Biomedical Engineering Reference
In-Depth Information
Recently, encapsulation, characterization and
in vitro
release of anti-TB
drug (RIF) using chitosan-polyethylene glycol nanoparticles were devel-
oped. Chitosan polyethylene glycol 600 (PEG) nanoparticles were pre-
pared by ionic gelation technology. h e preparation of these nanoparticles
is based on the interaction between positively charged chitosan solution
and negatively charged TPP solution. When PEG binds with chitosan-
rifampicin it changes the character and the surface of the nanoparticles
and slightly increases its particle size, as well as encapsulation of drugs also
increased. PEG bind with CS-RIF has resulted in more prolonged retention
as compared with non-coated CS-RIF. Various parameters and method-
ologies such as loading capacity, encapsulation ei ciency, SEM (Scanning
electron microscopy), FITR (Fourier transmission infra-red microscopy)
and in vitro release of drugs have been utilised for characterization of
nanoparticles [111].
Recently, there was targeted intracellular delivery of anti-TB to
Mycobacterium infected macrophages through functionalized mesopo-
rous silica nanoparticles. Mesoporous silica nanoparticle (MSNP) drug
delivery system was coated with polyethyleneimine (PEI) to release rifam-
picin. h ese mesoporous silica nanoparticles get internalized by human
macrophages and delivered to the lysosomes and to the acidii ed endo-
somes as a result intracellular release of high concentrations of antituber-
culosis drugs occurred. Coated MSNP have shown much greater loading
capacity than uncoated MSNP. h e amount of RIF loaded on the PEI coated
nanoparticles was determined at er elution by spectrophotometer at the
wavelength 475nm against RIF standards [112]. Microspheres are spheri-
cal, free l owing particles ranging in average particle size 1-50 microns.
Currently, the potential of microspheres as carriers for target drug delivery
systems has been exploring. Microspheres are prepared from the dif erent
methods such as protein gelation technique, sonication technique, solvent
evaporation technique, spray and freeze technique, polymerization tech-
nique and solvent extraction method [113].
Oral nanoparticles are also being used for the delivery of the antitu-
berculosis drugs. In an experiment, orally administered poly-lactide-
co-glycolide (PLG), a synthetic polymer nanoparticle encapsulating
antituberculosis drugs such as RIF, INH and PZA was developed for cere-
bral drug delivery in murine model. h ese nanoparticles were prepared by
multiple emulsion and solvent evaporation technique and then they were
administered orally to mice for their biodistribution, pharmokinetic and
chemotherapeutic studies. As a result of this experiment, a single oral dose
to mice maintains sustained drug levels for 5-8 days in the plasma and for
9 days in the brain. As well as in
M. tuberculosis
H
37
Rv infected mice, i ve
