title: Degradation kinetics of fluorouracil-acetic-acid-dextran conjugate in aqueous solution.
abstract: The degradation kinetics of fluorouracil-acetic-acid-dextran conjugate (FUAC-dextran) was investigated in various buffer solutions with different pH value and physiological saline solution at 60 degrees C and 37 degrees C, respectively. The hydrolytic reaction displayed pseudo-first-order degradation kinetics. Hydrolytic rate constant obtained was the function of pH value and independent of species of buffering agents. The smallest rate constant was observed at pH round 3.00. The activation energy of the hydrolytic reaction was estimated from Arrhenius equation as 88.73 +/- 6.00 kJ.mol-1. The special base catalytic degradation of the conjugate was observed from acidic to slight alkaline condition and the special base catalytic rate constants were calculated. The conjugate was more stable in physiological saline than that in buffer solution at pH 7.00 or 9.00 at 37 degrees C. The results revealed that the conjugate was stable in acidic condition and will degrade in alkaline condition.
authors.affiliation: Shenyang Pharmaceutical University, Shenyang City, Liaoning Province, P.R. China.
authors.forename: A J
authors.initials: AJ
authors.lastname: Hao
authors.forename: Y J
authors.initials: YJ
authors.lastname: Deng
authors.forename: T F
authors.initials: TF
authors.lastname: Li
authors.forename: X B
authors.initials: XB
authors.lastname: Suo
authors.forename: Y H
authors.initials: YH
authors.lastname: Cao
authors.forename: Y L
authors.initials: YL
authors.lastname: Hao
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry*; D002021:Buffers; D003911:Dextrans / Q000737:chemistry*; D004355:Drug Stability; D005472:Fluorouracil / Q000031:analogs & derivatives* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008956:Models, Chemical; D012965:Sodium Chloride / Q000737:chemistry; D012996:Solutions; D013696:Temperature; D014867:Water
chemical_list: D000970:Antineoplastic Agents; D002021:Buffers; D003911:Dextrans; D012996:Solutions; C515589:fluorouracil-acetic-acid-dextran conjugate; D014867:Water; D012965:Sodium Chloride; D005472:Fluorouracil