2.3 Compounding and Sterile Preparation

Quick Answer: Non-sterile compounding follows USP <795> while sterile compounding follows USP <797>. Sterile products require ISO Class 5 environment, proper aseptic technique, and appropriate beyond-use dating. USP <800> covers hazardous drug handling.

USP Compounding Chapters

Non-Sterile Compounding (USP <795>)

What Counts as Non-Sterile Compounding

The 2022 revision of USP <795> eliminated the old simple, moderate, and complex compounding categories. Reconstituting a manufactured product according to its labeling is not compounding under the chapter; reconstitution that departs from the labeling is.

Equipment for Non-Sterile Compounding

• Class A prescription balance (sensitivity 6 mg)
• Graduated cylinders
• Mortar and pestle
• Ointment slab or parchment paper
• Spatulas (metal and plastic)
• Weighing boats or papers
• Compounding log and formula records

Beyond-Use Dating for Non-Sterile Compounds

USP <795> (2022 revision), when there is no stability data:

No BUD may exceed the shortest remaining expiration date of any commercially available starting component.

Important: Beyond-use date (BUD) is different from expiration date. BUD is assigned by the compounder; expiration date is from the manufacturer.

Sterile Compounding (USP <797>)

ISO Classifications

Primary Engineering Controls (PECs)

Aseptic Technique Requirements

Proper Hand Hygiene:

1. Remove jewelry and artificial nails
2. Wash hands and forearms with soap and water for at least 30 seconds
3. Apply alcohol-based hand rub before gloving
4. Don sterile gloves, then apply sterile 70% IPA to them before compounding and regularly throughout

Example Garbing Order (USP <797> does not set one order; your facility's SOP does, in an order that reduces contamination):

1. Shoe covers
2. Head cover (hair cover)
3. Face mask
4. Hand washing
5. Non-shedding gown
6. Sterile gloves (donned in a classified room or SCA; never donned or doffed inside the ISO Class 5 PEC with bare hands exposed)

Beyond-Use Dating for Sterile Compounds (CSPs)

Category 1 CSPs (12 Hours or Less at Room Temp):

Category 2 CSPs (prepared in an ISO Class 5 PEC inside an ISO-classified anteroom and buffer room): the maximum BUD depends on how the CSP was made.

A shorter BUD applies when stability data call for it. Category 3 CSPs, made under extra quality requirements, may have longer BUDs.

Clean Room Behavior Rules

• No food, drink, or gum
• No cosmetics or perfume
• Speak minimally
• Move slowly and deliberately
• Never cough or sneeze toward work area
• Keep hands away from face
• Work at least 6 inches inside the front edge of the hood (ASHP guidance)
• Never block HEPA filter airflow

IV Preparation Basics

Common IV Solutions

IV Flow Rate Calculations

Formula: gtt/min = (Volume x Drop Factor) / Time in minutes

Worked Example: IV Flow Rate

Order: 1000 mL NS over 8 hours using 15 gtt/mL tubing

Step 1: Convert hours to minutes

• 8 hours x 60 = 480 minutes

Step 2: Apply formula

• gtt/min = (1000 mL x 15 gtt/mL) / 480 min
• gtt/min = 15,000 / 480 = 31.25 gtt/min (round to 31)

Hazardous Drug Handling (USP <800>)

Requirements for Hazardous Drugs

Categories of Hazardous Drugs

• Antineoplastic agents (chemotherapy)
• Hormones and hormone antagonists
• Some antivirals
• Immunosuppressants
• Bioengineered drugs

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USP Chapters That Govern Compounding

Three USP chapters define the standards the ExCPT tests. Know which chapter applies to which activity.

Exam Tip: If a question mentions a laminar flow hood, ISO-classified air, or aseptic technique, the governing chapter is USP <797>. If it mentions chemotherapy or a negative-pressure room, think USP <800>.

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Primary Engineering Controls and Air Quality

Sterile compounding occurs inside primary engineering controls (PECs). Air cleanliness is rated by ISO class, where a lower number is cleaner.

The direct compounding area inside a PEC must meet ISO Class 5. The buffer room is typically ISO Class 7 and the ante-room ISO Class 8.

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Beyond-Use Dates (BUD)

A beyond-use date is the date after which a compounded preparation must not be used. It differs from the manufacturer expiration date on commercial stock. BUDs depend on the preparation type, storage temperature, and sterility.

Worked Example: A repackaged tablet has a manufacturer expiration of 18 months away, but the repackaging guideline caps the BUD at 6 months. The label must show the 6-month BUD because you always assign the earlier date.

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Needles, Syringes, and Documentation

Sterile compounding also tests equipment knowledge. A higher needle gauge number means a thinner needle. Filter needles trap glass or rubber particles when drawing from an ampule. Every compounded or repackaged product requires documentation: ingredients, lot numbers, BUD, and the preparer's and checker's identities, retained per USP <795>/<797>.