OBJECTIVE: To establish an HPLC method for the determination of the contents of the related substances in metoclopramide.METHODS: The sample was separated on C18 column with the mobile phase consisted of acetonitrile-0.02 mol?L-1 phosphonic acid solution(19∶81) at a flow rate of 1.0 mL?min-1.The detection wavelength was set at 275 nm;the column temperature was kept under room temperature and the injected volume was 20 ?L.The contents of the related substances in metoclopramide were computed by self-control method of main constituent.RESULTS: Under the above described chromatographic conditions,metoclopramide was completely separated from its impurities.A good linearity between impurities' peak area and metoclopramide(contrast solution) concentration was achieved when the concentrations of impurities were over the range of 0.05%～4.0%.The lowest detectable limit of metoclopramide was 0.3 ng,and the contents of the related substances were all less than 0.26%.CONCLUSION: The method is convenient,accurate,sensitive and,specific,and it can be used for the determination of the related substances in metoclopramide.

Objective To evaluate the effect of desflurane-remifentanil anesthesia on balance between cerebral oxygen supply and demand during cerebral revascularization in the patients with moyamoya disease.Methods Forty patients of both sexes with moyamoya disease,aged 18-64 yr,with body mass index of 18-25 kg/m2,undergoing superficial temporal artery-middle cerebral artery anastomosis,were allocated into 2 groups using a random number table method:desflurane-remifentanil group (D group) and propofol-remifentanil group (P group),with 20 cases in each group.Anesthesia was induced by intravenously injecting etomidate 0.3 mg/kg,sufentanil 0.4-0.5 μg/kg,and cis-atracurium 0.15-0.2 mg/kg.The patients were mechanically ventilated after tracheal intubation,and the end-tidal pressure of carbon dioxide was maintained at 35-45 mmHg.Anesthesia was maintained with propofol 4-6 mg · kg-1 · h-1 (group P),4％-6％ desflurane (group D),remifentanil 0.1-0.3 μg· kg-1 · min-1,remifentanil 0.1-0.3 μg · kg-1 · min-1 and intermittent intravenous boluses of cis-atracurium,and BIS value was maintained at 40-60.At 15 min after intubation (T1),30 min after skin incision (T2),immediately after opening the dura mater (T3),immediately after vascular bypass and patency (T4),and at the end of surgery (T5),blood samples were obtained from the radial artery and internal jugular bulb for blood gas analysis,jugular venous oxygen saturation (SjvO2) was recorded,and arteriovenous blood O2 content difference (Da-jvO2) and cerebral O2 extraction rate (CERO2) were calculated.Results Compared with group P,Da-jvO2 at T3-6 and CERO2 at T4-6 were significantly decreased,and SjvO2 was increased at T4-6 in group D (P＜0.05).Compared with the value at T1,Da-jvO2 was significantly decreased,and SjvO2 was increased at T5 in group D (P＜0.05).CERO2 was significantly lower,and SjvO2 was higher at T5 than at T3 in group P (P＜0.05).Compared with the values at T4,CERO2 was significantly decreased,and SjvO2 was increased at T5 in P and D groups (P＜ 0.05).Conclusion Compared with propofol-remifentanil anesthesia,desflurane-remifentanil anesthesia can maintain the balance between cerebral oxygen supply and demand better during cerebral revascularization in the patients with moyamoya disease.