Influence of He-Ne laser on pharmacokinetics of timolol in ocular humor of rabbits

A reverse-phase high-performance liquid chromatography for the determination of timolol concentration in humor of rabbits was developed. The humor samples were deproteinized with methanol containing propranolol for internal standard on reversephase column ZORBAX-C8 at 400C. using methanol: HC1 0.15+NaCI 15 mmol/L in water (70:30,pH 4.0) as the mobile phase with variable wavelength uv detector at 295 nm. The assay method showed good peak heigh tratio, concentration linearity. precision and accuracy over the range of 0.05-50 vg/ml. The limit of detection was 0.05 vg/ml. The influence of He-Ne laser on pharmacokinetics of timolol in humor of rabbits indicated that AUC0-120 and AUCO-m of laser group were greater than those in the control group (p<0.05). However, there were no significant differences between the elimination rate constant K, t1/2, the peak concentration and the time of peak concentration of the 2 groups. Our data suggest that the option He-Ne laser radiance causes a higher bioavailability.