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Cards In This Set
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What is a semisolid?
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A semisolid is a system that is not pourable and does not flow under low shear stress at room temperature.
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What is an ointment?
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An ointment is a semisolid preparation incorporated into a specific hydrocarbon base, less than 20% water, more than 50% hydrocarbons.
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What is a cream?
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A semisolid dosage form with relatively fluid consistency, usually more than 20% water and less than 50% hydrocarbons
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What is a gel?
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A gel is a semisolid dosage form consisting of either small inorganic particles or large organic particles interpenetrated by a liquid.
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What is a paste?
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A paste is a semisolid dosage form wtih a large proportion (40-50%) of solids finely dispersed in a FATTY vehicle.
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What is a colloidion?
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A thick solution composed of pyroxylin dissolved in a mixture of alcohol and ether.
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What are the five types of semisolids?
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Emollient
Protective Occlusive Humectant Medicated |
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What does an emollient semisolid do?
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An emollient is an agent that softens the skin and soothes irritation in skin/mucous membranes.
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What does an occlusive agent do?
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An occlusive agent retains water in skin by forming a hydrophobic barrier that prevents evaporation.
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What does a humectant do?
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A humectant causes water to be retained due to its hygroscopic properties.
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What are desirable properties of semisolid bases?
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Chemically/Physically Stable
Non-Reactive Compatible Non-Toxic Non-Sensitizing Non-Irritating Aesthetically Appealing Removal if Desired |
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What are the four classes of ointment bases?
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Hydrocarbon
Anhydrous/(W/O) Emulsion Water Soluble Water Removable |
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What are some properties of a HC base?
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Won't absorb water
Emollient Occlusive Greasy Inexpensive, non-reactive, non-irritating Insoluble in Water Not water washable Anhydrous |
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What are some examples of an HC base?
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Petrolatum, white ointment, vegetable shortening
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Why is having low water absorption bad?
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Because you cannot incorporate water-soluble ingredients or absorb skin secretions.
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