Lecture 11 (Cut off for Exam 2)

Question 1

Blending of Powders

Answer 1

Two or more powdered substances are combined/blended to form a uniform mixture.

Question 2

Methods of blending (4)

Answer 2

1. Spatulation
2. Titration
3. Sifting
4. Tumbling

Question 3

Do you reduce the particle size before or after blending? Why?

Answer 3

Reduce particle size before blending. Creates a homogeneous mixture to work with for blending and better absorption down the road.

Question 4

Spatulation

Answer 4

Blending small amount, especially for eutectic mictures.

Question 5

Eutectic Mixtures

Answer 5

Two solids mixed together that become liquid when combined. Melting point for them combined is lower than each individually.

Question 6

Trituration

Answer 6

Used to both comminute and to mix powders (mortar and pestle). Utilizes geometric dilution.

Question 7

Geometric dilution

Answer 7

Adding a small amount of a potent drug to a portion of the base and well mixing. Continuing this pattern until the total amount is added and mixed.

Question 8

Sifting

Answer 8

Passing powder through sifters. NOT an appropriate method for potent drug mixing.

Question 9

Tumbling

Answer 9

Small and large scale motorized blenders (twin shell blender and ribbon blender).

Question 10

Segregation

Answer 10

Undesirable separation of the different components of the blend. Occurs in sifting/percolation, air entrapment (fluidization), and particle entrapment (dusting).

Question 11

Methods to Control Powder Segregation (6)

Answer 11

1. Minimize transfer steps and drop heights
2. Control of dust generation
3. Control of fluidization
4. Slow fill/transfer rate
5. Appropriate venting
6. Use of deflector, vane, or distributor

Question 12

Granules

Answer 12

• Powder like product
• Prepared from powders - agglomerates of small particles
• Generally small, irregularly-shaped chunks
• Tend to fit between size 4-12 sieves (2-5 mm)
• compressed into tablets

Question 13

Methods to Prepare Granules (2)

Answer 13

1. Wet
2. Dry

Choose method based on physical-chemical properties of active ingredient

Question 14

Wet Method

Answer 14

• Moisten powder mixture
• Press “dough” through sieve
• Dry granules
• Requires “binder,” water, and heat

Question 15

Dry Method

Answer 15

• Compress powder mixture into large cake
• Break into granules
• Use high pressure compression

Question 16

Advantages to Granules v.s. Powders

Answer 16

• Granules flow better compared to powders
• Less surface area, more stable to atmospheric conditions
• Less likely to cake or harden upon standing
• More easily wetted by liquids
• Easily compressed into tablets

Question 17

Granule Uses (2)

Answer 17

1. Tabletting - best flow, better compression, more uniform
2. Products for reconstituion - granules contain necessary excipient. Pharmacist adds water, mixes, and dispenses. EX: Antibiotic suspension (longer shelf life)

Question 18

Medicated Powder Uses (5)

Answer 18

1. Orally - systemic or local
2. Inhaled - systemic or local
3. Injection
4. Vaginal douche
5. Wounds

Can be internal or external use

Question 19

Medicated Powder Advantages

Answer 19

• Ease of swallowing
• Some drugs are too bulky to be encapsulated/tableted
• Faster rates of dissolution and absorption
• More stable than those in liquid formations
• Easy to adjust dose with powders

Question 20

Medicated Powder Disadvantages

Answer 20

• Undesirable taste (bitter)
• Dose titrations (potent drugs) - potential for patient to mistake correct method of use or dose
• Difficulty protecting powders from decomposition when they contain hygroscopic, deliquescent, and aromatic compounds
• Uniform individually wrapped powder doses

Question 21

Powders V.S. Tablets/Capsules

Answer 21

Powder lacks convenience of handling, ease of product identification, and ease of administration by patient that tablets and capsules have.

Question 22

Disintegration

Answer 22

Process tablets and capsules undergo to become granules/aggregates.

Question 23

Deaggregation

Answer 23

Process granules and aggregates undergo to become fine particles.

Question 24

Dissolution

Answer 24

Process tablets/capsules, granules/aggregates, or fine powders can undergo to dissolve in solution.

Question 25

Hygroscopic

Answer 25

Substances that tend to absorb water from the air.

Question 26

Deliquescent

Answer 26

Substances that have a tendency to become liquids.