Chapter 15. Nonsterile Compounding

Examples of nonsterile drug routes

oral

tube (i.e. gastric tube)

rectally

vaginally

topically

nasally

in the ear

What is nonsterile compounding primarily used for?

Prepare a dose/formulation that is not commercially available

Avoid an excipient

Add a flavor

Electronic balance (analytical balance/scale)

top-loading

higher sensitivity

no MWQ calculation required

Class III Torsion Balance (Class A Balance)

Has 2 Pans:

Internal weights for <1 gram

Use external weights for >1 gram

Requires MWQ calculation/SR

USP 795

Nonsterile preparations

USP 797

Sterile preparations

USP 800

Hazardous drugs

Who considers the USP chapters to be the minimum acceptable standards?

Foos Drug Administration

State Boards of Pharmacy

The Joint Commission

How often must staff demonstrate core competencies, such as hand hygiene and garbing, and have it documented?

On hire and every 12 months

T or F - nonsterile preparations can be done in ambient (room) air?

True - as long as its in a designated space separate from dispensing area

Equipment and ingredients must be stored off the floor

Minimum Weighable Quantity (MWQ) equation

sensitivity requirement (SR) (usually 6 mg) / acceptable error rate (usually 0.05)

Ex.: MWQ = 6/0.05 = 120 mg

What 2 materials can be used for weighing ingredients?

weigh boat

glassine weighing paper

DO NOT place ingredients directly on scale

Is a graduated cylinder or beaker more accurate?

graduated cylinder as it has the same diameter from top to bottom

The wider the mouth of a liquid measuring equipment, the ____________ accurate the piece of equipment is.

less

Measuring volumes that are smaller than _____ of the graduate's capacity can cause a measuring error.

20%

Ex.: 5 mL in 100 mL graduate has higher error risk than 87 mL in 100 mL graduate. A smaller (no larger than 25 mL) graduate is required to measure 5 mL

What are two commonly used names for injection syringes?

hypodermic

parenteral

What measuring device is the most accurate for small volumes?

syringes

especially for viscous liquids

What must be on oral syringes?

Stickers that say "for oral use only" over the syringe cap for safety purposes

What two materials are pipettes commonly made of?

thin plastic (disposable) or glass tubes

Which type of pipette only draws up a set volume?

volumetric pipette

Which type of pipette is graduated and can be used to measure different volumes?

Mohr pipette

Which type of mortar is good for liquids?

glass

Which type of mortar is good for compounds that are oily or can stain?

glass

Which mortar has a rough surface and is good for grinding dry crystals and hard powders?

wedgwood

Which mortar has a smooth surface and is preferred for blending powders?

porcelain

Which mortar is good for pulverizing gummy consistencies?

porcelain

What kind of spatulas are commonly used?

plastic

stainless steel

What is an ointment slab referred to when it is used to form pills?

pill tile

What is an alternative to an ointment slab for mixing ointments?

disposable parchment ointment pads

What is another name for a powder sieve?

sifter

What is the point of using a sieve or sifter?

ensure uniform particle size after a powder has been ground

Ointment Mill

Draws ointment (or other semi-solid preparation) between rollers that grind and homogenize to make uniform/smooth ingredients

Homogenizer

AKA electric mortar and pestle

used to mix ointments/creams/semi-solids

Grinders

Electric grinder used for grinding hard tablets into a rough powder

What can be used for a beaker on a hot plate to save time to mix and dissolve ingredients?

magnetic stirrer

What items can be made inside of molds?

tablets

lozenges

troches

suppositories

What can encourage soft delivery vehicles (e.g. lozenges, suppositories) to maintain their shape?

Disposable plastic molds

Refrigeration

Tablet press

Two plastic or metal plates used to compress damp powder into tablets

Capsules can be.....

soft gels

hard shells

Capsule shells may be made out of...

gelatin (pork-derived)

hypromellose (plant-derived)

What 2 things ensure ingredient quality?

Using the ones listed in the USP- NF (national formulary)

come from FDA-registered facility

For nonsterile compounding, if an ingredient product is missing an expiration, what should a pharmacist do?

assign a conservative date that is no more than 3 years from the date of receipt at the pharmacy

Surfactant stems from what words?

Surface active agents

What is the purpose of using a surfactant?

lower surface tension btwn two ingredients/phases to make them easier to mix together (miscible)

i.e. oil and vinegar (contains h2o) mix when shaken, but quickly settle d/t high surface tension. A surfactant prevents them from quickly separating.

What term describes surfactants being hydrophilic on one side and hydrophobic on the other

ampiphilic

Purpose of surfactant in a compounded prescription

Delivery of a more consistent dose by keeping drug dispersed for longer

Wetting agents/Levigating agents

Reduce surface tension between liquid and solid

levigation makes particles smaller by grinding with a small amount of liquid (aka wetting agent) in which solid is insoluble. Creates paste for suspension or ointment.

Common wetting/levigating agents

- Mineral oil for lipophilic (oil-soluble) compounds

- Glycerin, Propylene glycol for aqueous (water-soluble) compounds

Suspending agents/dispersants/dispersing agents/plasticizer

Added to suspensions to prevent solid particles from settling

What is a counseling point for patients who are prescribed a suspension?

shake prior to use (so particles re-disperse)

What is an example of a plasticizer in gelatin capsules?

sorbitol

What are important commercially available suspending agents?

Ora-Plus

- keeps drug suspended/prevents settling

- bland taste

Ora-Sweet

- provides flavor to Ora-Plus

- available in SF

Ora-Blend

- commerically available combination of plus and sweet

- available in SF

Simethicone is...

an anti-foaming agent (surfactant)

Categories of surfactants

wetting/levigating agents

suspending/dispersing/plasticizer agents

foaming agents

glycols and gels

emulsifiers

Polyethylene glycol (PEG) and poloxamer by itself or as P in PLO are examples of...

glycols and gels

Can be both surfactant and delivery vehicle

hydrophilic and hydrophobic parts

Emulsion

mixture of two or more liquids which are immiscible

(i.e. water and oil)

can be water in oil (w/o) or oil in water (o/w), which is the primary consideration for selecting surfactant

Emulsifier/emulgent

helps keep liquid droplets dispersed through liquid vehicle (prevents separation)

hydrophilic-lipophilic balance (HLB) number determines what?

type of surfactant required for emulsion

What is the HLB scale range?

0-20 (midpoint is 10)

What surfactants are more lipid soluble and what emulsion are they used for?

Low HLB (Low Likes Lipid); <10

w/o (makes h2o like lipid)

What surfactants are more water soluble and what emulsion are they used for?

High HLB (High Hugs H2O); >10

o/w (makes oil like water)

Low or High HLB: Span 65

Low

High or Low HLB: PEG 400

High

High or Low HLB: Tween 85

High

Binders

- Allow contents of tablet to stick together, but release on ingestion

- Provide stability and strength

Starch paste is an example of a...

Binder

Tablet/Capsule Fillers

- Lactose (sugar)

- Starches

- Calcium salts

- Cellulose

Topical filler

Petrolatum

Disintegrants

Alginic acid, cellulose (absorb water causing tablet to swell and release contents)

starches

Sweeteners

Aspartame, Sucralose (non-caloric, artificial)

Glycerin

Dextrose

Mannitol, sorbitol, xylitol (sugar alcohols)

Stevia

What surfactant neutralizes static charge and prevents powder from floating away?

sodium lauryl sulfate

Magnesium stearate is a...

lubricant/glidant; reduces particles sticking together to improve flowability

Which excipients should not be used in neonates?

preservatives, alcohols

Preservatives

- Chlorhexidine (antiseptic in surgical scrubs)

- Povidone iodine

- Sodium benzoate/benzoic acid, benzalkonium chloride

- Sorbic acid/potassium sorbate

- Methyl/ethyl/propyl parabens

- EDTA

- Thimerosal

- Cetylpyridiniyum chloride

Ionized compounds are more ______ which makes them more ________ soluble

polar, water

The pH of a buffer system can be calculated using what equation?

Henderson-Hasselbach

Adsorbants (keep powders dry)

magnesium oxide/carbonate

kaolin

Coatings (regular)

Shellac, gelatin, gluten (food grade)

Enteric coating

Cellulose acetate phthalate

Gelling (thickening) agents

Gelatin

Cellulose

Starches

Bentonite (clay)

Agar

Alginates

Acacia (natural gum), guan, xanthan

Poloxamer (pluronic) gels

Humectants

prevent dry/brittleness

added to emollient

Glycerin, glycerol

Propylene glycol

PEG

Types of purification (treat water to remove chemicals and contaminants)

- Distillation

- Reverse osmosis

- Deionization

Distilled water is commonly used for

Reconstitution (nonsterile)

Potable water is commonly used for

Hand washing

(tap water)

Sterile Water for Injection (SWFI)

for sterile drugs

Free of bacterial endotoxins (pyrogens) that inhabit water

T or F: Alcohols have high miscibility with water

True, used to dissolve solutes that would be insoluble in water

Benzyl alcohol is a...

preservative

fragrance

Hydrophilic solvent

What is the preferred disinfectant for sterile compounding?

IPA 70%

Is PEG lipid or water soluble?

water

Pegylated means...

PEG is linked to a protein drug

Increases half-life

Polybase

PEG mixture used as suppository base; emulsifer

What is the main ingredient of baby oil?

mineral oil (hydrophobic solvent)

Emollients (moisturizers)

soften and soothe skin

Ointments (emollient) are best for

extremely thick, dry skin

preventing water loss

0-20% water

Creams (emollient) are best for

normal and dry skin

20-50% water

most are o/w or w/o emulsions

Lotions (emollients) are best for

oily skin

contain the most water

Sometimes contain alcohol added to solubilize ingredients

What excipient may be added to emollients to pull in water from atmosphere to moisturize skin?

Humectants (glycerin, PEG)

Occlusive ointment examples

Create barrier to prevent water loss

- Petroleum jelly (i.e. white petrolatum)

- theobroma oil (i.e. cocoa butter)

- other waxes

What USP group of ointments are considered "oleaginous" ointments, meaning they contain no water and are oil?

Hydrocarbon bases

good for drug delivery

i.e. white petrolatum (vaseline petroleum jelly)

Common ointment examples

Petrolatum

Polybase

Aquaphor

Aquabase