This document discusses scale up considerations for semi-solid manufacturing. It begins by defining semi-solid dosage forms as ointments, pastes, creams, emulsions, gels and foams that cling to the skin. The raw materials can include hydrocarbons, silicones, oils and water-based ingredients. Key unit operations include addition of components, heating, mixing, homogenization and filling. Process parameters like temperature, mixing rates and particle size must be controlled during scale up. Proper plant layout and equipment selection is also important for effective semi-solid manufacturing.

1. Scale up for Semi-solid manufacturing
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Guided by:
Dr. Mahalaxmi Rathnanand
Associate Professor
Department of Pharmaceutics
MCOPS
Manipal Academy of Higher Education
Presented by:
PARAG RAJ BEHURA
Reg. No :190617006
M.Pharm (Industrial Pharmacy)
Department of Pharmaceutics
MCOPS
Manipal Academy of Higher Education

2. Contents:
• Definition
• Raw materials
• Unit operations
• Plant layout
• Conclusion
• Reference
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3. What is Semisolid dosage form ?
• Pharmaceutical semisolid preparation include ointments, pastes, cream emulsion,
gels and rigid foams .
• Their common property is the ability to cling to the surface of skin application for
reasonable duration before they are washed or worn off .
• This adhesion is due to their plastic rheological behavior, which allows the
semisolid to retain their shape and cling as a film until acted upon by an outside
force, in which case they deform and flow.
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4. Raw materials
• The raw material range from hydrocarbons, silicon oil to water (or water miscible) bases. In addition,
insoluble ingredients are also present. Approved and validated actives and excipients are used in the
formulations. Alternative supplies of raw materials and changes in the specifications for the performance
and stability is attempted through several batches of scale up .
• Aqueous phase and oil phase are heated to a temperature above the solidification phase of oil. When waxes
are used, their uniform dispersion needs heating of the liquid phase above solidification phase of wax. In
case of emulsion type semisolids, oil and water phases are homogenized at a predetermined temperature.
The working temperature range is critical .
• Once the equipment is selected, some of the critical parameters are evaluated. Heat transfer characteristics
and temperature gradient throughout the system are important. Temperature control is essential during the
critical emulsification stage. The critical processing conditions are listed.
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Addition of Components
Heating
Mixing
Homogenisation
Filling and Packing

6. • The individual phases or slurries are added in a sequence achieving intermittent mixing .
Scale up parameters:-
 Order of addition
 Rate of addition.
 Heating of phase
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Addition of Components

7. • Temperature need to be recorded and monitored. The improper control of
temperature can have several adverse effects .
Scale up parameters:-
 Temperature control
 Time required to increase temperature (650C)
 Time required to achieve batch cool down (650C-350C)
Equipment used: - Steam jacketed kettle
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Heating

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9. • Mixing rate, intensity and mixing time are critical factors. The Product needs to be less viscous during
manufacture, so that mixing of ingredient can be effective. Therefore, heating facilities are necessary.
• Changes in viscosity also need to be understood, in terms of conditions such as processing history of the
sample and age of the sample .
• The mixing equipment used should be able to effectively and continuously move the semisolid mass
from the outside walls to the Centre and from bottom to the top of the kettle. This action distributes the
ingredients and helps in rapid & efficient heat transfer to and from the product during the heating and
cooling process.
• Motors used to drive the mixing system should be sized to handle the product at its most viscous stage, as
the power required to carry out the mixing is directly related to the viscosity of the product.
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Mixing

10. On a small scale : Mixing may be conducted in a porcelain dish or glass beaker an
electronic mortar and pestle .
On a large scale: It is carried out in large steam jacketed kettles
Scale up parameters:-
• Mixing rate
• Time and Pressure
• Temperature
Equipment: - Kettle and tank fitted with agitator, Blade mixture and tumbler
IPQC: - pH, Viscosity, content uniformity, Potency
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11. • Particle size distribution of poorly soluble active ingredient is essential. This is controlled by choosing
appropriate clearance between stator and rotor.
• The heat produced during the milling is reduced by circulation of cold water through the jacket. At high
temperatures, the drug is solubilized leading to formation of metastable product.
• While other locations, drug may be crystallized. The crystallized product may be a different polymorphic
form or a different crystal type or size. Thus, the finished product characteristics may change.
Example of such changes are particle size distribution, loss of elegancy, altered stability and biological
activity.
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Homogenisation

12. Scale up Parameters:-
• Elevated temperature
• Cooling temperature
• Clearance between stator and rotor
• Particle size
Equipment: - end-runner mill, hammer mill, ball mill, colloid mill,
micronizer.
IPQC: - Particle size analysis, Density and flow rate of solid.
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13. • The finished product are transferred from the kettle to holding tanks. The contents are stirred throughout
this stage in order to maintain product uniformity .
• The following critical aspects must be evaluated and controlled during large-scale validation and
manufacturing runs
Scale up parameters
 Elevated temperature
 Stirring rate
 Pumping rate
Equipment: - Kettle and holding tanks
IPQC:- Viscosity , pH , appearance
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Filling and Packing

14. Plant layout for semisolid :-
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15. Conclusion
• Semi solid dosage form can be designed and in depth problems occurring
in various steps must be controlled.
• To prepare a successful product batch studies and testing should be done in
a broad level.
• Extensive future research studies should be conducted for more precise and
accurate product.
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16. References
• Industrial pharmacy : CVS Subrahmanyam J Thimmasetty : Chapter 7 : page no. 402- 404
• Pharmaceutical process validation: An international third edition , revised and expanded :
Introduction of semisolid : page no. 22-24
• The Theory and Practice of Industrial Pharmacy : Leon Lachman , Herbert A Lieberman ,
Joseph L Kanig : Section III : Chapter 18 :pharmaceutical dosage form : page no. 534.
• Dr. A.K. Seth; Pharmaceutics-II (Dispensing and Formulation); S. Vikas and Co. publishing
house; 262-319
• The Theory and Practice of Industrial Pharmacy; 3 rd edition; Varghese publication; 534-563
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17. • http://saspublisher.com/wpcontent/uploads/2014/03/SAJP32-153-161.pdf
• Patel P, Tyagi S, Patel CJ, Patel J, Chaudhari B, Kumar U: Recent advances in novel semisolid
dosage forms: An overview. Journal of biomedical and pharmaceutical research 2013; 2(1):9-
14.
• Mithilesh, S. (2020). [online] Available at:
• http://www.pharmainfo.net/free-books/novel-semisolid-dosage-forms
• http://www.pharmainfo.net/evaluation-ointments 47
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