Nanopartículas de quitosana e goma do cajueiro (Anacardium ocidentale) via complexação eletrolítica para o encapsulamento de primaquina

Abstract

Chitosan nanoparticles (QT) and cashew gum (CG) were synthesized by complexation polyelectrolytic. We investigated some parameters that influence the size of nanoparticles such as: concentration of polyelectrolytes, order of addition of polymer solutions and loads of polileletrólitos reason. Was synthesized nanoparticles with the following ratios of loads n +/n-: 0.2, 0.5, 1.0, 5.0, 10, 15 and 20. The nanoparticles were characterized by infrared spectroscopy (FTIR) and by UV / VIS, particle size and zeta potential. The FTIR spectrum showed main bands of chitosan and cashew gum in 1550 and 1647 cm-1. To nanoparticles QT GC, zeta potential ranged from -2.25 mV to +28 mV, observing that the higher the ratio of charge n +/n- higher and more stable is the zeta potential. The drug was initially incorporated in three different matrices in the ratios of loads n +/n- 0.5, 1.0 and 10. However, the method of incorporation and release of primaquine was used as a crosslinking agent and TPP nanoparticles with only positive surface charge were chosen for the incorporation of primaquine due to the possibility of interaction of positive charges with the negatively charged TPP forming a gel after centrifugation. Therefore, primaquine was incorporated in CPEs QTGC 1.0, 5.0 and 10 all with positive surface charge. Among the specimens incorporated QTGC Pr-10 showed the highest encapsulation efficiency of 32%, for the reason QT: TPP 2:1. The gel obtained after centrifugation and redispersed dried and characterized. The gel presented size of 800 nm, and higher than the particle size prior to addition of TPP which was 17.4 nm. This increase in particle size was expected since the addition of TPP form aggregates. The zeta potential decreased from + 26 mV to 0.03 mV indicating the neutralization of charges by the CPE postivas negative charges of TPP. The infrared spectrum shows the main bands of interaction between groups of chitosan positive and negative groups of tripolyphosphate (TPP). The gel showed a content of 9.35% encapsulation. The release kinetics were performed in phosphate buffer pH 7.4 at 37° C. The release was relatively slow where only 14% of the drug was released in 50 hours of testing. The kinetic study of the release of primaquine indicated that the release follows the Higuchi model.