formulation scientists, research personnel, and development teams responsible for pre-formulation studies and polymer screening in the development of gel-based pharmaceutical products.

3. Responsibilities

• Formulation Scientist: Responsible for conducting polymer screening studies and maintaining experimental data.
• R&D Chemist: Assists in preparation and testing of polymer-based trial formulations.
• QA Personnel: Ensures all data is accurately recorded and complies with GMP documentation practices.

4. Accountability

The Head – Gel Manufacturing and Head – Research & Development are accountable for ensuring the scientific robustness and regulatory compliance of this procedure.

5. Procedure

5.1 Preparation for Polymer Screening

1. Refer to target product profile (TPP) and required rheological characteristics (e.g., semi-solid, clear/opaque, thixotropic behavior).
2. Compile a list of commonly used pharmaceutical polymers: Carbopol grades (934, 940, 980), HPMC, Xanthan gum, Poloxamer 407, Sodium Alginate, etc.
3. Review polymer compatibility with API and excipients.

5.2 Preparation of Polymer Gels (Placebo)

1. Prepare 1% to 3% solutions/gels of each shortlisted polymer in purified water using a magnetic stirrer or overhead mixer.
2. Hydrate polymers at appropriate temperatures and conditions (e.g., continuous stirring at room temperature for Carbopol, heating for Poloxamer).
3. Adjust pH using neutralizing agents like triethanolamine or sodium hydroxide when required.

5.3 Evaluation Parameters

1. Viscosity measurement using Brookfield Viscometer at 25°C, using spindle No. 6 or 7.
2. Appearance: Transparency, color, homogeneity, air entrapment.
3. Spreadability Test: Place 1g gel between two glass slides and measure the diameter after applying fixed weight.
4. Syneresis Test: Observe for separation of water after 24, 48, and 72 hours at ambient and refrigerated conditions.
5. pH and Clarity: pH should range between 5.5–7.5 for topical gels unless otherwise specified.

5.4 Compatibility Assessment

1. Prepare API-loaded gels with top 2-3 polymer candidates and evaluate drug-polymer compatibility.
2. Conduct FTIR and DSC analysis to assess interaction between polymer and API.

5.5 Documentation

1. All test results to be documented in the Polymer Screening Logbook (Annexure-1).
2. Summarize findings in the Screening Summary Sheet (Annexure-2).
3. Finalize 1 or 2 polymers based on performance and submit results to formulation head for approval.

6. Abbreviations

• API: Active Pharmaceutical Ingredient
• DSC: Differential Scanning Calorimetry
• FTIR: Fourier Transform Infrared Spectroscopy
• HPMC: Hydroxypropyl Methylcellulose
• SOP: Standard Operating Procedure

7. Documents

1. Polymer Screening Logbook – Annexure-1
2. Screening Summary Sheet – Annexure-2
3. Polymer Compatibility Checklist – Annexure-3

8. References

• USP 43-NF 38 General Chapter on Semisolid Formulations
• ICH Q8(R2) – Pharmaceutical Development
• WHO TRS No. 961 – Annex 3: Development Pharmaceutics

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: Polymer Screening Logbook

Polymer Name	Concentration (%)	Viscosity (cPs)	Clarity	Syneresis
Carbopol 940	1.0	30000	Clear	No
Poloxamer 407	2.5	22000	Semi-clear	Low

Annexure-2: Screening Summary Sheet

• Best Performing Polymer: Carbopol 940
• Recommended pH Range: 6.0–7.0
• Requires Neutralizer: Yes (TEA)
• API Compatibility: Compatible

Annexure-3: Polymer Compatibility Checklist

• API-Polymer Interaction: None detected
• pH stability acceptable: Yes
• FTIR/DSC analysis performed: Yes
• Microbial growth within 7 days: No

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
02/06/2022	1.0	Initial SOP	New procedure	QA Head
02/06/2025	2.0	Expanded compatibility and evaluation criteria	Process improvement	QA Head