diffusion from pill to target receptor

• What is the role of diffusion in pharmacy?

  It drives liberation, absorption, distribution, and elimination of drugs
• What does chemical potential refer to in diffusion?

  Potential energy due to diffusive mass transfer
• How does diffusion affect drug processes?

  It is core to all pharmacy processes
• What does lattice theory describe in diffusion?

  Homogenous molecular dispersion in liquids
• What happens at steady state in diffusion?

  Concentration of diffusant becomes constant over time
• What factors can accelerate the rate of diffusion?

  Mechanical processing, pressure, and temperature
• What are the stages of diffusion from dosage form to target receptor?

  Liberation, absorption, distribution, elimination
• What does Fick's First Law of Diffusion state?

  Rate of diffusion is proportional to concentration gradient
• What is the formula for flux in Fick's First Law?

  J = -D(dC/dx)
• What does the diffusion coefficient (D) indicate?

  How well a solute can diffuse in a medium
• What factors influence the diffusion coefficient (D)?

  Molecular size, medium nature, and temperature
• What does Fick's Second Law describe?

  Change in concentration with time at a location
• What is the effect of temperature on diffusion?

  Higher temperature increases diffusion rate
• How does molecular weight affect diffusivity?

  As molecular weight increases, diffusivity decreases
• What is the relationship between solubility and diffusivity?

  Higher solubility generally increases diffusivity
• What does viscosity measure in a fluid?

  Resistance to flow and internal friction
• What is the significance of the nature of the barrier in diffusion?

  It affects the rate and efficiency of diffusion
• What is the purpose of controlled release in drug delivery?

  To manage the rate of drug release over time
• What is an example of a controlled release system?

  Levonorgestrel-releasing implant
• What is the role of the Franz diffusion cell?

  To measure flux and predict bioavailability
• What is excretion in the context of drug elimination?

  Removal of intact drug through the kidneys
• What are some driving forces in pharmaceutical systems?

  Concentration, pressure, temperature, electrical potential
• What are the learning outcomes of the course on diffusion from pill to target receptor?

  1. Explain the role of diffusion in pharmacy
  2. Describe diffusion with Fick’s laws
  3. Outline the role of the diffusion coefficient
  4. Describe factors influencing diffusivity
  5. State driving forces for diffusion
• What are the types of controlled release mechanisms in drug delivery?

  • Dissolution (matrix or reservoir)
  • Diffusion (matrix or reservoir)
• What are the factors influencing diffusion?

  • Temperature
  • Concentration gradient
  • Molecular weight
  • Chemical nature of drug
  • Nature of solvent (polarity, viscosity)
  • Nature of barrier (selectively permeable membrane)
• What are the effects of temperature on diffusion?

  • Cold medium: Slow diffusion
  • Hot medium: Rapid diffusion
• What is the significance of the concentration gradient in diffusion?

  • It is the driving force for diffusion
  • Critical in dissolution, absorption, and distribution of drugs
• What is the relationship between molecular weight and diffusivity?

  • As molecular weight increases, diffusivity decreases
• What is the relationship between solubility and diffusivity?

  • Higher solubility generally increases diffusivity
• What is the role of the barrier in drug diffusion?

  • Affects rate and efficiency of diffusion
  • Can be selectively permeable
• What are the driving forces for diffusion in pharmaceutical science?

  • Concentration
  • Pressure
  • Temperature
  • Electrical potential
• What are the examples of dosage forms that utilize diffusion for drug release?

  • Tablets
  • Creams
  • Patches
  • Depot injections
  • Implantable devices
  • Osmotic devices
• What is the significance of the Stokes-Einstein equation?

  • Defines the diffusion coefficient in relation to particle size and medium