ABSTRACT
OBJECTIVE: To identify the structure of illegal additive D- (-) -isoascorbic acid in vitamin C Yinqiao tablets and to screen for it in different samples. METHODS: The separation of D- (-) - isoascorbic acid in vitamin C Yinqiao tablets was performed on a CAPCELL PAK NH2 column (4.6 mm × 250 mm, 5 μm) with mobile phase consisting acetonitrile -20 mmol · L-1 ammonium acetate (adjusted to pH 2.5 with formic acid) (60:40), the flow rate was 1.0 mL · min-1. D-(-)-isoascorbic acid was detected by diode array detector at 246 nm. Electrospray ionization (ESI) source in positive ion mode was applied for the identification with following parameters; nebulizer pressure of 220 kPa, drying gas temperature of 350°C, flow rate of 12 L · min-1, and capillary voltage of 3.5 kV. The additive D-(-)- isoascorbic acid in vitamin C Yinqiao tablets was separated and prepared by HPLC for further structure confirmation by 13C-NMR. RESULTS: The structure of the additive was elucidated by analyzing the fragment of [M + H]+ of the additive and comparing with that the reference substance. The additive was further confirmed as D-(-)- isoascorbic acid by 13C-NMR. D-(-) - isoascorbic acid was detected in 64 of 366 batch samples. CONCLUSION: The LC-MS method is accurate and sensitive, which can be used for rapid screening and identification of the illegal additive D- (-) - isoascorbic acid in vitamin C Yinqiao tablets. Copyright 2012 by the Chinese Pharmaceutical Association.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate whether the separating brachial plexus block combined with preoperative analgesia by patient controlled analgesia (PCA) can be applied in tendon repair and postoperative active or passive functional exercise.</p><p><b>METHODS</b>Two hundred and ten cases with tendon injury were randomly divided into 3 groups and all of the patients were administered Bupivacaine (0.25%), Papaverine (0.0625 mg/ml), and Dexamethasone (0.25 mg/ml) in separating brachial plexus block through axillary approach. Group A was control group, and preoperative analgesia was not applied. Preoperative analgesia was applied in group B and C. Tramadol and Ondansetron were administered in group B, Midazolam was administered besides Tramadol and Ondansetron in group C. The injection volume in the PCIA pump was increased to 100 ml by mixing physiologic saline. The pump was started after separating brachial plexus block in velocity of 2 ml/h, and its maintenance time was 48 h. The effect of separating brachial plexus block at 1, 2, 3, 6 and 12 h after finishing brachial plexus block was compared. The VAS, Ramesay assessment scoring were recorded at 0, 12, 24 and 48 h after starting pump.</p><p><b>RESULTS</b>In each group, the effect of motor block became greater in the ascending order from 1, 2 to 3 h after finishing brachial plexus block, and less in the descending order from 3, 6 to 12 h after finishing brachial plexus block. Only at 6 and 12 h after finishing brachial plexus block, the effect of motor block of group B and group C was significantly less than that of group A (P < 0.05, < 0.01), the effect of motor block of group C was less than that of group B (P > 0.05). The effect of sensory block in the patients of all 3 groups was satisfactory. The VAS, Ramesay assessment scoring, effect of analgesia and sedation at 24 and 48 h after starting pump became greater in the ascending order from group A to group C, in which group B and group C were significantly greater than group A (P < 0.01).</p><p><b>CONCLUSIONS</b>The separating brachial plexus block combined with preoperative analgesia by 2 kinds of PCIA dispensation can be both applied in tendon repair, but the separating effect of brachial plexus block of group B was superior to the group C.</p>