personnel involved in designing and developing gel products at the formulation development facility.

3. Responsibilities

• Formulation Scientist: Responsible for designing, planning, and executing gel formulation activities.
• R&D Manager: Responsible for reviewing and approving the design strategy and associated data.
• QA Representative: Responsible for reviewing documentation for compliance with internal and external standards.

4. Accountability

The Head – R&D is accountable for the implementation and oversight of this SOP.

5. Procedure

5.1 Pre-Formulation Considerations

1. Review therapeutic objectives and intended route of administration (topical, transdermal, mucosal).
2. Conduct literature review and reference product evaluation for benchmarking.
3. Assess solubility, stability, and compatibility of APIs and excipients.
4. Evaluate API particle size, melting point, and hygroscopic nature.

5.2 Selection of Ingredients

1. API: Chosen based on therapeutic need and physicochemical properties.
2. Gelling Agent: Select based on desired viscosity and application characteristics (e.g., Carbomer, HPMC, Poloxamer).
3. Solvent System: Use purified water, ethanol, or propylene glycol based on API solubility.
4. Preservatives: Select suitable antimicrobial agents compatible with gelling agents.
5. pH Adjusters: Use triethanolamine or sodium hydroxide to achieve target pH.
6. Stabilizers/Antioxidants: If applicable, include agents like EDTA or BHT.

5.3 Design of Experiment (DoE)

1. Use factorial design or response surface methodology (RSM) to assess impact of formulation variables.
2. Define target product profile (TPP) including viscosity, clarity, spreadability, pH, microbial load.
3. Record all test variables and response values in formulation development sheets.

5.4 Prototype Development

1. Prepare small batches (10–100 g) of different prototype formulations using standard laboratory equipment.
2. Conduct preliminary evaluations: pH, viscosity, appearance, spreadability, and washability.
3. Document composition and preparation steps for each batch.

5.5 Evaluation and Short-Term Stability

1. Store formulations at accelerated and room temperature conditions for 7–14 days.
2. Monitor physical and chemical changes including phase separation, discoloration, viscosity drift.
3. Perform microbial tests and compatibility checks with packaging materials.

5.6 Documentation

1. Prepare formulation development report for each prototype batch.
2. Maintain logbooks, DoE charts, and formulation summary sheets.
3. Ensure cross-functional review by QA and Analytical Development teams.

6. Abbreviations

• SOP: Standard Operating Procedure
• API: Active Pharmaceutical Ingredient
• DoE: Design of Experiment
• TPP: Target Product Profile
• R&D: Research and Development

7. Documents

1. Formulation Development Log – Annexure-1
2. Design of Experiment Worksheet – Annexure-2
3. Formulation Evaluation Template – Annexure-3

8. References

• ICH Q8(R2) – Pharmaceutical Development
• WHO Guidelines on Stability Testing of Pharmaceutical Products
• USP <795> – Pharmaceutical Compounding – Nonsterile Preparations

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: Formulation Development Log

Batch ID	Composition Summary	Date	Prepared By	Remarks
GM-FD-001	Carbomer 940, API X, TEA, Water	01/06/2025	F123	Stable at room temp

Annexure-2: DoE Worksheet

Formulation Code	Variable 1 (Carbomer %)	Variable 2 (TEA %)	Response (Viscosity)
F1	0.5%	0.8%	22000 cps
F2	0.7%	1.0%	31000 cps

Annexure-3: Evaluation Template

Batch ID	Appearance	pH	Viscosity	Spreadability
GM-FD-001	Clear	6.8	27000 cps	Good

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/06/2022	1.0	Initial SOP creation	New SOP	Head – R&D
02/06/2025	2.0	Updated for DoE inclusion	Process optimization	Head – R&D