Objective:To establish a simple

feasible and precise quality control strategy for determination of concentration and entrapment efficiency of isopropylidene shikimic acid liposome. Method: Chromatographic conditions were: Agilent Eclipse Plus C18 column (4.6 mm×100 mm

3.5 μm)

column temperature of 30℃

mobile phase of acetonitrile-0.05% phosphoric acid solution(10:90)

flow rate of 1.0 mL·min-1

injection volume of 20 μL and detection wavelength at 220 nm.The content of ISA in liposomes was determined by HPLC;Encapsulation efficiency was determined by ultrafiltration

gel chromatography and dialysis method

respectively

and results were compared with each other. Result: After demulsification by adding 4 times the amount of methanol into ISA liposome and high speed centrifugal sedimentation

supernatant was used to determine

determination results showed a good specificity

precision and accuracy

regression equation showed a good linearity (r=0.999 9) within range of 1.004-150.6 mg·L-1

recovery was (102.01±1.18)%

reference substance solution of ISA was stable in 6 h;Entrapment efficiency of ISA liposome determined by ultrafiltration method

gel permeation method and dialysis method were (92.96±1.91)%

(91.23±2.23)%

(73.66±7.10)%

respectively. Conclusion: This established HPLC method was stable and reliable

it could be used for quality control and in vitro analysis;In determination of encapsulation efficiency

ultrafiltration method was simple and efficient

its results were close to gel permeation chromatography;Due to limit of measurement conditions

determination result of dialysis method might be lower for its time-consuming process and higher temperature

and also depending on stability of liposome solution and existence state of drugs in liposome.