This document summarizes an industrial seminar on rheology presented by Modh Sudipkumar. It discusses the importance of rheology in industrial processes and its effect on product cost, stability, and recalls. It outlines different types of viscometers and rheometers used in industry and their applications in evaluating stability of formulations like suspensions, emulsions, and ointments. Newer instruments like interfacial shear rheometers and stress rheometers are able to characterize more complex fluid behaviors at interfaces and under varying stresses. Rheology is presented as a rapid screening method to test stability by monitoring changes in storage and loss modulus.

1. A seminar on
Industrial Aspect
of Rheology
Presented by
Modh Sudipkumar c.
PA /2010 /11

2. Introduction
Rheology is Responsible for any formulation, production, appearance, usage, and
finally affect stability
Affects final cost of product
Class I recalls of Fentanyl Reservoir patches from Innovator and generic
manufacturers
In short………
If a material is pumped, sprayed, extended, extruded, molded, coated, mixed,
chewed, swallowed, rubbed, transported, stored, heated, cooled, aged …
RHEOLOGY is important ….!!
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3. contents
Viscometer vs. Rheometer
Types of the viscometer used in industry
Characteristics
Application of viscometer in stability and evaluation
Rheology: A Rapid Screening Method for Testing Stability
Latest types of viscometers and Rheometers
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4. Viscometer vs. Rheometer
• Viscometer: instrument that measures:
viscosity over a limited shear rate range
• Rheometer: instrument that measures:
• Viscosity over a wide range of shear rates, and…
• Viscoelasticity of fluids, semi-solids and solids
http://pioneer.netserv.chula.ac.th/~sanongn1/course.html
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5. Types of the viscometer used in industry:
Capillary viscometer
Falling sphere viscometer
Cup and bob viscometer
cone and plate viscometer
How will you choose appropriate viscometer?
•Newtonian types of fluids shear rate directly proportional to shear stress
•Instrument are operated at single shear rate can be used
-Capillary viscometer
-Falling sphere viscometer
but these give erroneous result
•Non Newtonian types of fluids shear rate not directly proportional to shear stress
•Instrument are operated at variety of shear rate can be used
-Cup and bob viscometer
-cone and plate viscometer
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6. Characteristics:
Capillary viscometer
Exp Ostwald viscometer
Based on poiseuille’s equation
According to US pharmacopeia capillary apparatus used for high viscous
methyl cellulose type of solution
Falling sphere viscometer
Exp hoeppler viscometer
Cup and bob viscometer
Exp Couette type
McMichael searle type
Roto viscometer
Brookfield viscometer(rotational type of viscometer)
cone and plate viscometer
Exp ferranti-shirley
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7. Application of viscometer in stability and evaluation:
1) Polaxomer vehicles
Used in tear solution for treating “dry eye syndrome “
For evaluation computer controlled couette viscometer is used
2) Suppositories
Release and absorption is depend on rectal temperature,
Brookfield viscometer is used study characteristic of triglycerides base at various
temperature
3) Emulsion
Stabilized with triethanolamine stearate at various temperature
Brookfield viscometer is used
4) cosmetic sticks
Ferranti-shirley cone plate viscometer used
Physical pharmacy by martin page 581-582
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8. 5) Tablet Excipient
Microcrystalline cellulose is used as granulating agent
Mixture torque rheometer is used to measure torque changes as water is added
6)Lamination *
process of lamination various stages
a) softening point of the resin -resin starts to soften and flow as elastic material
drops of viscosity (~107 poise down to 100 to 5000 poise)
b) material is most fluid, and reaction rates start to increase as viscosity starts to build
as the resin starts to gel.
at gel point tan delta is one
parallel plate Rheometer+ is used
*Focus on Rheology By Arlon, Materials for Electronics, Inc .
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9. +parallel plate Rheometer:
upper plate is attached to transducer to measure torque resulting from
strain upon the sample
system computer compares material stress to input strain and
determines tan delta
or phase angle along with the storage and loss modulus components
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10. 7)Suspensions
Settling of particles by Brookfield viscometer fitted with helipath attachment
Consists of rotating T bar spindle
Dial reads resistance at various levels of suspension
8)Ointment
Consistency measured by Burrell severs Rheometer with helipath attachment
Ointment is loaded into a cylinder and extruded with measured force
Amount extruded is measurement of consistency
9)Aerosol
Viscosity is measured by Brookfield viscometer
10)Paste
capillary extrusion viscometer for the viscosity measurement of fish protein paste
Journal compilation © 2008 Wiley Periodicals, Inc.
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11. capillary extrusion viscometer
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12. Rheology: A Rapid Screening Method for Testing Stability
• To understand rheology of viscoelastic fluids, frequency dependence of their G'
and G" material functions to be measured
shear storage modulus G'
shear loss modulus G“
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13. http://pioneer.netserv.chula.ac.th/~sanongn1/course.html
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14. An oscillatory (sinusoidal)
G’
deformation (stress or strain)
is applied to a sample.
the material response
G”
(strain or stress) is measured.
The phase angle δ, or phase
shift, between the deformation
and response is measured.
shear storage modulus G'
shear loss modulus G“
ideal solid, elastic Tan delta= 0º high viscosity
Newtonian fluid Tan delta= 90º low viscosity
http://pioneer.netserv.chula.ac.th/~sanongn1/course.html
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15. • The ratio of G"/G', known as tandelta is predictive parameter for studying
the storage stability of suspensions
• single rheological test can rapidly predict the stability of a drug suspension
by monitoring the value of a well-defined parameter tan delta#
Tan delta= G"/G'
Tan delta
• *http://www.pharmaceutical-int.com/article/rapid-screening-methods.html
• # http://ciks.cbt.nist.gov/~garbocz/SP946/node11.htm
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16. Latest types of viscometers and Rheometers
1)HAAKE RheoStress 6000 (2007)1
Universal Rheometer
variety of temperature control units
temperatures ranging from -80 up to 500°C
2) Brookfield viscometes2
2 Achieving the Basics in Viscosity Measurement to Comply with 21CFR Part 11 16
1© 2007/10 Thermo Fisher Scientific Inc. · By Len Thibodeau Rheometer

17. Significance of Helipath Stand
substances with yield values unsuitable for viscosity or consistency measurements
with rotational viscometers
rotating spindle, be it cylinder, disc, or paddle, will create channel
Produce negligible and meaningless torque
The Brookfield Helipath™ Stand is designed to slowly lower or raise rotating T-bar spindle
 By always cutting into fresh material, the problem of channelling or separating is
eliminated
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http://www.brookfieldengineering.com/products/accessories/helipath-stand.asp

18. 3) Interfacial Shear Rheometer
KSV NIMA
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19. Interfacial Shear Rheometer
Viscoelastic films relationships are nonlinear
intermediate between purely viscous and purely elastic responses in industry and in
biologicals
To define product stability in different industries such as food, petrochemical, cosmetics,
and pharmaceuticals
Application:
Prediction of emulsion, froth and foam stability
Determination of thin film structure
Examination of phase transitions
Real time monitoring of surface reactions
Continuous monitoring of molecule adsorption into interfaces
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20. 4) STRESSTECH
Where flow characteristic of a material determines its processibility, performance,
and/or consumer acceptance.
Rheological instrumentation for the characterization of polymers-BY STEVEN M. COLO,
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21. I never did anything worth doing by accident, nor did any of
my inventions come by accident; they came by work
- Thomas Alva Edison
I'm a great believer in luck, and I find, the harder I work, the
more I have of it.
-Thomas Jefferson
Thank u………
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