Table 1.
Monomeric composition of the soft contact lenses with different ionicities.
Table 2.
High performance liquid chromatography conditions.
Fig 1.
Schedule of the in vivo study.
Scheduled procedures were undertaken in the 5 groups, A-E, of 6 guinea pigs each, and a group of 3 guinea pigs, F. iso: anesthesia by isoflurane inhalation, EBiv: intravenous injection of Evans blue, PBS-ED: instillation of eye drops of 50 μL of phosphate buffered saline, EH-ED: instillation of eye drops of 50 μL of a 0.05% (w/v) solution of epinastine hydrochloride in phosphate buffered saline. PBS-SCL: insertion of a soft contact lens containing no epinastine hydrochloride, EH-SCL: insertion of a soft contact lens containing epinastine hydrochloride, challenge: instillation of eye drops of 10 μL of a 1% (w/v) solution of histamine in phosphate-buffered saline (soft contact lenses were removed just before the challenge), euthanasia: decapitation under deep anesthesia with isoflurane inhalation.
Fig 2.
An epinastine hydrochloride-releasing soft contact lens (EH-SCL) for guinea pigs.
An EH-SCL for guinea pigs is compared to an SCL for human use. DIA: diameter.
Table 3.
Water content.
Fig 3.
Epinastine hydrochloride (EH)-releasing profiles of the 5 kinds of soft contact lenses (EH-SCLs).
The maximum EH release was demonstrated by EH-SCL (A) after 2 h. Data are expressed as mean ± standard deviation (n = 3).
Fig 4.
Temporal change in the ratios of cumulative amount of released epinastine hydrochloride (EH).
Ratios of temporal cumulative amounts of EH released to the total amount released in 60 h are shown for the 5 kinds of EH-SCLs (n = 3). Relatively stable release profiles were demonstrated by EH-SCLs (E) and (A).
Fig 5.
Epinastine hydrochloride (EH) releasing profiles with different EH concentrations.
The amount of EH release increased as the concentration of the EH solution used to make the EH-releasing soft contact lenses increased.
Fig 6.
Correlations between epinastine hydrochloride (EH) concentrations and the release amounts.
The EH-releasing soft contact lenses (EH-SCLs) demonstrated EH release directly proportional to the concentration of EH solutions used to make the EH-SCLs.
Fig 7.
Evans blue (EB) extravasation per tissue.
The extravasation of EB was significantly inhibited in the eyes in which epinastine hydrochloride (EH) was administered in the form of either eye drops or soft contact lens. Twelve hours after each treatment, EH-SCLs made with a 0.005% solution of EH inhibited EB extravasation significantly more compared with EH-EDs. Groups A to E, n = 6; for group F, n = 3. For groups A to E, the data were analyzed using one-way ANOVA and Tukey-Kramer test. * and ** indicate P < 0.05 and P < 0.01, respectively. PBS-ED: treated with phosphate-buffered saline eye drops, EH-ED: treated with epinastine hydrochloride eye drops, PBS-SCL: treated with a soft contact lens containing no epinastine hydrochloride, EH-SCL: treated with a soft contact lens made with a 0.005% solution of epinastine hydrochloride.