ABSTRACT
Objective:To establish an HPLC coupled with post column derivatization method for the determination of gentamicin C components and the related substances based on the latest European Pharmacopeia and compare with the electrochemical method. Methods:A Hydrophilic C18(250 mm ×4.6 mm, 5 μm)column was used with acetonitrile-50 mmol·L-1 sodium hydroxide solution ( pH 2. 6) containing 0. 7% trifluoroacetic acid and 0. 025% pentafluoropropanoic acid (1. 5∶98. 5) as the mobile phase. The temper-ature of post-column reaction was set at 30℃, and the samples were detected by a fluorescence detector withλex of 340nm andλem of 430nm. A pulsed amperometric detector (PAD) was applied in the electrochemical method with golden working electrode in a four-po-tential working mode. Results: According to the results of the two detection methods, the linear range of C1a , C2 , C2a and C1 was 5.82-233.00,6.92-277.00,4.00-160.00and6.23-249.00 μg·ml-1(r >0.9993) , respectively. The limit of detection and quantization were 0. 92-3. 28ng and 1. 37-5. 19ng, respectively. Conclusion:There is no significant difference between the determina-tion results of the two methods.
ABSTRACT
Objective:To establish a method for the determination of sodion in cefalotin sodium by ion chromatography and investi-gate the salt-forming rate of the products. Methods: A TSKgelSuper IC-CR cation exchange column (150 mm × 4. 6 mm, 3. 0 μm) was used. The mobile phase was the mixture of 2. 2 mmol·L-1 methanesulfonic acid and 1 mmol·L-1 18-crown-6-ether with the flow rate of 0. 8 ml·min-1 . The column temperature was 40℃ and the injection volume was 20μl. The detector was an electric conductiv-ity detector. Results:The linear correlation of sodion was good within the range of 3. 0-60. 0μg·ml-1(r=0. 999 9). The average re-covery was 99. 8%(RSD=0. 8%, n=9). The mole number ratio of sodion to cefalotin was within the range of 0. 97-1. 03. Conclu-sion:The method is specific, precise and accurate, and can be used in the determination of sodion in cefalotin sodium. The salt-form-ing rate of the 8 batches of samples is promising.
ABSTRACT
Objective To study the effects of Pinacidil on Ventricular Repolarization in LQT2 Rabbit Heart.Methods 30 New Zealand white rabbits weighted from 2.5~3.0 kg were randomly divided into 3 groups:group A(control),group B(pinacidil),group C(pinacidil + glibenclamide).Left ventricular endocardium and epicardium MAPs and volume-conducted ECGs in isolated Langendorff-perfused rabbit hearts were recorded simultaneously.To induce bradycardia,the AV nodes of rabbit hearts were damaged.EAD and TdP were induced by means of bradycardia in the presence of high concentration of d-sotalol(10-4M).Results In group B,pinacidil(5?mol/L)shortened the APD90 on endocardium from 445.48?54.31ms to 278.87?44.45ms after administration of pinacidil for 5 minutes(P0.05 vs.group A for all).Conclusion Pinacidil can decrease prolonged action potencial duration and TDR induced by bradycardia and high concentration of d-sotalol in rabbit hearts.Also,pinacidil could abolish the EAD and TdP related to delayed repolarization that may provide a novel and useful intervention in the clinical LQTS patients.