Greco Lecture 1: Clarification/Powders

Question 1

What are the factors that must be considered for the administration route of medicine?

Answer 1

1. Potency
2. Physical chemical characteristics
3. Stability
4. Interaction with other active ingredients and/or excipients

Question 2

Describe what powders are?

Answer 2

1. Solid particles that are heterogenous (particle sizes and shapes are different)
2. Intermediates that lead to other dosage forms (tablets)

Question 3

What are the three characteristics of a powder?

Answer 3

1. Size (volume, shape and surface area)
2. Density
3. Flowability

Question 4

Describe what clarification is and the reason behind it?

Answer 4

1. Process of aiming at removing or separating a solid from a fluid
2. Remove unwanted particles from a liquid product
3. Collect solid as the product itself

Question 5

What are the different mechanisms of filtration and describe them?

Answer 5

1. Straining/sieving
   - Pores have to be big enough to allow liquid through but not powder
2. Impingement
3. Attractive Forces
4. Autofiltration
   - Material being filtered starts filtering itself

Question 6

What are the key parameters of filtering elements and describe them?

Answer 6

1. Capacity
   - Mass you can filter through a given filter before it gets blocked up
2. Efficiency
   - The measure of how good a filter is after gaining a particle size
3. Degree of filtration
   - Measure of the smallest particle size that the filter can contain
4. Porosity
   - Measure of the space in the filter that is essentially a ratio, such as void space and volume

Question 7

Describe a simple filtration method used in the lab?

Answer 7

1. Buchner funnel
2. Filter paper seated on base
3. Creates a vaccum
4. Filtering flask s

Question 8

How do you measure the rate of filtration?

Answer 8

The darcy equation

Question 9

How do you increase the filtration rate?

Answer 9

1. Increase the area
2. Increase delta P (pressure difference)
3. Decrease the viscosity of the liquid
4. Decrease the thickness of the filter cake
5. Increase the permeability of the cake

Question 10

What is centrifugation?

Answer 10

1. Particle of mass (m)
2. Spinning in a centrifuge radius (r)
3. Velocity (v)
4. Centrifugal force F=mv^2/r