Chapter 16: Compounding II - Equipment, Stability & Excipients Flashcards
A graduate should not be used to measure anything < ___% of its volume
20%
What are glass mortars used for?
Liquids such as suspensions and solutions & for compounds that are oily or can stain
What are wedgwood mortars used for?
For grinding dry crystals and hard powders (rough edges like wood)
What are porcelain mortars used for?
For blending powders and pulverizing gummy consistencies
What compounds should you avoid using a metal spatula with?
a mixture containing metal ions (will react with each other)
What is the largest and smallest size capsule
Largest: 000
Smallest: 5
Recommended compounding ingredients are listed in reputable sources such as
USP National formulary (USP-NF)
The Food Chemicals Codex (FCC)
If any substance comes from a non-FDA registered facility, a ____ should be obtained that confirms the specifications and quality
Certificate of Analysis (CoA)
If there is an ingredient without an expiration date, the pharmacist will assign a conservative date that is no more than ____ from the date of receipt. The label on the container should include which 2 things
3 years
Date of receipt and assigned expiration date
What is a surfactant used for?
To make two ingredients easier to mix together & keep the phases from quickly separating by lowering the surface tension (or the interfacial tension)
What is a wetting agent?
A type of surfactant
Reduces the surface tension between a liquid and a solid to allow the substance to more easily spread
Another name for wetting agent
Levigating agent
What is an emulsifier?
A type of surfactant
2 or more liquids which are not able to be blended together (such as water in oil). An emulsifier is added to an emulsion to help keep the liquid droplets dispersed throughout the liquid vehicle
What is a suspending agent?
A type of surfactant
A suspension is a solid in a liquid - to get the solid dispered suspending agents are used. These must still be shaken to redisperse before use
What is a levigating agent?
examples: glycerin or mineral oil
helps aid in grinding
What is added to suspensions to help keep the solid particles from settling?
Suspending agents (or dispersants or dispersing agents)
A suspending agent can also be a plasticizer, which means ….
It will make the preparation easier to shape or mold
Levigation and trituration are both used to …
grind down particles
What is the difference between levigation and trituration
Levigation uses a levigating agent like glycerin or mineral oil to aid in grinding & trituration is the grinding of particles without the addition of a liquid (the powder stays dry)
Mineral oil is a commonly used levigating agent for ____ compounds, and glycerin or propylene glycol are used for ____ compounds.
- lipophilic (oil-soluble)
- aqueous (water-soluble)
The ____ number determines the type of surfactant required to make an emulsion
hydophilic-lipophilic balance (HLB)
Surfactants with low HLB (<10) are more ____-soluble and are used for _____ (o/w or w/o)
Lipid (remember, Low = Lipid)
w/o (water-in-oil)
Surfactants with high HLB (>10) are more ____-soluble and are used for _____ (o/w or w/o)
Water (remember, High = H2O)
o/w (oil-in-water)
What is an example of a chelating agent to avoid metal ions from oxidating a drug?
Edetate disodium (EDTA)
What happens when epinephrine is oxidized?
Changes color to be amber (yellow/orange)
oxidation usually occurs at which functional group?
-OH (hydroxyl)
how to protect from oxidation?
- light protection
- correct storage temperature
- chelating agents
- antioxidants (free radical scavengers)
- control pH
What blocks metal ions from catalyzing oxidation reactions?
provide an example
chelating agents (EDTA, EDetate calcium disodium)
What binds to free radicals?
antioxidants
What are common antioxidants
Ascorbic acid (Vitamin C) and tocopherols (Vitamin E)
How do you maintain pH to avoid drug oxidation & hydrolysis?
Using a buffer
How can you prevent hydrolysis?
- avoid moisture
- Adsorbents (desiccants) to absorb moisture that enters container
- lyophilized (Free-dried) powder
- light protection, chelating agents
- hygroscopic salt (water absorbing)
- prodrug formulation (release drug from hydrolysis)
- control temperature
- control pH
functional groups susceptible to hydrolysis
esters, amides, lactams
Drugs can be stored as a ____ powder instead of a solution to avoid hydrolysis.
lyophilized (freeze-dried) powder
What kind of salt form of a drug can you use to absorb less water and will be less likely to degrade from hydrolysis
a salt form with lower hygroscopic properties
(hydroscopic = water-absorbing)
Hydrolysis occurs more rapidly at ____ (higher/lower) temperatures
Higher
compounds susceptible to UV light
ascorbic acid, nitroprusside, phytonadione (PM DEN = phynatodione, micafungin, doxycycline, epoprostenol, nitroprusside)
what are the 3 other reactions that degrade drugs?
- isomerization
- epimerization
- decarboxylation
Binders role
example
add cohesion to powders/tablets to allow them to stick together
acacia
Diluent and fillers role
diluents: dilute
fillers: bulk up small amount
both add size
diluent/filler examples (tabs/caps, liquids, topicals)
- tabs/caps: lactulose, starches, calcium salts, cellulose
- liquids: water, alcohol
- topicals: petrolatum
Disintegrants role
exs
facilitates the breakup of a tablet after oral administration
- aliginates and cellulose absorb water and cause tab to swell and burst
alginic acid, cellulose products polacrilin potassium, starches
disintegrant examples
alginic acid, cellulose products polacrilin potassium, starches
Sweeteners examples
aspartame, sucralose
glycerin, dextrose, mannitol, sorbitol, xylitol, stevia
Lubricants role
example
prevent ingredients from sticking to each other and equipment
(glidants improve powder flowability)
magnesium stearate
____ are most accurate for measuring small volumes and viscous liquids
Syringes
All syringe packages should be wiped off with ___ prior to being brought into the SEC or PEC
70% IPA
T/F: syringes should be recapped to prevent needle-stick injuries
False - do not recap
Which part of the syringe should not be touched due to contamination risk
plunger
Providing a quick bolus dose into a vein or into a vein through the catheter is called
IV push
A ___ pipette draws up a set volume only, which is the volume the pipette can hold
Volumetric
A ____ pipette is graduated and is used to measure different volumes
Mohr
____ balances have internal weights, which are used to weight quantities ≤ 1 gram
Class III (Class A) torsion balances
Torsion balances have a ____ requirement
Sensitivity
The minimum weighable quantity (MWQ) on a torsion balance calculation
0.05 or 5%
MWQ = SR / acceptable error rate (0.05 or 5%)
What is the most commonly used balance
electronic balance aka analytical balance or scale
Electronic balances are simple to use and have higher ____
sensitivity
A compounding pharmacy needs at least one ___ and one ____ mortar and pestle
1 glass
1 Wedgwood or porcelain
What equipment can be used to mix ingredients
Ointment mills, homogenizers, and grinders
Small particle size and increased surface area = (increased or decreased) rate of absorption
Increased
What is an ointment mill
Draws the ointment or another semi-solid preparation between rollers that grind and homogenize (i.e., make non-gritty, smooth and uniform) the ingredients in the preparation
Capsule shells are made from
gelatin, which is pork-derived or hypromellose or a similar plant-derived product
What are examples of commercially available suspending agents
Ora-Plus & Ora-Sweet
Example of an anti-foaming agent used in non-sterile compounding
Simethicone
What are both PEG and poloxamer used for?
delivery vehicles and surfactants
Poloxamer is useful for ___ drug delivery
topical
[poloxamer can be used to distribute ingredients in a preparation into the “like” phase (hydrophobic –> organic lipophilic phase)]
What are the 3 types of chemical reactions that can cause most drug products to become unstable and degrade
Oxidation-Reduction (OIL-RIG)
Hydrolysis
Photolysis
What are free radicals
metal ions that have an unshared electron. They can catalyze oxidation chain reactions. Chelators can be used to chelate the metal ions with the unshared electron
Examples of common fillers
Lactose, starches (many, including corn, rice, wheat), calcium salts, bentonite, cellulose, petrolatum
___ absorb water, causing tablets to swell and burst. ____ from plants can also absorb water well
Alginates
Cellulose
____ is a common anti-adherent and is used to improve powder flowability
Magnesium stearate
Examples of preservatives
Do not use preservatives in what population?
Chlorhexadine (used as a surgical scrub also), Povidone iodine, Sodium benzoate/benzoic acid, benzalkonium chloride, sorbic acid/potassium sorbate, methyl/ethyl/propyl parabens, EDTA, thimerosal, cetylpyridium chloride
NEONATES
____ compounds are more polar, which makes compounds more ___-soluble
Ionized
water-soluble
The pH of a buffer system can be calculated with
The Henderson-Hasselbalch equation
Types of purification (of water)
distillation, deionization, reverse osmosis
Distilled water is often used for
reconstitution to prepare oral suspensions and in non-sterile compounding preparations
sterile water must be free of ____ which is also known as ____
bacterial endotoxins = pyrogens
Alcohols have high miscibility (mixes easily) with ____
water
benzyl alcohol uses
solvent, preservative and fragrance
What is the preferred disinfectant in sterile compounding
IPA 70%
PEG is ___-soluble and ___-miscible
water
water
PEG is used as a
surfactant, solvent and lubricant
When PEG is linked to a protein drug (pegylated), such as PEG-filgrastim, it increased the
half-life
___ is a PEG mixture that is commonly used as a suppository base and is a good emulsifier
Polybase
An emollient is a product that
softens and soothes the skin
E mole on the skin
Purpose of occlusive ointments
form a protective barrier to prevent the loss of water molecules from the top layer of the skin
___ are put into many emollient formulations to pull in water from the atmosphere to moisturize the skin
Humectants
Examples of humectants
Glycerin or glycerol, propylene glycol and PEG
What percent of an ointment is water
0-20%
Ointments are best for
extremely dry skin and thick skin
Examples of ointments
petrolatum, polybase, aquaphor, aquabase
What is an oleaginous ointment?
example?
contains no water
petrolatum (vasoline)
Creams are greater than __% water and up to __% oil
20%
50% (about half and half)
Creams are best for
normal and dry skin
___ have the most water
Lotions
- can have a small amount of alcohol to solubilize ingredients
What is best for oily skin
Lotions
What are the 4 ointment groups
- Hydrocarbon bases - aka oleaginous (contain no water; examples are Vaseline)
- Absorption bases
- Water-removable bases (creams)
- Water-soluble bases (gels)
Aqueous solutions of poloxamers are ___ when refrigerated and ___ at room temp
liquid
gel
what is Poloxamer Lecithin Organogel (PLO)?
gel - contains one hydrophobic and 2 hydrophilic chains - can be used for both phobic and philic drug delivery
polybase, hydrogenated vegetable oils and gelatin can be used as ____
suppository bases
Examples of adsorbents
Magnesium oxide/carbonate, kaolin
Shellac, gelatin, gluten are used for ____
regular coating
cellulose acetate phthalate is used for
enteric coating
Avoid these agents in what patients:
1. alcohol
2. aspartame
3. gelatin
4. gluten
5. lactose
6. preservatives
7. sorbitol
8. sucrose
9. xylitol
- children
- phenylketonuria
- vegetarians and vegans (contains pork)
- celiac
- lactose intolerance
- neonates
- IBS
- diabetes
- dogs
