← Sterile Compounding – PTCB Exam Flashcards

PTCB Pharmacy Technician Certification Study Guide

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Sterile Compounding – PTCB Exam Study Guide


Overview

Sterile compounding requires strict adherence to USP <797> standards to prevent microbial contamination and ensure patient safety. This guide covers the critical areas tested on the PTCB exam, including regulatory standards, facility design, equipment, aseptic technique, and quality assurance. Mastery of these concepts is essential for pharmacy technicians working in or being tested on sterile compounding environments.


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USP <797> Standards


Summary

USP <797> is the governing chapter that establishes minimum standards for all compounded sterile preparations (CSPs). The 2023 revision introduced a simplified two-category risk classification system, replacing the outdated low/medium/high-risk model.


CSP Categories


| Category | BUD (Room Temp) | BUD (Refrigerated) | Testing Required |

|---|---|---|---|

| Category 1 | ≤ 12 hours | ≤ 24 hours | No sterility/endotoxin testing |

| Category 2 | Longer BUDs allowed | Longer BUDs allowed | Sterility + endotoxin testing required |

| Immediate-Use | Must be administered within 4 hours | N/A | Emergency/immediate care only |


Key Terms

  • • Beyond-Use Date (BUD) – The date and time after which a CSP must not be used, based on category and storage conditions
  • • Compounded Sterile Preparation (CSP) – A sterile drug product prepared in a pharmacy setting outside of standard manufacturing
  • • Immediate-Use CSP – A preparation intended for emergency situations requiring administration within 4 hours of preparation
  • • Bacterial Endotoxin Testing (BET) – A test required for Category 2 CSPs to detect fever-causing bacterial byproducts (pyrogens)

    • Watch Out For

    > ⚠️ Common Pitfall: The 2023 USP <797> revision eliminated the old low/medium/high-risk categories. Do not confuse the old system with the current Category 1 and Category 2 classification on your exam.


    > ⚠️ Common Pitfall: Immediate-use CSPs have a strict 4-hour window for administration — this does not extend to 12 or 24 hours even under refrigeration.


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    Cleanroom & ISO Classifications


    Summary

    Sterile compounding facilities must maintain specific air quality standards measured by ISO classifications. Each area of the facility has a required ISO class based on its proximity to the sterile product.


    ISO Classification Hierarchy


    | Area | ISO Class | Max Particles (≥0.5 µm/m³) | Pressure |

    |---|---|---|---|

    | Direct Compounding Area (DCA) | ISO Class 5 | 3,520 | — |

    | Buffer Room (Cleanroom) | ISO Class 7 | 352,000 | Positive (non-hazardous) / Negative (hazardous) |

    | Ante-Room | ISO Class 8 | 3,520,000 | Positive or Negative |


    Key Terms

  • • Direct Compounding Area (DCA) – Also called the critical zone; the highest-air-quality area where sterile products are actually manipulated
  • • Buffer Room – The ISO Class 7 cleanroom where compounding occurs
  • • Ante-Room – The ISO Class 8 transition zone between unclassified spaces and the buffer room
  • • Positive Pressure – Air flows outward, preventing outside contaminants from entering (used for non-hazardous compounding)
  • • Negative Pressure – Air flows inward, containing hazardous particles within the room (used for hazardous drug compounding)

    • Watch Out For

    > ⚠️ Common Pitfall: A lower ISO number means cleaner air. ISO Class 5 is cleaner than ISO Class 7, which is cleaner than ISO Class 8.


    > ⚠️ Common Pitfall: Remember the pressure distinction — non-hazardous = positive pressure, hazardous = negative pressure. Mixing these up is a frequent error.


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    Laminar Airflow & Equipment


    Summary

    The correct engineering controls protect both the sterile product and compounding personnel. Equipment selection depends entirely on whether the drug being compounded is hazardous or non-hazardous.


    Equipment Quick Reference


    | Equipment | Used For | Air Direction | Protects |

    |---|---|---|---|

    | Horizontal LAFW (HLAF) | Non-hazardous sterile drugs | Horizontal (toward operator) | Product only |

    | Vertical LAFW | Non-hazardous sterile drugs | Vertical (downward) | Product only |

    | Biological Safety Cabinet (BSC) | Hazardous drugs | Vertical + recirculated/exhausted | Product and operator |

    | Compounding Aseptic Containment Isolator (CACI) | Hazardous drugs | Contained/isolated | Product and operator |


    Key Terms

  • • HEPA Filter – High-Efficiency Particulate Air filter; removes 99.97% of particles ≥0.3 µm
  • • Laminar Airflow Workbench (LAFW) – Equipment that provides ISO Class 5 air quality using HEPA filtration
  • • BSC (Biological Safety Cabinet) – Required engineering control for hazardous drug compounding
  • • CACI (Compounding Aseptic Containment Isolator) – An isolator used for hazardous drug compounding
  • • Purge Time – The 30-minute minimum run time required before compounding can begin in a LAFW

    • Watch Out For

    > ⚠️ Common Pitfall: A horizontal LAFW blows air toward the operator — this is acceptable for non-hazardous drugs but would expose the operator to hazardous drug particles. Never use a horizontal LAFW for hazardous drug compounding.


    > ⚠️ Common Pitfall: Remember that HEPA filters capture particles ≥0.3 µm at 99.97% efficiency — this is a commonly tested fact.


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    Aseptic Technique


    Summary

    Aseptic technique refers to the practices that prevent microbial contamination during sterile compounding. Every step — from handwashing to needle insertion — is designed to maintain sterility of the final product.


    PPE Donning Order (Dirtiest to Cleanest)


    ```

    1. Shoe covers

    2. Hair cover

    3. Face mask / beard cover

    4. Gown

    ↓ (Move into buffer room)

    5. Hand washing (at least 30 seconds)

    6. Sterile gloves (donned LAST)

    ```


    Critical Aseptic Technique Steps


  • • Hand Washing – Minimum 30 seconds with soap and water, covering hands and forearms
  • • Swabbing Vial Stoppers – Use 70% isopropyl alcohol (IPA) with a single unidirectional stroke; allow to dry completely before needle insertion
  • • Opening Ampules – Swab neck with 70% IPA → wrap with sterile gauze → snap away from body → withdraw solution with a filter needle or filter straw to remove glass particles
  • • Placement in LAFW – Nothing should be placed behind the sterile product in a horizontal LAFW, as this disrupts airflow

    • Key Terms

  • • Aseptic Technique – Methods used to prevent introduction of microorganisms during sterile compounding
  • • First Air – The uninterrupted, HEPA-filtered air flowing directly from the filter over the critical site; must never be blocked
  • • Critical Site – Any surface or opening at risk of contamination (e.g., needle, vial stopper, ampule opening)
  • • 70% Isopropyl Alcohol (IPA) – The standard disinfectant used for surface cleaning and vial stopper swabbing in sterile compounding
  • • Filter Needle / Filter Straw – Used when withdrawing solution from ampules to remove glass shards

    • Watch Out For

    > ⚠️ Common Pitfall: Gloves are always donned last, after entering the buffer room and completing hand hygiene. Donning gloves in the ante-room before washing hands is incorrect procedure.


    > ⚠️ Common Pitfall: The swabbing technique is unidirectional (one direction, one stroke) — back-and-forth scrubbing can reintroduce contaminants.


    > ⚠️ Common Pitfall: Always use a filter needle when drawing from an ampule. Regular needles do not remove glass particles.


    > ⚠️ Common Pitfall: "First air" must remain unobstructed — hands, vials, or other objects placed between the HEPA filter and the critical site break the sterile air path.


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    Quality & Sterilization


    Summary

    Quality assurance in sterile compounding involves proper sterilization methods, routine personnel testing, and environmental monitoring to ensure every CSP meets sterility standards before reaching the patient.


    Sterilization Methods


    | Method | Description | Used When |

    |---|---|---|

    | Autoclaving | Moist heat at 121°C for ≥15 minutes | Heat-stable preparations |

    | Filtration | 0.22 µm (0.2 µm) membrane filter | Heat-sensitive solutions |

    | Dry Heat | Higher temperatures, longer times | Glassware, oils, powders |


    Quality Testing Requirements


  • • Sterility Testing – Required for Category 2 CSPs; confirms absence of microbial contamination
  • • Bacterial Endotoxin Testing (BET) – Required for Category 2 CSPs; detects fever-causing pyrogens from gram-negative bacteria
  • • Media-Fill Test – Simulation using growth media to validate personnel aseptic technique; any microbial growth = technique failure
  • • Gloved Fingertip & Thumb Sampling – Performed initially (before independent compounding) and at least annually thereafter

    • Key Terms

  • • Autoclave – Device used for moist heat sterilization; the gold standard for heat-stable CSPs
  • • 0.22 µm Filter – Membrane filter used for sterilization by filtration; removes bacteria and most microorganisms
  • • Media-Fill Test – Aseptic technique validation using a microbiological growth medium instead of a drug
  • • Pyrogen – A fever-inducing substance, typically bacterial endotoxins; detected by BET
  • • Gloved Fingertip Sampling – A quality test where personnel press gloved fingertips into growth media to check for contamination

    • Watch Out For

    > ⚠️ Common Pitfall: Filtration uses a 0.22 µm filter — not 0.45 µm (which is used for clarification, not sterilization). Only the 0.22 µm size achieves sterilization.


    > ⚠️ Common Pitfall: Media-fill tests evaluate personnel technique, not equipment performance. Failed media fills reflect on the compounding personnel, not the hood.


    > ⚠️ Common Pitfall: Category 1 CSPs do not require sterility or endotoxin testing — these requirements apply to Category 2 CSPs only.


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    Quick Review Checklist


    Use this checklist to confirm you can recall each key concept before your exam:


  • • [ ] USP <797> governs sterile compounding standards
  • • [ ] Category 1 BUDs: ≤12 hours (room temp), ≤24 hours (refrigerated)
  • • [ ] Immediate-use CSPs must be administered within 4 hours
  • • [ ] Category 2 CSPs require sterility testing and bacterial endotoxin testing
  • • [ ] ISO Class 5 = Direct Compounding Area (DCA / critical zone)
  • • [ ] ISO Class 7 = Buffer Room (cleanroom)
  • • [ ] ISO Class 8 = Ante-Room
  • • [ ] Non-hazardous buffer rooms = positive pressure
  • • [ ] Hazardous drug buffer rooms = negative pressure
  • • [ ] Use a horizontal LAFW for non-hazardous; BSC or CACI for hazardous drugs
  • • [ ] LAFW must run for 30 minutes before compounding begins
  • • [ ] HEPA filters capture 99.97% of particles ≥0.3 µm
  • • [ ] PPE is donned in order from dirtiest to cleanest (shoe covers → gloves last)
  • • [ ] Hand washing minimum = 30 seconds
  • • [ ] Vial stoppers swabbed with 70% IPA, single unidirectional stroke, allowed to dry completely
  • • [ ] First air must never be interrupted at the critical site
  • • [ ] Ampules must be opened with sterile gauze; use a filter needle to withdraw solution
  • • [ ] Autoclaving = 121°C for ≥15 minutes (heat-stable preparations)
  • • [ ] 0.22 µm filter = sterilization by filtration
  • • [ ] Media-fill tests validate personnel aseptic technique
  • • [ ] Gloved fingertip sampling = initially + at least annually

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    Good luck on your PTCB exam! Focus on the numbers (temperatures, BUDs, ISO particle counts, filter sizes) as these are highly testable details.

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