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Endogenous opioid deltorphin I (DEL I) and its three analogues (progressive, stepwise repositioning of Asp from 5 to 7) were synthesized by solid phase method. DEL I at 10(-14)-10(-10) mol.L-1 in vitro and at 0.5-5 micrograms.kg-1 in vivo was found to increase the percentages of erythrocyte rosette forming cells (E-RFC) and red blood cell C3b receptor garland (RBC-CR1). This augmentative effect of DEL I was antagonized by naloxone. The results indicate that DEL I enhanced the immune function of rats. The order (from strong to weak) of the analgesic and immune activity was shown to be Asp4, Asp7, Asp5, Asp6 and Asp4, Asp7, Asp6, Asp5 respectively.

Bencynonate is a newly developed anticholinergic drug. After a dose (2 mg/person or 4 mg/person) of bencynonate, the circulating concentrations are so low that therapeutic drug monitoring studies have previously been impossible. Radioisotope assay and radioaccepter assay had been used in rat experiments, but the detections limits of these methods were not sensitive enough for the therapeutic drug monitoring. Further, the two methods were unsuitable in the human. For evaluation of the pharmacokinetics and the relative bioavailability of bencynonate in man, a gas chromatographic--mass spectrometric method for quantitative analysis of bencynonate in human plasma was developed. Deuterated bencynonate served as the internal standard and selected-ion monitoring of the fragments of bencynonate and internal standard permitted the quantitation of bencynonate down to 25 pg.ml-1 of plasma. The linearity was in the range from 25 pg.ml-1 to 3 ng.ml-1 of bencynonate plasma concentration. At 0.25 ng.ml-1 level the recovery and relative standard deviation of variation are 54.3% and 19.1%, respectively. Application of the method to clinical studies gave the results of pharmacokinetics and relative bioavailability of bencynonate in man.

Analytical methods of GC/FID and GC/MS for identification and determination of meperidine, an analgesic drug, and its metabolites were established. The determination of meperidine spiked in urine was shown to have a good linear relationship in the range of 0.1-8.0 micrograms/ml urine (Y = 0.4995X + 0.1201, r = 0.9996). The detection limit was 20 ng/ml urine. With the developed methods, meperidine and its metabolites in urine collected from a meperidine addict were identified and determined. Meperidine, normeperidine, meperidinic acid in free and conjugate forms, normeperidine acid in free and conjugate forms, and acetyl-normeperidine were detected. Among these metabolites, acetyl-normeperidine was reported for the first time.

A method for the monitoring of dihydroetorphine hydrochloride, a powerful anesthetic and analgesic drug, in biological fluid was developed by means of GC-MS with selected ion monitoring. Dihydroetorphine was extracted from human blood and urine with dichloromethane, and then was derivatized with N-heptafluorobutyrylimidazole after it was concentrated to dryness. A dihydroetorphine monoheptafluorobutyl derivative was formed, which showed good characteristics on GC-MS with electronic impact mode. Its M+ was m/z 609. Besides this, its main fragments included m/z 576, 534, 522 and 508. These main ions were all selected as the ions of identification due to their relative peak intensity and stability. The detection limit was 1 pg. The target drug was identified based on its retention time multiple ion monitoring and relative peak intensity. This method has been successfully used for detection of dihydroetorphine hydrochloride in blood and urine from dihydroetorphine addict and poisoned patient, respectively. Good results have been obtained.

SP-6 was synthesized by solid phase method in 95% purity on HPLC. The data obtained from amino acid analysis and fast atom bombardment were in good agreement with theoretical values. Intravenous injection of SP-6 in rabbits at the dosage of 14.3 micrograms/kg. resulted in blood pressure reduction of 4.4 kPa, i.e. 34% (P < 0.001). When the concentration of SP-6 in Tyrode solution was 5.2 x 10(-4) mg/ml the contraction of rabbit duodenum longitudinal muscle increased by 105%. (P < 0.001). When the concentration was more than 1 x 10(-3) mg/ml, the contractile effect was restrained significantly. Dropping 30 microliters of SP-6 (1 x 10(-3) mg/ml) to toad intestinum tenue mesenteriale in situ, the mesentery arterioles were expanded by 30%.

This paper reports the determination of promethazine hydrochloride with Nafion coated glassy carbon electrode by anodic stripping voltammetry. There is a linear relationship between the concentration and peak height in the range of 4 x 10(-8)-5 x 10(-5) mol/L and 8 x 10(-5)-1 x 10(-3) mol/L for promethazine hydrochloride. The raw material and tablets of promethazine hydrochloride have been analysed and good results were obtained.

This paper discusses the reasons why the stability of procaine coated wire electrode is bad. A coated wire electrode was made by coating polyvinyl alcohol (containing procaine hydrochloride) on Ag-AgCl wire followed by covering with PVC membrane. This electrode show to have fine response performance, the stability is also improved greatly.

Using platinum plate coated with PVC membrane as indicator electrode, amitriptyline hydrochloride was titrated with sodium tetraphenylborate by zero-current oscillo-potentiometry titration and zero-current oscillo-bipotentiometric titration. Both methods are precise, audio-visual, simple and convenient and can be used in the determination of other medicines.