Standard Operating Procedure for Determination of Enteric Coating Integrity in Analytical Method Development
| Department | Analytical Method Development |
|---|---|
| SOP No. | SOP/AMD/291/2025 |
| Supersedes | SOP/AMD/291/2022 |
| Page No. | Page 1 of 11 |
| Issue Date | 21/05/2025 |
| Effective Date | 23/05/2025 |
| Review Date | 21/05/2026 |
1. Purpose
To establish a validated procedure for evaluating the integrity of enteric coatings on solid oral dosage forms, ensuring the dosage unit resists disintegration in acidic
2. Scope
This SOP applies to the Analytical Method Development and Quality Control departments responsible for testing enteric-coated tablets or capsules during formulation development, stability studies, and batch release.
3. Responsibilities
- Analytical Scientist: Designs and validates acid resistance and buffer dissolution methods.
- QC Analyst: Conducts routine integrity testing and reports results.
- QA Executive: Reviews data and ensures regulatory compliance.
4. Accountability
The Head of Analytical Method Development is accountable for ensuring accurate, validated, and compliant methods to verify enteric coating performance across batches.
5. Procedure
5.1 Apparatus
- USP Dissolution Apparatus I (Basket) or II (Paddle)
- Disintegration Tester (optional)
- UV-Visible Spectrophotometer or HPLC
5.2 Acid Resistance Test
- Use 0.1N HCl as medium, 750 mL per vessel at 37 ± 0.5°C.
- Set apparatus: Paddle at 50 rpm or Basket at 100 rpm.
- Place 6 dosage units and run for 2 hours.
- Check for visual disintegration or drug release (NMT 10%).
- Collect sample at end of acid stage, filter, and analyze using UV or HPLC.
5.3 Buffer Dissolution Test
- Add 250 mL of pre-warmed phosphate buffer (pH 6.8) to each vessel to make total volume 1000 mL.
- Continue run as per dissolution specification (e.g., 45 or 60 minutes).
- Withdraw samples at predetermined time points (e.g., 15, 30, 45 min).
- Filter samples and measure absorbance at λmax or inject into HPLC.
5.4 Evaluation and Acceptance Criteria
- Acid Stage: NMT 10% of drug should be released after 2 hours.
- Buffer Stage: NLT 80% drug should be released within specified time (typically 45 minutes).
5.5 Validation Parameters
- Specificity: No interference in acid and buffer stage media.
- Linearity: r² ≥ 0.999 over 50%–150% range.
- Accuracy: Recovery 98%–102% in both stages.
- Precision: RSD ≤ 2% at each stage.
- Robustness: Evaluate at ±5 rpm and ±0.1 pH media variation.
6. Abbreviations
- HCl: Hydrochloric Acid
- UV: Ultraviolet
- HPLC: High Performance Liquid Chromatography
- RSD: Relative Standard Deviation
7. Documents
- Enteric Coating Integrity Test Log – Annexure-1
- Dissolution Profile Data – Annexure-2
- Validation Summary Report – Annexure-3
8. References
- USP <711>: Dissolution
- ICH Q2(R1): Validation of Analytical Procedures
- FDA Guidance for Enteric-Coated Products
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | Ritika Deshmukh | Vishal Patil | Sunita Reddy |
| Designation | Dissolution Analyst | QA Reviewer | Head – AMD |
| Department | Analytical Method Development | QA | Analytical Method Development |
11. Annexures
Annexure-1: Enteric Coating Integrity Test Log
| Sample ID | Acid Release (%) | Buffer Release (%) | Status |
|---|---|---|---|
| ECI-291-01 | 6.3% | 91.2% | Pass |
Annexure-2: Dissolution Profile Data
| Time (min) | % Release |
|---|---|
| 15 | 35% |
| 30 | 68% |
| 45 | 91% |
Annexure-3: Validation Summary Report
The enteric coating integrity method was validated for specificity, precision, accuracy, and robustness. Results confirmed the integrity and performance of the enteric layer under simulated gastrointestinal conditions.
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 21/05/2025 | 2.0 | Updated buffer media conditions and validation acceptance criteria | Annual Review | Sunita Reddy |
| 01/11/2022 | 1.0 | Initial SOP Release | New SOP | QA Head |