Gel Manufacturing: SOP for Development of Oil-Based Gels – V 2.0

Standard Operating Procedure for Developing Oil-Based Gel Formulations in Gel Manufacturing

Department	Gel Manufacturing
SOP No.	SOP/GM/168/2025
Supersedes	SOP/GM/168/2022
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 systematic procedure for developing and formulating oil-based gel products, ensuring optimal consistency, stability, and therapeutic effectiveness.

2. Scope

This SOP applies to formulation development teams, R&D departments, and manufacturing personnel involved in creating oil-based gels for pharmaceutical, cosmetic, and cosmeceutical applications.

3. Responsibilities

Formulation Development Team: Responsible for the design, evaluation, and documentation of oil-based gel formulations.
R&D Chemist: To conduct pre-formulation studies, compatibility assessments, and stability testing.
Quality Assurance (QA): To ensure compliance of the formulation process with regulatory and quality standards.

4. Accountability

Head – Gel Manufacturing

and Head – Quality Assurance are accountable for implementation and adherence to this SOP.

5. Procedure

5.1 Selection of Oil Phase

Select suitable oils (e.g., light liquid paraffin, isopropyl myristate, caprylic/capric triglycerides) based on:
- Solubility of active pharmaceutical ingredients (APIs)
- Spreadability and skin feel
- Stability and oxidation resistance

5.2 Selection of Gelling Agent

Identify suitable lipophilic gelling agents such as:
- Colloidal silica
- Hydrogenated castor oil derivatives
- Aluminum/magnesium stearates
Evaluate compatibility with oil base and API.

5.3 Pre-formulation Studies

Conduct solubility studies for API in selected oil.
Evaluate rheology, pH, and spreadability of oil-gel base without API.
Perform accelerated stability testing at 40°C and 75% RH.

5.4 Manufacturing Process Development

Weigh and mix oils under a nitrogen blanket to prevent oxidation if required.
Disperse the gelling agent into the oil with continuous stirring using high-shear mixers.
Incorporate the API, solubilized in oil (if applicable), under controlled mixing.
Homogenize until a uniform gel structure is achieved.

5.5 Evaluation of Formulation

Test key parameters:
- Viscosity
- Homogeneity
- pH
- Appearance (clarity/opacity)
- Drug content uniformity
Check for any phase separation or oil exudation after centrifugation.

5.6 Documentation

Record experimental design and trial batches in the Formulation Development Record – Annexure-1.
Document physical and chemical evaluation results in the Evaluation Summary Sheet – Annexure-2.
Prepare a Finalized Formulation Report including selected formula and process parameters – Annexure-3.

6. Abbreviations

API: Active Pharmaceutical Ingredient
QA: Quality Assurance
RH: Relative Humidity
R&D: Research and Development

7. Documents

Formulation Development Record – Annexure-1
Evaluation Summary Sheet – Annexure-2
Finalized Formulation Report – Annexure-3

8. References

ICH Q8 – Pharmaceutical Development
USP General Chapter <1207> – Oil-Based Dosage Forms
FDA Guidance on Topical Dermatological Drug Products

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation	Formulation Chemist	QA Executive	Head – Manufacturing
Department	Gel Manufacturing	Quality Assurance	Manufacturing

11. Annexures

Annexure-1: Formulation Development Record

Trial No.	Oil Type	Gelling Agent	Concentration (%)	Remarks

Annexure-2: Evaluation Summary Sheet

Test	Method	Result	Specification	Remarks
Viscosity	Brookfield		8000–15000 cps
pH	pH Meter		5.5–7.0

Annexure-3: Finalized Formulation Report

Final Formula
Process Parameters
Stability Summary
Approval Signature

Revision History

Revision Date	Revision No.	Change Description	Reason	Approved By
15/05/2022	1.0	Initial issue	New SOP	QA Manager
09/06/2025	2.0	Included detailed annexures	Format upgrade	QA Manager