Pharmacy Practice MCQ » PHARMACAREERS

Pharmacy Practice MCQ, in this article we will solve, Practice MCQ under subject physical pharmaceutics II. Read following article for your reference.

Rheological Properties Of Emulsions And Emulsion Formulation By HLB Method » PHARMACAREERS

What is an emulsion?
- a) A homogeneous mixture of two or more liquids that are typically immiscible
- b) A solution of solid particles in a liquid
- c) A suspension of gas bubbles in a liquid
- d) A solution where particles dissolve completely
Which of the following is an example of an emulsion?
- a) Saltwater
- b) Milk
- c) Sugar solution
- d) Air
What are the two phases present in an emulsion?
- a) Solid and liquid
- b) Liquid and liquid
- c) Gas and liquid
- d) Solid and gas
What is the dispersed phase in an emulsion?
- a) The liquid in which particles are dispersed
- b) The solid particles in a solution
- c) The liquid that forms droplets within the continuous phase
- d) The gaseous phase surrounding the droplets
What is the continuous phase in an emulsion?
- a) The liquid that forms droplets within the dispersed phase
- b) The medium in which the dispersed phase is distributed
- c) The solid particles in a suspension
- d) The gas in a foam
What is the main purpose of emulsifying agents?
- a) To increase the solubility of the dispersed phase
- b) To reduce interfacial tension and stabilize the emulsion
- c) To increase the size of the dispersed phase droplets
- d) To enhance the color of the emulsion
Which of the following is a common emulsifying agent?
- a) Sodium chloride
- b) Lecithin
- c) Ethanol
- d) Glycerin
What is the HLB value?
- a) Hydrophilic-Lipophilic Balance, a measure of the balance between the hydrophilic and lipophilic portions of a surfactant
- b) High Lipid Balance, indicating the amount of lipid in an emulsion
- c) Hydrophilic Lipid Balance, indicating the water content
- d) High Lipophilic Balance, indicating the fat content
Which HLB value range is suitable for emulsifying oil-in-water (O/W) emulsions?
- a) 1-3
- b) 3-6
- c) 6-9
- d) 8-18
Which HLB value range is suitable for emulsifying water-in-oil (W/O) emulsions?
- a) 1-3
- b) 3-6
- c) 6-9
- d) 12-15
What does a high HLB value indicate about a surfactant?
- a) It is more hydrophobic and oil-soluble
- b) It is more hydrophilic and water-soluble
- c) It has no effect on solubility
- d) It enhances the color of emulsions
Which theory of emulsification explains the role of surface-active agents in reducing interfacial tension?
- a) Surface tension theory
- b) Oriented-wedge theory
- c) Interfacial film theory
- d) Phase inversion theory
What is the primary mechanism by which emulsifying agents stabilize emulsions?
- a) By increasing the viscosity of the medium
- b) By reducing interfacial tension and forming a protective film around droplets
- c) By increasing the size of the droplets
- d) By enhancing the solubility of the dispersed phase
Which type of emulsion has oil droplets dispersed in a continuous water phase?
- a) Water-in-oil (W/O) emulsion
- b) Oil-in-water (O/W) emulsion
- c) Multiple emulsion
- d) Microemulsion
Which type of emulsion is commonly used in pharmaceutical and cosmetic formulations?
- a) Water-in-oil (W/O) emulsion
- b) Oil-in-water (O/W) emulsion
- c) Multiple emulsion
- d) Microemulsion
What is the significance of the phase inversion temperature in emulsification?
- a) The temperature at which an emulsion becomes a solution
- b) The temperature at which an oil-in-water emulsion inverts to a water-in-oil emulsion or vice versa
- c) The temperature at which the color of the emulsion changes
- d) The temperature at which the emulsion solidifies
What is a multiple emulsion?
- a) An emulsion with only one dispersed phase
- b) An emulsion where droplets of one emulsion are dispersed in another continuous phase
- c) An emulsion with a gaseous phase
- d) An emulsion with no droplets
What is the role of rheological properties in emulsions?
- a) To determine the color of the emulsion
- b) To assess the flow and deformation behavior of the emulsion
- c) To measure the solubility of the dispersed phase
- d) To enhance the stability of the emulsion
Which instrument is commonly used to measure the viscosity of emulsions?
- a) Spectrophotometer
- b) Viscometer
- c) Micrometer
- d) Colorimeter
What is thixotropy in the context of emulsions?
- a) The ability of an emulsion to become more viscous when shaken
- b) The property of an emulsion to become less viscous when subjected to shear stress and return to original viscosity when the stress is removed
- c) The property of an emulsion to dissolve completely
- d) The property of an emulsion to change color
What does the term ‘cream’ refer to in emulsions?
- a) The formation of a separate, concentrated layer of the dispersed phase at the top or bottom of an emulsion
- b) The complete dissolution of the emulsion
- c) The solidification of the emulsion
- d) The change in color of the emulsion
Which factor can contribute to the instability of emulsions?
- a) High temperature
- b) Addition of electrolytes
- c) Mechanical agitation
- d) All of the above
What is coalescence in emulsions?
- a) The merging of small droplets to form larger droplets, leading to phase separation
- b) The dispersion of droplets into the continuous phase
- c) The dissolution of droplets in the medium
- d) The reduction in particle size
What is the Bancroft rule in emulsification?
- a) The phase in which an emulsifier is more soluble constitutes the continuous phase
- b) The phase with the highest density constitutes the continuous phase
- c) The phase with the highest viscosity constitutes the continuous phase
- d) The phase with the lowest density constitutes the continuous phase
Which of the following is a non-ionic emulsifier?
- a) Sodium lauryl sulfate
- b) Tween 80 (Polysorbate 80)
- c) Calcium stearate
- d) Cetyl alcohol
What is the role of the HLB system in emulsion formulation?
- a) To determine the color of the emulsion
- b) To select the appropriate emulsifier based on its hydrophilic-lipophilic balance
- c) To measure the density of the emulsion
- d) To enhance the solubility of the dispersed phase
Which property is assessed using a rotational viscometer?
- a) Color of the emulsion
- b) Size of the dispersed phase droplets
- c) Viscosity of the emulsion
- d) Solubility of the dispersed phase
What does a low HLB value indicate about an emulsifier?
- a) It is more hydrophilic and water-soluble
- b) It is more lipophilic and oil-soluble
- c) It has no effect on solubility
- d) It enhances the color of emulsions
What is a microemulsion?
- a) An emulsion with large droplets
- b) An emulsion with droplet sizes in the range of 10-100 nm, appearing clear or slightly opalescent
- c) An emulsion with no droplets
- d) An emulsion with gaseous phase
What is the significance of the phase volume ratio in emulsion stability?
- a) It determines the color of the emulsion
- b) It influences the viscosity and stability of the emulsion
- c) It measures the solubility of the dispersed phase
- d) It affects the density of the emulsion

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