L 2200 multisolvent delivery system

A high-performance liquid chromatography (HPLC) assay was used to determine the drug concentration standard curve. The HPLC analyses were conducted on a Hitachi L-2200 Multisolvent Delivery System. A Symmetry C8 3.9 cm ×150 mm HPLC column (Waters Corporation, Milford, MA, USA) was used to separate the vancomycin and ceftazidime. The mobile phase used for vancomycin contained 0.01 M heptanesulfonic acid (Fisher Scientific UK Ltd., Loughborough, UK) and acetonitrile (Mallinckrodt Pharmaceuticals, Dublin, Ireland) (85/15, v/v). The absorbance was monitored at a wavelength of 280 nm at a flow rate of 1.4 mL/min.
The mobile phase used for ceftazidime contained methanol and 5 mM of pH 7.5 phosphate buffer (Sigma-Aldrich) (10/90, v/v). The absorbance was monitored at a wavelength of 254 nm at a flow rate of 0.6 mL/min.
All experiments were carried out in triplicate and the sample dilutions were performed to bring the unknown concentrations into the range of the standard curve. A calibration curve was prepared for each set of measurements (correlation coefficient >0.99). The elution product was specifically identified and quantified with high sensitivity using the HPLC system.

HPLC analyses were conducted on a Hitachi L-2200 Multisolvent Delivery System. A SYMMETRY C₈ column (3.9 cm ×150 mm) was used to characterize vancomycin and ceftazidime (Waters, Milford, MA, USA). The mobile phase containing 0.01 mol heptanesulfonic acid (Fisher Scientific, Loughborough, UK) and acetonitrile (Mallinckrodt, St Louis, MO, USA) (85/15, v/v) was employed to separate vancomycin. The absorbance wavelength was set at 280 nm, while the flow rate was 1.4 mL/min. The mobile phase used for ceftazidime contained methanol and 5 mM phosphate buffer, pH 7.5 (Sigma-Aldrich) (10/90, v/v). The absorbance was monitored at 254 nm with a flow rate of 0.6 mL/min. All experiments were performed in triplicate (N=3).

An elution method was used to detect the in vitro release of PTU from the nanofiber. The nanofiber coated with PTU (25 μg/mm²) was placed in a glass test tube that contained 1 mL PBS (0.15 mol/L, pH 7.4; one sample per test tube) at 37°C for 24 hours. The eluent was then collected and analyzed daily for 28 days.
The PTU concentration in the eluent was determined using a high-performance liquid chromatography (HPLC) assay as described.8 (link) The HPLC analysis was conducted on a Hitachi L-2200 Multisolvent Delivery System. A SYMMETRY C₈ (3.9 cm×150 mm HPLC column; Waters) was used for the separation of PTU. The mobile phase contained 0.01 mol/L heptanesulfonic acid (Fisher Scientific U.K. Ltd.) and acetonitrile (85/15, v/v; Mallinckrodt, St. Louis, MO, USA). Absorbency was monitored at a wavelength of 254 nm with a flow rate of 1.4 mL/min. All experiments were conducted in triplicate, and the sample dilutions brought the unknown concentrations into the range of a standard curve. A calibration curve was made for each set of measurements (correlation coefficient >0.99). The elution product was identified and quantified with a high degree of sensitivity using the HPLC system.

The in vitro release properties of ticagrelor from the nanofibers were determined using an elution process for 30 days. Samples with a diameter of 3.5 mm, a length of 20 mm with two ticagrelor loadings (low and high doses) were put in glass test tubes (n=3) with 1 mL of PBS.
Ticagrelor concentrations were obtained by performing an HPLC assay using a Hitachi L-2200 Multisolvent Delivery System. A Hypersil BDS C18 column (100×4.6 mm, 5 µm) was used to separate out the ticagrelor.24 Blood samples of 100 µL were collected from rabbits (n=9) on days 7, 14, 21, and 28 days after they had been stented, in tubes that contained an anticoagulant. Plasma was prepared within 30 minutes of blood sampling by centrifugation at 1,500× g for 10 minutes at 4°C. The lower limit of quantification (LLOQ) of the method was 0.00503 µM.