution is effected by viscosity, phase volume ratio, density
of phases etc.
▪ An optimum degree of size distribution range should be chosen to
achieve maximum physical stability.
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31. CHARGE OF ELECTRICAL DOUBLE LAYER
▪ When ionic type of emulsifier is employed, the electrical double
layer(interface between oil and water)possesses charge.
▪ The repulsive forces, due to like charges on the surface of the globules
prevent the flocculation of globules.
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32. PHASE INVERSION
▪ The emulsion is checked for phase inversion.
▪ Phase inversion means a change of emulsion type from o/w to w/o or
vice versa.
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33. Fig; phase inversion in w/o emulsion.
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34. TEMPERATURE FLUCTUATIONS
▪ Elevated temperatures alter the partition characteristics of the
emulsifiers and preservatives results in instability.
▪ Temperature also enhances the chemical degradation of drugs and
other ingredients.
▪ At lower temperature the aqueous phase may contain ice crystals which
rupture the interfacial film and break the emulsion.
▪ So care should be taken to prevent temperature fluctuations during
manufacture and storage.
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35. CONCLUSION
▪ IPQC tests are carried out during the manufacturing to ensure stable,
safe and quality product.
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36. REFERENCES
1. Tangri P , Mamgain P, Shaffi , ML Verma , Lakshmayya, IN PROCESS
QUALITY CONTROL: A REVIEW, Int. J of Industrial Pharmacy and Bio
Sciences 2014.
2. Leon lachman, Herbert liberman, Joseph L. kanig , The theory and
practice of industrial pharmacy , 3rd Edition , Indian Edition, Varghese
publishing house , Mumbai .
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