Standard Operating Procedure for Preparation of Nanocrystals for Drug Delivery

1) Purpose

This SOP describes the process for preparing drug nanocrystals, which enhance the solubility and bioavailability of poorly water-soluble drugs. The goal is to standardize the preparation of nanocrystals for drug delivery applications.

2) Scope

This SOP applies to all laboratory staff involved in the formulation and preparation of drug nanocrystals for pharmaceutical and drug delivery purposes.

3) Responsibilities

• Operators: Responsible for following the SOP to prepare nanocrystals according to the specified protocols.
• QA: Ensures compliance with the protocol and verifies the quality of prepared nanocrystals.

4) Procedure

4.1 Preparation of Drug Solution

4.1.1 Drug Selection and Dissolution

• 4.1.1.1 Select the poorly water-soluble drug to be formulated into nanocrystals.
• 4.1.1.2 Dissolve the drug in an organic solvent or a mixture of organic solvents suitable for the nanocrystal formulation.

4.2 Nanocrystal Formation

4.2.1 Precipitation Method

• 4.2.1.1 Add the drug solution dropwise into an aqueous phase containing stabilizers while continuously stirring to precipitate the drug nanocrystals.
• 4.2.1.2 Maintain stirring for 15–30 minutes until nanocrystals are formed.

4.2.2 High-Pressure Homogenization

• 4.2.2.1 Homogenize the suspension at high pressure to reduce the particle size and achieve nanoscale dimensions.
• 4.2.2.2 Monitor the size reduction using dynamic light scattering (DLS) or another particle-sizing method.

4.3 Washing and Collection of Nanocrystals

4.3.1 Filtration

• 4.3.1.1 Filter the nanocrystal suspension using a filtration unit to remove any remaining organic solvents.
• 4.3.1.2 Wash the nanocrystals with distilled water to remove any excess stabilizers or solvents.

4.3.2 Centrifugation

• 4.3.2.1 Centrifuge the suspension to collect the nanocrystals, discarding the supernatant.
• 4.3.2.2 Repeat the washing and centrifugation process as needed to ensure the purity of the nanocrystals.

4.4 Characterization of Nanocrystals

4.4.1 Particle Size Measurement

• 4.4.1.1 Measure the particle size using DLS or other appropriate methods to confirm that the nanocrystals meet the desired size specifications.

4.5 Storage of Nanocrystals

4.5.1 Storage Conditions

• 4.5.1.1 Store the nanocrystals in sterile containers, preferably under refrigeration (4°C) or freeze-drying for long-term stability.

5) Abbreviations, if any

• DLS: Dynamic Light Scattering
• QA: Quality Assurance

6) Documents, if any

• Nanocrystal Preparation Logbook

7) References, if any

• Good Manufacturing Practice (GMP) guidelines for drug formulation

8) SOP Version

Version 1.0

Annexure

Nanocrystal Preparation Logbook Template

  

    
Date
    
Batch Number
    
Drug Name
    
Particle Size
    
Encapsulation Efficiency
    
Operator Initials
    
QA Initials
  
  

    
DD/MM/YYYY
    
Batch Number
    
Drug Name
    
Size in nm
    
% Encapsulation
    
Operator Name
    
QA Name