Standard Operating Procedure for Preparation of Liposomal Lyophilized Products

1) Purpose

This SOP outlines the procedures for the preparation of liposomal formulations for lyophilization, ensuring that the liposomes maintain their structural integrity and function during the lyophilization process and subsequent reconstitution.

2) Scope

This SOP applies to all personnel involved in the formulation and preparation of liposomal-based products for lyophilization, including formulation scientists, production operators, and QA personnel.

3) Responsibilities

• Formulation Scientists: Responsible for designing the liposomal formulation and selecting the appropriate excipients and stabilizers.
• Operators: Responsible for preparing the liposomal solution and following the steps outlined in the Batch Manufacturing Record (BMR).
• QA: Responsible for verifying the process and ensuring all steps are properly documented.

4) Procedure

4.1 Preparation of Liposomal Solution

4.1.1 Equipment Setup

• 4.1.1.1 Ensure that all equipment (e.g., homogenizers, mixers) is cleaned, sanitized, and calibrated before use.
• 4.1.1.2 Prepare sterile containers for the liposomal solution and maintain aseptic conditions during preparation.

4.1.2 Lipid Dispersion

• 4.1.2.1 Weigh the required lipids and excipients using a calibrated balance as per the formulation instructions in the BMR.
• 4.1.2.2 Dissolve the lipids in an organic solvent (e.g., chloroform or ethanol) and mix until completely dissolved.

4.1.3 Liposome Formation

• 4.1.3.1 Remove the organic solvent using a rotary evaporator or similar equipment to form a lipid film on the container wall.
• 4.1.3.2 Hydrate the lipid film by adding the aqueous phase (e.g., water for injection, WFI) to form liposomes.
• 4.1.3.3 Homogenize the mixture using a mechanical homogenizer to ensure uniform liposome size distribution.

4.2 Incorporation of Active Ingredient

4.2.1 Active Ingredient Addition

• 4.2.1.1 If the active ingredient is to be encapsulated within the liposomes, add it during the lipid hydration process and continue homogenizing.
• 4.2.1.2 If the active ingredient is to be surface bound, add it after liposome formation and homogenize gently to avoid disrupting the liposomes.

4.2.2 Filtration

• 4.2.2.1 Filter the liposomal solution using a sterile 0.22-micron filter to remove any particulates and ensure sterility.

4.3 Lyophilization Preparation

4.3.1 Addition of Cryoprotectants

• 4.3.1.1 Add cryoprotectants (e.g., sucrose or trehalose) to the liposomal solution to protect the liposomes during lyophilization.
• 4.3.1.2 Stir the solution gently to ensure the cryoprotectants are fully dissolved and evenly distributed.

4.3.2 Filling and Freezing

• 4.3.2.1 Fill sterile vials with the liposomal solution under aseptic conditions, ensuring uniform volumes are dispensed into each vial.
• 4.3.2.2 Freeze the filled vials at -80°C or lower to solidify the solution before lyophilization.

4.4 Documentation

Record all steps, including lipid dispersion, liposome formation, active ingredient incorporation, and cryoprotectant addition in the Liposomal Preparation Logbook. All documentation must be verified by the QA team.

5) Abbreviations

• BMR: Batch Manufacturing Record
• QA: Quality Assurance
• WFI: Water for Injection

6) Documents

• Liposomal Preparation Logbook

7) References

• Scientific articles on liposome preparation and lyophilization techniques

8) SOP Version

Version 1.0

Annexure

Liposomal Preparation Logbook Template

Date	Lipid Name	Batch No.	Active Ingredient	Cryoprotectant	Operator Initials	QA Verification
DD/MM/YYYY	Lipid Name	Batch Number	Active Ingredient Name	Cryoprotectant Name	Operator Name	QA Initials