摘要

The polymers that respond to chemical changes, such as pH, are used in the modified drugs release. This paper presents the microencapsulation of diclofenac sodium, it has the disadvantage to produce gastric irritation, therefore it is suitable for encapsulation.
As coating was used carboxymethylcellulose (CMC) grafted with benzyl chloride. The microencapsulation method used was spray drying. It was obtained encapsulation efficiency to 90 % and a 57 % yield. Particles were characterized by FTIR, X rays diffraction and SEM.
In vitro dissolution test allowed to evaluate release of the active in simulated gastric and intestinal juice. The results showed excellent response in acid medium giving 2.7 %, result that confirmed the enteric behavior. The kinetic release showed that Pep pas model was the best to match the experimental points. Diffusional exponent indicates that the drug transport had non-fickian behavior. The difference between Peppas and Schott models is discussed.

  • 出版日期2015-4