Standard Operating Procedure for Out-of-Specification (OOS) Handling in API Manufacturing

1. Purpose

To establish a systematic procedure for handling Out-of-Specification (OOS) results generated during testing of raw materials, intermediates, and final Active Pharmaceutical Ingredients (APIs), ensuring thorough investigation, documentation, and compliance with applicable regulations.

2. Scope

This SOP applies to all Quality Control (QC) personnel, analysts, reviewers, and QA officers involved in handling and investigating test results that fall outside approved specification limits during any phase of testing at the API manufacturing facility.

3. Responsibilities

• QC Analyst: Identify and report OOS results immediately and initiate documentation.
• QC Reviewer: Confirm the validity of the result and initiate investigation if required.
• QA Officer: Participate in investigation, approve corrective/preventive actions, and close the OOS record.
• Department Head (QC/QA): Review the investigation, assess impact, and approve final disposition.

4. Accountability

The Head – Quality Assurance is accountable for ensuring timely and compliant investigation and resolution of all OOS events in accordance with regulatory expectations and internal SOPs.

5. Procedure

5.1 Identification of OOS

1. An OOS result is defined as any test result that falls outside the approved specification or acceptance criteria.
2. OOS results may arise during testing of:
   • Raw materials
   • In-process materials
   • Finished APIs
   • Stability samples
3. Analyst must immediately inform the QC supervisor and record the result in the OOS Notification Form (Annexure-1).

5.2 Phase I: Laboratory Investigation

1. Review the analytical method, calculation, raw data, instrument logs, reagents, and analyst’s technique.
2. Perform a system suitability check.
3. If no obvious errors are found, repeat the test using the same sample preparation (if stable).
4. If the repeat result is within limits and there is an assignable error, document and conclude.
5. If the repeat result is still OOS or the cause is not found, proceed to Phase II.

5.3 Phase II: Full-Scale Investigation

1. QA initiates a formal investigation using OOS Investigation Form (Annexure-2).
2. Investigate:
   • Manufacturing process deviations
   • Sample mix-up or contamination
   • Storage conditions
   • Previous batch trends and history
3. Interview involved personnel and document findings.
4. Define root cause and propose CAPA (Corrective and Preventive Action).
5. QA reviews and approves the investigation report.

5.4 Re-sampling and Re-testing Criteria

1. Re-sampling is allowed only if there is evidence of sample compromise or handling error.
2. Re-testing is permitted under QA-approved protocol with documented justification.
3. Original OOS result cannot be disregarded unless invalidated with scientifically sound reason.

5.5 Final Disposition

1. Based on investigation outcome, QA recommends:
   • Batch rejection
   • Reprocessing or re-testing
   • Product recall or reporting to regulatory authorities (if applicable)
2. Final decision is documented in the OOS Final Disposition Log (Annexure-3).

5.6 Trending and Review

1. QA shall review all closed OOS records quarterly to identify recurring issues.
2. Prepare trend reports and present during management review meetings.

6. Abbreviations

• OOS: Out of Specification
• CAPA: Corrective and Preventive Action
• QA: Quality Assurance
• QC: Quality Control
• SOP: Standard Operating Procedure

7. Documents

1. OOS Notification Form (Annexure-1)
2. OOS Investigation Form (Annexure-2)
3. OOS Final Disposition Log (Annexure-3)
4. CAPA Register

8. References

• US FDA Guidance for Industry: Investigating Out-of-Specification (OOS) Test Results
• ICH Q7 – GMP for APIs
• 21 CFR Part 211
• MHRA GxP Data Integrity Guidance

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: OOS Notification Form

Annexure-2: OOS Investigation Form

Annexure-3: OOS Final Disposition Log

Revision History:

Standard Operating Procedure for Documentation and Review of QC Results in API Manufacturing

1. Purpose

To establish a clear and standardized procedure for the documentation, review, and approval of analytical test results generated during Quality Control (QC) analysis of raw materials, intermediates, and Active Pharmaceutical Ingredients (APIs).

2. Scope

This SOP is applicable to all QC personnel involved in the generation, recording, review, and approval of test results within the API manufacturing facility. It includes manual entries, instrument printouts, electronic records, and analytical worksheets.

3. Responsibilities

• QC Analyst: Accurately record test results, observations, and calculations in the approved format.
• QC Reviewer: Verify correctness of data, calculations, and compliance with specifications.
• QA Officer: Review completed records for completeness and adherence to data integrity principles.

4. Accountability

The QC Head is accountable for ensuring proper documentation practices and review controls are followed, in alignment with GMP and regulatory expectations.

5. Procedure

5.1 Documentation of Test Results

1. Use blue or black permanent ink for manual entries. Corrections should be made by striking through the error with a single line, initialing, and writing the correct entry alongside.
2. Document results in approved QC worksheets or logbooks immediately after test completion.
3. Each result entry must be traceable to:
   • Sample ID / batch number
   • Test method / STP number
   • Instrument ID (if applicable)
   • Analyst initials and date
4. Attach relevant instrument printouts (chromatograms, pH meter printouts, etc.) with sample ID and analyst signature.

5.2 Review of Results

1. All results must be reviewed by a qualified reviewer who was not involved in performing the test.
2. Ensure:
   • Calculations are correct
   • Values fall within the specification limits
   • Raw data matches reported values
   • Any OOS/OOT is clearly documented and investigated
3. Sign and date all reviewed pages with comments, if applicable.

5.3 Out-of-Specification (OOS) and Out-of-Trend (OOT) Handling

1. OOS or OOT observations must be recorded in the data sheet and immediately notified to QA.
2. Initiate the investigation as per the OOS/OOT SOP and attach a reference copy with the analytical report.
3. Do not alter or overwrite original entries or results.

5.4 Approval and Archiving

1. After review, QC Head or designee must approve the final analytical report with date and signature.
2. Transfer completed and reviewed analytical records to the document control department for archival.
3. Retain records for a minimum of 5 years post batch expiry or as per regulatory requirements.

5.5 Data Integrity Practices

1. Follow ALCOA+ principles:
   • Attributable
   • Legible
   • Contemporaneous
   • Original
   • Accurate
   • Complete, Consistent, Enduring, and Available
2. Avoid use of pencils, correction fluid, or unapproved abbreviations.
3. Ensure all electronic data is backed up, secure, and access-controlled.

6. Abbreviations

• QC: Quality Control
• QA: Quality Assurance
• GMP: Good Manufacturing Practice
• OOS: Out of Specification
• OOT: Out of Trend
• STP: Standard Test Procedure
• ALCOA: Attributable, Legible, Contemporaneous, Original, Accurate

7. Documents

1. QC Analytical Worksheet (Annexure-1)
2. Instrument Printout Attachment Log
3. OOS/OOT Investigation Form

8. References

• ICH Q7 – GMP for APIs
• 21 CFR Part 211 – US FDA
• MHRA Data Integrity Guidance
• WHO TRS 996 – Annex 5

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: QC Analytical Worksheet

Revision History:

Standard Operating Procedure for Preparation and Storage of Working Standards in API Manufacturing

1. Purpose

To lay down a uniform procedure for the preparation, labeling, qualification, usage, and storage of working standards derived from primary/reference standards used in the analytical testing of Active Pharmaceutical Ingredients (APIs).

2. Scope

This SOP applies to all working standards prepared in the Quality Control laboratory for analytical testing in API manufacturing. It includes both in-house and pharmacopeial reference-based working standards.

3. Responsibilities

• QC Analyst: Prepare and qualify working standards using approved procedures.
• QC Supervisor: Review and approve working standard preparation records.
• QA Officer: Ensure traceability, proper labeling, and expiry management.

4. Accountability

The Head – Quality Control is accountable for the preparation, storage, verification, and documentation of all working standards used in analytical operations.

5. Procedure

5.1 Preparation of Working Standards

1. Obtain a qualified reference standard with valid CoA and expiry date.
2. Weigh an accurately known amount (e.g., 100 mg) of reference standard using a calibrated balance.
3. Dilute with a suitable solvent or buffer to a known concentration (e.g., 1000 µg/mL) using volumetric glassware.
4. Label the working standard solution with:
   • Working Standard Code (e.g., WS-API-001)
   • API name
   • Concentration
   • Date of preparation
   • Prepared by
   • Expiry date

5.2 Qualification

1. Compare the working standard with the reference standard using appropriate tests:
   • Assay by HPLC/UV
   • Identity by IR, TLC, or other validated techniques
2. Calculate the correction factor or purity value if applicable.
3. Record results in the Working Standard Qualification Report (Annexure-1).
4. Approve the standard for routine use only if all results are within acceptable criteria.

5.3 Storage Conditions

1. Store solid working standards in amber-colored, airtight containers with desiccant.
2. Store solution standards in amber-colored vials at recommended conditions (e.g., 2–8°C or as defined in STP).
3. Do not use beyond the assigned expiry date or if discoloration/precipitation is observed.

5.4 Usage and Expiry

1. Use working standards only for the analysis for which they are qualified.
2. Assign a validity of ≤ 6 months from the date of preparation unless otherwise justified.
3. Document each use in the Working Standard Usage Log (Annexure-2).

5.5 Disposal

1. Discard expired or disqualified working standards following the SOP for chemical waste disposal.
2. Record disposal details in the Working Standard Destruction Log (Annexure-3).

6. Abbreviations

• API: Active Pharmaceutical Ingredient
• WS: Working Standard
• QC: Quality Control
• QA: Quality Assurance
• HPLC: High Performance Liquid Chromatography
• IR: Infrared Spectroscopy

7. Documents

1. Working Standard Qualification Report (Annexure-1)
2. Working Standard Usage Log (Annexure-2)
3. Working Standard Destruction Log (Annexure-3)
4. STP and Reference Standard CoA

8. References

• ICH Q7 – Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients
• 21 CFR Part 211 – US FDA cGMP Guidelines
• Pharmacopoeial Monographs (USP, BP, IP)

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: Working Standard Qualification Report

Annexure-2: Working Standard Usage Log

Annexure-3: Working Standard Destruction Log

Revision History:

Standard Operating Procedure for Reference Standard Qualification and Handling in API Manufacturing

1. Purpose

The purpose of this SOP is to establish a standardized procedure for qualification, handling, storage, and periodic review of reference standards used in the analysis of Active Pharmaceutical Ingredients (APIs). This ensures that all reference standards are reliable, traceable, and meet regulatory and internal quality requirements.

2. Scope

This SOP applies to all reference standards (including working and primary standards) used in API manufacturing, covering their qualification prior to use in analytical testing, proper handling, storage conditions, and periodic requalification or replacement.

3. Responsibilities

• QC Analyst: Prepare and verify reference standards as per the approved protocols.
• QC Supervisor: Ensure that reference standards are properly stored and documented before use.
• QA Officer: Review qualification data and storage conditions, and authorize periodic requalification.
• Production Manager: Ensure that only qualified reference standards are used in the manufacturing process.

4. Accountability

The Head – QC is accountable for the implementation and control of reference standard qualification and handling procedures. The QA Head is responsible for ensuring that all reference standards are maintained in accordance with cGMP guidelines.

5. Procedure

5.1 Qualification of Reference Standards

1. Upon receipt, record all details of the reference standard including:
   • Certificate of Analysis (CoA)
   • Lot number
   • Expiry date
   • Storage conditions
2. Perform initial qualification tests (identity, purity, potency) as per the approved analytical method or pharmacopeial monograph.
3. If the reference standard meets specifications, assign a unique Reference Standard Code (e.g., RS-API-001) and log details in the Reference Standard Logbook (Annexure-1).
4. If deviations are noted, quarantine the standard and initiate an investigation. Do not use unqualified standards for analytical testing.

5.2 Handling and Storage

1. Store qualified reference standards in a dedicated controlled environment:
   • Temperature: As recommended on the CoA (e.g., 2–8°C for sensitive materials, 25°C ± 2°C for stable materials)
   • Humidity: Maintain as per CoA requirements (e.g., less than 60% RH)
2. Ensure the storage area is secure and accessible only to authorized personnel.
3. Periodically inspect storage conditions and update the log accordingly.

5.3 Use of Reference Standards

1. Before use, verify that the reference standard is within its expiry date and storage conditions have not been compromised.
2. Document the usage of the standard in the Reference Standard Usage Log (Annexure-2), noting:
   • Date of use
   • Sample and analysis type
   • Operator details
3. Any observed anomalies during use must be reported immediately to the QC Supervisor.

5.4 Periodic Requalification and Replacement

1. Conduct requalification of reference standards annually or as determined by risk assessment and storage conditions.
2. Reperform critical tests (identity, purity, etc.) and compare results with the original CoA.
3. If the standard fails requalification, remove it from inventory, document the deviation, and replace it with a newly qualified standard.
4. Update the Reference Standard Logbook to reflect requalification outcomes and any changes to stock.

5.5 Documentation and Record Keeping

1. Maintain all documentation relating to reference standard qualification, usage, storage, requalification, and disposal in their respective logs:
   • Reference Standard Logbook (Annexure-1)
   • Reference Standard Usage Log (Annexure-2)
   • Reference Standard Replacement/Disposal Records
2. All records must be reviewed monthly and archived as per company document control policy.

6. Abbreviations

• RS: Reference Standard
• QC: Quality Control
• QA: Quality Assurance
• CoA: Certificate of Analysis
• cGMP: Current Good Manufacturing Practices
• API: Active Pharmaceutical Ingredient

7. Documents

1. Reference Standard Logbook (Annexure-1)
2. Reference Standard Usage Log (Annexure-2)
3. CoA and Qualification Reports
4. Requalification Review Form

8. References

• ICH Q7 – GMP for Active Pharmaceutical Ingredients
• USP Monographs pertaining to reference standards
• 21 CFR Part 211 – US FDA cGMP
• WHO Guidelines for Reference Standards

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: Reference Standard Logbook

Annexure-2: Reference Standard Usage Log

Standard Operating Procedure for Stability Testing of API Batches

1. Purpose

To define the procedure for conducting stability testing of Active Pharmaceutical Ingredient (API) batches to assess product integrity over time and establish or confirm shelf-life in accordance with ICH Q1 guidelines.

2. Scope

This SOP applies to all Quality Control and Quality Assurance personnel involved in the planning, execution, evaluation, and documentation of stability studies for development, validation, and commercial batches of APIs.

3. Responsibilities

• QC Analyst: Perform stability sample testing as per defined intervals and STP.
• QA Officer: Monitor storage conditions and maintain stability chambers.
• Stability Coordinator: Maintain inventory, pull schedules, and data compilation.
• QC Reviewer: Verify results and compile interim and final stability reports.

4. Accountability

The Head – Quality is accountable for the scientific justification, regulatory compliance, and execution of the stability program for API batches.

5. Procedure

5.1 Study Design

1. Refer to ICH Q1A(R2) and ICH Q1E for designing stability protocols.
2. Include:
   • Study type (accelerated, long-term, intermediate)
   • Storage conditions (25°C/60% RH, 30°C/65% RH, 40°C/75% RH)
   • Testing intervals (e.g., 0, 3, 6, 9, 12, 18, 24 months)
   • Specifications to be monitored (appearance, assay, impurities, moisture content, etc.)

5.2 Sample Storage

1. Stability samples must be:
   • Representative of production batches
   • Packed in containers that simulate market packaging
   • Labeled with unique stability ID, batch number, storage condition, and interval schedule
2. Place samples in qualified stability chambers monitored continuously using calibrated temperature and humidity sensors.

5.3 Testing Procedure

1. At each interval, withdraw samples per schedule and perform testing as per STP.
2. Ensure all tests are conducted within ±5 days of the scheduled interval date.
3. Use validated analytical methods and retain all chromatograms and raw data for review.
4. Document observations such as color change, precipitation, or odor.

5.4 Data Compilation and Evaluation

1. Compare results against acceptance criteria and note any trends.
2. Prepare interim reports after each interval and a comprehensive report at the end of the study.
3. Include graphical trends for key parameters (e.g., assay, impurity).

5.5 Out-of-Trend or OOS Results

1. If any OOT or OOS result is observed:
   • Notify QA immediately
   • Initiate deviation/investigation
   • Conduct root cause analysis
   • Evaluate impact on shelf-life and future batches

5.6 Record Keeping and Archival

1. All stability data, test records, and reports must be retained for at least 5 years post expiry of the batch.
2. Ensure electronic and physical copies are secured and backed up.

6. Abbreviations

• API: Active Pharmaceutical Ingredient
• STP: Standard Test Procedure
• OOS: Out of Specification
• OOT: Out of Trend
• ICH: International Council for Harmonisation
• RH: Relative Humidity

7. Documents

1. Stability Protocol
2. Stability Sample Inventory Log (Annexure-1)
3. Stability Pull and Testing Log (Annexure-2)
4. Stability Reports

8. References

• ICH Q1A(R2) – Stability Testing of New Drug Substances and Products
• ICH Q1E – Evaluation of Stability Data
• 21 CFR Part 211 – US FDA cGMP
• WHO Technical Report Series 1010

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: Stability Sample Inventory Log

Annexure-2: Stability Pull and Testing Log

Revision History:

Standard Operating Procedure for Sampling and Testing of Raw Materials in API Manufacturing

1. Purpose

To establish a standardized procedure for the sampling and testing of raw materials used in API manufacturing to ensure quality, identity, and compliance with approved specifications before use in production.

2. Scope

This SOP applies to Quality Control (QC) personnel responsible for sampling, testing, and approving raw materials received for use in the API manufacturing process, including active ingredients, excipients, and solvents.

3. Responsibilities

• QC Sampler: Collect samples using clean tools and label containers properly.
• QC Analyst: Test samples as per STP and record results in logbooks and reports.
• QC Reviewer: Review and approve the results; determine compliance with specifications.
• QA Officer: Ensure raw materials are not used before approval; verify traceability.

4. Accountability

The Head – QC is accountable for ensuring raw materials are sampled and tested according to validated methods and GMP standards.

5. Procedure

5.1 Material Receipt and Quarantine

1. Upon receipt, store raw materials in the quarantine area with a “To Be Sampled” status label.
2. Verify material against invoice, delivery challan, and purchase order.

5.2 Sampling Plan

1. Use appropriate sampling techniques based on material category:
   • Random sampling (for general materials)
   • Stratified sampling (for critical materials or multiple containers)
2. Follow guidelines in Annexure-1 for number of containers and sample quantity.

5.3 Sampling Technique

1. Use cleaned and dried sampling tools (e.g., thief sampler, pipette).
2. Wear gloves and PPE before sampling.
3. Open container under LAF or designated area to prevent contamination.
4. Transfer sample to clean, labeled container indicating:
   • Material Name
   • Batch/Lot Number
   • Date of Sampling
   • Sampler’s Initials
5. Seal the sample container and send it to the QC lab.

5.4 Sample Identification and Coding

1. Assign a unique Raw Material Sample Number as per internal coding format (e.g., RM/25/04/XXX).
2. Enter details in the Sampling Logbook (Annexure-2).

5.5 Analytical Testing

1. Test raw material samples as per the respective Standard Test Procedure (STP).
2. Perform identity, assay, impurity, pH, LOD, and other tests based on material specifications.
3. Record results in analytical worksheets and sign off upon completion.

5.6 Review and Release

1. Compare results against the approved specification.
2. If compliant, release the material with “Approved” status label and update inventory system.
3. If out-of-specification (OOS), initiate investigation and inform QA.

5.7 Retention Sample

1. Store a representative sample (minimum 25 g or as per policy) of each raw material batch in labeled container for reference.
2. Store retention samples under defined conditions for at least 1 year after material expiry.

6. Abbreviations

• QC: Quality Control
• QA: Quality Assurance
• RM: Raw Material
• STP: Standard Test Procedure
• OOS: Out of Specification

7. Documents

1. Sampling Logbook (Annexure-2)
2. Raw Material Specification and STP
3. Analytical Report
4. Retention Sample Log

8. References

• ICH Q7 – GMP for APIs
• 21 CFR Part 211
• WHO Technical Report Series No. 986

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: Sampling Quantity Guideline

Annexure-2: Sampling Logbook

Revision History:

Standard Operating Procedure for Water Analysis by Karl Fischer (KF) Titration in API Manufacturing

1. Purpose

To define a standardized procedure for the accurate determination of water content in pharmaceutical substances, excipients, and APIs using Karl Fischer (KF) titration, ensuring reproducibility and regulatory compliance.

2. Scope

This SOP is applicable to Quality Control laboratory personnel performing water content determination using Karl Fischer titration (volumetric or coulometric) for raw materials, intermediates, and final APIs.

3. Responsibilities

• QC Analyst: Perform the titration using validated procedure and record results accurately.
• QC Reviewer: Verify the water content value, reagent standardization, and calculations.
• QA Officer: Ensure documentation, compliance, and verification during audits.

4. Accountability

The Head – QC is accountable for ensuring that Karl Fischer analysis is conducted as per validated methodology, and all data are traceable and reviewed.

5. Procedure

5.1 Equipment and Reagents

1. Karl Fischer titrator (volumetric or coulometric)
2. Dry methanol (KF grade)
3. KF reagent (e.g., Hydranal, Aquastar)
4. Certified water standard (e.g., sodium tartrate dihydrate)
5. Drying oven and desiccator (for sample preparation, if required)

5.2 Standardization of Karl Fischer Reagent

1. Weigh ~100 mg of water standard (e.g., sodium tartrate dihydrate) into a clean dry titration vessel.
2. Titrate using KF reagent until endpoint is reached.
3. Calculate KF factor:
   KF Factor = mg water / mL KF reagent consumed
4. Acceptable %RSD for three determinations: ≤ 2.0%

5.3 Sample Preparation

1. Ensure sample is finely powdered and homogenous.
2. Weigh accurately the sample (typically 10–200 mg based on expected moisture content).
3. Transfer sample to the titration vessel using dry spatula or syringe (for liquid samples).

5.4 Titration Procedure

1. Pre-titrate methanol blank before analysis.
2. Introduce the weighed sample into the titration vessel and start titration.
3. Allow the instrument to automatically reach the endpoint and display the volume used.
4. Record the final volume of reagent and perform the calculation.

5.5 Calculation

1. Use the formula:
   % Water = (Volume of KF reagent × KF Factor × 100) / Weight of Sample (mg)

5.6 Precautions

1. Handle KF reagents with care; avoid exposure to atmospheric moisture.
2. Close reagent bottles immediately after use.
3. Use gloves and eye protection while working with solvents and reagents.
4. Do not reuse reagents once contaminated.

6. Abbreviations

• KF: Karl Fischer
• QC: Quality Control
• API: Active Pharmaceutical Ingredient
• RSD: Relative Standard Deviation
• % Water: Percent water content

7. Documents

1. KF Titration Logbook (Annexure-1)
2. Reagent Standardization Record
3. Sample Analysis Report

8. References

• USP <921> – Water Determination
• ICH Q6A – Specifications
• 21 CFR Part 211 – US FDA GMP Guidelines

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: KF Titration Logbook

Revision History:

Standard Operating Procedure for LOD and Moisture Content Determination in API Manufacturing

1. Purpose

To define the procedure for determining Loss on Drying (LOD) and moisture content in Active Pharmaceutical Ingredients (APIs) using both conventional oven method and Karl Fischer titration, ensuring consistency and regulatory compliance.

2. Scope

This SOP is applicable to Quality Control personnel involved in the analysis of LOD and moisture content in raw materials, intermediates, and final APIs using gravimetric and Karl Fischer techniques.

3. Responsibilities

• QC Analyst: Perform LOD/moisture analysis and record data accurately.
• QC Executive: Review results and ensure compliance with specified limits.
• QA Officer: Audit test procedures and review LOD and KF logbooks.

4. Accountability

The Head – QC is accountable for ensuring that all LOD and moisture determinations are conducted as per validated procedures and recorded in compliance with cGMP.

5. Procedure

5.1 Loss on Drying (Oven Method)

1. Calibrate the analytical balance and drying oven before use.
2. Dry a suitable weighing bottle (with lid) in oven at 105°C for 30 minutes and cool in desiccator.
3. Weigh accurately 1-2 g of sample in the dried bottle (W1).
4. Dry the sample at specified temperature (usually 105°C) for 3 hours or as per STP.
5. Cool the bottle in a desiccator for 30 minutes and weigh again (W2).
6. Repeat drying until constant weight is achieved (not more than 0.5 mg difference).
7. Calculate LOD using the formula:
   % LOD = ((W1 – W2) / W1) × 100

5.2 Karl Fischer Method (Moisture Content)

1. Ensure Karl Fischer apparatus is calibrated with certified water standard.
2. Weigh accurately the sample (10–100 mg depending on expected moisture) and transfer to KF titration cell using syringe, septum, or direct introduction.
3. Perform blank titration and standardization if necessary.
4. Titrate until endpoint is achieved (stable measurement over 30 seconds).
5. Record volume of Karl Fischer reagent used and calculate % moisture:
   % Moisture = (Volume × Factor × 100) / Sample Weight (mg)

5.3 Acceptance Criteria

1. Compare observed results with specification mentioned in STP or pharmacopoeia (e.g., NMT 1.0% for moisture content).
2. Document results in LOD/Moisture Content Worksheet (Annexure-1).

5.4 Precautions

1. Use tongs/gloves to handle hot containers during LOD analysis.
2. Ensure reagents used in KF method are within expiry and moisture-free.
3. Keep desiccators tightly closed when not in use.

6. Abbreviations

• LOD: Loss on Drying
• KF: Karl Fischer
• STP: Standard Test Procedure
• API: Active Pharmaceutical Ingredient
• QA: Quality Assurance
• QC: Quality Control

7. Documents

1. LOD and Moisture Content Worksheet (Annexure-1)
2. KF Calibration Log
3. Drying Oven Calibration Record

8. References

• USP <921> – Water Determination
• ICH Q6A – Specifications: Test Procedures and Acceptance Criteria
• 21 CFR Part 211 – US FDA GMP

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: LOD and Moisture Content Worksheet

Revision History:

Standard Operating Procedure for Impurity Profiling in API by HPLC

1. Purpose

To establish a standardized procedure for performing impurity profiling of Active Pharmaceutical Ingredients (APIs) using HPLC, ensuring accurate identification and quantification of known, unknown, and specified impurities as per regulatory and pharmacopeial requirements.

2. Scope

This SOP is applicable to all Quality Control (QC) personnel engaged in the analysis of impurities in APIs using validated HPLC methods during batch release, stability studies, or regulatory submissions.

3. Responsibilities

• QC Analyst: Prepare samples and standards, perform HPLC runs, integrate peaks, and calculate impurity levels.
• QC Reviewer: Review chromatograms, retention times, and impurity limits compliance.
• QA Officer: Verify results and ensure traceability for regulatory audits and documentation.

4. Accountability

The QC Head is accountable for ensuring that impurity testing procedures are scientifically justified, properly documented, and in accordance with approved analytical methods.

5. Procedure

5.1 Reference Documents and Preparation

1. Refer to the approved analytical method or pharmacopoeial monograph for:
   • Mobile phase composition
   • Column specification
   • Detector wavelength
   • Injection volume and flow rate
2. Prepare impurity standards and working standards in accordance with method SOPs.

5.2 System Suitability

1. Inject system suitability solution or standard mixture containing known impurities.
2. Ensure:
   • Resolution between critical peaks ≥ 2.0
   • Retention time repeatability within ±2%
   • %RSD of impurity area for repeat injections ≤ 10%

5.3 Sample Injection and Data Acquisition

1. Inject test solution and record chromatograms under validated conditions.
2. Identify peaks based on relative retention time (RRT) compared to standard.
3. Integrate all peaks above 0.05% (unless otherwise justified in validation).

5.4 Quantification

1. Calculate individual impurity % using response factor or area normalization method as per method validation.
2. Total impurity = sum of all impurities above threshold level.
3. Compare with acceptance criteria from:
   • ICH Q3A/B
   • Regulatory filing (e.g., DMF)
   • In-house specifications

5.5 Reporting Format

1. Report impurity profiling in the Impurity Profiling Report Sheet (Annexure-1) with:
   • Impurity name/RRT
   • Retention time
   • Observed area
   • Calculated percentage
   • Limit
   • Status (Pass/Fail)

5.6 Investigation of Unidentified Peaks

1. Any unknown impurity above reporting threshold must be:
   • Assigned an RRT and tracked in stability studies
   • Subject to identification via MS/NMR if consistently observed
   • Considered for toxicological evaluation if >0.1%

6. Abbreviations

• API: Active Pharmaceutical Ingredient
• HPLC: High-Performance Liquid Chromatography
• RRT: Relative Retention Time
• RSD: Relative Standard Deviation
• DMF: Drug Master File
• ICH: International Council for Harmonisation

7. Documents

1. Impurity Profiling Report Sheet (Annexure-1)
2. System Suitability Checklist
3. Instrument Run Sequence

8. References

• ICH Q3A – Impurities in New Drug Substances
• ICH Q3B – Impurities in New Drug Products
• USP <621>, <466>, and applicable monographs

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: Impurity Profiling Report Sheet

Revision History:

Standard Operating Procedure for Residual Solvent Testing by Gas Chromatography in API Manufacturing

1. Purpose

To define the procedure for the determination and quantification of residual solvents in Active Pharmaceutical Ingredients (APIs) using Gas Chromatography (GC), ensuring compliance with ICH Q3C and applicable pharmacopeial limits.

2. Scope

This SOP is applicable to all QC analysts performing residual solvent testing on raw materials, intermediates, and finished APIs using headspace or direct injection gas chromatography techniques.

3. Responsibilities

• QC Analyst: Prepare samples, standards, and run GC analysis as per validated method.
• QC Reviewer: Verify chromatograms, peak integration, and calculated values against limits.
• QA Officer: Ensure compliance with documentation and data integrity requirements.

4. Accountability

The QC Head is accountable for ensuring timely and accurate testing of residual solvents, proper qualification of GC instruments, and training of analysts.

5. Procedure

5.1 Sample and Standard Preparation

1. Prepare standard solutions using certified residual solvent reference standards as per STP.
2. Prepare sample solutions using suitable diluent (e.g., DMSO, DMF, water) under specified conditions.
3. Use headspace vials for volatile solvent extraction; seal with crimp caps.

5.2 Instrument Setup

1. Use qualified GC system equipped with FID or TCD detector and headspace or autosampler.
2. Check the following:
   • Column: Capillary column suitable for residual solvent separation
   • Carrier gas flow rate and pressure
   • Oven temperature program as per method
   • Injection volume and split ratio

5.3 System Suitability

1. Run system suitability test using standard mixture.
2. Acceptance criteria:
   • Resolution ≥ 1.5 between critical pairs
   • RSD of peak area ≤ 15% for replicate injections
   • Retention time repeatability within ±5%

5.4 Sample Analysis

1. Inject the sample solution as per sequence defined in the test method.
2. Record chromatograms and identify residual solvent peaks based on retention times.
3. Quantify using external standard calibration or area normalization method.

5.5 Calculation and Reporting

1. Calculate concentration of each solvent using calibration curve or response factor.
2. Compare against ICH Q3C and pharmacopoeial permissible limits (Class 1, 2, or 3 solvents).
3. Report result as:
   • Below detection limit (BDL) if peak not observed
   • Pass/Fail based on specification compliance

5.6 Disposal and Cleanup

1. Dispose residual solvent standards, sample remains, and headspace vials as per hazardous waste SOP.
2. Clean GC injection port, liner, and column after analysis if contamination is suspected.

6. Abbreviations

• GC: Gas Chromatography
• FID: Flame Ionization Detector
• TCD: Thermal Conductivity Detector
• BDL: Below Detection Limit
• LOD: Limit of Detection
• LOQ: Limit of Quantification
• QA: Quality Assurance
• QC: Quality Control

7. Documents

1. Residual Solvent Testing Worksheet (Annexure-1)
2. System Suitability Checklist
3. Sample Preparation Logbook

8. References

• ICH Q3C – Impurities: Guideline for Residual Solvents
• USP <467> – Residual Solvents
• 21 CFR Part 211 – US FDA GMP Guidelines

9. SOP Version

Version: 2.0

10. Approval Section

11. Annexures

Annexure-1: Residual Solvent Testing Worksheet

Revision History: