VAL-070 Cleaning Validation Analytical Methods

5.1 General Overview

5.1.1 Validation of cleaning validation analytical methods involves validation of both the sampling (generally swab or rinse) method and the analytical test method.  Validation of the sampling procedure demonstrates that the residue of interest can be recovered by the sampling method at the required level and validation of the analytical test method demonstrates that the residue recovered by the swab from the equipment surface can be reported at the levels it was present on the equipment.

5.1.2 Validation of residue recovery must include the recovery from both a representative equipment surface and the sampling technique (e.g. swab / rinse).  The validation must demonstrate that the residues are recoverable from the product contact surface material and the sampling material.

5.1.3 The Validation Protocol must document the validation parameters being evaluated, acceptance criteria for each parameter and if known, Test method numbers/SOPs.

5.1.4 The Validation Report must document what was accomplished during protocol execution and provide a summary of results. This report must be approved by the QA Manager or Designee and a representative from the Site Quality Authority, independent of the Laboratory Manager where the validation work was conducted.

5.1.5 For legacy methods, the acceptability of existing data is determined on a case by case basis. Supplementary data may be required. There must be a documented justification for appropriate sections not being performed. Legacy Methods may require validation according to local regulatory requirements. A Concurrent Validation approach may be used to support the analytical method validation.

5.1.6 The following factors must be considered when selecting an analytical method for use in equipment cleaning validation studies and for determining acceptable criteria:

a. Type of residue being measured (e.g. organic, inorganic)

b. Sampling method (e.g. swab or rinsate)

c. RAL (Residue Acceptance Limit) in the analytical sample.

5.1.7 The validation of a cleaning validation analytical method for product residue must be based on the RAL calculated for that material as defined in cleaning validation plan.

5.1.8 The method may be considered valid for any RAL within the validated RAL recovery range.  If the RAL is outside this recovery range the method must be re-validated with respect to the affected parameters / characteristics (refer to Section 5.2 – 5.4).

5.1.9 Sections 5.2 – 5.6, must be considered for each validation. A description of how these parameters will be performed such as experimental design, sample concentrations, swabbing materials should be outlined in the protocol. Parameter consideration may be dependant on the type of assay/ method being validated or its intended use. Where appropriate, provide a rationale as to why a parameter may not be included in the validation.

5.2 Cleaning Validation Analytical Method

5.2.1 System Suitability (Instrument Precision)

System suitability limits should be established to demonstrate the instrument is working satisfactorily. A solution at LOQ (or lower if required) should be analysed to ensure the instrument is able to detect at this level. Blank samples should be prepared using same batch of swab/ rinsate as the samples.

Where applicable, precision should be validated at the 100% RAL level, as this is the most critical concentration at which the sample recovery is validated.  Precision at recovery concentrations around 100% of the RAL determine whether the sample passes / fails where as precision at sample recoveries less than or greater than 100% levels give information on the extent of the pass / fail.

5.2.2 Method Precision

Precision is demonstrated by using a minimum of two sample preparations of known concentration, for a minimum of six replicates. Record the RSD% of the relative response factors from the injections.  The precision of other analytical methods must be documented and justified in the validation protocol. If the RSD is not specified in the relevant SOP or protocol, NMT 10% is used.

5.2.2.1 Intermediate Precisions (Repeatability)

Intermediate Precision is demonstrated by a single analyst performing method/recovery in triplicate at three concentrations that span the analytical range.  Intermediate Precision should also include the use of a second Lab analyst on a different day using different solutions and where possible different analytical equipment. This must be conducted unless there is a documented rationale (e.g. a reliable and robust swabbing verification program).

5.2.3 Linearity

Linearity is demonstrated by assaying known concentrations of the analyte of interest over a specified range. The levels chosen for linearity should cover a suitable range. At a minimum, cover the expected residue limit.  If applicable, the lower end of the linearity study shall take into consideration the correction factor for sampling recovery, (e.g., if the RALs have a range of 4-6 ug/cm² and the recovery is 50%, the linearity study must include levels of 2-6 ug/cm²).

Linearity is determined by running triplicate standards at a minimum of three concentrations including one at the expected residue limit. The regression line of the linear range shall be calculated.

The linear coefficient (r²) is usually > 0.98 when all concentration levels are taken into account.

5.2.4 Accuracy

Accuracy should be determined across the linear concentration range with a minimum of three determinations from each of the three concentration levels. Accuracy determines the closeness between theoretical and calculated results of the samples. This allows accurate reporting of recovery results between these limits.

If necessary, increase the product concentration from until a percentage is reached where the accuracy acceptance criteria are met.  All sample recoveries during the validation of the cleaning methods that are less than this concentration are reported as less than or equal to this level.

If necessary, decrease the product concentrations until a percentage is reached where the acceptance criteria is achieved.  All sample recoveries during validation of cleaning methods in question that are greater than this level are reported as greater than or equal to this level.

5.2.5 Limit of Quantitation (LOQ)

The LOQ should be determined based on the standard deviation of the response for linearity of the lowest standard solution and the slope of the linearity curve.

It is important to establish an LOQ expressed as µg/swab equivalent since the RAL may be subject to change (e.g. additional product may be added on equipment train).

LOQ typically has a 10:1 the noise ratio. Sensitivity of the assay is based solely on the LOQ.

5.2.6 Limit of Detection (LOD)

Limit of Detection (LOD) is not required for cleaning validation analytical methods.  Residue concentrations below the minimum validated recovery are reported for information only. LOD typically has a 3:1 the noise ratio.

5.2.7 Range

Range is established by confirming that the analytical method provides and acceptable degree of linearity, accuracy, and precision when applied to the sample concentrations with the analytical residue limits within the linear range.

5.2.8 Robustness

Robustness will be demonstrated by making small deliberate changes in the system parameters that are determined to be critical. The method of precision of the assay when utilizing deliberate changes should meet current acceptance criteria for the %RSD.

5.2.9 Instrument Conditions

The conditions of the instrument being utilized to analyse samples should be documented/reference in the protocol.

5.2.10 Specificity of Method

Use of a specific (e.g. HPLC) or a non-specific method (e.g. TOC) is acceptable for determining residues after cleaning.  Specificity experiments must be based on the type and purpose of the method being considered.

A specific method must be capable of detecting and quantifying the analyte of interest in the presence of other materials that may also be present in the sample.  Consideration must be given to potential interferences including: swab / rinsate extraction, cleaning agents, excipients and other compounds potentially present.

If a specific method is being validated for a cleaning agent the only specifity experiment that must be executed is specificity from swab extractables.

Specifity can be determined by ensuring that the result for the analyte in question is separate from all other readings which may be caused by swab extraction, cleaning agents, substances related to the analyte or other excipients.

In cases where a non-specific method (e.g., TOC) is used the response must be considered to be from the analyte of interest.

5.2.11 Product Contact Surface Material

Recovery Validation is performed on the primary material of the product contact surface in the manufacturing environment.  Recovery may also be performed for other surface that will be swabbed for the product of interest.

5.2.12 Swab Recovery Procedure

Swab/ Rinse recoveries are to be performed from representative surface types. Swab/ Rinse recoveries should demonstrate adequate recovery in the appropriate range for the analyte of interest and should be performed on each surface type with a minimum of three replicate samples at each of the three concentrations. The accuracy and precision of sample recovery is performed spiking the primary surface with known amounts of the product of interest and allowing it to dry for a predetermined minimum period as stated in the protocol.

The recovery sample concentrations should be prepared at, above and below the expected residue limit. Ensure the recovery range accommodates the critical limits e.g. a higher level 150% of the expected residue level and a suitable low level, LOQ or 50% of the expected residue level and the expected residue level are spiked. The spike is recovered as per the relevant swabbing procedures. In addition, a blank solution is dried onto the surface.  Three successful runs are required.

5.2.13 Sample Recovery Accuracy and Precision Acceptance Criteria

Typical acceptance criteria are that the recovery from the surface is not less than 50% and that the RSD of the swab sample preparation at 100% of the cleaning validation acceptance limit is not more than 12%.  The acceptance criteria may change depending on the nature of the product.

If the recovery is greater than or equal to 50% but less than 90% a correction factor should be used with all samples recovered using this method (swab / rinse).  The correction factor is obtained by dividing the percentage recovery into 100%.  The recoveries are then multiplied by the correction factor.

5.2.14 Rinse Sampling Solutions and Solubility

Composition of solution and solvent must be considered.  Solvent selection for rinsate should be based on product solubility in the rinsate solvent.

Solvent handling practices, safety and environmental requirements must be considered when selecting the rinsate solvent.

5.2.15 Recovery at More Than One Acceptance Limit

In some instances, validation of cleaning cycles may be performed on more than one piece of equipment and therefore there may be more than one RAL or expected residue limit.  Validation of recovery may be performed on a minimum of three different concentration levels that covers of all the expected residue limits.  However, if the expected residue limits are of similar concentration, recovery validation may be combined.  In this case, the lowest, highest (or equivalent figures) levels are used to validate recovery below and above the expected residue acceptance limits.  The accuracy and precision of each expected residue limit is validated.

5.2.16 Stability

Stability of the standard and the sample (swab and rinse solutions) must be determined or referenced, if previously performed.  Standard and swab solutions should be analysed initially at time 0 and days as is appropriate.  A minimum twenty four hour study must be completed for all validations.

A typical acceptance criteria is 12%.  This should be carried out in duplicate.

5.3 Sampling Method

5.3.1 The sampling technique (e.g., swab / rinse) must address the following relevant factors:

a. Swab type (including wipes) and size

b. Composition of the solvent (i.e. solution used to wet swab prior to swabbing the equipment surface)

c. Composition of the swab recovery solution (i.e. solution used for extraction)

d.  Sampling technique and procedure must be defined in an SOP

e. Rinsate volume

f. Sampling area.

5.3.2 The type of swab used to collect samples from equipment must be the same type as those used in the recovery studies.

5.3.3 The type(s) of swab to be used must be well defined for consistency.  If a special swab is required for a particular product it should be documented.  The rationale to use the same swab for all products and/or specific types should also be defined.

5.3.4 The same sampling technique must be used to validate the analytical method and to collect the samples from the equipment in the plant.

5.3.5 If it is determined that a special pre-treatment is required for the swabs, the relevant SOP or protocol should define what is required.  It should include the type of pretreatment to be performed prior to use of the swabs, storage conditions and/or shelf life of treated or untreated swabs.  Special requirements related to the swab or product may also be included.

5.3.6 The area to be sampled must be well defined for consistency, including any special requirements and/or calculations for specific areas.

5.3.7 Where possible choose solid, flat or semi flat surfaces when selecting swab locations.  Swab locations must also be chosen based on their difficulty to clean, not the difficulty to sample.  If a porous or irregular surface must be swabbed some consideration should be given regarding how much the swab surface area should be adjusted to correct the change in swabbed surface area.  If the surface area to be swabbed is changed in the geometric plane of primary interest to accommodate an irregular shape the rationale must be documented.

5.3.8 Swabbing must be performed as per relevant documented procedures and sampling personnel must be trained in the recovery of a predetermined amount of material from a substrate from which it is most difficult to recover the material.

5.4 Rinse Water Analysis

A solution (usually water) is spiked onto the surface in question and allowed to dry.  The spikes are rinsed and the accuracy and precision of sample recovery is determined.  Rinsing is performed for a predetermined time and predetermined volume of rinse solution (usually water).  Samples are taken during or at the end of the rinse step.  The rinse step should be based on the rinse step of the cleaning cycle being validated or a rinse step performed as part of the validation study.

5.5 Acceptance Criteria Failures

If a recovery sample fails to meet acceptance criteria, the failure must be investigated as per SOP LAB-055Laboratory Results-out of Specification Investigation and SOP QMS-035Deviation Report System.  If a cause for the failure is identifiable, document and rectify the root cause and repeat the sample recovery.  Use the new result if acceptable to perform all calculations.  If a cause for failure is not identifiable, repeat all samples three times and substitute the repeat results for the original.

For some material, the acceptance criteria (accuracy and precision) may not be suitable.  Development work on such material should demonstrate the ability of the material to meet acceptance criteria.

5.6 Validation Documentation

5.6.1 Each protocol is assigned a unique identification number.

5.6.2 The method validation protocol must be prepared to document the validation parameters, the acceptance criteria for each parameter and the test methods.  It must include or reference, but not limited to, the following:

a. Approval Page with signature and dates of approvals

b. Approved sampling and analytical methods

c. Validation Strategy

d. Experiments to be executed

e. Validation parameters

f. Acceptance Criteria of validation parameters

g. Residue Acceptance Limit (RAL).

5.6.3 As a new product is introduced, the new product actives and excipients that require recovery validation must be identified and Acceptable Limits must be determined as per the methodology established in Cleaning Validation Plan. The accuracy and precision of sample recovery must be validated prior to the validation of cleaning methods.

5.6.4 A description of the laboratory method selected and the rationale for its selection must be included in the method validation protocol and report. The analytical method selected should be able to detect residual product at the acceptance level specified.  Specific test methods are not required.

5.6.5 A method validation report must be prepared that references the protocol and documents the results and outcomes of the validation study. This report must include an evaluation of each parameter against the acceptance criteria and a conclusion.

5.6.6 Any deviations from the protocol and its impact must be discussed within the report. Refer to SOP QMS-035 Deviation Report System. The report must be approved by the Quality Laboratory Manager, Technical Services and Quality Assurance and Compliance.