Physical Characteristics of Erythropoetin Encapsulated into Alginate Polymer Using Aerosolization Technique

The aim of this research was to evaluate physical characteristics of erythropoietin encapsulated into alginate polymer using a microparticle technology called aerosolization technique at different polymer concentrations. Erythropoetin is a model of neuroprotectant drugs. The sodium alginate concentrations used were 1%, 2%, and 3% with 1M cross-linker CaCl2. The physical characteristics in terms of morphology, particle size, swelling index, yield, and structural integrity of erythropoietin-Ca alginate microspheres were determined. Microsphere evaluation included FT-IR, DTA, moisture content, morphology using SEM, particle size distribution using optical microscopy, determination of swelling index, and yield. SDS PAGE electrophoresis was also conducted to evaluate the molecular weight of erythropoietin before and after the microencapsulation process. The resulting microspheres had spherical form, smooth surface, and the sizes below 5 μm. The determination of swelling index was performed using two methods, namely calculation of mass differentiation and size differentiation at 24 and 30 hours. Results of examination from swelling indices in F1, F2, F3 were 0.58, 1.25, 1.43 (at 24 hours) and 0.78, 1.78, 2.16 (at 30 hours), respectively, whereas resulted of swelling index of 0.50, 1.15, 1.32 (by size method at 24 hours), and 0.65, 1.80, 1.98 (at 30 hours). The result of yield microspheres of F1, F2, F3 were 75.55% ± 0, 350; 77, 84% ± 0, 290; and 86, 65% ± 0, 191. Statistical result showed that an increase of alginate concentration causes an increse in particle size, swelling indeks, and yield. From SDS PAGE profile, it was confirmed that erythropoietin maintains its structural integrity evidenced by the similar molecular weight before and after encapsulation process. This study has demonstrated the potential of erythropoietin-alginate microspheres that may be effective as a neuroprotectant drug.