3.4 Flashcards
______ the property of certain gels in which they liquefy when agitated and revert to a gel upon standing.
thixotropy
______ liquid is a plastic or pseudo-plastic liquid that when left standing, is a restrictive network of interacting solute.
thixotropic
Upon stress of thixotropic liquid, the interations are disrupted and the liquid becomes…
thin, gel-sol transformation
non-free flowing to free-flowing (i.e. viscosity decreases)
An example of thixotropic liquid is …
bentonite magma
Suspending agents may have properties in which they differ from one another such as…
pH dependency, charge, rheological properties, temperature stability
Xantham gum is a ________, a suspending agent. Has pseudopastic property and thixotropic property.
natural polysaccharide
Acacia gum best used in _______, it is a suspending agent.
emulsions
____ an kelp extract, natural polysaccharide, suspending agent that produces a firm gel on contact with calcium.
Alginates
Hydroxypropylmethylcellulose at low concentrations can be used as a ______- agent and increase viscosity.
suspending
______ a suspending agent that is common in gels and good for topical medications.
Carbomer (polyacrylic acid)
______ preparations containing a mixture of two immiscible liquids, one of which is uniformly dispersed as droplets throughout the other.
Emulsions
dispersed dosage form
Types of emulsions are based on internal and external phases. O/W is
oil droplets suspended in water
oil is non-continuous, while water is continuous phase
Topical route dominate for _____
emulsions
In emulsions, oil is given as small globules rather than bulk which allows increased ______ of the oil and can improve digestibility or effectiveness.
palatability (bad-tasting oil is masked by water)
In emulsions, with small droplet size (increased surface area), the oil is easily broken down in the GI tract. This improves…
digestibility
