Standard Operating Procedure for Determining Alcohol Evaporation Rate in Elixir Formulations
| Department | Elixir Department |
|---|---|
| SOP No. | SOP/ELX/234/2025 |
| Supersedes | SOP/ELX/234/2022 |
| Page No. | Page 1 of 7 |
| Issue Date | 11/04/2025 |
| Effective Date | 15/04/2025 |
| Review Date | 11/04/2026 |
1. Purpose
To define the procedure for evaluating the rate of alcohol evaporation from elixir formulations under simulated storage conditions, helping assess formulation stability, packaging suitability, and shelf-life integrity.
2. Scope
This SOP applies to the Quality Control and Formulation Development Departments for monitoring ethanol or isopropanol evaporation in elixirs during formulation studies, packaging compatibility, and stability evaluations.
3. Responsibilities
- Formulation Scientist:
- Design experiment protocol for alcohol loss estimation during product development.
- QC Analyst:
- Perform alcohol content analysis at specified intervals using validated methods.
- QA Officer:
- Ensure compliance of data with regulatory expectations and retain documentation.
4. Accountability
The QC Head is accountable for execution of the evaporation study and data integrity. The QA Head ensures analytical compliance and documentation for audits and regulatory submissions.
5. Procedure
5.1 Equipment and Materials
- Gas Chromatograph (GC) with
FID or HPLC with RI detector
Alcohol reference standard (ethanol, isopropanol)
Volumetric flasks, syringes, and vials
Glass containers or commercial packaging with sealing caps
5.2 Sample Preparation
- Fill elixir formulation containing alcohol into the intended packaging container and seal as per commercial practice.
- Label the containers clearly with batch number, date, and storage condition.
5.3 Storage Conditions
- Store samples under:
- 25°C ± 2°C / 60% RH ± 5% RH (Long-term)
- 40°C ± 2°C / 75% RH ± 5% RH (Accelerated)
- Keep one set at room temperature with and without secondary packaging (e.g., cartons).
5.4 Time Points for Testing
- 0 (Initial)
- 1 Week
- 2 Weeks
- 1 Month
- 3 Months
- 6 Months
5.5 Analytical Testing Procedure
- Withdraw a 1–2 mL aliquot of the elixir sample.
- Prepare calibration standards for alcohol (ethanol or IPA) in the same matrix.
- Inject both standards and samples into GC/HPLC and record retention time and peak area.
- Calculate % alcohol content using the calibration curve.
5.6 Calculations
Alcohol loss (%) = [(Initial content – Current content) / Initial content] × 100
5.7 Acceptance Criteria
- Alcohol content should not deviate by more than ±10% of label claim unless justified by safety and efficacy data.
- Consistent loss patterns must be addressed with improved sealing or packaging redesign.
5.8 Documentation
- Record all results in the Alcohol Evaporation Study Logbook (Annexure-1).
- Attach chromatograms, calculations, and trend graphs to the product stability file.
- Document cap integrity and any observed changes in packaging.
6. Abbreviations
- SOP: Standard Operating Procedure
- GC: Gas Chromatography
- FID: Flame Ionization Detector
- RH: Relative Humidity
- QA: Quality Assurance
- QC: Quality Control
7. Documents
- Alcohol Evaporation Study Logbook (Annexure-1)
- Instrument Calibration and Maintenance Logs
- Stability Summary Report
8. References
- USP Monograph for Alcohol Determination
- ICH Q1A(R2) – Stability Testing of New Drug Substances and Products
- 21 CFR Part 211.166 – Stability Testing Requirements
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Alcohol Evaporation Study Logbook
| Date | Batch No. | Storage Condition | Time Point | Alcohol Content (%) | Loss (%) | Tested By | Verified By |
|---|---|---|---|---|---|---|---|
| 11/04/2025 | ELX-0425-051 | 40°C / 75% RH | 1 Month | 4.48% | 6.5% | Rajesh Kumar | Sunita Reddy |
Revision History:
| Revision Date | Revision No. | Revision Details | Reason for Revision | Approved By |
|---|---|---|---|---|
| 01/01/2024 | 1.0 | Initial SOP Release | New SOP Creation | QA Head |
| 11/04/2025 | 2.0 | Added packaging condition comparisons and threshold values | Method Refinement | QA Head |