16. Compounding II: Equipment, Stability, and Excipients

Question 1

A graduate should not be used to measure volumes less than __% of the graduate’s capacity

Answer 1

20%

Question 2

___ are most accurate for measuring small volumes and especially useful for measuring viscous liquids (e.g. glycerine, mineral oil)

Answer 2

Syringes

Question 3

You need to draw up 5mL. You have 1mL, 3mL, 5mL, and 10mL syringes. Which syringe will you use?

Answer 3

10mL - do NOT use the exact size syringe needed because the plunger can become dislodged. Use closest syringe size above the size needed (do NOT add 2 different syringe sizes for a dose

Question 4

Minimum weighable quantity formula

Answer 4

WMQ = sensitivity requirement (SR) / acceptable error rate (0.05 or 5%)

Question 5

What kinds of mortar and pestles do compounding pharmacies must have?

Answer 5

1 glass and 1 Wedgewood or porcelain

Question 6

___ mortars are used for liquids, such as suspensions and solutions, and for mixing compounds that are oily or can stain

Answer 6

Glass

Question 7

___ mortars are preferred for grinding dry crystals and hard powder d/t their rough surface

Answer 7

Wedgewood

Question 8

___ mortars are preferred for blending powders and pulverizing gummy consistencies d/t their smooth surface

Answer 8

Porcelain

Question 9

T/F: a metal spatula should be used if making a mixture that contains metallic ions

Answer 9

False - should NOT be used

Question 10

What kind of spatula is used to handle corrosive material?

Answer 10

Rubber

Question 11

Capsule sizes for human use range from 000 (largest/smallest) size and 5 (largest/smallest) size

Answer 11

Largest, smallest

Question 12

Where can you find a list of ingredients recommended for compounding?

Answer 12

USP national formulary (USP-NF) or Food Chemicals Codex (FCC) substances list

Question 13

If there is an ingredient w/o an expiration date, the pharmacists will assign a conservative date that is no more than __ from the date of receipt

Answer 13

3 years

Question 14

Surfactants are used to (increase/lower) the surface tension between 2 ingredients (or phases) to makes them more miscible

Answer 14

lower

Question 15

___ is a mixture of 2 or more liquids which are not able to be blended together

Answer 15

Emulsion

Question 16

___ are substances that reduce the surface tension between a liquid and solid to permit the substance to more easily spread

Answer 16

Wetting agents

Question 17

___is a solid dispersed in a liquid

Answer 17

Suspension

Question 18

What is the difference between levigation and trituration?

Answer 18

Levigation uses a levigant such as glycerin (for aqueous) or mineral oil (for lipophilic) to aid in grinding
Trituration is grinding of particles without the addition of a liquid

Question 19

T/F: oil in water (o/w) emulsions are typically used for topical formulations given bad taste

Answer 19

False - oil in water emulsions are typically used for oral formulations

Question 20

T/F: water-in-oil (w/o) emulsions are typically used for topical formulations given bad taste

Answer 20

True

Question 21

Explain hydrophilic-lipophilic balance (HLB)

Answer 21

HLD scale range is 0 to 20 (midpoint 10)
Surfactants with low HLB (<10) = more lipid soluble (w/o)
Surfactants with high HLBD (>10) = more H2O soluble (o/w)

Question 22

USP emphasizes 3 types of chemical reactions that cause most drug products to become unstable and degrade. Name them.

Answer 22

1. oxidation-reduction
2. hydrolysis
3. photolysis

Question 23

A compound is oxidized when it (loses/gains) electrons and reduced when it (loses/gains) electrons

Answer 23

oxidize = lose
reduced = gains

Question 24

Which compounds are likely to become oxidized?

Answer 24

hydroxyl (-OH) group directly bonded to an aromatic ring
Examples: catecholamines (e.,g. epinephrine), phenolics (e.g. phenylephrine), aldehydes

Question 25

How to prevent oxidation?

Answer 25

Light protection (amber glass, etc.)
Adequate storage
Chelating agents (common ones edetate disodium (EDTA), edetate calcium disodium, and edetic acid)
Antioxidants (inhibits free radicals - common ones: ascorbic acid (vit C), tocopherols (vit E), ascorbyl palmitate, Na ascorbate, Na bisulfate, Na sulfoxylate, and Na thiosulfate)
Maintain pH (with buffer)

Question 26

____ occurs when water causes the cleavage of a bond in a molecule

Answer 26

Hydrolysis

Question 27

Which compounds are likely to be hydrolyzed?

Answer 27

esters, amides, and lactams

Question 28

___ is a carbonyl group bonded to an OR group

Answer 28

Ester

Question 29

___ is a carbonyl group bonded to a nitrogen

Answer 29

Amide

Question 30

How to prevent hydrolysis?

Answer 30

Light protection
Desiccants (to absorb moisture)
Lyophilized powders (freeze-dried)
Chelating agents
Hygroscopic salt (water-absorbing salt)
Pro-drug formulation (hydrolysis activates the drug - e.g. acetylsalicylic acid (aspirin) hydrolyzed to salicylic acid (analgesic) and acetic acid)
Temperature (hydrolysis occurs more rapidly at higher temperatures)
Maintain pH (with buffer)

Question 31

T/F: hydrolysis occurs more rapidly at colder temperatures

Answer 31

False - higher temperatures

Question 32

UV light exposure can cause ____

Answer 32

photolysis

Question 33

What are some examples of compounds likely to degrade by light exposure?

Answer 33

Ascorbic acid
folic acid
nitroprusside
phytonadione injection

Question 34

____ is when a compound changes into a form with the same atoms but an inactive structure

Answer 34

Isomerization

Question 35

___ is when a compound changes into an isomer that differs only in the configuration of atoms. 2 compounds are stereoisomers, this process creates a chiral counterpart (can be inactive or active)

Answer 35

Epimerization

Question 36

____ can happen to compounds with dissolved carboxylic acids. Should be kept refrigerated

Answer 36

Decarboxylation

Question 37

Aqueous solutions of ___ aer liquid when refrigerated and form a gel at room temp

Answer 37

poloxamers (pluronic gel, PLO gel)

Question 38

Alcohol (used as a solvent) should be avoided in ___ (patient population)

Answer 38

children

Question 39

Aspartame (contains phenylalanine, used as sweeter) should be avoided in ___ (patient population)

Answer 39

phenylketonuria (PKU), not able to metabolize phenylalanine

Question 40

Gelatin (used to form capsule shells) should be avoided in ___ (patient population)

Answer 40

Vegetarians and vegans, anyone who wishes to avoid pork
Alternatives: hypromellose capsule shells (cellulose-based, vegan and vegetarian friendly)

Question 41

Gluten (used as starch/filler) should be avoided in ___ (patient population)

Answer 41

Celiac, anyone who wishes to avoid gluten
Alternatives: non-gluten source starch like corn, potato, tapioca

Question 42

Lactose (used as sweetener, to compress tabs and as filler/diluent) should be avoided in ___ (patient population)

Answer 42

Lactose intolerance or allergy

Question 43

Preservatives (e.g. benzyl alcohol) should be avoided in ___ (patient population)

Answer 43

neonates
Use preservative-free formulations

Question 44

Sorbitol (used as sweetener) should be avoided in ___ (patient population)

Answer 44

Irritable Bowl Syndrome (IBS) – can cause GI distress in IBS patients

Question 45

Sucrose (table sugar, used as sweetener and coating)

Answer 45

Diabetes

Question 46

Xylitol (used as sweetener) should be avoided in ___ (patient population)

Answer 46

Dogs - can cause xylitol toxicosis (hypoglycemia and liver damage)
May cause GI upset in humans