Dosage forms exam 1 Preformulation

  1. Dosage forms
    If not a solution the drug must be liberated from its dosage form
  2. Drugs must have sufficient____ solubility and _____ solubility
    • Water- be in molecular form in body
    • Lipid- traverse lipid membranes
  3. Drug properties for preformulation
    • Physical properties
    • Dissolution
    • PArtitioning
    • Stability
  4. Crystalline form
    Common. Has a repeating arrangement of the individual molecules that creates the crystal lattice.
  5. Crystal habit defined by
    The internal structure
  6. Different habits can result from
    minor changes in synthetic conditions
  7. Amorphous form
    No repeating arrangement, molecules are random no crystal lattice... looser arrangement
  8. Flow properties
    Important for dosage uniformity
  9. Bioavailabity
    Function of drug dissolution, fraction of administered drug that reaches systemic circulation.
  10. Solid state stability
    hygroscopicity and polymorphism
  11. Metastable
    Being in an unstable or transient but relatively long lived state of chem or physical form.
  12. Metastable polymorphs are generally ___ soluble that their _____ stable counterpart. This is due to what?
    • more soluble
    • More stable
    • Weaker interaction
  13. psuedopolymorphisms
    Hydrates or solvates
  14. solvate solubilty
    changes in hydrate form can affect solubility.
  15. T/F Hydrates are more soluble than their anyhydrous counterparts.
  16. Detection of polymorphism is by?
    Melting points, different polymorphs= different melting points.
  17. Griseofulvin
    micronization reduced dose by 50%
  18. Nitrofurantoin
    Crystals were too small, dissolved too fast caused nausea
  19. Particle flow effects
    • Mixing and pouring
    • Speed of processing during manufacture
    • Settling or statifying
  20. Factors for particle flow
    Electrostatic, absorbed moisture, density, shape, size.
  21. miscible liquids
    liquids dissolved in each other
  22. Halothane
    General anesthetic (gas+liquid)
  23. Dissolution of crystalline solute
    • 1) remove solute from molecule
    • 2) create hole in solvent
    • 3) place solute in hole
  24. Solubilty definition
    Amount dissolved per volume
  25. Hydrophilic substituents hydrogen bond with ______
  26. Phenol is 100X more soluble than _____ due to what?
    Benzene due to hydrophilic substituents.
  27. Estraidiol
    corticosteroid ring structure with 2 hydroxyl groups, solubility is 5 mcgrams/mL
  28. Ionization state is one of the most important physicochemical properties.
    Affects dosage formulation, absorption, distribution, and excretion.
  29. pH=pKa + log (A-/HA)
    • Hendersen hasselbeck
    • A- salt
    • HA Acid
  30. Base hendersen
    • B Base
    • BH+ salt
  31. Weak Acid solubility equation
    pH=pKa + Log ([S-So]/So)
  32. Weak base equation
    Same but flip the So/[S-So]
  33. What does S and So stand for
    • S is overall solubilty
    • So solubility in unionized form
  34. Solvent pH affects the drugs
    Ionization state
  35. Surfactants and Cyclodextrins are examples of
    Solubilizing agents
  36. T/F dissolution is an exothermic process because energy is needed to break bonds in the solid.
    False! Endothermic.

    Greater heat input generally leads to greater solubility of a solid.
  37. Creation of solid form must consider several properties
    Solubility and stability (hydroscopicity and metastability)
  38. Griseofulvin/PEG known for
    Significant solubility improvement
  39. Very common method of altering a drug's properties.
    Salt formation
  40. How salt is formed:
    Salt is crystallized from the solvent
  41. T/F Salt formation is only for increasing drug solubilty.
    False, can increase or decrease
  42. T/F A drug in suspension is more stable than a drug in solution.
  43. Decreased drug solubilty can help mask
  44. T/F Propoxyphene napsylate is less bitter than Propoxyphene hydrochloride because it is more soluble.
    False! Because it is LESSSSSS Soluble
  45. Salt can improve solubilty thus
    Greater degree of interaction with Water molecules.
Card Set
Dosage forms exam 1 Preformulation