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An HPLC method was established for the assay of epinephrine sulfonate (impurity F) in epinephrine injection. The determination was performed on an AQUASIL C18 (100 mm × 4.6 mm, 3 μm) column with a gradient elution system, and the mobile phase was consisted of monopotassium phosphate solution (mobile phase A) and acetonitrile (mobile phase B). The injection volume was 40 μL. The detection wavelength was at 210 nm and the column temperature was 25 ℃. The total analytical time was 40 min. The results showed that the standard cure of epinephrine sulfonate (impurity F) between peak area and concentration exhibited good linear relationship within the ranges of 0.520-12.480 μg·mL-1 and the R2 = 0.999 8. The average recovery rate was 103.04% and the RSD was 2.00%. The limit concentration of detection was 0.104 μg·mL-1 and the limit concentration of quantitation was 0.520 μg·mL-1. The method could be applied to the determination of epinephrine sulfonate in epinephrine injection with high accuracy and precision, as well as good sensitivity. It could also enhance the quality standards of epinephrine-related products.
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Chronic kidney disease (CKD) is a progressive disease with many complications (eg, cardiovascular disease and acidosis and anemia) and high morbidity and mortality occurs in the population. There is no cure for this disease, current treatments including renin-angiotensin-aldosterone pathway inhibitors and sodium-glucose co-transporter 2 inhibitors can only delay the progression to end-stage renal disease. With the identification of more key factors and mechanisms in CKD development, new potential therapeutic approaches for CKD can be developed. This review summarizes the mainstays of therapy and strategies for CKD and related comorbidities to support the development of novel treatments.
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Objective: To develope and validate a reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of vardenafil concentration in plasma of rat. Methods: Plasma samples of normal Sprague-Dawley rats were collected. A Phenomenex Synergi Polar-RP 80A column (2.0 mm×50 mm, 4 µm) was used. Column temperature was set at 30 ℃. Mobile phase A was 0.1% formic acid in water; mobile phase B was 0.1% formic acid in acetonitrile. The flow rate was 0.4 ml/minutes. Quantitative determination was performed by electrospray ionization, operating in positive ion multiple reaction monitoring (MRM) mode. Cisapride was used as the internal standard. The feasibility of the method was evaluated by examining its specificity, linearity and quantitative range, precision and accuracy, matrix effects, and stability. Results: Under the selected chromatographic and mass spectrometry conditions, the monitoring ions of vardenafil and internal standard were mass-to-charge ratio（m/z) 489.3/151.2 and 466.4/234.2, the retention times of vardenafil and internal standard were 2.62 and 2.80 minutes, respectively, and the peak shape was satisfactory. The method has good linearity in the concentration range of 0.2-200 ng/ml. The intra-batch precision (%CV) and accuracy (%DEV) of vardenafil were 1.5%-9.7% and -6.8%-6.6%, respectively. The inter-batch precision and accuracy of vardenafil were 3.1% -8.4% and -3.7%-4.6%, respectively. In this sample processing method, the extraction recovery rate of vardenafil was obtained at range of 88.2%-104.6%, which met the requirements for the investigation of extraction recovery rate. In this sample processing method, the normalized matrix factor of each quality control concentration of vardenafil was 1.04, 0.85, and 1.04, and the coefficient of variation (%CV) was in the range of 1.7%-10.7%, which met the requirements for the investigation of matrix effects. Variations of short-term stability, long-term stability, and stability of 4 freeze-thaw cycles of vardenafil was within ±15%, and the coefficient of variation were within 5%. Conclusion: The high performance liquid chromatography-tandem mass spectrometry method established in this study is feasible for the measurement of concentration of vardenafil in rat plasma and this method has good specificity and high accuracy, and can be used to detect the concentration of vardenafil in rat plasma.
Subject(s)
Animals , Rats , Chromatography, Liquid , Feasibility Studies , Rats, Sprague-Dawley , Reproducibility of Results , Sensitivity and Specificity , Tandem Mass Spectrometry , Vardenafil DihydrochlorideABSTRACT
OBJECTIVE: To prepare a vardenafil cross-linked hydrogel patch and evaluate its quality characteristics. METHODS: The vardenafil cross-linked hydrogel patch was prepared by using sodium polyacrylate as the basic matrix material and aluminum hydroxide as the crosslinking agent, which was compared on transdermal permeation properties in vitro with vardenafil hydrochloride cross-linked patch and vardenafil hydrochloride gel. Transdermal permeation properties and drug content were determined by transdermal diffusion cell and HPLC. Then adhesive force was evaluated by initial adhesion tester, adhesion tester and peel tester. Besides, deformation resistance with moisture, heat and cold resistance, formability and skin irritation were also investigated. RESULTS: The vardenafil cross-linked hydrogel patch was a transparent and gelatinous solid with suitable viscidity. The method of content determination was validated in accordance with the requirements. The in vitro permeation rate of vardenafil cross-linked hydrogel patch fitted the zero-order release realation, and its permeation rate was higher than rates of vardenafil hydrochloride cross-linked patch and vardenafil hydrochloride gel in 24 h. And the cross-linked patch has better deformation resistance with moisture, heat and cold resistance, formability and no skin irritation. CONCLUSION: The vardenafil cross-linked hydrogel patch has good transdermal permeation properties and vardenafil is more suitable for transdermal delivery system than vardenafil hydrochloride, which provides theoretical and practical references for further research.
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Aim To observe the preventive protection of Yingxindan on acute myocardial ischemia induced by sublingual injection of pituitrin ( pit) in rats.Methods Sixty rats were randomly divided into saline group , model group, nifedipine 12.6 mg · kg -1 group, and Yingxindan 25.2, 12.6, 6.3 mg · kg -1 groups.The saline group and model group were given the same vol-ume of water.After administration for 7 d, an acute myocardial ischemia model was induced by sublingual intravenous injection of pit 1 U · kg -1 in the rats 1 h after last administration .The changes of the II electro-cardiogram(ECG) ST segment at different time points , as well as the positive rate of myocardial ischemia and arrhythmia were observed .Meanwhile , the levels of serum creatine kinase ( CK ) , creatine kinase isoenzyme ( CK-MB ) , glycogen phosphorylase isoenzyme BB ( GPBB ) , cardiac troponin I ( cTnI ) and cardiac troponin T ( cTnT ) were observed .Re-sults Yingxindan could suppress the changes of ST segment of electrocardiogram in rats with acute myocar-dial ischemia induced by pit and reduce the positive rate of myocardial ischemia and arrhythmia .The con-tents of myocardial injury markers CK , CK-MB, GPBB, cTnI and cTnT in serum significantly de-creased, and the corresponding relationship existed . The greater the dose of Yingxindan , the smaller the content of myocardial injuried markers in serum .Con-clusion Yingxindan has significant preventive protec-tion effect on acute myocardial ischemia by pit .