Physicochemical characterization of novel albendazole suspensions for paediatric treatment of helminth infections.

FRENKE, M.; FERRARI, A.; BARRERA, M. G.; LAMAS, M. C.

Cordoba

Congreso; Ricifa 2014; 2014

Ricifa

Helminth diseases may be the commonest cause of chronic infection in children, in many low income countries. The recommended drug is albendazole (ABZ), a benzimidazole carbamate with a broad-spectrum activity. ABZ low water solubility, which may cause a variable bioavailability after oral administration, as already reported. Several attempts to increase the aqueous solubility/dissolution rate of ABZ by using solid dispersions, liposomes, microparticles and cyclodextrins have been reported. The aim of the present research work was to prepare and full characterize novel ABZ-microparticles suspensions to improve the drug release. Chitosan (CH) microparticles were prepared by spray drying technique and further characterized by means of X-ray powder diffractometry, scanning electron microscopy, and dissolution profiles. Then the microparticles-suspensions were formulated employing hydrophilic polymers and electrolytes (NaCl and sodium citrate) to regulate the zeta potential, viscosity and ionic strength in order to determine the interactions among the microparticles and the rheological properties. The microparticle-suspensions increased significantly the ABZ dissolution rate values in comparison to the pure drug. ABZ is poorly soluble in water (1 µg/mL) and it is well demonstrated in the extent of drug dissolved after 60 min (7%). ABZ-CH microparticles released 80% after 60 minutes, while after 180 minutes it was observed nearly the 100% of drug released. The diffractograms of ABZ-CH microparticles displayed amorphous patterns, indicating that the drug underwent a transition from a crystalline to an amorphous state. The presence of NaCl up to 1.5% (w/v) did not increase the viscosity of the suspensions significantly (p > 0.05). The rheological behaviour of the formulations showed a non-Newtonian behavior, due to the reorientation of solids in the flow field and solid-solid interactions. Therefore, the ABZ-CH microparticles may be employed as a promising alternative for the delivery of ABZ from oral suspensions. Keywords: suspensions, microparticles, zeta potential, rheological properties.