Simultaneous determination of pirlindole enantiomers and dehydropirlindole by chiral liquid chromatography.

Liquid chromatography was employed for the determination of pirlindole enantiomers and its oxidation product dehydropirlindole (DHP). The direct separation of pirlindole enantiomers and DHP was achieved on a cellulose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase (Chiralcel OD-R). Acetonitrile was used as the organic modifier and sodium perchlorate was used as an ionic additive in the mobile phase. The influence of acetonitrile and sodium perchlorate concentrations on enantioselectivity and achiral selectivity towards DHP was investigated in order to find suitable conditions for the determination of low amounts of each analyte. The mobile phase selected consisted of a mixture of acetonitrile and phosphate buffer (pH 5.0) containing sodium perchlorate (0.05 M) (35:65, v/v) and the UV detector was set at 220 nm. The method developed was validated and was found to be linear in the 0.1-5 microg ml(-1) range (r2 = 0.999 for the three compounds). Repeatability and the intermediate precision for the three analytes at a concentration of 0.1 microg ml(-1) were about 3 and 4%, respectively. This concentration corresponds to the quantification of 0.1% for the minor enantiomer. Actual determinations of enantiomeric purity for single enantiomers of pirlindole were performed.

[Ulcer risk caused by reflux prevention? Results of jejunal interposition]. / Ulcusrisiko durch Refluxverhütung? Ergebnisse der Jejunum-Interposition.

The results of isoperistaltic jejunal interposition in reconstructive ulcer surgery are demonstrated on the basis of 62 patients, operated one and a half to nine years ago. The operations had been done because of dumping, reflux gastritis and afferent loop syndrome. Now 38 (65.5%) of the followed-up patients had a Visick I or II grading, 16 (27.5%) were Visick III. The endoscopical gastric mucosal biopsy showed normal mucosa as well as superficial gastritis or atrophic gastritis in different patients. By comparison with the preoperative biopsies no protective effect of the bile diversion on the gastric mucosa could be demonstrated. On the contrary 12 of 58 patients (20.5%) developed stomal ulcerations, which were often asymptomatic, mostly superficial and in 8 cases had to be operated in the meantime. The gastric acidity analysis showed a low gastric output with low pH values (pH 2.7--3.4). The incidence of stomal ulceration in jejunal interposition seemed to correlate with the reflux preventive effect. The longer the segment and the better the reflux preventive effect were, the higher was the ulcer risk. The parallelity of reflux preventive ulcer surgery and the ulcer provocation by the Mann-Williamson experiment is demonstrated. Therefore reflux preventive surgery should be used very carefully and in reconstructive procedures only. Using the jejunal interposition the segment should not be longer than 12--15 cm and a vagotomy has always to be added.