Biomedical Engineering Reference
In-Depth Information
developed as oral sustained delivery carriers for the anti-TB drugs. h ese
microparticles were developed using ionotropic/external gelation method.
Microparticles were formulated into three dif erent forms containing
rifampicin, isoniazide and pyrazinamide in the ratio of 1:2:2 (drug: sodium
alginate: chitosan). h ese prepared microcapsules were then evaluated by
SEM analysis, size analysis, spherecity, drug content, encapsulation ei -
ciency, swelling studies and mucoadhesion which was then compared to
the pure drug.
In vitro
release studies were carried out and the amount of
drug released was analysed and was compared with the free drug [83].
Sung tested PA-824 (an alternative anti-TB candidate) which resulted in
sustained release of the drug and maintained its level in the lungs for 32h
[84]. PLG nanoparticles encapsulating anti-TB drugs such as PYZ, RIF,
INH and ETB remained in the circulation for 72h. As a result, PLG encap-
sulated INH was found to be higher than its MIC value (0.1mg/ml) [85]
.
A
single subcutaneous dose of PLG encapsulated nanoparticles maintained
drug level in the plasma, lungs, and spleen concentrations for more than 1
month and led to undetectable bacterial counts in the dif erent organs [86].
Stearic acid encapsulating RIF, INH and PZA drugs nanoparticles at er a
single oral administration, the therapeutic concentration was maintained
in the plasma for 8 days and in the organs for 10 days whereas free drugs
get cleared within 1-2 days [87].
h e nebulization of the drug loaded PLG nanoparticles with anti-TB
drugs RIF, INH, and PZA was detected in plasma at er 6h and therapeutic
concentrations were detected until day 6 for RIF and day 8 for both INH,
PZA. Nebulization of the nanoparticles to the
M. tuberculosis-
infected
guinea pigs at every 10
th
day, no detection of the tubercle bacilli in the
lungs was observed at er only 5 doses of treatment, whereas 46 daily doses
of orally administered drug required obtaining an equivalent therapeutic
benei t [88].
In tracheal administration of Ol oxacin-loaded hyaluronan particles
resulted in 50% lower serum bioavailability with respect to the intrave-
nous or oral ol oxacin. h is observation led to the conclusion that inhaled
nanoparticles reduce systemic side ef ects, but it also suggested that extra
pulmonary TB cannot be treated only by the inhaled therapies [89]. Saraogi
et al
prepared mannosylated gelatin nanoparticles for the selective delivery
of INH to the alveolar macrophages and concluded that these nanopar-
ticles can be a potential carrier for the safer and ei cient management of
TB through targeted drug delivery [90].
Ohasi
et al
designed RIF loaded biodegradable PLGA nanoparticles
which were incorporated into the mannitol microspheres in single step by
means of a four-l uid nozzle spray drier. As a result due to mannitol, the
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