DSF Exam 1 Preformulation part 2

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DSF Exam 1 Preformulation part 2
2010-10-27 00:42:19
Dosage forms Exam preformulation part

Preformulation part 2
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  1. Examples of salts that improve drug solubility
    • Phytoin sodium for injection
    • Ampicillin sodium in oral suspension/injection
  2. Intrinsic solubility
    Solubility of unionized drug
  3. Intrinsic solubilty must be below ___ for a need to be salt form
    Less than 1 mg/ml
  4. Salts from weak bases yield more ____ solutions.
    Salts from Weak acids yield more ____ solution.s
    • Acidic
    • alkaline
  5. Minocylcline HCl IV solution has a pH of
    2 to 2.8
  6. Salt form has a ______ percent of active drug compared to non-salt form.
  7. Prodrug
    Synthetic derivative of a drug that is transformed in vivo to liberate an active drug molecule.
  8. Purpose of prodrug
    • Biostability/prolonged action
    • Targeting
    • Solubility
  9. Erythromycin ethylsuccinate is less soluble than
    Erythromycin for better taste (suspension), Bypass gastric degradation (degrade in stomach), and better absorption (more lipophilic).
  10. Phosphate is added to
    Increase water solubility, added to create a phosphate-ester derivative.
  11. T/F phosphate ester is the same as a phosphate salt
    FALSE Example is disopyramide phosphate
  12. Rate limiting step for absorption
    Drug dissolution rate for oral bioavailability
  13. Dissolution of solid in liquid occurs in 2 phases
    Interfacial reaction liberates molecules from solid phase

    Diffusion of liberated molecules away from solid into the bulk liquid.
  14. Noyes whitney equation dissolution rate
    dm/dt= kA(Cs-C)

  15. Terms for dissolution equation
    • dm/dt= mass dissolved in time
    • A is surface area
    • Cs is drug solubility
    • C is concentration
    • k is dissolution rate constant

    • D is diffusion coefficient of solute in medium
    • h is thickness of static boundary layer
  16. Dissolution equation affected by
    Size, Solubility in water, volume of dissolution medium, and thickness of static boundary.
  17. Partition
    to move from one phase to another (polar and nonpolar phases)
  18. Partition is important to
    Traverse lipid bilayers
  19. Partition coefficient
    Oil over water
  20. partition phenomena
    • Into fat
    • Into microorganisms
    • Into plastic
    • between oil and water
  21. Most common organic solvent used
    Octanol because it mimics membrane
  22. Butanol mimics ______
    Chloroform mimics _____
    • Buccal membrane
    • Blood brain barrier
  23. Unionized drug has higher partition coefficient and is
    less polar
  24. Drug absorption most likely found in regions with pHs
    favoring unionized form