IJUP08 - Universidade do Porto

Liposome-incorporated Zanthoxylum tingoassuiba essential oil:
preparation and characterization
C. Detoni 1,2 , B. Sarmento 2 , D. Ferreira 2 and E.C.M. Cabral-Albuquerque 1
1 Medical Subject Research Laboratory, Pharmacy Faculty, Federal University of Bahia, Brasil.
2 Department of Technology, Faculty of Pharmacy, University of Porto, Portugal.
Alfa-bisabolol and essential oils, such as Chamomilla recutita and Zanthoxylum tingoassuiba
oils, are of pharmaceutical and cosmetic industries interest for its known antimicrobial and
antiphlogistic actions[1,3]. Recent investigations also found a possible anticancer activity of
alfa-bisabolol on glioma cells[1,2]. Despite the known activities of Zanthoxylum tingoassuiba
essential oil as a promising non-toxic drug, it has presented low biological in vitro activity
because of its low solubility in water. One of the most recent strategies for overcoming this
drawback is a reversible association of the essential oil to liposomes[3,4]. The objective of this
research work was to prepare and characterize Zanthoxylum tingoassuiba essential oil-loaded
liposomes regarding further evaluation of liposomal inclusion on the antimicrobial activity of
this essence.
The essential oil was incorporated in multilamellar (MLV) and unilamellar (LUV) vesicles of
synthetic dipalmitoil-phosphatidylcholine (DPPC) by the thin-lipid film hydration and high
pressure homogenization-extrusion methods respectively. The formulations were characterized
regarding the mean particle size by photon correlation spectroscopy, surface charge by laser
Doppler Anemometry, the morphology by transmission electron microscopy, alfa-bisabolol
incorporation efficiency and release by high-performance liquid chromatography (HPLC) with
UV detection.
The results obtained show that the produced liposomes have spherical shape. The mean size of
MLV´s was 10.6 μm and of LUV´s was 0.26 μm. The liposomes electric charge did not change
after oil incorporation, indicating that the oil was not adsorbed on the surface. The
incorporation efficiency varied with the preparation technique, being over 50% for MLV but
lower for LUV. The in vitro release profile presented a sustained and incomplete release of
MLV-incorporated EO for 24h, suggesting that EO-loaded liposomes will be useful in
pharmaceutical application to enhance essential oil targeting to cells that can not cross the
cytoplasmatic barrier.
Zanthoxylum tingoassuiba essential oil was successfully incorporated in liposomes and the
results confirm the potentiality of MLV formulations for pharmaceutical and cosmetic use.
References:
[1] Perbelin, L., Gottardo,R., Caprini, A., Bortolotti,F., Marioto, S. and Tagliaro, F. (2004),
Determination of alpha-bisabolol in human blood by micro-HPLC–ion trap MS and head space-
GC–MS methods, Journal of Chromatography, 812 , 373–377.
[2] Cavalieri, E., Marioto, S.,Fabrizi, C.,Prati, A.C.,Gottardo, R.,Leone, S., Berra, L.V.,Lauro, G.
M., Ciampa, A.R. and Suzuki H. (2004), α-Bisabolol, a nontoxic natural compound, strongly
induces apoptosis in glioma cells, Biochemical and Biophysical Research Communications, 315
(3), 589-594.
[3]Cabral-Albuquerque, E.C., Hohlemweger, S., Detoni, C., Matos, J., Sampaio,C., Barros, T.,
Veloso, E.(2007) Essential Oil from Zantoxyllum tingoassuiba Loaded into Multilamellar
Liposomes Useful as Antibiotic and Antimicrobial. In: 34th Controlled Release Annual Meeting &
Exposition,Long Beach/CA. CD-Rom transactions of the 34th Annual Meeting & Exposition -
Controlled Release Society.
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