Compounding II: Equipment, Stability, & Excipients Flashcards

1
Q

The wider the mouth of the cylinder, the _________ the accuracy.

A

lower
- graduate cylinders are more accurate than conical graduates or beakers

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2
Q

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

A

20%

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3
Q

For drawing up a medication, should you use the exact size syringe needed?

A

No, you should not use the exact size syringe needed because the plunger can easily become dislodged. Select the closest syringe size above the size needed. Do not add two different syringe sizes for a dose.

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4
Q

difference between a volumetric pipette & a Mohr pipette

A

volumetric pipette - draws up a set volume only, which is the volume it can hold

Mohr pipette - is graduated & used to measure different volumes; commonly used in compounding

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5
Q

What type of balance is the “older” balance that is still used but less commonly than the electronic balance?

A

Class III torsion balance (sometimes called a Class A balance)

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6
Q

Explain sensitivity requirement (SR) and minimum weighable quantity (MWQ) of a torsion balance.

A

Torsion balances have a sensitivity requirement (SR) that is most often 6 mg, meaning 6 mg can be added or removed before the dial moves 1 division

MWQ = SR / acceptable error rate (0.05 or 5%)
ex. MWQ = 6 mg / 0.05 = 120 mg

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7
Q

Which balance is used most commonly?

A

top-loading electronic balance (called an analytical balance or scale)
- simple (not necessary to calculate a MWQ)
- has higher sensitivity
- must “tare” or “zero out” the balance after placing weigh boat or glassine paper on scale
- always place material to be weighed on a weigh boat or glassine paper (never directly on the balance)

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8
Q

A compounding pharmacy needs how many and what kinds of mortars & pestles?

A

at least one glass & at least one Wedgewood or porcelain

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9
Q

Glass mortars are used for…

A

liquids, such as suspension & solutions, and for mixing compounds that are oily or can stain

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10
Q

Wedgewood mortars have a rough surface & are preferred for…

A

grinding dry crystals & hard powders

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11
Q

Porcelain mortars have a smooth surface, & are preferred for…

A

blending powders & pulverizing gummy consistencies

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12
Q

When would a steel (metal) spatula NOT be used?

A

if making a mixture that contains metallic ions

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13
Q

Sieves are sifters similar to those used in baking. After a powder has been ground fine, it is sifted in order to ensure…

A

a uniform particle size

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14
Q

Ointment mills & grinders _________ the particle size, which ___________ the surface area & the rate of drug absorption.

A

Ointment mills & grinders decrease the particle size, which increases the surface area & the rate of drug absorption.

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15
Q

Capsule sizes for human use range from _____ (the largest size) to _____ (the smallest size). Veterinary pharmacists can order larger capsule sizes for use in larger animals.

A

000 (largest) to 5 (smallest)

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16
Q

Capsules can be ________ or __________.

A

soft gels or hard shells, which are most commonly used for compounding
- shells are made of gelatin, which is pork-derived & will not be suitable for some patients, or from hypromellose or a similar plant-derived product

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17
Q

Ingredients that are recommended for use will be listed in…

A

either:
- USP National Formulary (USP-NF)
- Food Chemical Codex (FCC) substances list

18
Q

Preferably, ingredients should be manufactured at an FDA-registered facility. If any substance comes from a non-FDA registered facility, a __________________ should be obtained.

A

Certificate of Analysis (CoA), confirms the specifications & quality

19
Q

Surfactants ___________ the surface tension (i.e., the interfacial tension) between two ingredients (or phases) in a preparation to make them more _________.

A

Surfactants lower the surface tension (i.e., the interfacial tension) between two ingredients (or phases) in a preparation to make them more miscible (i.e., easier to mix together).

20
Q

Surfactants are ____________.

a. lipophilic
b. hydrophilic
c. amphiphilic

A

c. amphiphilic
- both hydrophilic (on one side) & hydrophobic (on the other)

21
Q

Surfactants are called by a variety of names, depending on the use or the type of preparation. What are the types of surfactants?

A

WETTING AGENTS

EMULSIFIERS

SUSPENDING AGENT

LEVIGATING AGENTS

FOAMING AGENTS

22
Q

Describe wetting agents

A

reduce surface tension b/t a liquid & solid (ex. a fine powder that will be incorporated into a suspension is wetted with a wetting agent)

23
Q

Describe emulsifiers

A

emulsion is a mixture of two or more liquids that are immiscible; emulsifier added to help keep the liquid droplets dispersed throughout the liquid vehicle

24
Q

Describe suspending agents

A
  • suspension is a solid dispersed in a liquid; suspending agent added to help keep solid particles from settling
  • can be called dispersants (or dispersing agents)
  • can be a plasticizer, meaning to make a preparation easier to shape or mold (ex. sorbitol can be used as a plasticizer for gelatin capsules)
25
Q

Describe levigating agents

A

Levigation & triturations are both used to grind down particles (i.e., make particles smaller)
- levigation uses a levigating agent (AKA a levigant) such as glycerin or mineral oil to aid in the grinding
- mineral oil is a commonly used levigating agent for lipophilic compounds & glycerin or propylene glycol are used for aqueous compounds

26
Q

Foaming agents help foam to form by lowering the surface tension of water. In non-sterile compounding, anti-foaming agents are more commonly used (i.e., _____________)

A

simethicone

27
Q

Polyethylene glycol (PEG) and poloxamer by itself or as the P in PLO gel are both __________ vehicles & ____________.

A

delivery vehicles & surfactants
- have both hydrophilic & lipophilic parts
- poloxamer is useful for topical drug delivery

28
Q

What determines the type of surfactant required?

A

hydrophilic-lipophilic balance (HLB)
- HLB scale is 0-20

29
Q

Surfactants with a low HLB number (< 10) are more _______-soluble & used for ____________ emulsions.

A

Surfactants with a low HLB number (< 10) are more lipid-soluble & used for water-in-oil (w/o) emulsions.
*think L in low for L in lipid soluble

ex. Span 65 has a HLB less than 10 -> possible option for w/o emulsion.

30
Q

Surfactants with a high HLB number (> 10) are more _______-soluble & used for ____________ emulsions.

A

Surfactants with a high HLB number (> 10) are more water-soluble & used for oil-in-water (o/w) emulsions.
*think H in High for H2O soluble

ex. PEG400 & Tween 85 have HLB greater than 10 -> options for o/w emulsion

31
Q

USP emphasizes three types if chemical reactions that cause most drug products to become unstable & degrade:

A
  • oxidation-reduction
  • hydrolysis
  • photolysis
32
Q

A compound is oxidized when it ______ electrons & is reduced when it _______ electrons.

A

A compound is oxidized when it loses electrons & is reduced when it gains electrons.
*see examples on pg. 257

33
Q

The molecular structures most likely to oxidize are those with a ________ group directly bonded to an aromatic ring.

A

The molecular structures most likely to oxidize are those with a hydroxyl (-OH) group directly bonded to an aromatic ring.

34
Q

How can oxidation be prevented?

A

LIGHT PROTECTION
- with amber glass, UV light-blocking containers, light-protective sleeves
ADEQUATE STORAGE
- temp control with refrigeration, control of room temps, & (occasionally) freezer storage
CHELATING AGENTS
- use chelators to chelate metal ions that have an unshared electron in the outer shell; these are free radicals which can catalyze oxidation chain reactions.
ANTIOXIDANTS (AKA free radical scavengers)
- inhibit free radicals
CONTROL pH
- maintain pH with a buffer

35
Q

example of a chelating agent

A

commonly have the letters ED; ex. EDTA

36
Q

common antioxidants

A

ascorbic acid (vitamin C), tocopherols (vitamin E), etc.

37
Q

Hydrolysis occurs when _______ causes the cleavage of a bond in a molecule.

A

Hydrolysis occurs when water causes the cleavage of a bond in a molecule.
- Dessicants are sometimes used to soak up any moisture that enters the container

*see example on pg. 257

38
Q

The most common functional groups susceptible to hydrolysis are…

A

esters, amides, & lactams
- the carbonyl group is subject to hydrolysis
- ester = carbonyl group bonded to an OR group
- amide = carbonyl group bonded to an N
- lactam = a cyclic amide

39
Q

How can hydrolysis be prevented?

A

LIGHT PROTECTION, CHELATING AGENTS
- see oxidation flashcard for more info
ADSORBENTS (DESSICANTS)
- to absorb any moisture
LYOPHILIZED POWDERS
- drugs can be stored as a lyophilized (freeze-dried) powder instead of in solution
HYGROSCOPIC SALT
- hygroscopic means water-absorbing; in some cases, a salt form of the drug can be chosen that is less hygroscopic
PRODRUG FORMULATION
- prodrugs that release the active drug by hydrolysis can be formulated (e.g. aspirin is hydrolyzed to salicylic acid & acetic acid)
CONTROL TEMPERATURE
- hydrolysis occurs more rapidly at higher temps
CONTROL pH
- maintain pH with a buffer

40
Q

Photolysis can be prevented with…

A

light protection
- many drugs are senstivie to UV light exposure

41
Q

What compounds are likely to become degraded by light exposure? (give examples)

A

Compounds that are sensitive to light include ascorbic acid, folic acid, nitroprusside, & phytonadione injection

42
Q

left off on pg

A

257