SOP for Determination of Liposome Size Distribution Over Time

SOP for Determination of Liposome Size Distribution Over Time

Determination of Liposome Size Distribution Over Time

1) Purpose

The purpose of this SOP is to outline the procedure for determining the size distribution of liposomes over time. Monitoring size distribution helps assess the stability of liposomal formulations, as any significant changes in size can indicate aggregation, degradation, or instability during storage.

2) Scope

This SOP applies to personnel involved in the quality control and stability testing of liposome formulations. It covers the preparation, sampling, and measurement of liposome size distribution using dynamic light scattering (DLS) or other suitable techniques over specified time intervals.

3) Responsibilities

  • Formulation Scientists: Responsible for preparing liposome samples for size distribution analysis and ensuring that all data is accurately documented.
  • QC Team: Responsible for conducting particle size analysis and documenting the results at defined intervals during stability studies.
  • QA Team: Responsible for reviewing the size distribution data and ensuring compliance with regulatory standards.
See also  SOP for Conducting Long-Term Stability Studies on Liposomes

4) Procedure

4.1 Sample Preparation

  • 4.1.1 Prepare liposome formulations according to the batch manufacturing procedure.
  • 4.1.2 Store the samples at the designated conditions (e.g., 25°C/60% RH, 30°C/65% RH) for stability testing.
  • 4.1.3 Label the samples with batch number, preparation date, and storage condition.

4.2 Instrument Calibration and Setup

  • 4.2.1 Calibrate the dynamic light scattering (DLS) instrument or another suitable device according to the manufacturer’s instructions.
  • 4.2.2 Set the appropriate parameters for particle size measurement, including the scattering angle, temperature, and refractive index.

4.3 Particle Size Measurement

The following steps outline the procedure for measuring liposome size distribution:

  • 4.3.1 Take a sample of the liposome formulation from the storage condition at each time point (e.g., 0 days, 1 month, 3 months, 6 months).
  • 4.3.2 Dilute the sample with deionized water or another appropriate medium if necessary, to ensure the correct particle concentration for analysis.
  • 4.3.3 Load the sample into the DLS instrument and initiate the particle size analysis.
  • 4.3.4 Record the mean particle size, polydispersity index (PDI), and size distribution profile for each sample.
See also  SOP for Preparation of Aqueous Phase for Liposomal Formulations

4.4 Data Recording and Analysis

  • 4.4.1 Record the particle size distribution results in the Liposome Size Distribution Report (see Annexure 1).
  • 4.4.2 Compare the results over time to assess any changes in size distribution, which may indicate aggregation, degradation, or instability.
  • 4.4.3 Analyze the data to determine the stability of the liposome formulation based on the size distribution profile over time.

4.5 Acceptance Criteria

The liposomal formulation is considered stable if the following criteria are met throughout the study period:

  • 4.5.1 Mean particle size remains within acceptable limits, with no significant increase or aggregation.
  • 4.5.2 The polydispersity index (PDI) remains below 0.3, indicating a narrow size distribution and good uniformity.
  • 4.5.3 No significant changes in the size distribution profile that would indicate instability.
See also  SOP for Formulating Self-Emulsifying Drug Delivery Systems (SEDDS)

5) Abbreviations

  • DLS: Dynamic Light Scattering
  • PDI: Polydispersity Index
  • QC: Quality Control
  • QA: Quality Assurance

6) Documents

  • Liposome Size Distribution Report
  • Batch Manufacturing Record (BMR)
  • Instrument Calibration Report

7) References

  • ICH Q1A: Stability Testing of New Drug Substances and Products
  • FDA Guidance on Liposome Drug Products

8) SOP Version

Version 1.0

Annexure

Annexure 1: Liposome Size Distribution Report Template

Time Point Storage Condition Mean Particle Size (nm) PDI Size Distribution Operator Initials
Initial 25°C/60% RH 100-200 nm 0.2 Uniform Operator Name
3 Months 30°C/65% RH 100-200 nm 0.2 Uniform Operator Name

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