Ocular pharmacokinetic study on baicalin in lens of rabbits following intragastric administration

Purpose This paper is to study the pharmacokinetic features of baicalin in lens through observing baicalin’s concentration changes in lens of rabbits following intragastric administration. Methods Forty-four rabbits were randomly divided into 11 groups. The lens were collected at the beginning without any intragastric administration, and then collected after 15 minutes following intragastric administration of 80 mg/kg baicalin, and continually collected individually after 0.5,0.75,1,1.5,2,3,5,8,12 hours: the concentration of baicalin was measured by reversed-phase high-performance liquid chromatography (RP-HPLC). Results There were two obvious peaks in the drug concentration-time diagram, appearing respectively at half an hour and 2 hours after the intragastric administration. The highest level of baicalin’s concentration in lens (C max , = 4.997 μg/ml) was obtained 0.9 hour (T max = 0.906 h) after application of baicalin. Area under the concentration time curve (AUC), half-life of the drug elimination (T 1/2 ) and clearance ratio were 3.542 µg/ml*h., 1.576 h and 8.114 l/h respectively. Conclusions Baicalin can penetrate blood–eye barriers and enter the lens following intragastric administration.