1. SOLID LIPID NANOPARTICLE AS PROMISING
DRUG DELIVARY SYSTEM
DEPARTMENT OF PHARMACEUTICS
ANURADHA COLLEGE OF PHARMACY, CHIKHLI.
2011-2012.
Seminar on: Recent Trends in Pharmaceutical Sciences
Presented by:
Gajanan S.Ingole
Guided by:
Mr. K.B.Charhate
1

2. Introduction
Advantages & disadvantages
Aims of SLNs
Principal of drug release
Methods of Preparation
Analytical characterization of SLNs
Applications of SLNs
Routes of administration
References
CONTENTS :
2

3. Solid lipid nanoparticles
The solid lipid nanoparticles(SLN’s) are submicron colloidal carriers
which are composed of physiological lipid, dispersed in water or in an
aqueous surfactant solution.
They consist of macromolecular materials in which the active principle
is dissolved, entrapped, and or to which the active principle is adsorbed
or attached.
No potential toxicity problems as organic solvents are not used.
SLNs are spherical in shape & diameter range from 10-1000nm.
To overcome the disadvantages associated with the liquid state of the oil
droplets, the liquid lipid was replaced by a solid lipid shown in fig, 3

4. The reasons for the increasing interest in lipid based system are :
1. Lipids enhance oral bioavailability and reduce plasma profile variability.
2. Better characterization of lipoid excipients.
3. An improved ability to address the key issues of technology transfer and
manufacture scale-up.
Fig. 1: Structure of solid lipid nanoparticle (SLN)
4

5. Advantages of SLN
1) Control and target drug release.
2) Excellent biocompatibility.
3) Improve stability of pharmaceuticals.
4) High and enhanced drug content.
5) Easy to scale up and sterilize.
6) Enhanced bioavailability of entrapped bioactive compounds.
7) Much easier to manufacture than biopolymeric nanoparticles.
8) No special solvent required. 5

6. 9) Conventional emulsion manufacturing methods applicable.
10) Raw materials essential the same as in emulsions.
11) Can be subjected to commercial sterilization procedures.
Disadvantages of SLN
1) Particle growth.
2) Unpredictable gelation tendency.
3) Unexpected dynamics of polymeric transitions
Aims of solid lipid nanoparticles
1) Possibility of controlled drug release.
2) Increased drug stability. 6

7. 3) High drug pay load.
4) No bio-toxicity of the carrier.
5) Avoidance of organic solvents.
6) Incorporation of lipophilic and hydrophilic drugs.
Principles of drug release from SLNs
The general principles of drug release from lipid nanoparticles are as
1. Crystallinization behaviour of the lipid carrier and high mobility of
the drug lead to fast drug release.
2. Higher surface area due to smaller particle size in nanometer range
gives higher drug release.
3. Slow drug release can be achieved when the drug is homogenously
dispersed in the lipid matrix. It depends on type and drug
entrapment model of SLN.
7

8. Methods of preparation of solid lipid nanoparticles
1. High pressure homogenization
A. Hot homogenization
B. Cold homogenization
2. Ultrasonication
A. Probe ultrasonication
B. Bath ultrasonication
3. Solvent evaporation method
4. Solvent emulsification-diffusion method
5. Microemulsion based method
6. Spray drying method
8

9. 7. Double emulsion method
8. Precipitation technique
9. Film-ultrasound dispersion
First method to prepare solid lipid nanoparticle are as
1. High pressure homogenization
A. Hot homogenization
9

10. Fig: Solid lipid nanoparticles preparation by hot homogenization
process
10

11. B. cold homogenization process
11

12. 2. Ultrasonication/high speed homogenization
SLNs are also prepared by ultrasonication or high speed homogenization
techniques.
For smaller particle size combination of both ultrasonication and high
speed homogenization is required
Advantages
Reduced shear stress.
Disadvantages
Potential metal contamination.
Physical instability like particle growth upon storage.
12

13. 3. Solvent evaporation
4. Solvent emulsification-diffusion method
13

14. 5. Microemulsion based method
Fig. : Microemulsion method
14

15. 6. Spray drying method
It's an alternative procedure to lyophilization in order to transform
an aqueous NLC dispersion into a drug product.
It's a cheaper method than lyophilization. But his method can
cause particle aggregation due to high temperature, shear forces and
partial melting of the particle.
7. Double emulsion method
Here the drug is encapsulated with a stabilizer to prevent the
partitioning of drug in to external water phase during solvent evaporation
in the external water phase of w/o/w double emulsion.
15

16. 8. Precipitation method
The glycerides are dissolved in an organic solvent (e.g.
chloroform) and the solution will be emulsified in an aqueous phase.
After evaporation of the organic solvent the lipid will be precipitated
forming nanoparticles.
9. Film-ultrasound dispersion
lipid + drug add in to organic solutions, after decompression,
rotation and evaporation of the organic solutions, a lipid film is formed.
Then the aqueous solution which includes the emulsions was added,
Using the ultrasound with the probe to diffuser at last, the SLN with the
little and uniform particle size is formed. 16

17. 1) Measurement of particle size
Static light scattering (SLS)
Electron microscopy
Acoustic methods.
Atomic force microscopy (AFM)
DSC
Analytical characterization of SLN
17

18. 2) Measurement of crystallinity & lipid modification
X-ray photoelectron spectroscopy
Laser doppler anaemometry
DSC
Gel chromatography
Electrophoresis.
DSC.
IR.
X-ray scattering.
Raman spectroscopy
3) Co – existence of additional structures
18

19. Routes of administration
1. Parenteral administration
2. Oral administration
3. Rectal administration
4. Nasal administration
5. Respiratory delivery
6. Ocular administration
7. Topical administration
19

20. 1. SLN as potential new adjuvant for vaccines.
2. Solid lipid nanoparticles in cancer chemotherapy.
3. Solid lipid nanoparticles for delivering peptides and proteins.
4. Solid lipid nanoparticles for targeted brain drug delivery.
5. Solid lipid nanoparticles for parasitic diseases.
6. Solid lipid nanoparticles for ultrasonic drug and gene delivery.
7. SLN applied to the treatment of malaria.
8. Solid lipid nanoparticles in tuberculosis disease.
9. SLN in cosmetic and dermatological preparations.
10. SLN for potential agriculture applications
Applications of SLN
20

21. Vyas S.P. and Khar R.K. Targeted And Controlled Drug Delivery
System, 1stEdition, 2002, CBS Publication;
249 - 277.
Jain N. K., Controlled and novel Drug Delivery, 1st edition 2001,
CBS Publication; 292 - 301.
Mukherjee S., Ray S., Thakur R.S. “ Solid lipid nanoparticles: a
modern formulation approach in drug delivery system” Indian journal
of Pharmaceutical sciences, 71(2009) 349-358.
Heurtault B., Saulnier P., Pech B., Proust J.E., Benoit J.P. “
Physico-chemical stability of colloidal lipid particles’’ Biomaterials 24
(2003) 4283-4300
REFERENCE
21

22. Feng S., Chien S. “ Chemotherapeutic engineering: application and
further development of chemical engineering principles for
chemotherapy of cancer and other diseases” Chemical engineering
science 58 (2003) 4087-4114.
Gasco M.R. “ Lipid nanoparticles: perspectives and
challenges”Advanced drug delivery reviews, 59 (2007)
377-378. Muller R.H., Mader K., Gohla S. “ Solid lipid
nanoparticles (SLN) for controlled drug delivery – a review of the
state of art” European journal of Pharmaceutics & Biopharmaceutics,
50 (2000) 161-177
Kaur I.P., Bhandari R., Bhandari S., Kakkar V. “ Potential of Solid
lipid nanoparticles in brain targeting” Journal of Controlled release,
127 (2008) 97-109 22