Abstract:Objective To study pharmacodynamics of the compound riboflavin in situ forming eye gel. Methods We observed the retention time of compound riboflavin eye gel in New Zealand rabbit's eye surface after fluorescein staining under cobalt blue light. Eye stimulation scale was used to score and investigate the ocular surface irritation of compound riboflavin in situ forming eye gel for 1 h, 24 h, 48 h and 72 h after single administration of the in situ eye gel and the cumulative or sustained damage was used to the ocular surface on the 7th day and 14th day after multiple administration of the drug. Corneal injury model was made with 0.25% NaOH solution. Twelve New Zealand rabbits were randomly divided into three groups: model group, eye drops group and in situ eye gel group. The right eye of the rabbits were with the corresponding drug, and the left were used as the blank control. Corneal injury was inspected on the 1st, 3rd, 5th and 7th day after modeling.The rabbits were sacrificed on the 7th day and the corneal tissue was taken for HE staining.The histomorphologic changes were observed to evaluate the therapeutic effect of drugs on corneal injury recovery. Results The retention time of compound riboflavin ophthalmic in situ gel was (306.0?±?33.3) s, and that in eye drops was (9.67?±?2.52) s, which was shorter than the previous one (P?< 0.05). The in situ eye gel was with no irritation to the rabbit eye surface. After the successful modeling of corneal injury, there were significant differences between the in situ eye gel group and the model group on the 5th day and the 7th day (P?0.05). It was discovered that the ocular surface damage of the type gel group and the eye drops group was gradually recovered on the 7th day after the model was made when compared with blank control group. Conclusion The gel significantly increased the retention time of the drug with no irritation. It is found that compound riboflavin in situ ophthalmic gel can benefit to corneal injury repair.