Powders and Granules

Question 1

Why are Oral, solid dosage forms preferred?

Answer 1

Convenience: Transportation, Administration, Identification

from a pharmaceutical standpoint: easy manufacturing and shipping costs, Most drugs are stable in solid form

Question 2

What are the advantages of Granules and Powder OVER capsules and tablets?

Answer 2

Advantage:
-larger dose can be dissolved in water instead of a big tablet
-skip the disintegration step -> faster dissolution than capsules and tablet
-convenient for patients who can’t swallow
-ingredients are powders already
-easy does adjustment

Question 3

What are the disadvantages of granules and powders?

Answer 3

-Volatile, hygroscopic, oxidizing, deliquescent (sticky) drugs create obvious difficulties when dispensed as powders

-dose inaccurate: patients spilling the powder

-often bitter
-misunderstand the method of administration -> not well shaken (drug on the bottom, drinking the water -> low dose), not well reconstituted -> overdose

Question 4

Definition of powder:

Answer 4

The mixture of finely divided drug (API) + excipients in dry form
Internal powder -> oral powder
External powder -> topical powder

Question 5

What are other powder types?

Answer 5

-Insufflated powder: applied in a body cavity (nose, ears, tooth socket, vagina, throat - using insufflator or puffer

-Inhalational/aerosol powder: micronized particles to reach the lungs through inhalators - often for anti-asthmatic drug

Question 6

In which two forms are powders dispensed?

Answer 6

Divided Powders: Single doses, wrapped in cellophane, metallic foil, or paper -> measured for the patient, More accurate dosage form

Bulk powders: Non-potent; big size, dosed with acceptable accuracy (tsp, insufflator)
-> often for antacids, dietary supplements, laxatives, few analgesics

Question 7

Are divided powders also available in commercially?

Answer 7

Yes, not restricted to compounding only

Question 8

What are examples of Bulk powders?

Answer 8

They are non-potent, no worries about the dose dispensed
-Antacids (counteracts acid in the stomach)
-Douche powder (vaginal cleansing solution)
-Medicated topicals
-Brewers yeast powder (beer brewing, diet supplement)
-Talcum powder (absorbs moisture from skin)

Question 9

What are the powder properties?

Answer 9

-For topical powders: Fine particles (fast absorption), free-flowing

-For solution and suspension: small particle size -> dissolution -> but too fine particles will form a cake, we want narrow size distribution

-For oral, rectal, and parental: small particle size, and narrow size distribution

-For Manufacture: for mixing granules and powders

Question 10

What are powders with physicochemical behavior causing difficulties in compounding?

Answer 10

-Eutectic (mixture): two powders mixed forming a liquid bc mixed together the melting point is lower than the single

-Hygroscopic: tendency of absorbing water -> swelling
-Deliquescent: absorbs moisture (water) until it liquefies

-Efflorescent: powders with water of hydration (.H2O), when applying force the water is liberated and it gets sticky (compounding)

Question 11

How are the physicochemical issues in compounding solved

Answer 11

-Eutectic: we want a powder but it has liquified -> add a adsorbent absorbing the liquid like starch, MgO2, Mg carbonate

-Hygroscopic and Deliquescent: add a dry bulky powder to reduce the surface area exposed to the air, add a desiccant packet, dispense in a tight container, and store in a dry place

-Efflorescent: use anhydrous forms, don’t apply too much force, and add a dry bulky powder

Question 12

What are Granules?

Answer 12

Powders (high cohesion, and usually different sizes) are converted to Granules (spherical)

add a binding solution (often starch) and pass it through a sieve (4-12 mesh)

Question 13

What is Granulation and which properties may be modified?

Answer 13

used for the production of capsules and tablets
-Flow (might stick to punches ->
-Particle size and shape (narrow distribution) for acceptable dissolution in the body
-API release kinetics: how the drug is released

Question 14

Advantage features of Granulation:

Answer 14

-predict the particle size
-avoid powder segregation -> uniform
-narrow size distribution
-Higher porosity: they have voids in between -> porosity increases compressibility
-Less hygroscopy
-reduction of dust in processing

Question 15

What is Comminution?

Answer 15

Reducing particle size by
-Trituration
-Pulverisation
-Levigation

Question 16

What is levigation?

Answer 16

Using a non-dissolving thick liquid to disperse solids by using pressure via spatulation (Brot schmieren) (reduce particle size, grinding)

Question 17

What is Trituration?

Answer 17

Rubbing or grinding of powder in a mortar with a pestle

Question 18

What is Pulverization by intervention?

Answer 18

Dissolve the powder in a solvent (intervening) that evaporates like alcohol, ether, camphor
-> when it evaporates it leaves a fine film of powder with reduced particle size

Question 19

How to administer amoxicillin 500 mg for a suspension (125mg/5ml) and a capsule?

Which one has faster absorption?

Answer 19

For a suspension: we need 500 mg so we need 125 mg dose 4x
-> reconstitute 20 ml -> contains 500 mg

For a capsule: 500 mg capsule

The suspension has faster absorption bc no disintegration step is required prior dissolution

Question 19

What type of powder is amoxicillin?

Answer 19

Suspension: It is an internal powder; the other form would be a topical powder administered on the skin

Question 20

What to do before dispensing suspension like amoxicillin?

Answer 20

-Add a label to the prescription: the product needs to be mixed
-Counsel the patient
-review the label, route of administration, storage
requirements
-demonstrate how to mix
-ensure measuring devices and educate how to clean it