Formulation of Anti-tuberculosis Drug Loaded Starch Propionate Microparticles for Controllable Drug Delivery

The goal of this study was to use an emulsification solvent evaporation approach to formulate anti-tuberculosis drug (isoniazid, rifampicin, and pyrazinamide) loaded starch propionate microparticles (ATD-SPMPs). Fourier transform infrared spectrometry revealed that starch propionate (SP) exhibited new bands at 1749cm-1 and 1236cm-1, whereas SPMPs had identical peaks. The A-type pattern of native starch was entirely changed into the V-type pattern of SP by X-ray diffraction, while SPMPs showed a similar type pattern with SP having reduced crystallinity. Propionylation improved the thermal stability of native starch by reducing the number of hydroxyl groups in the modified starch molecule. SPMPs have superior thermal stability than SPMPs due to their semi-crystalline structure. In the optimized formulation, the highest percentage encapsulation efficiency of isoniazid, rifampicin, and pyrazinamide was determined to be 37.6%, 45.2%, and 43.1%, respectively. Scanning electron microscopy revealed that propionylation partially disturbed the granule morphology of native starches, and the imperfections and porosity structures of SP granules were completely changed into the uniform-sized spherical shape of SPMPs. The geometric particle sizes of the blank SPMPs, isoniazid, rifampicin, and pyrazinamide loaded SPMPs were 1.243 ± 0.3 μm, 1.65 ± 0.2 μm, 2.73 ± 0.7 μm, and 2.69 ± 0.5 μm, respectively. The dialysis bag method was used to study drug release from ATD-SPMPs and in-vitro drug release data was also analyzed using several kinetic models. The in-vitro drug release investigation revealed that drug release from SPMPs was controlled in comparison to pure ATD using the Korsmeyer-Peppas model, indicating drug release by anomalous diffusion, i.e., non-Fickian diffusion. Overall, the formulated ATD-SPMPs may be regarded as a potential anti-tuberculosis micro-drug, offers a path forward for tuberculosis clinics.