OBJECTIVETo compare the action of miosis of 1% pilocarpine liposome with 1% pilocarpine solution in rabbits.

METHODS18 white rabbits were randomly divided into 3 groups. Test group received 1% pilocarpine liposome, positive control group received 1% pilocarpine solution, negative control group received liposome. Each eye drop instilled into left eye of rabbits and sterile saline solution instilled into right eye as control. The pupil diameter was measured at time intervals of beginning, 0.25, 0.5, 1, 2, 3, 4, 5, 7 hours.

RESULTSThe mean pupil diameter change of 3 groups in both eyes was not significant (P > 0.05) at beginning. The strongest action of miosis took place 0.25 h in positive control group and 0.5 h in test group after instillation. The dilation of pupil in both groups took place 1 h and 3 h, and the restoration of pupil in both groups took place at 5 h and 7 h. The mean pupil diameter of negative control group was not significant in seven hours.

CONCLUSIONSThe results suggest that 1% pilocarpine liposome improves the bioavailability and prolong the duration of its action.