Powders And Granules

Front 1

What are powders?

Back 1

mixtures of dry, finely divided drugs intended for internal or external use.

Front 2

What are the advantages and disadvantages of powders?

Back 2

A) faster dissolution and absorption, easier to swallow, improved dry stability

D) undesirable taste, poor flow

Front 3

How have powders been historically used?

Back 3

orally, through nose as snuffs, insufflation, externally to compromised area.

Front 4

How are particle sizes differentiated?

Back 4

Very coarse, Coarse, Moderately Coarse, Fine, or Very Fine

Front 5

How are particles characterized?

Back 5

by morphology, purity, stability, and size

Front 6

6 methods to determine particle size?

Back 6

Sieving, Microscopy, Sedimentation, light scattering, laser holography, and cascade impactor

Front 7

What is a cascade impactor?

Back 7

multi-stage impaction device for separating airborne particles by size.

Front 8

How can particle sizes be reduced?

Back 8

MANUALLY by trituration or levigation, good for small pharmacy

Mechanically by blade grinders which are good for industry

Front 9

Describe methods of small scale blending

Back 9

1)spatulation - using spatula, not good for large quantities or potent drugs

2) trituration - mortar and pestle, good for community pharmacy

3) levigation - mortar and pestle, a paste is formed by combining powder and liquid

Front 10

Describe methods of large scale blending

Back 10

1) Sifting - results in light, fluffy product

2) Tumbling - rotating chamber, thorough mixing

3) Twin Shell Blender - rolling rather than sliding, simple cleaning

4) Vertical Impeller - little floor space, screw-type impeller

5) Fluidized Mixer - air stream enters bottom and powder is fluidized

Front 11

When are oral powders useful?

Back 11

1) local (laxative, antacid) or systemic (analgesic) effects

2) patients with difficulty swallowing

3) for large dose meds too bulky for tablets

4) easily mixed with food/beverage

Front 12

Describe topical powders

Back 12

contain micronized particles mostly used for anti fungal or antibacterial. stored in a sifter-type container

Front 13

Describe insufflated powders

Back 13

used to deliver drug to ear, nose, throat, tooth socket or skin but with difficulty in proper dose delivery

Front 14

Describe aerosol powders

Back 14

uses a dry-powder metered inhaler with particles 1-6 micrometers

Front 15

Describe problems with Eutectic powders. How is this overcome?

Back 15

- some powders may become sticky, pasty, or may even liquefy when mixed
-to overcome, mix powders with a bulky powder absorbent (Magnesium Carbonate) and triturate very lightly with a spatula

Front 16

What are Hygroscopic and Deliquescent powders? How are the problems with these overcome?

Back 16

Hygroscopic - absorb moisture
Deliquescent - absorb moisture from air and liquefy

To overcome, disperse in tight containers with dessicant, and instruct to store in a dry place.

Front 17

What are bulk powders?

Back 17

powders dispersed in bulk and measured out doses by the patient, limited to non-potent meds

Front 18

Examples of Bulk Powders

Back 18

1)antacids (sodium bicarbonate)
2)Laxatives (metamucil)
3)Douche powders (mussengill)
4)Topical anti-infectives (bacitracin zinc)

Front 19

What are divided powders?

Back 19

commonly used for potent drugs, blended by geometric dilution and over dose is divided into individual dosing units

Front 20

Describe the process of preparing charts for divided powders

Back 20

For potent drugs: weigh each powder quantity

For non-potent drugs: block and divide method

Front 21

Describe the process of dispensing charts for divided powders

Back 21

1)place weighed powder into small zipper bag
2)place self-contained powder papers into zipper bag
3)place powders into powder papers, which are folded and boxed

Front 22

Describe packaging of bulk, divided, topical, and insufflation powders

Back 22

Bulk - in glass, plastic or metal with wide mouth

Divided - individually folded

Topical - poured into sifter-top containers or powder shakers

Insufflations - filled into plastic units

Front 23

Describe the 4 types of paper used for divided powders

Back 23

Bond - for powders not affected by air or moisture

Vegetable - limited barrier against moisture

Glassine or Glazed - limited barrier against moisture

Waxed - waterproof, may be double wrapped

Front 24

Describe how quality is controlled with bulk and divided powders

Back 24

Bulk - compare final weight with theoretical weights to examine for uniformity and freedom from caking

Divided - individually weigh packets and compare to theoretical weight, each checked for uniformity

Front 25

How should be powders be stored?

Back 25

dry places and may require protection from light

Front 26

What are granules?

Back 26

agglomerates of smaller powder particles. irregularly shaped, but may be spherically prepared

Front 27

Describe the 2 dry methods of preparing granules

Back 27

DM1: pass dry powder through set of rollers running in opposite directions, dense sheets collected and then passed through granulating machine

DM2: slugging used to prepare large tablets or slugs

Front 28

Describe the 2 wet methods of preparing granules

Back 28

WM1: moisten powder then pass through screen, collect in drying tray and dry by air or heat

WM2: fluid bed processing, disperse and suspend particles, spray liquid excipient to add consistency and dry to form granules

Front 29

What are advantages of granules over powders?

Back 29

flow better, less surface area, and are "wetted" by liquids easier

Front 30

What are effervescent granulated salts?

Back 30

-granules or coarse/very coarse powders
-contain medicinal agent in dry mix of sodium bicarbonate, citric acid and tartaric acid
-when added to water, the acids and bases react to liberate CO2, resulting in effervescence

Front 31

What are advantages of effervescent salts over powder?

Back 31

-masking of bad taste
-granules reduce rate of dissolution and prevent uncontrollable effervescence

Front 32

Why use citric and tartaric acid together when forming effervescent salts?

Back 32

Because Citric Acid alone produces sticky mixture which is hard to granulate and Tartaric acid alone produces granules that lose firmness and crumble

Front 33

Describe the fusion method of preparing effervescent salts

Back 33

1)Citric Acid crystals powdered
2)Mix with other powders
3)mix rapidly in low humidity
4)place in dish and heat to 34-40 celsius
5)citric acid releases water of crystallization, dissolving powder mixture
6)remove from oven, run through sieve to produce granules
7)dry and seal in tight containers

Front 34

Describe the wet method of preparing effervescent salts

Back 34

-uses water added to alcohol as binding agent.
- water is added to powder to prepare a mass and then granulated as in fusion method