Galaxie chromatography workstation

Tetracaine quantification during the encapsulation efficiency and in vitro permeation studies was performed using a high performance liquid chromatography (HPLC) system (Varian ProStar, equipped with a PS 325 UV-Vis detector, PS 210 solvent delivery module with Galaxie™ Chromatography Workstation, Varian, Inc. Walnut Creek, CA, USA). Briefly, a Luna (5μm, 250 × 4.6 mm) reversed-phase C18 column (Phenomenex^®, Torrance, CA, USA) was employed, with an isocratic elution employing a mobile phase composed of ammonium phosphate (10 mM, pH 3.0): acetonitrile, 70:30 (v/v). The detection wavelength, eluent flow rate, and injection volume were set at 280 nm, 1.5 mL/min, and 30 µL, respectively. The method was successfully validated, with a linear calibration curve (r² = 0.9998), in the concentration range from 0.03 mM to 1.2 mM. The TTC retention time was 5.3 ± 0.1 min and the TTC limits of quantification and detection were 1.5 × 10⁻⁴ mM 4.5 × 10⁻⁵ mM, respectively.