Procedure for Testing Spreadability of Ointments
| Department | Quality Control (QC)/Quality Assurance (QA)/Analytical Development |
|---|---|
| SOP No. | SOP/Ointment/068 |
| Supersedes | V 1.0 |
| Page No. | Page X of Y |
| Issue Date | [Insert Issue Date] |
| Effective Date | [Insert Effective Date] |
| Review Date | [Insert Review Date] |
1. Purpose
The purpose of this Standard Operating Procedure (SOP) is to define the method for testing the spreadability of ointments, which determines ease of application and uniform distribution on the skin. Spreadability is a key quality attribute affecting the efficacy and consumer acceptability of the product.
2. Scope
This SOP applies to all personnel in the Quality Control (QC), Quality Assurance (QA), and Analytical Development departments responsible for testing the spreadability of ointments during formulation development, in-process control, and final batch release.
3. Responsibilities
- Quality Control Analyst: Conducts spreadability testing and records results.
- Quality Assurance Personnel: Reviews and approves test results.
- Production Supervisor: Ensures that ointment batches conform to spreadability specifications.
- R&D and Analytical Development Team: Investigates deviations and suggests corrective actions.
4. Accountability
The QC, Analytical Development, and QA Managers are accountable for ensuring that spreadability testing is conducted accurately and documented as per regulatory and GMP standards.
5. Procedure
5.1 Equipment and Materials
- Glass slides (two, standard size)
- Standard weights (e.g., 100 g, 200 g, 500 g)
- Ruler (calibrated, in mm)
- Timer (stopwatch)
- Data recording sheets
- Ointment sample (standardized quantity, e.g., 0.5 g – 1 g)
5.2 Sample Preparation
- Ensure the ointment sample is at room temperature (25°C ± 2°C).
- Weigh an exact amount of ointment (0.5 g – 1 g) using a calibrated balance.
- Place the ointment sample on the center of a clean glass slide.
- Place a second glass slide over it, ensuring uniform contact.
5.3 Spreadability Testing Methods
5.3.1 Parallel Plate Method
- Apply a known weight (e.g., 100 g, 200 g, or 500 g) onto the upper glass plate.
- Allow the weight to remain for 1 – 5 minutes, ensuring even spreading.
- Remove the weight carefully without disturbing the sample.
- Measure the diameter of the spread ointment using a ruler.
5.3.2 Sliding Plate Method
- Place the ointment sample between two glass slides.
- Apply a weight to the upper slide and allow the sample to spread naturally.
- After 5 minutes, measure the spread area.
5.4 Calculation of Spreadability
- Spreadability (S) is calculated using the formula:
- S = M × L / T
- Where:
- S = Spreadability (g.cm/sec)
- M = Weight applied (g)
- L = Length of the ointment spread (cm)
- T = Time required for spreading (sec)
- Compare results against the predetermined spreadability specification.
5.5 Acceptance Criteria
- The spreadability of the ointment should be within the defined specification range (e.g., 5 – 10 cm under 100 g weight).
- Deviations from the standard range require further investigation.
5.6 Documentation
- Record all spreadability test results in the Spreadability Test Log.
- Document weights used, time taken, and spread diameter.
- QA personnel must review and approve results before batch release.
6. Abbreviations
- GMP – Good Manufacturing Practices
- QA – Quality Assurance
- QC – Quality Control
7. Documents
- Spreadability Test Log (Annexure-1)
- Ointment Batch Spreadability Report (Annexure-2)
8. References
- WHO GMP Guidelines for Pharmaceutical Manufacturing
- USP <1174> – Semisolid Drug Products
- ICH Q2 (R1) – Validation of Analytical Procedures
9. SOP Version
Version 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Spreadability Test Log
| Date | Batch Number | Sample Weight (g) | Weight Applied (g) | Spread Diameter (cm) | Result | Verified By |
|---|---|---|---|---|---|---|
| 01/02/2025 | OINT-101 | 0.5 | 100 | 6.2 | Pass | QA Officer |
| 02/02/2025 | OINT-102 | 0.5 | 100 | 5.8 | Pass | QA Officer |
Annexure-2: Ointment Batch Spreadability Report
| Date | Batch Number | Test Method | Acceptance Criteria | Result | Final Status | Approved By |
|---|---|---|---|---|---|---|
| 01/02/2025 | OINT-101 | Parallel Plate | 5 – 10 cm | 6.2 cm | Approved | QA Head |
| 02/02/2025 | OINT-102 | Parallel Plate | 5 – 10 cm | 5.8 cm | Approved | QA Head |