Objective: To develop a HPLC method for simultaneous determination of chlorogenic acid

forsythiaside A and baicalin in rat plasma

and investigate pharmacokinetics characteristics of these three ingredients from Shuanghuanglian powder injection. Method: Plasma samples were precipitated by acetonitrile-methanol (1:1).HPLC was adopted to simultaneous determine contents of chlorogenic acid

forsythiaside A and baicalin with puerarin as internal standard

mobile phase composed of acetonitrile(A)-0.1% phosphoric acid(B) with a gradient elution program(0-10 min

10%-20% A;10-35 min

20%-35% A;35-40 min

35% A;40-40.5 min

35%-10% A;40.5-55 min

10% A)

detection wavelength of chlorogenic acid

forsythiaside A

baicalin and puerarin were 328

328

277

249 nm

respectively. Result: Excellent linear relationships were obtained in the range of 0.2-20 mg·L-1 for chlorogenic acid and forsythiaside A

but it was 2.0-300 mg·L-1 for baicalin (r>0.999 4);RSD of both intra-day and inter-day precisions were less than 13.6%

the assay recoveries at three levels were 88.3%-109.3%

the extract recoveries were more than 80.8%.Main pharmacokinetic parameters of chlorogenic acid

forsythiaside A and baicalin:AUC0-t were (8.406±1.175)

(9.696±2.349) and (145.35±22.02) mg·h·L-1;MRT0-t were (0.619±0.105)

(0.634±0.115) and (0.456±0.068) h;t1/2 Z were (0.532±0.064)

(0.732±0.357) and (0.542±0.175) h;Vz were (0.384±0.050)

(0.673±0.422) and (0.324±0.072) L·kg-1;CLZ were (0.504±0.067)

(0.634±0.150) and (0.426±0.066)L·h-1·kg-1

respectively. Conclusion: This determination method was sensitive

simple and accurate

it was suitable for determining contents of chlorogenic acid

forsythiaside A and baicalin in rat plasma and pharmacokinetics of Shuanghuanglian powder injection.