In Vitro Release of Essential Oil

The release of MEO from MEO-GS was evaluated by the dialysis bag method [29 (link),30 (link)], using Spectra/Por^® regenerated cellulose membranes with 3.5 KDa MWCO), by Repligen Europe B.V. (Breda, The Netherlands), and it was compared to the release from a DMSO solution of MEO, at the same concentration of essential oil as used to prepared glycerosomes (10 mg/mL). The experiment was carried out with 1 mL of sample, magnetically stirred in 200 mL of PBS, used as release medium. The temperature was set at 37 °C; 0.5 mL of medium was collected at specified time points (30, 60, 120, 240, 360, 1440 min) and they were replaced by equal volumes of fresh medium, thus maintaining the sink conditions [31 (link)]. The collected release medium was analyzed by HPLC-DAD. The amount of released MEO was expressed as percentage of citral amount recovered in the release medium, as against citral amount contained inside the cellulose bag.