Repeated dose toxicity study of Vibrio cholerae-loaded gastro-resistant microparticles.

CONTEXT: Microencapsulation of antigens has been extensively studied over the last decades aiming at improving the immunogenicity of vaccine candidates.

OBJECTIVE

Addressing microparticles (MPs) toxicity in rats.

MATERIAL AND

METHODS

Spray-dried Eudragit® L 30 D-55 MPs and Eudragit® L 30 D-55 alginate MPs were elaborated and characterized. MPs obtained were administered to rats, three groups were defined: G1, control group; G2, administered with Vibrio cholerae (VC)-loaded MPs; G3, receiving VC-loaded alginate MPs. Animals received three vaccine doses. Body weight, food and water intake were controlled during the study. Haematological parameters, vibriocidal titres, organ weight and histology in necropsy were also analyzed.

RESULTS

All animals grew healthy. Body weight gain, food and water intake and haematological parameters remained within physiological values, showing no treatment-related differences. Moreover, organ weight changes were not detected and animals developed protective vibriocidal titres.

CONCLUSION

VC-loaded MPs and VC-loaded alginate MPs have proved to be safe and effective in the assessed conditions.