Objective: To compare dissolution of chlorogenic acid

phillyrin and forsythoside A in decoction of different compatibility proportions of Lonicerae Japonicae Flos and Forsythiae Fructus

and investigate effects of different compatibility proportions on in vivo pharmacokinetics of chlorogenic acid in rats. Method: HPLC was adopted to determine the contents of chlorogenic acid

phillyrin and forsythoside A in single decoction and co-decoction of Lonicerae Japonicae Flos and Forsythiae Fructus;Rats were intragastric adiministrated co-decoction of Lonicerae Japonicae Flos and Forsythiae Fructus with ratio of 1: 1 and 1: 2 (dosage of chlorogenic acid was 60 mg·kg-1)

then the concentration of chlorogenic acid was determined

pharmacokinetic parameters were calculated with DAS software by non-compartment model. Result: The contents of chlorogenic acid and phillyrin in co-decoctions were higher than that in single decoctions

but the content of forsythoside A was decreased when Lonicerae Japonicae Flos and Forsythiae Fructus decocted together.After intragastric adiministrated co-decoction of Lonicerae Japonicae Flos and Forsythiae Fructus with ratio of 1: 1 and 1: 2

AUC0-t were 0.95

1.19 μg·h·mL-1

and Cmax were 0.18

0.26 mg·L-1

respectively;Pharmacokinetics had no significant difference. Conclusion: Dissolution of chlorogenic acid and phillyrin were increased with compatibility of Lonicerae Japonicae Flos and Forsythiae Fructus

while forsythoside A was decreased in co-decoctions.Pharmacokinetic parameters of chlorogenic acid showed no significant differences between 1: 1 and 1: 2 decoctions at the same dosage of chlorogenic acid.