1. Responsibilities

1.1. Departments

The responsibility for validation activities is shared between members of a multi-disciplinary group as identified in the Validation Plan for a particular project.

1.1.1. Validation

This area is responsible for training in the use of this SOP, document preparation and testing requirements for particular projects.  Provide instruction on specific test procedures and written test protocols.  Develop and implement relevant testing templates and calculation spreadsheets. For large validation projects provide a testing and documentation resource to complete the validation activities.

1.1.2.     Quality Assurance (QA Manager or Validation Manager)

Review and authorisation of documentation associated with cleaning validation.

1.1.3. Engineering (Projects)

Review and checking documentation associated with cleaning validation.  Engineering is responsible for design, installation, and commission and in some projects validation of new and modified cleaning equipment processes.  Systems include but are not limited to: product transfer pipework, mixing vessels.  Initiating changes to current cleaning processes and procedures by initiation of change requests.

1.1.4. Operations

Initiating changes to current cleaning processes and procedures by initiation of change requests.  Review of validation plans and validation test protocols.  Provide resource assistance to the specific cleaning validation tasks such as running collecting swab and rinse samples, removal of complex equipment components.

1.1.5. Laboratory

Provide validated Analytical test methods for accurate product residue detection, including swab and rinse surface recovery data.  Perform Analytical testing of swab and rinse samples collected during validation using validated procedures.  Review and approve Analytical test methods and results, provide documented test results to relevant departments. Review sampling procedures and acceptance criteria for bioburden sampling after cleaning.  Perform analysis of bioburden samples and report results

2. Types of Cleaning Process and Cleaning Agents

2.1. Manual Cleaning

Effective manual cleaning practices must be established by focusing on the following two areas:

2.1.1. Standard Operating Procedures (SOP)

SOPs will be developed during the Operational Qualification phase of the project. This will be outlined as part of the Validation Plan.  If consistently unacceptable or erratic results are obtained the SOP should be considered one of the possible problems and modifications to the procedure may be required.  Procedures must be written in a manner, which prevents variation between operators.

2.1.2. Operator Training

Operators must be suitably trained in the use of the manual cleaning SOP.

2.2. Automatic Cleaning In Place (CIP)

CIP is the procedure by which flush and rinse solutions are brought into immediate contact with all internal product soiled surfaces, without the intervention of operators, and continuously re-circulated or flushing to drain for a pre-determined time.  For an automated procedure the SOP does not need to state precisely how the equipment is cleaned, however validation must document and verify that the automated process functions according to its design requirements.

CIP Operating Criteria

1. Most CIP applications will use fresh Distilled Water discharged through fixed spray ball(s) which provide complete coverage of the inside of vessels or discharged directly into product transfer pipework via change piece.
2. The CIP flow velocity, temperature and required cleaning time must be verified and documented for each cleaning validation test.  Where CIP flow switches are installed verification of correct alarm operation should be included.

2.3. Cleaning Agents

Cleaning Agents such as detergents and other chemical aids should only be used when the cleaning process using water or solvents is not adequate. This may be due to insoluble materials, equipment that is difficult to clean or environmental factors.

The selection of appropriate cleaning agents and their control should take into consideration safety, product/equipment compatibility, vendor/material controls, and change control.

Only approved cleaning agents should be used which are of known composition, to permit analytical measurement of residues and proven to be easily removable.

As there is usually no clinical data for detergent residues a criteria of 10ppm is acceptable.

3. Cleaning Validation Procedure

3.1. Identify process, equipment and product type

Identify the process and the types of products being produced. Include these details in the validation plan, validation protocol or change request, whichever is relevant for the work or project being undertaken.

3.2. Check if Cleaning Validation is required

3.2.1. If the process or equipment is any of the following a cleaning validation assessment is required:

a. Holding vessel

b. Mixing vessel

c. Product transfer Line

d. Other equipment, which performs an automated cleaning of product contact parts.

3.2.2. New Processes/Equipment

Full validation testing is required in the majority of cases. This involves three tests of worst-case product with the appropriate number of samples collected.  Reduced testing is feasible if all of the following conditions are met:

1. Identical process/equipment is installed.
2. Identical cleaning controls and procedures are achievable.
3. Worst-case product is the same as previously validated and acceptance criteria is the same or higher than previously validated.
4. Cleaning validation data is available on the previously validated identical process.

An explanation for reduced testing should be described in the relevant Validation Plan, protocol or change request for the process.  Reduced testing may include reducing the number of tests and reducing the sample locations to a few key critical areas known to be “critical sites” or “hot spots”.

For changes to current cleaning processes and procedures the extent of retesting will in most cases be reduced to a single test, this shall be stated and approved as part of the change request process as in SOP QMS-030.

3.3. Select Worst-Case Product for Cleaning

For multi-product equipment it is not practical to validate cleaning of all products produced in a particular process/equipment that has one cleaning process and where products are alike in formulation and dosage form.  In such cases, it is considered acceptable to select a worst-case product to represent all products in the process for the purposes of cleaning validation.  The worst-case selection is based on a scientific justification i.e. the least soluble product produced on a particular equipment or process.  This product is then used to validate cleaning for that process/equipment.

3.4. Select Product to use for acceptance criteria calculations

1. Calculation of acceptance criteria is to be based on the most toxic product within a group of products produced in a given process.
2. Find the product within the product group, which has the lowest active toxicity value in mg/kg, this is the most toxic product.  This product will be used for the calculation of acceptance criteria.

3.4.1. Example of selecting worst-case product and product for acceptance criteria calculations

            Note – a low toxicity value means high toxicity, a high value means low toxicity.

From the above table of product data, Active 1 is the least soluble product in water since it has a value of 60 mg/mL and is therefore the worst-case product in this group.

Active 3 is the most toxic product since it has the lowest toxicity value of 0.3 mg/kg.  Therefore the acceptance criteria is calculated using active 3 product data.

3.4.2. New Products Introduced to the Production Facility

a. If a new product is introduced into the facility the solubility and toxicity of the new product should be compared against the current list of products in the same product type group and following assessment should be made:

b. If the new product is less soluble than the current least soluble product within the product group then this product becomes the new worst-case product for that process.  Cleaning validation, including analytical method validation should be conducted for the new product.

c. If the new product is more toxic than the most toxic product within the group then the worst-case product does not change but the acceptance criteria to be applied to the worst-case product must be recalculated according to the product data for the new product.  If previous validation data shows the results meet the new acceptance criteria no further cleaning validation is required.

d. If the solubility of the new product is not less and the toxicity not higher than the current listed products then no cleaning validation is required for the new product.

3.5. Check if Analytical Method Validation is required

After selecting the worst-case product check if an analytical method is validated for that product.  If it is not, analytical method validation is required.  Refer to Section 4 for procedure for completing analytical method validation.  If a method is validated proceed to step 3.6.

3.6. Calculate Acceptance Limits for Rinse and Swab Samples

3.6.1. Basis of Calculations

The Lowest concentration of the most toxic active in a product group will be used in combination with a safety factor of 1/1000th to calculate the acceptance limits as detailed below.  Once an agreed acceptance limit is established it is applied to an area/weight limit based on factors such as batch size and calculated surface area of product contact.  The final limits calculated are then applied to the worst-case product in a product group.

3.6.2. Establishment of Acceptance Criteria

The most stringent of the following limits should be applied:

1. Absence of visible residues AND Maximum Allowable Carryover as calculated in section 3.6.3.

OR

2. Absence of visible residues AND No more than 10ppm carryover of the previous product will appear in any subsequent batch.

Therefore option 2 is applied when the calculated Maximum Allowable Carryover (MAC) is above 10ppm OR if there is no clinical data such as lowest concentration dose for the residue to be calculated.

3.6.3. Calculating Maximum Allowable Carry Over (MAC)

When batch and single active concentration volumes for multi-product equipment are known, the total MAC (in the entire processing system) is calculated as follows:

MAC       = (LC) x (SBS)

                 (SF) x (LVSD)

MAC      = maximum allowable carry-over

LC        = lowest concentration (in mg)

SBS       = smallest batch size (in ml) made in the same equipment

LVSC     = largest volume single concentration (active) of any product made in the same equipment (in ml)

SF         = safety factor = 1000. This is based on biological activity levels of 1/1000
of the normal active concentration.

Example Calculation

MAC   =  0.25mg x 200,000mL _{= 25.0 mg}

                 1000 x 2.0mL

Therefore the total quantity of residual product allowable in a subsequent production batch is 25.0 mg.

3.6.4. Calculating Acceptance Limits For Swabs

1. Take the calculated MAC for the product and divide this number by the total internal surface area of the total product processing system, i.e. preparation and holding vessels + pipework + filling machine.  This figure is the amount of residue allowed throughout the entire process, the assumption being that there is even distribution of product residue throughout the process equipment.
2. Example calculation:

The allowed residue in the entire process = MAC/total surface area

= 25.0mg/56715 cm²

= 0.00044 mg/cm² (MAC/cm²)

The overall surface area is derived from the following (only as example):

.

This calculated value determines the amount of residual product allowed to remain on 1 square centimetre of the equipment after cleaning.  This value is then multiplied by the area to be swabbed to give the allowed limit per swab sample.

If swabbing a 10 cm x10 cm (100 cm²) surface area and placing the swab in 25.0ml of swabbing solution then the following applies:

Limit for swab sample    = MAC/cm² x Swab area

Volume of Swab Solution

            = 0.00044 mg/cm² x 100 cm²  = 0.0088 mg/mL (8.8mg/ml or ppm per swab)

                              25.0 ml

In this case, swab sample results for 100 cm² must be £ 8.8 mg/mL of active to prove that the cleaning process is satisfactory.  The value 0.00044 mg/cm² was derived from the MAC allowed per swab calculation above.

3.6.5. Calculating Acceptance Limits For Rinse Samples

1. Calculating required rinse volume:

Rinse recovery method validation tests have been conducted with a particular volume of solution per surface area of the test material.  This data is shown in the reference spreadsheet. From this ratio of rinse volume to surface area apply this to the area of the process to be sampled. For example, rinse recovery method validation records the ratio of rinse: surface area to be 20mL:100cm², for a pipe of surface area 2500 cm², the required volume is 20/100 X 2500 = 500mL (0.5L).

2. Calculating Limits

To calculate take the MAC and divide it by the total internal surface area of the processing system.  For example, using the MAC calculated on above, rinse sample limits are calculated as follows:

Limit for rinse sample           = (MAC/cm²) x Pipe or Vessel Surface Area *

                                                                         Rinse Water Volume

                         = 0.00044 mg/cm² x 965 cm²       = 0.00085 mg/mL or 0.85 ppm

                                                                 500 mL

*actual surface area of the specific pipe or vessel being rinsed.

In this example a 500 mL rinse water sample of the transfer line, with a surface area of 965 cm², must be £ 0.85 ppm of residual active to prove the cleaning process is satisfactory.

3.6.6. LOD and LOQ Check

After calculating the final swab and rinse limits, check that the Limit of Quantitation (LOQ) for the worst-case product is below the calculated acceptance criteria.  If accurate analysis is restricted by the limit of quantitation (LOQ), the limit of detection (LOD) can be used to provide a pass/fail result.  For example, if the LOQ is 700 parts per billion (ppb) and the LOD is 200 ppb, for a swab sample with a failed result of 190 ppb, the laboratory would record a “FAIL”, as opposed to a numeric value.

3.7. Flowchart – Cleaning Validation

4. Analytical Method Validation for Cleaning

4.1. Active Residue Analytical Testing

Complete protocol template “Cleaning, Active analysis method validation”.

The template is a test protocol that provides full details of the test objective, acceptance criteria and the test method to be followed.  This protocol should be used as a draft, any relevant changes should be made prior to use and the final test protocol checked and authorised.

This test is conducted to determine the accuracy of measuring the active at concentrations above and below the calculated acceptance criteria levels for cleaning.  This is done simply by preparing the relevant concentrations in volumetric flasks and analysing the samples by Chromatographic procedures or by Total Organic Carbon.  This tests the accuracy and precision of the analytical method, without any effects of sampling recovery from surfaces by swabbing or rinsing.

4.2. Rinsing Recovery Studies

Complete protocol template “Cleaning, Rinsing Method Validation.”

The template is a test protocol that provides full details of the test objective, acceptance criteria and the test method to be followed. This protocol should be used as a draft, any relevant changes should be made prior to use and the final test protocol checked and authorised.

4.2.1. Purpose

Rinse recovery studies must be conducted for the specific product to be tested on the production equipment.  This must be completed before rinse samples can be taken from equipment surfaces.  This will ensure that the product can be recovered from the equipment surface with an adequate recovery level.

Method validation studies shall determine the repeatability, reproducibility, and recovery of the rinsing analysis from the equipment surfaces.  If recovery results do not meet the acceptance criteria a different solvent, or a larger rinsing volume may need to be used.

4.2.2. Rinsing Procedure

Rinse recovery studies are performed by spiking 316L stainless steel plates (or other production material if more relevant for a given process).  Product is evenly distributed onto the plate at concentrations above and below the acceptance criteria calculated in step 3.6, “Calculating limits for Rinse and swab samples”.

The stainless steel plates must be large enough to allow a 10 cm x 10 cm surface area to be rinsed.  Allow the product to dry on the sample surface before rinsing. Rinse the plate with a specified and accurate amount of water, i.e. by using a pipette. Collect the rinse water into a beaker and analyse the rinsate as per analytical procedure using High Performance Liquid Chromatography or by Total Organic Carbon.

TOC samples should always be analysed as soon as possible after sample collection. i.e. within 12 hours.

4.3. Swabbing Recovery Studies

Complete protocol template “Cleaning, Swabbing Method Validation”.

The template is a test protocol that provides full details of the test objective, acceptance criteria and the test method to be followed.  This protocol should be used as a draft, any relevant changes should be made prior to use and the final test protocol checked and authorised.

4.3.1. Purpose

Swab recovery studies must be conducted for the specific product to be tested on the production equipment.  This must be completed before swab samples can be taken from equipment surfaces.  This will ensure that the product is adequately recovered from the equipment surface based on the appropriate selection of swab material and solvent.

Method Validation studies shall determine the repeatability, reproducibility, and recovery of the swabbing analysis from the equipment surfaces.  If recovery results do not meet the acceptance criteria, a different swab type, different solvent, or different swabbing method may need to be used.

4.3.2. Swabbing Procedure

Swab recovery studies are performed by spiking 316L stainless steel plates (or other production material if more relevant for a particular process).  Product is evenly distributed onto the plate at concentrations above and below the acceptance criteria calculated in step 3.6, “Calculating limits for Rinse and swab samples”.

The stainless steel plates must be large enough to allow a 10cm x 10cm (100cm) surface area to be swabbed.  Allow the product to dry on the sample surface before swabbing.

Following is a recommended procedure to follow which has been shown to work well for Method Validation tests:

Figure

Place 2 swabs into 1 clean 40mL Total Organic Carbon (TOC) vial containing the required volume of extraction solvent (usually 25mL).  The 2 swabs are to be used for the same 10x10cm surface and placed back into a single vial.

The swab surface is pressed on the side of the glassware to express excess water prior to use.  The swabbing is conducted covering the area in one direction then using the flip side of swab surface swab in a perpendicular direction.  Firmly press down on the swab handles to ensure proper surface contact.  The second swab is removed from the solvent and the first swab placed back into the solvent.

The procedure is repeated with the second swab ensuring that the exact same
10cm x 10cm area is swabbed; the swab is placed back into the solvent.  The swab handles are cut with a clean pair of scissors making certain that no foreign particles are introduced into the solution.  The solution is vortexed for 30 to 60 seconds.

TOC samples should be analysed as soon as possible after sample collection, i.e. within 12 hours.

4.3.3. Why Two Swabs?

Two swabs are in most method validation cases necessary to give increased recovery from equipment surfaces.  The 1st swab may collect 70% of residue; the second clean swab is then able to absorb the remainder more easily from the surface.  Also when two swabs are then placed inside the 40mL TOC sample vial this provides a greater mixing action than 1 swab when the samples are vortexed.

4.4. Selection of Analytical Testing Instruments

For most applications Method Validation should be performed by using both TOC and HPLC analysis.  However if the product to be validated has no additional excipients containing organic carbon other than the active ingredient then only HPLC needs to be used.  If however it is necessary to have the flexibility of using either TOC or HPLC analysis then both analytical tests must be validated.  The detailed analytical test method used for quantifying the results must be recorded in the analytical method validation files.

5. Cleaning Validation Test Protocols

To prepare the protocol use template “OQ Test Protocols”. The template provides an outline of a test objective, acceptance criteria and the test method to be followed.  This protocol should be used as a draft version, any relevant changes for a particular project should be made prior to use and the final test protocol checked and authorised by the relevant staff.

5.1. Test Objective

Number of Tests Required

For new processes a minimum of three consecutive tests of the cleaning process must meet the acceptance criteria for all swab and rinse samples in order to have a validated cleaning process/procedure.  Tests not meeting these criteria must be explained with a suitable justification and corrective action i.e. Validation discrepancy.

5.2. Acceptance Criteria

Calculated swab and rinse limits for the product group as described in section 3.6.

5.3. Equipment Contamination

Whenever possible contamination of equipment should be under worst-case conditions i.e. leave machine contaminated and drained overnight before cleaning.  It is important that all product contact areas are completely covered with the product contaminate.

5.4. Selection of Sample locations

Swab sampling locations should be selected for areas which are known to be difficult to clean and/or theoretically maybe difficult to clean.  The names of areas sampled must be clearly indicated and defined in the results.

5.5. Sampling Procedures

Sampling procedures in most situations will involve rinse water and swab techniques.  For difficult to clean areas and when contact surfaces are physically accessible swabbing will be used.  Surfaces inaccessible to swab samples such as transfer pipes will be sampled using a pre-determined volume of final rinse solution, usually water.  Sampling procedures must be included in individual Protocols.  The procedure must indicate the sample materials required, the sample solution (e.g. water type), the rinse volume or swab sample areas, and the sample locations.

5.5.1. Swab sampling

The swab method should be based on the procedure validated by the analytical laboratory.  In many cases the surface of production equipment will not be a flat stainless steel surface.  Therefore the swab must be done as close as practically possible to the validated swab procedure.

Non-standard swab areas

Where it is not possible to swab 100cm² the actual area swabbed is recorded and an adjustment to the acceptance limit is made.  For example, if the swab area is only 50cm² the limit is halved.  

5.5.2. Rinse sampling

The rinse method should be based on the procedure validated by the Analytical laboratory.

Non-standard rinse volumes

Where it is not possible to rinse to the required ratio of Rinse:Surface area, the actual volume used is recorded and an adjustment to the acceptance limit is made.  For example, if the rinse volume calculated is 1L and 2L was required the limit is then halved.  

5.6. Monitoring During Automated Cleaning Cycle

The main data required from any test is cleaning water flowrates, cleaning time and water temperatures.

5.7. Collecting Rinse Samples

In some cases for each rinse sample both a chemical and microbiological sample is required, if this is the case collect the microbiological sample 1^st then aseptically transfer some of the solution into a sample container for chemical testing.

For manual rinse samples the following precautions should be followed.  Containers for collecting samples i.e. sample jars, trays, buckets, etc. must be clean and thoroughly rinsed with distilled water, especially when taking conductivity measurements and for TOC analysis. For TOC testing use clean TOC vials or glass Schott bottles.  Any devices such as manual valves used to collect samples must be of a cleanable design and always cleaned prior to use.  Containers used to pressure transfer water samples through product lines must also be clean and rinsed thoroughly with Distilled water.  For TOC testing it is important to collect a small sample of the rinse water used as a blank sample to measure the background TOC.

5.8. Collecting Swab samples

The principles explained under rinse samples also apply to swab sampling.  The swabbing procedure must be based on the procedure validated as part of the analytical method validation.  The relevant file for method validation should be used as a basis for describing the swabbing procedure in the test protocol.

5.9. Collecting Microbiological samples (bioburden)

The main requirements are that sample containers are pre-sterilised; the sample valves used are clean and pre-sanitised by flushing with 80^°C distilled water for 5 minutes.

5.10. Failed Results

Any failures of the rinse and swab samples must be dealt with by investigating the reasons for the failure; making changes to procedures and then repeating the test.  Sampling, testing, re-sampling and re-testing the same equipment should not be conducted if test results continually fail to meet the Acceptance Criteria.  The “test until clean approach” or testing until the desired results are obtained demonstrates the cleaning process is not in control. If this occurs an improvement to the cleaning procedure must be investigated.  This may include alteration of product contact materials such as flexible transfer tubing or improvement of the cleaning cycle, extending the flushing time or removing potential dead-legs.

6. Change Control/Revalidation

6.1. Change Control

Before any changes to validated processes or process equipment are conducted the change request form must be approved to determine whether it will impact on previous cleaning validation studies (see SOP QMS-030.).  If the change has the potential to decrease cleaning effectiveness of product residuals, retesting will be required documenting the change and the results from the new tests.

6.2. Revalidation

For automatic cleaning processes ongoing verification may not be required provided that the process is validated such that it is proven to be in control and reproducible.

An assessment of any revalidation requirements will be made in the final Validation Report for a given process.

7. Summary of Changes