Pharmaceutical Preservatives and Non-ionic Surfactants Quiz
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Questions and Answers

What is the hydrophobic group in a-Dodecyl dimethyl benzyl ammonium chloride?

  • Benzyl
  • Dodecyl (correct)
  • Dimethyl
  • Ammonium
  • Which type of surfactants do not ionize in solution?

  • Cationic Surfactants
  • Ester Linked Surfactants
  • Anionic Surfactants
  • Ether Linked Surfactants (correct)
  • What is the general formula of Sorbitan fatty acid esters (Spans)?

  • R is the hydrophobic group and x is usually halogen
  • R-O-CH2- CH2
  • R-OH + H2C - CH2 O OH
  • R – O – (CH2 CH2 O)n H (correct)
  • What role do Ether Linked Surfactants play in emulsions?

    <p>Prepare O/W emulsions</p> Signup and view all the answers

    How are Sorbitan fatty acid esters prepared?

    <p>Esterification of sorbitan with fatty acid</p> Signup and view all the answers

    What role does the hydrophilic group play in surfactants?

    <p>Attract water</p> Signup and view all the answers

    Where are non-polar solubilizates dissolved inside the micelle?

    <p>In the micelle core</p> Signup and view all the answers

    What is the term used to describe the process of bringing water-insoluble molecules into aqueous solution by incorporating them into micelles?

    <p>Solubilization</p> Signup and view all the answers

    In which position within the micelle do water-insoluble compounds containing polar groups orient themselves?

    <p>At the micelle surface</p> Signup and view all the answers

    Which type of drugs are examples of micelle-solubilized drugs according to the text?

    <p>Vitamins (A, D, E &amp; K)</p> Signup and view all the answers

    What is the oldest application of solubilization mentioned in the text?

    <p>Solubilization of cresol in soap solution</p> Signup and view all the answers

    Where does solubilization occur in non-ionic polyoxyethylanated surfactants?

    <p>In the polyoxyethylene shell</p> Signup and view all the answers

    What is the optimal HLB range for a wetting agent to function efficiently?

    <p>6 to 9</p> Signup and view all the answers

    Which type of emulsion do ionized surfactants with strong polar groups favor?

    <p>Oil-in-water (O/W)</p> Signup and view all the answers

    What characteristic of nonionic surfactants determines whether they favor O/W or W/O emulsion?

    <p>Possession of polyoxyethylene moieties</p> Signup and view all the answers

    Which type of emulsion can have greater than 50% disperse phase according to the text?

    <p>Oil-in-water (O/W)</p> Signup and view all the answers

    What do detergents primarily aim to remove?

    <p>Dirt</p> Signup and view all the answers

    How do emulsifying agents significantly alter coalescence rates?

    <p>By decreasing coalescence</p> Signup and view all the answers

    What does a contact angle of 0° signify between a liquid and a solid?

    <p>Complete wetting</p> Signup and view all the answers

    Which equation represents one of the alternative forms of Young’s equation that excludes γS or γSL?

    <p>S = γL (cos θ – 1)</p> Signup and view all the answers

    When does the contact angle between a water droplet and a greasy surface result?

    <p>When the water wets the greasy surface incompletely</p> Signup and view all the answers

    What happens when a drop of water is placed on a scrupulously clean glass surface?

    <p>It spreads spontaneously with no contact angle</p> Signup and view all the answers

    What does adding an appropriate wetting agent to water cause on a greasy surface?

    <p>Increased wetting</p> Signup and view all the answers

    In which scenario would the spreading coefficient be high on clean glass?

    <p>Contact angle of 0° between water and cleaned glass</p> Signup and view all the answers

    What is the process of holding molecules at the surface of a solid called?

    <p>Sorption</p> Signup and view all the answers

    Which action of surfactants involves the wetting of both dirt and the surface to be cleaned initially?

    <p>Initial wetting of dirt and surfaces</p> Signup and view all the answers

    How do surfactants exert their antimicrobial activity through adsorption on the cell surface?

    <p>Decreasing permeability of the lipid cell membrane</p> Signup and view all the answers

    In what situation does adsorption on a solid interface occur?

    <p>To reduce the surface free energy</p> Signup and view all the answers

    What is one mechanism through which surfactants may increase the activity of other antibacterial compounds?

    <p>Decreasing interfacial tension between liquid phase and cell wall</p> Signup and view all the answers

    What distinguishes adsorption on a liquid interface from adsorption on a solid interface?

    <p>Reduction of interfacial tension only in liquid interface adsorption</p> Signup and view all the answers

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