Initial study on preparation and properties of porous Bletilla striata polysaccharides gum / 中草药

ABSTRACT

Obiective Guided by the thought of unification of drug and adjuvant, Bletilla striata polysaccharides gum (BSPG) was got from traditional Chinese medicine of Bletilla striata. Methods In this research, the porous BSPG was prepared and its functional properties in solid and gel states were characterized by using infrared-assisted extraction, ethanol fractionation precipitation, freeze drying, and texture analyzer. BSPG40, BSPG60, and BSPG80 were fractionated by repeated precipitation method, using 40%, 60%,and 80% ethyl alcohol as precipitant and these polysaccharides content were determined with Phenylhydrate-Sulfuric acid. Octadecanol as the adjunct and the porous BSPG as the material, porous and non-porous tablets were prepared by direct compression method. The capabilities of floating, water absorption, expansibility, and the degradation performance were measured in artificial gastric juice to give an initial research on the feasibility that the porous BSPG can be used as adjuvant. Results It showed that the total polysaccharide content of BSPG, BSPG40, BSPG60, and BSPG80 was 64.15%, 69.33%, 57.64%, and 42.83%, respectively and the yield of BSPG40, BSPG60 and BSPG80 account for 83.25%, 12.16%, and 4.49%. BSPG80 is too little to get and exhibits typical “weak gel” properties, so properties of BSPG, BSPG40, BSPG60 were tested. By freeze drying, all samples were loose and porous. Hardness increased as the concentrations increased, and at equal concentrations, the hardness of BSPG, BSPG40, and BSPG60 gradually increased but filling power gradually decreased as the hardness increased. Elasticity of BSPG, BSPG40, and BSPG60 is better at the concentration of 15, 20, and 20 mg/mL respectively. While gel strength and adhesion of BSPG, BSPG40, and BSPG60 was gradually weaken. This study’s preliminary experiments indicated that tablets of porous BSPG had good ability of floating, water absorption, expansibility and the degradation performance. Conclusion The experiment results showed that different concentration of ethanol fractionation precipitation exercises a great influence on the texture properties and at the same time, different concentration of BSPG which obtained by the same concentration of ethanol fractionation precipitated has different texture properties and low concentrations of ethanol fractionation precipitated had better performance of hardness, filling power, gel strength, adhesion and played a better role in pharmacy. Besides, porous BSPG is a potential excipient of floating to prolong the gastric retention time. Therefore, this study provided important theoretical evidence and made great significance to future exploration and development of the new excipient of porous BSPG.