30 Questions
What is the hydrophobic group in a-Dodecyl dimethyl benzyl ammonium chloride?
Dodecyl
Which type of surfactants do not ionize in solution?
Ether Linked Surfactants
What is the general formula of Sorbitan fatty acid esters (Spans)?
R – O – (CH2 CH2 O)n H
What role do Ether Linked Surfactants play in emulsions?
Prepare O/W emulsions
How are Sorbitan fatty acid esters prepared?
Esterification of sorbitan with fatty acid
What role does the hydrophilic group play in surfactants?
Attract water
Where are non-polar solubilizates dissolved inside the micelle?
In the micelle core
What is the term used to describe the process of bringing water-insoluble molecules into aqueous solution by incorporating them into micelles?
Solubilization
In which position within the micelle do water-insoluble compounds containing polar groups orient themselves?
At the micelle surface
Which type of drugs are examples of micelle-solubilized drugs according to the text?
Vitamins (A, D, E & K)
What is the oldest application of solubilization mentioned in the text?
Solubilization of cresol in soap solution
Where does solubilization occur in non-ionic polyoxyethylanated surfactants?
In the polyoxyethylene shell
What is the optimal HLB range for a wetting agent to function efficiently?
6 to 9
Which type of emulsion do ionized surfactants with strong polar groups favor?
Oil-in-water (O/W)
What characteristic of nonionic surfactants determines whether they favor O/W or W/O emulsion?
Possession of polyoxyethylene moieties
Which type of emulsion can have greater than 50% disperse phase according to the text?
Oil-in-water (O/W)
What do detergents primarily aim to remove?
Dirt
How do emulsifying agents significantly alter coalescence rates?
By decreasing coalescence
What does a contact angle of 0° signify between a liquid and a solid?
Complete wetting
Which equation represents one of the alternative forms of Young’s equation that excludes γS or γSL?
S = γL (cos θ – 1)
When does the contact angle between a water droplet and a greasy surface result?
When the water wets the greasy surface incompletely
What happens when a drop of water is placed on a scrupulously clean glass surface?
It spreads spontaneously with no contact angle
What does adding an appropriate wetting agent to water cause on a greasy surface?
Increased wetting
In which scenario would the spreading coefficient be high on clean glass?
Contact angle of 0° between water and cleaned glass
What is the process of holding molecules at the surface of a solid called?
Sorption
Which action of surfactants involves the wetting of both dirt and the surface to be cleaned initially?
Initial wetting of dirt and surfaces
How do surfactants exert their antimicrobial activity through adsorption on the cell surface?
Decreasing permeability of the lipid cell membrane
In what situation does adsorption on a solid interface occur?
To reduce the surface free energy
What is one mechanism through which surfactants may increase the activity of other antibacterial compounds?
Decreasing interfacial tension between liquid phase and cell wall
What distinguishes adsorption on a liquid interface from adsorption on a solid interface?
Reduction of interfacial tension only in liquid interface adsorption
Test your knowledge on pharmaceutical preservatives like a-Dodecyl dimethyl benzyl ammonium chloride and non-ionic surfactants. Learn about their general formulas, properties, and classifications based on linkage types. Ideal for pharmacy students and professionals.
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