16. Compounding II: Equipment, Stability, and Excipients Flashcards
A graduate should not be used to measure volumes less than __% of the graduate’s capacity
20%
___ are most accurate for measuring small volumes and especially useful for measuring viscous liquids (e.g. glycerine, mineral oil)
Syringes
You need to draw up 5mL. You have 1mL, 3mL, 5mL, and 10mL syringes. Which syringe will you use?
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
Minimum weighable quantity formula
WMQ = sensitivity requirement (SR) / acceptable error rate (0.05 or 5%)
What kinds of mortar and pestles do compounding pharmacies must have?
1 glass and 1 Wedgewood or porcelain
___ mortars are used for liquids, such as suspensions and solutions, and for mixing compounds that are oily or can stain
Glass
___ mortars are preferred for grinding dry crystals and hard powder d/t their rough surface
Wedgewood
___ mortars are preferred for blending powders and pulverizing gummy consistencies d/t their smooth surface
Porcelain
T/F: a metal spatula should be used if making a mixture that contains metallic ions
False - should NOT be used
What kind of spatula is used to handle corrosive material?
Rubber
Capsule sizes for human use range from 000 (largest/smallest) size and 5 (largest/smallest) size
Largest, smallest
Where can you find a list of ingredients recommended for compounding?
USP national formulary (USP-NF) or Food Chemicals Codex (FCC) substances list
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
3 years
Surfactants are used to (increase/lower) the surface tension between 2 ingredients (or phases) to makes them more miscible
lower
___ is a mixture of 2 or more liquids which are not able to be blended together
Emulsion
___ are substances that reduce the surface tension between a liquid and solid to permit the substance to more easily spread
Wetting agents
___is a solid dispersed in a liquid
Suspension
What is the difference between levigation and trituration?
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
T/F: oil in water (o/w) emulsions are typically used for topical formulations given bad taste
False - oil in water emulsions are typically used for oral formulations
T/F: water-in-oil (w/o) emulsions are typically used for topical formulations given bad taste
True
Explain hydrophilic-lipophilic balance (HLB)
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)
USP emphasizes 3 types of chemical reactions that cause most drug products to become unstable and degrade. Name them.
- oxidation-reduction
- hydrolysis
- photolysis
A compound is oxidized when it (loses/gains) electrons and reduced when it (loses/gains) electrons
oxidize = lose
reduced = gains
Which compounds are likely to become oxidized?
hydroxyl (-OH) group directly bonded to an aromatic ring
Examples: catecholamines (e.,g. epinephrine), phenolics (e.g. phenylephrine), aldehydes
How to prevent oxidation?
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)
____ occurs when water causes the cleavage of a bond in a molecule
Hydrolysis
Which compounds are likely to be hydrolyzed?
esters, amides, and lactams
___ is a carbonyl group bonded to an OR group
Ester
___ is a carbonyl group bonded to a nitrogen
Amide
How to prevent hydrolysis?
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)
T/F: hydrolysis occurs more rapidly at colder temperatures
False - higher temperatures
UV light exposure can cause ____
photolysis
What are some examples of compounds likely to degrade by light exposure?
Ascorbic acid
folic acid
nitroprusside
phytonadione injection
____ is when a compound changes into a form with the same atoms but an inactive structure
Isomerization
___ 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)
Epimerization
____ can happen to compounds with dissolved carboxylic acids. Should be kept refrigerated
Decarboxylation
Aqueous solutions of ___ aer liquid when refrigerated and form a gel at room temp
poloxamers (pluronic gel, PLO gel)
Alcohol (used as a solvent) should be avoided in ___ (patient population)
children
Aspartame (contains phenylalanine, used as sweeter) should be avoided in ___ (patient population)
phenylketonuria (PKU), not able to metabolize phenylalanine
Gelatin (used to form capsule shells) should be avoided in ___ (patient population)
Vegetarians and vegans, anyone who wishes to avoid pork
Alternatives: hypromellose capsule shells (cellulose-based, vegan and vegetarian friendly)
Gluten (used as starch/filler) should be avoided in ___ (patient population)
Celiac, anyone who wishes to avoid gluten
Alternatives: non-gluten source starch like corn, potato, tapioca
Lactose (used as sweetener, to compress tabs and as filler/diluent) should be avoided in ___ (patient population)
Lactose intolerance or allergy
Preservatives (e.g. benzyl alcohol) should be avoided in ___ (patient population)
neonates
Use preservative-free formulations
Sorbitol (used as sweetener) should be avoided in ___ (patient population)
Irritable Bowl Syndrome (IBS) – can cause GI distress in IBS patients
Sucrose (table sugar, used as sweetener and coating)
Diabetes
Xylitol (used as sweetener) should be avoided in ___ (patient population)
Dogs - can cause xylitol toxicosis (hypoglycemia and liver damage)
May cause GI upset in humans
