Gel Manufacturing: SOP for Weighing Micro Quantities of APIs for Gels – V 2.0
Standard Operating Procedure for Weighing Micro Quantities of APIs in Gel Manufacturing
| Department |
Gel Manufacturing |
| SOP No. |
SOP/GM/165/2025 |
| Supersedes |
SOP/GM/165/2022 |
| Page No. |
Page 1 of 10 |
| Issue Date |
09/06/2025 |
| Effective Date |
11/06/2025 |
| Review Date |
09/06/2027 |
1. Purpose
To establish a standard procedure for accurately weighing micro quantities (below 100 mg) of Active Pharmaceutical Ingredients (APIs) used in gel formulation to ensure dosing precision, product quality, and regulatory compliance.
2. Scope
This SOP applies to weighing of APIs in micro quantities used in gel products manufactured at the Gel Manufacturing Department. It includes the use of microbalances, controlled environment protocols, and documentation requirements.
3. Responsibilities
- Production Chemist: Responsible for execution of weighing activity and recording data.
- QA Officer: Responsible for
verifying weighed quantities and ensuring compliance with SOP.
Engineering: Responsible for maintaining and calibrating microbalances used for weighing.
4. Accountability
Department Head – Gel Manufacturing and Manager – Quality Assurance are accountable for compliance and implementation of this SOP.
5. Procedure
5.1 Pre-Weighing Preparation
- Ensure that the microbalance is calibrated and within its valid calibration period.
- Clean the balance area using lint-free cloth and 70% IPA prior to activity.
- Check balance leveling and ensure the draft shield is functioning properly.
- Verify room temperature and humidity are within acceptable limits (as per validation protocol).
5.2 Material Verification and Documentation
- Receive the dispensing slip approved by QA for the specific batch.
- Verify API label, batch number, retest date, and quantity required against BMR.
- Document material issuance in the raw material logbook and balance logbook.
5.3 Weighing Procedure
- Use pre-cleaned and tared weighing vessels such as watch glasses or plastic scoops with known weights.
- Weigh API using micro spatula gently to avoid spillage and static disturbances.
- Target quantity should be weighed within ±2% accuracy; reject and reweigh if out of tolerance.
- Once weighing is complete, close the sample and tare container to avoid contamination.
5.4 Transfer of Weighed API
- Transfer the weighed API container to manufacturing area in a closed, double-bagged labeled container.
- Label should include API name, weight, batch number, date, and analyst signature.
- Get QA clearance before transferring material for further processing.
5.5 Post-Weighing Cleanup and Documentation
- Clean the microbalance surface and surroundings after activity.
- Log the final weighed quantity in the batch record and in the Weighing Logbook.
- QA to review and sign the weighing activity in the logbook and BMR.
6. Abbreviations
- API: Active Pharmaceutical Ingredient
- BMR: Batch Manufacturing Record
- IPA: Isopropyl Alcohol
- QA: Quality Assurance
7. Documents
- Micro Weighing Log – Annexure-1
- Weighing Checklist – Annexure-2
- Material Transfer Label – Annexure-3
8. References
- ICH Q7 – Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients
- GMP Guidelines – WHO TRS 986
- Internal Quality and Compliance Manual
9. SOP Version
Version: 2.0
10. Approval Section
|
Prepared By |
Checked By |
Approved By |
| Signature |
|
|
|
| Date |
|
|
|
| Name |
|
|
|
| Designation |
Jr. Production Chemist |
QA Executive |
Head – Manufacturing |
| Department |
Gel Manufacturing |
Quality Assurance |
Manufacturing |
11. Annexures
Annexure-1: Micro Weighing Log
| Date |
API Name |
Batch No. |
Target Quantity |
Actual Quantity |
Container No. |
Analyst Signature |
|
|
|
|
|
|
|
Annexure-2: Weighing Checklist
| Checklist Item |
Yes/No |
Remarks |
| Microbalance calibrated? |
|
|
| Room condition verified? |
|
|
| Correct API selected? |
|
|
| Container pre-tared? |
|
|
Annexure-3: Material Transfer Label
| API Name |
|
| Batch No. |
|
| Weighed Quantity |
|
| Date of Weighing |
|
| Analyst |
|
| Container ID |
|
| QA Clearance |
|
Revision History
| Revision Date |
Revision No. |
Change Description |
Reason |
Approved By |
| 25/05/2022 |
1.0 |
Initial release |
New SOP |
QA Manager |
| 09/06/2025 |
2.0 |
Revised procedure and annexures |
Compliance update |
QA Manager |