Doxofylline and methylprednisolone sodium succinate are stable and compatible under normal injection conditions

To assess the physical compatibility and chemical stability of doxofylline with methylprednisolone sodium succinate in 0.9% sodium chloride or 5% dextrose injection for intravenous infusion. Twenty mL doxofylline solution [0.74 mg/mL] and 1 mL methylprednisolone sodium succinate solution [0.15 mg/mL] were added into 250 mL polyolefin bags containing 5% dextrose injection or 0.9% sodium chloride injection, and stored for 24 h at 20-25[degree]C. Chemical compatibility was measured with high-performance liquid chromatography [HPLC], and physical compatibility was determined visually. The results showed that samples were clear and colorless when viewed in normal fluorescent room light. The pH value exhibited little change. The particulate content of >/= 25 micro m was low and within the specification limit. The particulate content of >/= 10 micro m decreased over time and was similar to the control solution. Analysis of chemical stability revealed that doxofylline is stable with methylprednisolone sodium succinate for up to 24 h, and the degradation of methylprednisolone sodium succinate is unrelated to doxofylline, but is closely related to the pH value of the solution. Doxofylline and methylprednisolone sodium succinate did not affect the stability of each other

Determination of Concentration and Pharmacokinetics of Ampicillin in Human Plasma by HPLC / 中国药房

OBJECTIVE:To determine ampicillin concentration in human plasma by HPLC.METHODS:The chromatographic column was Waters Sunfire C18 with mobile phase consisted of acetonitrile and 0.05 mol?L-1 potassium dihydrogen phosphate(6.5∶93.5,V∶V)at a flow rate of 1.2 mL?min-1.The UV detection wavelength was 210 nm;the column temperature was 35 ℃ and the injection volume was 20 ?L.RESULTS:The linear range of ampicillin was 0.2～16.0 ?g?mL-1(r=0.999 9).The limit of quantization was 0.2 ?g?mL-1.The average methodological recovery was 99.88%～104.45%,and the average extraction recovery was 95.69%～100.56%.Both the inter-day RSD and the intra-day RSD were all less than 10%.CONCLUSION:This method is stable,rapid and sensitive,and suitable for the pharmacokinetic study for ampicillin preparation.