Study the Behavior of Microspheres Obtained from Natural Polymer as Drug Carriers

Natural polymers have various advantages, such as being inexpensive, nontoxic, biocompatible, and biodegradable. Due to these numerous benefits, alginate microspheres have garnered significant interest as a novel drug delivery system. This study evaluated the influence of sodium alginate concentration on the properties of alginate microspheres and investigated the relationship between the rheological properties and structural characteristics of microspheres. Alginate microspheres were prepared using a single-step water-in-oil emulsion technique. The emulsion used in this study consisted of an alginate solution as the water phase, sunflower oil as the oil phase, and Span 80 as the surfactant. Aceclofenac was employed as the biomacromolecular drug model. The results showed that as alginate concentration increased, the particle size of the microspheres also increased due to the higher viscosity of the alginate solution. The particle size of the alginate microspheres ranged from 32.062 to 475.164 mu m, with a spherical shape at all concentrations.The shear-thinning phenomenon is dominant in all alginate solutions. The Power Law and Hersch Bulkley models provided better fits than the Casson and Bingham models for the curve fitting of alginate at different concentrations. The transmittance spectrum of alginate microspheres did not exhibit an additional peak, according to Fourier transform infrared (FTIR) analysis, which explains that the alginate only acted as a carrier for the drug, delivering it to the target position and then degrading without any chemical reaction occurring. The DSC test showed an increase in the melting point compared to that of the pure drug alone when the drug was loaded into microspheres, indicating that the drug was incorporated into the polymer matrix. An increased melting point occurs because the drug is loaded into the microspheres and confined.