PH-responsive release system of isoniazid using palygorskite as a nanocarrier

Abstract

Isoniazid (INH) is one of the most effective first-line drugs in the treatment and prevention of TB. The present work studied the achievement of a pH-responsive system INH, using the palygorskite (PAL) as nanocarrier. The incorporation process was evaluated through a factorial design, in order to investigate the influence of some factors on the drug adsorption. The experiment using the maximum INH concentration (0.075 mg/mL), lower mass of PAL (300 mg) and lower pH (pH 2) was the most efficient compared to the other experiments, resulting in the highest incorporated dose, which was equivalent to 12.93 mg of INH/g of PAL. The results obtained by the characterization techniques proved the incorporation of the drug in the clay and helped to elucidate the mechanism of interaction between the drug and the material. By means of the in vitro release studies, the efficacy of the pH-dependent system obtained was demonstrated. More than 60% of the dose was released in the intestinal medium (pH 6.8 and pH 7.4) and the kinetic study showed that the zero-order model was the one that best fitted the experimental data, indicating that INH is released from the PAL in a prolonged way.