shortly afterwards
The first basic review about SLN)appeared which gave an overview of research groups active in this new field
Their results are reviewed which cover many different administration routes
03
2.miscibility of drug melt and lipid melt;
The development of SLN
2012
1990
1991
1995
The first experiments in the production of They were followed by two lipid nanoparticles independent patent were performed in applications and the first publications appeared academic labs.
Lipids
• Ra domska- Soukharev (2007) demon strated that the selection of lipid excipients was dependent on chemical stability of excipients itself and SLNs stability.
.
melting point
velocity of lipid crystallization
source of chemicals
Lipids
lipid hydrophilicity shape
surface area
Emulsifiers
Crystallization of lipid is a major phenomenon during the emulsification process . However, use of emulsifier could slow down this process By changing the nature and c o n c e n t r a t i o n o f t h e s t a b i l i zi n g emulsifier, gelation after a certain period of storage time can be avoided Proper selection and concentration of emulsifier does not only stabilize but also increases the entrapment efficiency of drug in SLNs charge developed on the surface of the SLNs by emulsifier may also affect the drug release and stability of SLNs
Figure 4. Absorption of NPs by oral route from a different segment of the GIT. Figure indicates possible absorption mechanisms and extent of NP absorption from different regions of GIT
Characteristic of drug-loaded SLNs
Figure 3. A. Biphasic response of ODA-FITC-loaded SLNs in plasma after oral administration; B. Biphasic response of ODA-FITC-loaded SLNs in lymph after oral administration.
Advantages of SLNs
Table 1. Advantages of SLNs over other nanoparticulate systems
of preparation of SLNs
high-shear homogenization (HSH)
High pressure homogenization (HPH)
3
4
Optimization of oral SLNs
Preparation of cryptotanshinon-loaded SLNs
5 Conclusion
5
Background
oral route
nanoparticulate systems. Liposomes Polymeric nano -particles. Nanoemulsions Nanosuspensions
SLNs
improved oral BA of drugs
reduced toxicity reduced multidrug resistance (MDR)
Improved stability of drugs entrapped in SLNs
SLN are particles made from solid lipids (i.e. lipids solid at room temperature and also at body temperature and stabilised by surfactant(s) which diameter are between approximately 50 and 1000 nm
SLNs
advantages disadvantages
poor oral BA
Description of the contents
Description of the contents
Poor oral bioavailability (BA)
Poor solubility
Poor permeability
Hepatic first-pass metabolism
poor oral bioavail -ability
Nanoparticles (NPs) are considered as alternatives to various conventional drug delivery techniques .
Yuan H, Chen J, Du Y-Z, et al.Studies on oral absorption of stearic acid SLN by a novel fluorometric method.Colloids Surf B Biointerfaces 2007;58:157-64
500 nm
particles > 500 nm have been reported to show erratic delivery through the abdominal cavity and targeting was restriced
The optimization of oral SLNs
Methods of preparation of SLNs
Ultrasonication
The other methods
Analytical characterization of SLN
1. particle size and zeta potential;
2. degree of crystallinity and lipid modication;
Factors affecting absorptions of SLNs through GIT
mechanistic absorption
smaller particles show greater absorption while larger particles are retained for longer duration in the Peyer’ s patches
Solid lipid nanoparticles: an oral bioavailability enhancer vehicle
Name : Li Jing Major : pharmaceutics Mentors : Doctor Chen
Contents
1
Introduction
2 Absorption of drug-loaded SLNs
The various parameters that influence the absorption and stability of SLNs in vivo are discussed as follows: Lipids Emulsifiers
include drug properties, methods of Preparation Miscellaneous. homogenization related parameters and solvents.
1
2
3
The stability of SLNs after peroral administration
To avoid generation of an unstable metastable form of SLNs, the cooling rate and stabilizer play Important roles. Cooling rate and stabilizer
hydrophobicity
particle size
surface properties
surface charge