Standard Operating Procedure for Emulsification-Solvent Evaporation in Nanoparticle Formulations
1) Purpose
This SOP outlines the emulsification-solvent evaporation technique, commonly used to prepare nanoparticles for drug delivery systems. The goal is to standardize the process to ensure consistent nanoparticle size and encapsulation efficiency.
2) Scope
This SOP applies to all laboratory personnel responsible for preparing nanoparticle formulations using the emulsification-solvent evaporation technique.
3) Responsibilities
- Operators: Responsible for following the emulsification-solvent evaporation protocol to prepare nanoparticles.
- QA: Ensures compliance with protocols and verifies the final product quality.
4) Procedure
4.1 Preparation of Organic Phase
4.1.1 Solubilization of Polymer and Drug
- 4.1.1.1 Dissolve the polymer (e.g., PLGA) and drug in a volatile organic solvent (e.g., dichloromethane) under constant stirring.
- 4.1.1.2 Continue stirring until the polymer and drug are fully dissolved.
4.2 Emulsification
4.2.1 Preparation of Aqueous Phase
- 4.2.1.1 Prepare an aqueous phase containing a stabilizer (e.g., PVA) to prevent nanoparticle aggregation.
4.2.2 Formation of Emulsion
- 4.2.2.1 Slowly add the organic phase into the aqueous phase under high-speed stirring to form an emulsion.
- 4.2.2.2 Continue stirring for 15–20 minutes to ensure stable emulsion formation.
4.3 Solvent Evaporation
4.3.1 Removal of Organic Solvent
- 4.3.1.1 Allow the volatile organic solvent to evaporate under reduced pressure or by stirring at room temperature, leading to nanoparticle formation as the polymer solidifies.
- 4.3.1.2 Monitor the evaporation process until no solvent remains.
4.4 Nanoparticle Collection
4.4.1 Centrifugation
- 4.4.1.1 Centrifuge the nanoparticle suspension at 10,000–15,000 g for 30 minutes to collect the nanoparticles.
- 4.4.1.2 Wash the nanoparticles with distilled water to remove any unencapsulated drug or residual stabilizers.
4.5 Characterization of Nanoparticles
4.5.1 Particle Size Measurement
- 4.5.1.1 Use dynamic light scattering (DLS) or similar methods to measure the particle size of the nanoparticles.
- 4.5.1.2 Record the average size and polydispersity index (PDI) to ensure the nanoparticles meet the required specifications.
4.6 Storage of Nanoparticles
4.6.1 Storage Conditions
- 4.6.1.1 Transfer the nanoparticle suspension into sterile, labeled containers and store at 4°C or freeze-dry for long-term stability.
5) Abbreviations, if any
- DLS: Dynamic Light Scattering
- PDI: Polydispersity Index
6) Documents, if any
- Emulsification-Solvent Evaporation Logbook
7) References, if any
- Formulation protocols for nanoparticles using the emulsification-solvent evaporation method
8) SOP Version
Version 1.0
Annexure
Emulsification-Solvent Evaporation Logbook Template
| Date | Batch Number | Polymer Type | Particle Size | Encapsulation Efficiency | Operator Initials | QA Initials |
|---|---|---|---|---|---|---|
| DD/MM/YYYY | Batch Number | Polymer Name | Size in nm | % Encapsulation | Operator Name | QA Name |
