17 Questions
What are the disadvantages associated with packaging semisolids in tubes?
Bacterial contamination, product oxidation, increase in water loss
Which of the following materials are commonly used for making tubes for semisolids?
Aluminum and plastic
What coatings are applied to aluminum tubes to prevent interaction with components?
Epoxy resin or vinyl
Which tube sizes are commonly used for semisolid preparations?
5, 15, 30 g tubes
What is the approximate weight of ophthalmic semisolid preparation tubes?
~3.5 g
Which feature makes tubes a preferable choice over jars for packaging semisolids?
Greater protection against external contamination and environmental conditions
What makes aluminum tubes suitable for packaging semisolid preparations?
Lightweight and chemically inert
Thixotropy in gels refers to the ability of the gel to become ______ when sheared and regain its viscosity when the shearing force is removed.
fluid
______ is the expulsion of liquid from a gel upon standing or aging.
Syneresis
The process of ______ occurs when a polymer matrix swells and absorbs water or another solvent.
imbibition
To prepare a carbopol gel, the polymer is first dispersed in ______ before neutralizing with a base.
water
The pH of the dispersion medium can affect the ______ of the polymer chains in a hydrophilic gel.
ionization
Preparation conditions, such as ______, can influence the final properties of a gel.
temperature
The concentration of the gelling agent plays a crucial role in determining the ______ of the resulting gel.
viscosity
Carbopol gels are typically prepared by first dispersing the polymer in water and then ______ with a base.
neutralizing
The rate of ______ can affect the swelling and gel formation process.
stirring
Gels can exhibit ______ behavior, where they can flow under shear stress and regain their structure when the stress is removed.
thixotropic
Test your knowledge on the preparation of pastes and creams in semi-solid preparations according to lectures by Dr. Dina M. Gaber. Learn about the methods used to prepare pastes and the characteristics of creams as semisolid emulsions.
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