Fabrication of plant protein microspheres for encapsulation, stabilization and in vitro release of multiple anti-tuberculosis drugs

An attempt has been made to encapsulate anti-tuberculosis drugs in microspheres. For the present studies Zein has been chosen for the preparation of microspheres. The effect of various constituents on the microspheres fabrication has also been investigated. Various parameters and methodologies such as percentage yield, encapsulation efficiency, optical microscopy, SEM, FTIR and in vitro release have been utilized for characterization of microspheres. Stability studies as reviewed from turbidity results show that increase in the relative turbidity is indicative of agglomeration in different pH mediums. Dissolution of drugs from different formulations (single, binary, ternary mixture) has been analyzed using ratio derivative and double divisor ratio derivative methods. The kinetics of drug release and its release mechanism have been analyzed using different mathematical models. Rifampicin gives non-Fickian release from the single drug formulation and Fickian release in the presence of other drugs (binary, ternary mixtures). The results for isoniazid and pyrazinamide in all the formulations indicate a Fickian release mechanism. (C) 2011 Elsevier B.V. All rights reserved.