Effect of Gum Karaya on release pattern of Amoxycillin trihydrate from Encapsulated Matrix-based Formulations

Hydrophilic swellable polymers can be well used for the fabrication of matrix formulations. The present investigation aimed to develop controlled release matrix formulations of Amoxicillin trihydrate with different concentration of gum karaya, without changing the other factors. The matrix granules, prepared by wet granulation process were first evaluated for different micrometrics properties like bulk density, tapped density, Hausner’s ratio, Carr’s index. The drug content and swelling behavior were also investigated in granular form. After that the matrix granules were encapsulated in empty gelatin shell. The encapsulated granules of Amoxycillin trihydrate were subjected to dissolution studies. The drug release data were analyzed to interpret the drug release kinetics. The drug release data was fitted in kinetic models of zero order, first order, Higuchi and Korsmeyer-Peppas equation. For the formulations with higher concentration of gum karaya, the cumulative percent of drug released versus time plot exhibits curvilinear nature, which suggests that drug release is not dominated by zero order kinetics. The results showed that drug release is much more acquainted with Korsmeyer–Peppas and Higuchi models. The granules with 10-15% of gum karaya reveal the dominance of the highly swollen layer which controls the drug release from the matrix granules.