2.5 Drug Release Study
Four swatches of hydrogel (20mm × 20mm) were added into 50 ml artificial
sweat solution with pH5.5. The solution was prepared by dissolving 1g
lactic acid (Bendosen), 1g urea (Biofroxx) and 5g sodium chloride
(Mallinckrodt) in 1L of distilled water. Then, 50 µL of the sample was
withdrawn from each flask at 0, 2, 4, 6, 8, 12, 24, 48 and 72 hours. The
sample was filtered using a 0.22 µm syringe filter. Then, the amount of
phomopsidione released was analyzed using the High-Performance Liquid
Chromatogram (Sahadan et al., 2019). The mobile phase used was
chloroform/methanol at a ratio of 3:7 (v/v) with an HPLC (Perkin Elmer
Series 200) coupled with Breeze software. The HPLC was set up with a
wavelength of 245 mm, column (C18) particle size 5 µm,
length 120 mm, and injection volume of 20 µL. The amount of
phomopsidione was determined based on the calibration curve (0 to 1000
µg/ml phomopsidione).