The intrascleral implant was incubated in 50 mL of phosphate-buffered solution (0.1 M, pH 7.4) in a shaking water bath (BT-25; Yamato Scientific Co., Ltd., Tokyo, Japan) at 37°. At predetermined intervals, the entire volume was sampled, and 50 mL of fresh medium was added to the sample vial to approximate a perfect sink condition. The amount of BM released into the medium was measured by HPLC using a C-18 reversed-phase column (150 × 6.0 mm inner diameter; YMC-Pack ODS-A312; YMC Co., Ltd., Kyoto, Japan). A pump (PU-980; Japan Spectroscopic Co., Ltd., Tokyo, Japan) was used at a constant flow rate of 1 mL/min. The mobile phase was a mixture of methanol and 50 mM potassium dihydrogen phosphate aqueous solution (55:45). The column oven (860-CO; Japan Spectroscopic Co.) was equipped and set at 40°. A spectrophotometer detector (model L-4000; Hitachi, Ltd., Tokyo, Japan) was used at a wavelength of 240 nm. Fluorometholone (Wako Pure Chemical Industries) was used as an internal standard.