In Vitro Diclofenac Release Kinetics

The release of DICL was accomplished through the immersion of the DICL-loaded hydrogels in 25 mL of selected media, i.e., 0.01 M HCl, water, unbuffered PBS solution, and 0.01 M NaOH. The release of diclofenac was monitored spectrophotometrically, using the UV–Vis spectrometer Specord 200 (Analytic Jena, Jena, Germany), via measuring the absorbance at λ_max = 278 nm, which is characteristic of DICL [33 (link),34 (link),35 (link)]. The release experiments were carried out until a plateau was observed in the release curves, which was a sign that no more DICL would be able to be released from the tested hydrogels.