Validation Protocol of Ethylene Oxide Sterilization Process

TITLE:- VALIDATION PROTOCOL FOR ETHYLENE OXIDE STERILISATION PROCESS
VALIDATION PROTOCOL NO: / EFFECTIVE DATE:-

VALIDATION PROTOCOL OF ETHYLENE OXIDE STERILIZATION PROCESS

Company Name

Eto Sterilizer manufacturer name:

Date of Purchasing:

Date of Installation:

Model number:

Capacity:

Operator Name:

Department (Place)

Table of Contents

1.PROTOCOL APPROVAL SHEET

2.REVISION HISTORY

3.OBJECTIVE:-

4.SCOPE:-

5.RESPONSIBILITY:-

6.STANDARDS FOR REGULATORY REQUIREMENT:-

7.LIST OF DOCUMENTS:-

8.PRE-REQUISITE:-

Equipment qualification

Calibration:

Product qualification

Product and packaging material evaluation

Product grouping

Selection of family representative

9.Process and Validation Approach:-

Process Validation Procedure:-

Bioburden assessment

Selection of Process Challenge Device (PCD

BI or PCD placement in the product load: -

Temperature and Humidity sensor in product load:

Load Temperature

Identification of the worst case location or cold spot

Process Qualification Runs

a)Half Cycle Method

b)Bioburden /BI method

Maintainace of Validation:

Requalification

10.Sampling method and test method:-

LIST OF TEST TO BE EXECUTED

12.Process parameter check steps

Environmental preconditioning: -

Initial evacuation: -

Humidification: -

Gas injection and gas dwell: -

Post exposure gas purge and air in bleed: -

Heated aeration: -

Appendix 1 Simulation of Anticipated Process Conditions

Appendix 2:- Determination of Bioburden

Determination of Bioburden

Appendix 3(GLOSSARY)

1.PROTOCOL APPROVAL SHEET

The Validation Protocol shall be Prepared, Reviewed and Approved by the concerned personnel. It shall be signed and dated as shown below.

Prepared by:

NAME / DESIGNATION / SIGNATURE / DATE
Assistant manager- QA(validation)

Checked by:

NAME / DESIGNATION / SIGNATURE / DATE

Approved by:

NAME / DESIGNATION / SIGNATURE / DATE

2.REVISION HISTORY

REVISION / REVISION DATE / REASON FOR REVISION/CHANGE REQUEST / REVISED BY
01 / Original release

3.OBJECTIVE:-

To determine that Ethylene oxide sterilization process consistently performs as intended by running the system and recording all relevant information. The Data and Test results must demonstrate that the process meets pre-determined specifications under normal conditions as well as worst case conditions.

4.SCOPE:-

The scope of validation protocol is to provide sterilization validation strategies for ethylene oxide sterilization of medical device. This document will show two approaches for reducing or eliminating bioburden on medical devices. This will also show test method, sampling method and acceptance criteria used in validating ethylene oxide sterilization of medical devices.

5.RESPONSIBILITY:-

Person / Responsibility
Validation team / Preparation of protocol
Organization of validation activity
Collecting the samples and sending to QC
Review and interpretation of final results
Preparation of report
Quality control / Review of protocol and report
Analyzing the test samples
Reporting and interpretation of results
Production / Review of protocol and report
Conducting the validation activity as per the protocol
Quality assurance manager / Review and approve the validation protocol

6.STANDARDS FOR REGULATORY REQUIREMENT:-

ISO 11135-1:2007, Sterilization of health care products- Ethylene oxide- Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices
ISO 10993-7, Biological evaluation of medical devices- Part 7: Ethylene oxide sterilization residuals
ISO 11737-1, Sterilization of medical devices — Microbiological methods —Part 1: Determination of a population of microorganisms on products
ISO 11737-2, Sterilization of medical devices — Microbiological methods — Part 2: Tests of sterility performed in the validation of a sterilization process
ISO 10993-1:2002, Biological evaluation of medical devices Part 1: Evaluation and testing

7.LIST OF DOCUMENTS:-

SOP for ethylene oxide sterilization process
SOP for environmental monitoring
SOP for sampling procedure
SOP for testing method
SOP for material handling including biological indicator
Sterilization cycle parameter specification sheet

8.PRE-REQUISITE:-

The following requisite must be fulfilled before the ethylene oxide sterilization process validation.

Equipment qualification:-

Equipment associated with ethylene oxide sterilization process must be qualified prior to process qualification.

Calibration: - All process sensing, controlling, indicating, and recording devices on the sterilizer or independent systems associated with sterilizer must be calibrated and recoded. Calibration program must be documented and detailed procedure of calibration frequency for all the instruments should be identified.

Product qualification:-

Product and packaging material evaluation: - As per ISO 11135 product and packaging material must be evaluated for ethylene oxide and humidity penetration.

Product grouping: - For efficient and cost effective performance validation similar device can be grouped in to families. A family of products can be considered to be all those products of similar design and material of construction, similar bioburden levels but can be consist of different sizes.

Devices can be grouped based on several criteria:

Similarity of materials of construction
Same product design of different sizes, lengths or thickness
Design complexity
Similar method of manufacture
Multiple combinations of devices
Amount and type of packaging

Selection of family representative: - Each family of products will contain a number of devices. From these devices, the representative challenge product is selected. The selected device will present a greater challenge to the sterilization process and will be the most difficult to sterilize device in the family group and will be used as the BI carrier.

Following criteria can be used to select the family representative:-

Longest tubing with the smallest lumen
The highest bioburden
Smallest opening into the interior of a device
Most subassemblies,
Most convoluted passageways
Most dense package configuration

9.Process and Validation Approach:-

Parameters to be Verified

Process Validation Procedure:-

Bioburden assessment: - An understanding of the population of viable microorganisms on a finished device (bioburden) is necessary and required to support the validation process. The bioburden assessment includes the total number of microorganisms with their identities. The identification needs confirmation of gram stain characteristics and genus. It provides useful information and can be used to monitor changes over time and as a comparison to organisms recovered during environmental monitoring. For determination of bioburden Refer to Appendix 2

Selection of Process Challenge Device (PCD):- Process challenge device can be selected from the family representatives in order to reduce the number of products tested during the validation. Internal PCD is the most difficult to sterilize device seeded with a BI. For ease of sample removal an external PCD can be used in the validation. External PCDs are the external BI test pack that replaces the internal PCD. External PCD should serves as a resistance greater than or equal to that of the internal PCD. The external PCD is usually placed on the outside of the sterilization load between cases, just inside the case or under the stretch wrap.

BI or PCD placement in the product load: - After the product load challenge has been identified, the BI or PCD positioning and placement can be determined. BIs and PCDs should be distributed throughout the product load and, as much as possible, in the same orientation (e.g., vertical).

Following minimum number of BIs/PCDs to be included in each validation cycle (as per ISO 11135-1: 2007):-

Up to 10 m3, the number of BIs is m3, with a minimum of 5.
From 10 m3 up to 100 m3, the number of additional BIs is one per additional cubic meter.

Temperature and Humidity sensor in product load:- For humidity check in preconditioning and conditioning/sterilization one humidity sensor per 2.5 m3, with minimum number of sensor is two should be placed in sterilization load and it should include pallet centers, edges and surfaces.

For temperature monitoring in validation one temperature sensor per cubic meter of product volume with a minimum of 3 sensors should be placed in the load.

Load Temperature: - ISO 11135-1:2007 requires that the minimum temperature of product permitted to enter preconditioning be determined. Load temperature prior to entrance to preconditioning should be determined at the lowest temperature zone. Direct placement of cold loads into preconditioning can result in excessive water condensation and load wetting, which can cause product damage and reduced lethality. In process validation it requires to simulate the worst condition to which the load will ever be exposed. The anticipated load temperature extremes can be simulated during validation by following techniques described in the appendices 1.

Identification of the worst case location or cold spot: - temperature is the easiest variable to measure and monitor, therefore temperature is used as an indicator of the worst case location in the sterilization load. During the preconditioning or conditioning phase temperature profile against time of the sterilization load measured and based on that data the worst case location or cold spot is identified.

Process Qualification Runs:-

For validation, a microbial challenge will be performed to demonstrate the adequacy of the process to achieve the desired Sterility Assurance Level. Two methods are used

a)Half cycle method (Overkill approach)

b)Bioburden / BI method

a)Half Cycle Method: - During the bioburden assessment, if characterization of bioburden is not performed and the bioburden level is more than 100 CFU than the following steps are performed. In this method one fraction cycle, 3 one-half cycle and one full cycle is performed.

Place Biological Indicator (BI) with 10⁶ spores of Bacillus atropheus in the PCDs and product samples in each pallet with humidity and temperature sensor. (Place PCDs to cold spot of the product load)

Load pallets of sterilization load in to the sterilization chamber

Run fractional cycle according to prescribed cycle parameter

(Use ¼ or ⅙ gas exposure time than full cycle)

Aerate the product

Remove the product sample and PCDs from the load

Perform sterility test on product sample and BIs.

Additionally perform Bacteriostasis/Fungi stasis test on the product sample.

If product sterility samples show survival, repeat the run on new load with elevated gas exposure time until no survival in product and growth in BI (evaluation of BI appropriateness)

Run 3 consecutive half cycle according to prescribed cycle parameter

(Use ½ gas exposure time than full cycle)

Aerate the load

Remove the product sample and PCDs and perform sterility test on product sample and BIs

Sterility test should show no growth for both product and BIs samples

Perform one full cycle (routine process exposure time) on the aerated sterilization load.

Place addition product sample for the additional test.

Aerate the load

Remove the product sample and PCDs

Perform following test on product sample

LAL test (pyrogen test)
Product and packaging functionality test
Biocompatibility test
Ethylene oxide residue test

b)Bioburden /BI method: - This method requires that bioburden level be demonstrated to be relatively consistent over time and the resistance of the bioburden be shown to be equal to, or less resistant than, the resistance of the biological indicator. During the bioburden assessment, if the characterization of bioburden performed and level of bioburden is less than or equal to 100 CFU which indicating a lesser challenge than the BI than the following steps can be followed.

Establish worst case location in the product load based on temperature distribution and humidity of load

Place BI with known amount of microorganism in the PCDs, temperature and humidity sensor

Perform 5 fractional cycles with graded exposure time (e.g. 0, 4, 8, 12, 16 minutes)

Aerate the load

Perform sterility test on BI

Calculate rate of inactivation (D value) using survival curve or fractional negative method

Calculate half cycle and full cycle exposure time

Place product sample and PCDs in each pallet with temperature and humidity sensor

Run 3 half cycle according to prescribed cycle parameter

Aeration

Remove product sample and PCDs.

Perform sterility test on product sample and BIs.

Additionally perform fungi stasis/ Bacteriostasis test.

Perform one full cycle (routine process exposure time) on the aerated sterilization load.

Place addition product sample for the additional test.

Aerate the load and remove the product sample and PCDs

Perform following test on product sample

LAL test (pyrogen test)
Product and packaging functionality test
Biocompatibility test
Ethylene oxide residue test

Maintainace of Validation:-

Requalification: -

Any significant change in product, manufacturing process, packaging, sterilization equipment or process, product loading or density may necessitate requalification. A documented formal review of any change should be undertaken to make this determination.
To ensure continued control, periodic repetition (annually is recommended) of all or part of the performance validation should be considered.

10.Sampling method and test method:-

Sampling method:-

Sample taken for validating sterilization process should be representative of entire batch and it should be taken from most critical part of load configuration. Sample must be taken from each separate packaging system place on.

LIST OF TEST TO BE EXECUTED

No / Test / Objective / References
1 / Bioburden determination / To check the liable micro organism in the product. / AS ISO 11737:1 and ISO 11737:3
2 / Sterility testing / Product Sterility Testing is determine any viable microorganisms remain on product during sterilization / AS ISO 11737:2
3 / Biological Indicator Testing / To challenge the sterilization process and are used during validation and routine processing. / ISO11139:2006
4 / Fungi stasis/
Bacteriostasis / To determine the recovery percentage, microbial growth and will be used to correct Bioburden results. / AS ISO 11737:1
5 / LAL test / To determine Endotoxin level (pyrogen-end product of gram negative bacteria) / TGO NO. 50, USP (161) & (85)
6 / Product package functionality test / To evaluate the outer packaging of a device. / ISO 11607-1
7 / Product functionality test / To evaluate the changes in the product characteristic. / ISO 11607-1
7 / Biocompatibility

Cytotoxicity test
Biodegradation test
Carcinogenicity test
Sensitization test
Irritation test

/ Biocompatibility testing is ensure that sterile devices are compatible with biological systems / ISO 10993-1- 9 to 12
8 / Ethylene oxide residue test / To ensure the amount of ethylene oxide residual levels are within limits. / ISO 10993-7

Test result and acceptances criteria:-

No. / Test / Acceptance criteria / Test results
1 / Sterility Testing / No Growth for product sample
2 / Biological Indicator Sterility Testing / Fractional cycles:-
No growth
Half Cycles:-
No growth
Full Cycles:-
No growth
All positive controls must show growth
3 / Fungi stasis/
Bacteriostasis / Must be negative
4 / LAL test / Endotoxin and pyrogen must be absent
5 / Product Package Functionality Test / Packaging integrity must be intact
6 / Product Functionality Test / Product should not show any degradation, discoloration and physical changes
7 / Biocompatibility Test / Product must be biocompatible
8 / Ethylene Oxide Residue Test / Ethylene oxide residue levels must be in limit at the day of release
9 / Process parameters / All parameter must meet with specified cycle parameters

Process parameter check steps:-

Environmental preconditioning: -

Parameters to be checked / Actual / Specification
Temperature of preconditioning room
Humidity of the preconditioning room
Duration of preconditioning

Acceptance Criteria met [yes]/ [no]

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