|691-1||Development and application of amphotericin B-loaded liposomes prepared from bixin.|
|Autores:||Rafael Teruiti de Oliveira Takamoto (FCF-USP - Faculdade de Ciências Farmacêuticas-Univ. de São Paulo) ; Míriam Cristina Sakuragui Matuo (FCF-USP - Faculdade de Ciências Farmacêuticas-Univ. de São Paulo) ; Terezinha de Jesus Andreoli Pinto (FCF-USP - Faculdade de Ciências Farmacêuticas-Univ. de São Paulo) ; Irene Satiko Kikuchi (FCF-USP - Faculdade de Ciências Farmacêuticas-Univ. de São Paulo) |
Colorants obtained from annato or urucum (Bixa orellana L.) have been used in cosmetics and foods for many years. These colorants can be found covering the external surface of urucum seeds and the major compound (about 80%) is bixin, a monomethylester of carboxilic acid of norbixin.
Bixin is an insoluble carotenoid in aqueous solutions while norbixin is soluble in alkaline aqueous solutions. This work demonstrates the liposome obtaining from bixin and its capacity as drug carrier. We used amphotericin B as model of drug to be carried due this compound be insoluble in water and high toxicity when administered in patients.
Liposomes from bixin were prepared by ethanolic injection method. Stock solution of Amphotericin B in dimethyl sulfoxide (DMSO) was prepared and followed by 10-fold dilution in ethanol. Prepared BX-ETOH and ANFO-ETOH were mixed to obtain several concentrations of both and then followed by dilutions.
Efficacy of bixin liposomal formulation was compared with commercial products (Ambisome® and Amphocil®) using Candida albicans (ATCC 10231) as microorganism test. Microorganisms were incubated on Sabouraud Dextrose Agar for 48 hours at 30 °C and suspension was prepared by washing the surface with 5 mL of sterile saline solution and transferring 1 mL to 100 mL of Antibiotic Medium 19 (Difco). Volume of 8 mL of this culture medium was transferred to each Petri dish.
50 µL of each sample were applied on the Agar medium and incubated for 24 hours at 30 °C and then, each growth inhibition zone was measured.
We used n=10 to each sample and carried out 3 independent tests. ANOVA was applied as statistical analysis (p-value<0,05).
Liposome from bixin was submitted to particle size measurement in ZetaPlus Zeta Potential Analyzer (Brookhaven Instruments) equipped with laser at 570 nm and light angle of 90° and presented diameter of 151.9 ± 0.9 nm and Zeta Potential of -14.30 ± 0.95 mV.
Amphotericin B incorporated into vesicles of bixin presented the highest growth inhibition zone when compared to Ambisome, Amphocil and Amphotericin in ideal solvent (DMSO and ethanol).
Bixin demonstrated to be capable to form vesicles when submitted to ethanolic injection technique in water or aqueous solutions. This formulation allowed incorporation of drugs like amphotericin B, an hydrophobic compound. When several amphotericin preparations were submitted to in vitro assay, the bixin liposomal formulation presented the highest effect to inhibit the microorganism growth.
Bixin has high potential as drug carrier due no toxicity in animals and more studies are necessary to elucidate the mechanism of action.
Palavras-chave: Drugs, Liposomes, Bixin, Amphotericin B, Nanotechnology