To screen the film-forming materials of different extracts of Rheum palmatum L.

Objective To screen out the appropriate film-forming materials of Rheum palmatum L.extracts as a reference for the consperg film agent.Methods According to the results of the dissolving experiments of the film-forming materials,polyvinyl pyrrolidone(PVP),polyvinyl alcohol(PVA),ethyl cellulose(EC),methyl cellulose(MC) and polyvinyl butyral(PVB) were used to test their film-forming properties in the different extracts of Rheum palmatum L.by analyzing the filming photos which were screened by the microscope and photo software.Results The film properties of PVP-K30 in the extracts of the Rheum palmatum L.were very fine.PVP-K90 could film,but was poor in the extraction solution of 40%(φ) ethanol and 60%(φ) ethanol.PVA-17-88 could film,but the membrane surface was uneven and rough.EC could form a favorable film in absolute ethyl alcohol extract of Rheum palmatum L..The solubility and film-forming properties of MC became worse and worse as the concentration of ethanol solution increased.PVB could form a film only in absolute ethyl alcohol extract of Rheum palmatum L..Conclusion The polarity of solvent showed a greater effect on the film-forming materials.The film-forming properties of PVP-K30 were fine in the different extracts of the Rheum palmatum L.,so it was the best choice for the consperg film agent in film-forming materials.