Čes. slov. farm. 2004, 53(4):177-182
Liberation of Folic Acids from Composite Chitosan Films
- 1 Katedra farmaceutické technologie Farmaceutické a biochemické fakulty Univerzity Záhřeb, Záhřeb, Chorvatsko
- 2 Katedra farmaceutické technologie Farmaceutické fakulty Univerzity Karlovy, Hradec Králové
Thin films were prepared by the method of evaporation of aqueous solutions of chitosan or itsmixtures with poloxamer 407, gelatin, or polyvinyl alcohol. Films of varying thickness werecross-linked with phosphate ions. They contained micronized folic acid in a concentration of 9.1 %or 3.2 %. Prolonged several hours' liberation of folic acid into isotonic phosphate buffer at pH 5.5,6.0,and 6.5was examined. In the initial stage, the mechanism of liberationwas governed by diffusionof the dissolved fraction, at higher pH values a higher rate of dissolution of the substance played itsrole. In some composites, sorption of folic acid to chitosan in an extent dependent on the compositionof composites and current acidity of the medium was demonstrated.
Keywords: chitosan; composites; thin films; folic acid; liberation
Published: April 1, 2004 Show citation