ABSTRACT
Intracranial atherosclerosis (ICAS) is a common cause of ischemic stroke. The symptomatic ICAS is closely associated with frequent stroke recurrence, while the asymptomatic ICAS has evidently higher risk of future stroke onset. High-resolution magnetic resonance imaging is regarded as a significant emerging method. In addition to non-invasive identification of intracranial artery stenosis causes, accurate stroke mechanism judgment and plaque stability evaluation, it has great advantages and clinical value in observing the dynamic evolution of lesions and characteristics of perforating arteries, evaluation of drug efficacy and guidance of intravascular treatment of intracranial artery stenosis. The article aims to review the recent development of researches in the mentioned aspects.
ABSTRACT
OBJECTIVE:To establish a method for the determination of related substances in bisacodyl raw material and enteric-coated tablet. METHODS:HPLC was performed on the column of Hibar C18 with mobile phase of acetonitrile-20 mmol/L ammonium acetate (acetic acid adjust pH to 5.0)(55∶45,V/V),detection wavelength was 265 nm,flow rate was 1.0 ml/min, column temperature was 30℃,and the injection volume was 20 μl. RESULTS:The linear range of bisacodyl was 0.25-5.0 mg/ml (r=0.999 9);the limits of detection and quantification were 19-25 ng and 61-68 ng for bisacodyl and impurity A,B,C,D and E;RSDs of precision,stability and reproducibility tests were lower than 2%;recovery was 99.50%-101.00%(RSD=0.5%,n=9). CONCLUSIONS:The method is specific, sensitive and reproducible, and can be used for the determination of related substance in bisacodyl raw material and enteric-coated tablet.
ABSTRACT
OBJECTIVE:To establish a method for simultaneous residual determination of dichloromethane and ethyl acetate in bisacodyl raw material. METHODS:Head-space GC was performed on the capillary column of 6% cyanopropyl phenyl-94% di-methyl polysiloxane(DB-624)by temperature programming,the temperature of injector was 220 ℃,detector was flame ionization detector with temperature of 250 ℃,carrier gas was high purity nitrogen with the flow rate of 3.0 ml/min,split ration was 1∶10, headspace heating temperature was 70 ℃,equilibration time was 30 min,volume of headspace vial was 5 ml,and the injection volume was 1 ml. RESULTS:The linear range was 6-120μg/ml for dichloromethane(r=0.999 9)and 50-1 000μg/ml for ethyl ac-etate(r=0.999 9);the limit of quantitation was 0.2,1.7 μg,limit of detection was 0.06,0.5 μg;RSDs of precision,stability and reproducibility tests were no higher than 3%;recoveries were 100.30%-102.00%(RSD=0.63%,n=9) and 100.10 %-101.30%(RSD=0.44%,n=9). CONCLUSIONS:The method is simple and accurate,and can be used for the simultaneous residual deter-mination of dichloromethane and ethyl acetate in bisacodyl raw material.