Speak the Lingo...Learning Sterile Compounding-Related Terminology

can the preparation retain identity, strength, quality, and purity for its stated shelf-life? think drug molecules surviving the situation you put them in.

stability

select all that apply:

where do you find the stability information?

1. manufacturer (package insert)

2. Lexicomp

3. Trissel's

select all that apply:

what changes stability?

1. temperature

2. time

3. light (UV/fluorescent)

4. concentration

5. mixing sequence

6. pH

7. container

do ingredients play nicely? (drug-drug, drug-excipient, drug-container). good = no clinically significant interaction (no precipitate, no potency loss, no hazardous byproduct).

compatibility

select all that apply:

where do we check for compatibility?

1. Lexicomp

2. Trissel's Handbook/database

select all that apply:

what are some factors that can affect compatibility?

1. temperature

2. time

3. light

4. concentration

5. order of mixing

6. pH

7. container

calcium + phosphate in TPN → follow solubility curves; add ________ first, ____________ last, keep pH higher, temp lower, osmolarity lower, use calcium gluconate (less reactive) if possible.

phosphate, calcium

undesirable physical or chemical reaction between mixed components or with the container.

physical (easy to see): precipitation, haze, gas, color change, phase separation, cream/cracking in emulsions.

chemical (harder): hydrolysis/oxidation → potency loss without any cloudiness.

incompatibility

select all that apply:

what are the impacts of incompatibilities on the patient?

1. therapeutic failure

2. phlebitis and pain

3. particulate emboli → thrombosis

4. multi-organ failure, death

absence of viable microorganisms. you can demonstrate/assume by either:

actual testing (outsourced/in-house), or predicted using USP

every CSP must comply. this is not optional. your label's BUD (beyond-use date) comes from

sterility

made under least controlled conditions; short BUDs (≤12 h RT, ≤24 h fridge).

Category 1

made under stricter environmental controls; longer BUDs per Table 13.

Category 2

even more controls, more testing (endotoxin/sterility as applicable), longest BUDs (within Table 14 limits).

Category 3

select all that apply:

how do we think through a real order?

1. what's in it?

2. where will it live?

3. pick BUD ceiling

4. check chemical stability

5. final BUD = the shorter value

6. compatibility sanity check

BUD ≠ ______________. BUD starts when you compound or puncture the container.

manufacturer expiration date

the final CSP (compounded sterile preparation) you get after you put the additive (drug) into an IV solution bag (vehicle). think of it as everything living in the bag after you're done mixing.

IV admixture

select all that apply:

which of the following is included in the IV admixture?

1. additive name

2. additive amount

3. additive concentration

4. additive volume

5. vehicle

6. IV bag volume

7. total volume

8. special instructions

read the vial/ampule label. check drug name, strength, lot, exp date. do not pass go with expired stock.

additive

what the order calls for. Units: usually mg (could be mcg, g, units).

example order line: "cefazolin 2 g in NS 100 mL IVPB over 30 min."

additive amount

for powder vials, you must add a specific diluent type + volume to create an injectable solution. the reference tells you what to use (e.g., SWFI or NS) and how much to add. after you'll have a new concentration in the vial.

reconstitution

what's in the vial when you draw. solution vials/ampules: it's on the label (e.g., 1 mg/mL). powder vials: compute: drug amount added/final volume after reconstitution

additive concentration

how many mL of drug solution you inject into the bag. compute: additive amount (mg)/additive concentration (mg/mL)

additive volume

the fluid the drug rides in (NS, D5W, LR...). choose per PI/Lexicomp/Trissel's and patient factors (e.g., avoid D5W in severe hyponatremia/↑ICP; avoid LR if you must avoid K⁺).

always verify compatibility of drug.

IV solution

use the one on the order/protocol, or the standard for that medication. common sizes: 50, 100, 150, 250, 500, 1000 mL or custom-filled empty bags.

IV solution bag volume

once you know the dose and the final total volume, compute: additive amount/total final volume

final concentration in the bag

_________________ = bag volume ± additive volume

if you don't remove from the bag: additive volume INCREASES the total. if you do remove an equal amount first: total volume stays at the stated bag size.

final total volume

the actual fluid in the bag after you add drug and after any volume you intentionally removed.

total volume

how strong the bag is after mixing—how many mg (or mcg/units) of drug per mL the patient gets. formula = total drug amount ÷ total volume

final concentration

you're spreading the same amount of drug into a larger volume → concentration drops, amount stays the same.

dilution

intermittent infusions with a fixed time (e.g., "over 30 minutes")

rate (mL/hr) = total volume (mL) ÷ infuse time (hr) - no concentration needed

example: 50 mL over 30 min → 50 mL ÷ 0.5 hr = 100 mL/hr.

concentration-independent (aka non-concentration-dependent)

continuous infusions where the dose is ordered per time (mg/hr, mcg/min, units/hr), sometimes per weight (mcg/kg/min, units/kg/hr). here you must use the bag's final concentration.

concentration dependent

how long will this bag last?

infuse over time

time (hr) = total volume (mL) ÷ rate (mL/hr)

example: 50 mL at 100 mL/hr → 50/100 = 0.5 hr = 30 min

concentration-independent setups

additive route: time = total drug amount ÷ ordered dose rate (units must match)

volume route (using Fc): find rate (mL/hr) as above, then time = TV ÷ rate.

example: bag: 100 mg drug total; order 5 mg/hr → time = 100/5 = 20 hr. (same answer you'd get via Fc then TV ÷ mL/hr.)

concentration-dependent (continuous) setups

"over 30 minutes / over 1 hour"? → ____________ → rate = TV / time.

concentration-independent

"mcg/min, mg/hr, units/kg/hr"? → _________________ → compute Fc, then rate = dose rate / Fc.

concentration-dependent

drug pushed directly into the vein/IV line over a short time (commonly ≤ 5 minutes). usually small volume (often a single sterile syringe, ~10-20 mL total). concentration-independent. you typically do not calculate mL/hr; you just follow "give over X minutes."

IV push

a scheduled dose diluted in an IV bag, infused over a short, defined time (e.g., 15, 20, 30, 60 min). think "dose → done → off until next time."

typical volume: ≥ 50 mL (50-250 mL common). concentration-independent.

rate (mL/hr) = total volume (mL) ÷ infuse time (hr).

IV intermittent

runs nonstop to maintain a steady level or physiologic goal (MAP, sedation, etc.). can be titrated.

typical volume: ≥ 50 mL bag (often 100-250 mL). concentration-dependent. you must use final concentration of the bag.

IV continuous

how often you give a dose. common intervals: q4h, q6h, q8h, q12h, q24h, or continuous for drips.

frequency

the extra instructions that drive the math/logic. what they include: starting dose/rate, titration steps, targets (e.g., "MAP ≥ 65"), administration time ("over 2 minutes"), diluent choice, and total volumes.

from CPOE order comments or copied from Lexi/package insert.

in this lab, assume order details are appropriate; in real life, verify everything.

order details