ADT Exam 2

  1. Thixotropic systems demonstrate a ____ in viscosity with time under constant shear
    decrease
  2. Rheopectic materials becomes ___ viscous as the duration of applied force increases
    more
  3. pseudoplastic flow
    • decreased viscocity with shaking
    • polymer systems
  4. thixotropical flow
    viscosity decreases with shear but increases when shearing is stopped
  5. examples of pseudoplastic
    • ketchup
    • toothpaste
    • polymer solutions
  6. examples of rheopectic
    cement and drilling mud
  7. thixotropical examples
    • corn syrup
    • engine oil
  8. measurement of thixotropy
    • hysteresis loop
    • viscometers
  9. Factors affecting thixotropic properties
    • Temperature
    • pH
    • polymer concentration
    • polymer combination
    • polymer modification
    • addition of cations
    • addition of excipients
  10. mucin
    • 1.5% of fluid
    • main roll is regulating viscocity
    • highly glycosylated glycoproteins
  11. acidic pH maintained by
    • doiderlein's bacillus which produce lactic acid
    • Lactobacillus produce hydrogen peroxide
    • Na/H and Cl/HCO3 exchangers
  12. Factors affecting drg release profile and efficacy of the intravaginal delivery system
    • microbicide concentration
    • loading weight
    • flow rate
    • pH
    • speed of rotation
    • site of application
Author
Rx2013
ID
114936
Card Set
ADT Exam 2
Description
Thixotropic properties
Updated