Revolution in the field of drug delivery and healthcare

1. Formulation and Characterization
of Solid Lipid Nanoparticles
NIVETA SINGH
M.Tech Scholar
Dept. of Biomedical Engg.

2. CONTENTS
1. Introduction
 Definition of Solid lipid Nanoparticles
 Significance of Lipid Based systems
 Types of Solid lipid Nanoparticles
 Method of Preparation of SLNs
 Characterization of SLN
 Principle of drug release from SLNs
 Advantages and Disadvantages
 Applications of SLNs

3. Definition of Solid lipid Nanoparticles (SLNs)
 Solid lipid nanoparticles(SLNs) are sub-micron colloidal carriers
ranging from 50-1000 nm, which are composed of a physiological
lipid dispersed in water or in aqueous surfactant solution.
 They consist of macromolecular materials in which the active
component is dissolved, entrapped, or to which the active
component is adsorbed or attached.
 SLNs are generally spherical in shape and diameter range from 10-
1000 nm.
 Solid lipid nanoparticles were initially designed to overcome the
disadvantages associated with the liquid state of the oil droplets.
 Solid lipid nanoparticles were discovered by Gasco and Muller in
1991.
INTRODUCTION

4. Significance of Lipid Based Systems
 Lipids enhance oral bioavailability of drugs
 Better control over drug release kinetics
 Much easier to manufacture than bio polymer NPs
 Wider range of base materials(lipids)
 Very high long-term stability
 Chemical protection of labile incorporated compounds
 No special solvents required
 Application versatility

5. Types of Solid Lipid Nanoparticles
Solid lipid Nanoparticles can be divided into
3 types on the basis of drug loading:
I. SLN Type I
(homogeneous matrix model)
II. SLN Type II
(drug-enriched shell model)
III. SLN Type III
(drug-enriched core model)

6. Methods of preparation of Solid Lipid NPs
1. High Pressure Homogenization
a) Hot homogenization
b)Cold homogenization
2. Ultrasonication/ high speed homogenization
a) Probe Ultrasonication
b) Bath Ultrasonication
3. Solvent evaporation method
4. Solvent emulsification-diffusion method
5. Micro emulsion based method

7. HOT HOMOGENIZATION METHOD

8. COLD HOMOGENIZATION METHOD

9. Organic
Phase
Aqueous
Phase
COARSE EMULSION OBTAINED
BATH SONICATION
NANOPARTICLES OBTAINED
CENTRIFUGE
Preparation of Nanoparticles:

10. Characterization of Solid Lipid NPs
1) Determination of particle size and morphology
- SEM
-TEM
- PCS/DLS
2) Measurement of Zeta Potential
- Zeta potential under 30 mV are required for full electrostatic
stabilization
- Allows predictions about the storage stability of colloidal
dispersions
3) Measurement of degree of Crystallinity and lipid
Modification
- DSC
- X-ray scattering used to investigate status of lipid
- IR
Proper characterization of the formulations is necessary to control the
product quality, stability and release kinetics thus accurate and sensitive
characterization methods should be used.

11. Principles of drug release from SLNs
The general drug principles of drug release from lipid nanoparticles are as
follows:
 Crystallinity behavior of the lipid and high mobility of the drug
lead to fast drug release. Crystallization degree and mobility of
drug are inversely proportional to each other.
 Slow drug release can be achieved when drug is homogenously
dispersed in the lipid matrix. It depends on the type and the drug
entrapment model of SLN
 Higher surface area due to smaller particle size in the nanometer
size range gives higher drug release.

12. Advantages of Solid lipid NPs
 Excellent biocompatibility
 Improve stability of pharmaceuticals
 High and enhanced drug content
 Easy to scale up and sterilize
 Enhanced bioavailability of entrapped bioactive compounds
 Chemical protection of labile incorporated compounds
 Much easier to manufacture than bio polymeric NPs
Disadvantages of Solid Lipid NPs
 Poor drug loading capacity
 Drug expulsion after polymeric transition during storage
 Relatively high water content of the dispersions( 70-99.9 %)
 Low capacity to load hydrophilic drugs due to partitioning
effects during the production process.

13.  SLN as potential new adjuvant for vaccines
 SLNs in cancer chemotherapy
 SLN as targeted carrier for anticancer drug to solid tumor
 SLNs for delivering peptides and proteins
 SLNs for targeted brain drug delivery
 SLNs for ultrasonic drug and gene delivery
 SLN in cosmetic and dermatological preparations
 SLN form an excellent carrier system for Bioactive compounds
Applications of SLNs