[An experimental study on corneal collagen shield vehicle for delivery of pilocarpine]

The study was designed to clarify the role of corneal collagen shield made in China as a drug vehicle for the delivery of pilocarpine in different ways.

80 eyes of New Zealand white rabbits were randomly divided into three groups, corneal collagen shield immersed with pilocarpine, corneal collagen shield with topical application of pilocarpine and synthetic collagen pilocarpine shield. At 0.5, 1, 3 and 6 hours after the delivery, the aqueous concentrations of pilocarpine and the pupillary sizes of all the eyes were measured.

This study showed that shortly after the delivery of pilocarpine in the 3 groups, in spite of difference in ways of its delivery, its aqueous concentrations reached a relatively high level and maintained for more than six hours, the shield acting as a temporary "drug source". The aqueous pharmacokinetics of corneal collagen shield for pilocarpine delivery was consistent with the first-order kinetics and it was confirmed by the observations of miotic response.

The corneal collagen shield made in China is a fine vehicle for drug delivery.