Separation and Characterization of Unknown Impurities and Isomers in Cefminox Sodium and Study of the Forming Mechanisms of Impurities by Liquid Chromatography Coupled with Ion Trap/Time-Of-Flight Mass Spectrometry.

Thirteen unknown impurities and isomers in cefminox sodium were separated and characterized by liquid chromatography coupled with high-resolution ion trap/time-of-flight mass spectrometry (LC-IT-TOF-MS) with the positive mode of electrospray ionization (ESI) method. New HPLC-gradient elution method was developed for the detection of impurities in cefminox sodium. And the ESI ion trap multiple-stage tandem mass spectrometry had been applied successfully to the direct investigation of impurities and isomers in cefminox sodium. The fragmentation patterns and structural assignment of these impurities were studied. Full scan liquid chromatography-mass spectrometry (LC-MS) was first performed to obtain the m/z value of the protonated molecules and formulas of all detected peaks, LC-MSn (n = 1-6) were then carried out on the compounds of interest. Structures of 13 degradation products in cefminox sodium were deduced based on the high-resolution MSn (n = 1-6) data, assisted by the UV spectra and stress testing. And the forming mechanisms of degradation products in cefminox were also studied. The method of LC-IT-TOF-MSn (n = 1-6) was worthy of widespread use and application for the further improvement of official monographs in pharmacopoeias with the advantages of stability and repeatability.

Quantitative determination of semisynthetic cephamycins in human serum and urine by ion-exchange, reversed-phase and ion-pair chromatography.

High-performance liquid chromatographic methods have been developed for the determination of semisynthetic cephamycins: cefoxitin, cefmetazole and cefminox in human serum and urine samples. Serum samples spiked with each cephamycin were combined with an equal volume of methanol to remove proteins and, after centrifugation, and aliquot of the supernatant was analysed by ion-exchange, reversed-phase and ion-pair chromatography with hexadecyltrimethylammonium bromide as the ion-pairing agent. Urine samples were diluted, filtered and analysed by same chromatographic procedure. The cephamycins were detected by their ultraviolet absorbance (265-272 nm). It was possible to determine concentrations of cephamycins to 0.2 micrograms/ml in serum 2 micrograms/ml in urine samples with a good level of reproducibility and accuracy.

Determination of cefoxitin in serum and tissue.

A simple, rapid and sensitive method for the clean-up and analysis of cefoxitin in serum and tissue is described. Serum (0.5 ml) and tissue (100 mg) samples after homogenization underwent high speed centrifugation. Chromatography was performed on a muBondapak C18 cartridge using a mobile phase of 0.005 M potassium dihydrogen phosphate-acetonitrile-glacial acetic acid (77.5:22:0.5, v/v/v) with a flow-rate of 2.0 ml/min. Ultraviolet detection occurred at 235 nm. The procedure produced a linear curve for the concentration range 100-5000 ng/ml. The assay produced accurate, repeatable and rapid results for both tissue and serum samples without the need for chemical extraction.

Development of indicators for cephamycin bioassay.

Several species of bacteria have been tested, for their sensitivity to cephamycin C and other beta-lactam antibiotics with a view to develop an indicator system for identification and quantitation of cephamycin. During the study, a mutant derived from E. coli K 802, exhibited a 10-fold increased sensitivity to cephamycin C than E. coli ESS (reference strain)1,2 and was designated as supersensitive E. coli K 8025. Another interesting feature observed during the investigation was that a strain of Serratia, showed a high degree of resistance to penicillins and cephalosporins however, it was sensitive to cephamycin and its derivative. It has been suggested that E. coli K 8025 and Serratia would serve as good indicator organisms for detection and quantitation of cephamycin.

Analysis of binary mixtures of cephalothin and cefoxitin by using first-derivative spectrophotometry.

A method for the analysis of two-component mixtures of cephalothin and cefoxitin using zero-crossing first-derivative spectrophotometry is described. This technique permits the quantification of these drugs with closely overlapping spectral bands without any separation step. Linear calibration graphs of first-derivative values at 235.00 and 236.75 nm for cephalothin and cefoxitin, respectively, with negligible intercepts were obtained versus concentration in the range 4.0-32.0 micrograms ml-1 for both antibiotics. This paper presents a systematic examination of the experimental data by applying an exhaustive statistical analysis to demonstrate the validity of the method. The results of the determination of these antibiotics in mixtures of injectable dosage forms are also presented, together with their determinations in physiological serum and glucosed physiological serum.

[Transference of antibiotics into prostatic tissues: sampling method by transurethral resection for the measurement of the concentration of antibiotics in prostatic tissue].

The transeference of two antibiotics, i.e. cefmetazole (CMZ) and fosfomycin (FOM), into prostatic tissues was examined. Prostatic tissue samples were obtained from patients with benign prostatic hyperplasia while undergoing open prostatectomy or transurethral resection of the prostate (TUR-P). 2 g of CMZ or 4 g of FOM was intravenously administered within about 10 minutes starting 1 hour before the removal or resection of the prostate, and blood samples were collected at the end of the administration and during surgery. In TUR-P, resected prostatic tissues were washed with the TUR perfusate and the antibiotic in the tissue was presumed to be released into the perfusate. The following preliminary experiments were, therefore, carried out. The removed prostate was divided into three segments, i.e. urethral region, central region and capsular region, and the CMZ or FOM level in each tissue was measured. The remaining tissues were cut into small pieces for immersion in the TUR perfusate for 10-90 minutes. The tissue fragments were removed every 10 minutes to measure the tissue concentration of CMZ or FOM. The concentration of CMZ or FOM in the prostatic tissues did not vary among the three regions, however it markedly decreased with increase in the period of immersion. This suggested that the concentration of these agents into the prostatic tissues was represented by the concentration in the tissues near the urethra obtained immediately after the start of TUR-P.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of cefminox on bacterial flora in human adult feces].

Cefminox (CMNX), a new cephamycin, was administered by one shot intravenous injection twice daily with a dose of 1,000 mg each time for 5 days to seven healthy male volunteers whose ages ranged from 21 to 28 years (mean: 25 years) and body weights were from 60 to 92 kg mean: 72 kg). The effect of the drug on fecal bacterial flora was investigated and the concentrations of the drug in feces were measured on 5th day before the treatment, on 0, 3rd, and 5th day (the final day of the treatment) during the treatment, and on 3rd, 5th, and 10th day after the treatment. Antibiotic susceptibility tests of CMNX, cefmetazole (CMZ) and cefotaxime (CTX) against several strains of organisms isolated from feces of the seven volunteers were performed. Clinical adverse reactions and effect on laboratory examinations were also investigated. The results of the study are described as follows. Among Enterobacteriaceae, populations of E. coli, Klebsiella sp. and Citrobacter sp. temporarily disappeared during the treatment of CMNX. After 5-day-treatment, that of Citrobacter sp. transiently increased and the isolation of Enterobacter sp. increased during treatment and up to 5 days after treatment, while those of Proteus sp., H. alvei, or Serratia sp. did not show a definite change. The mean Enterobacteriaceae population in general was 10(8) to 10(9) cells/g feces, showing almost no variation, on all examination days except 5th day during treatment when these organisms were not isolated from only one subject. No remarkable change was not found in populations of other isolated organisms including Gram-negative bacilli; Aeromonas sp., Pseudomonas sp. and Acinetobacter sp., and Gram-positive bacteria; Staphylococcus sp., Enterococcus sp., Micrococcus sp. and Candida sp. Among anaerobes, the mean population of Bacteroides sp. was 10(10) to 10(11) cells/g feces, showing almost no variation, and C. difficile was not isolated from any subject, however the toxin was detected in samples from 5 of 7 subjects; one subject showed always positive for toxin on all examination days; 1 on 5th day during treatment to 10th day after treatment; 2 on 5th and 10th day after treatment, and 1 only on 10th day after treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Drug monitoring by a fully automated high-performance liquid chromatographic technique, involving direct injection of plasma.

A procedure involving direct injection of whole plasma for analyses of drugs by an automated high-performance liquid chromatograph was developed. This system comprised two columns, two pumps, one detector, two programmable switching valves, an automatic sample injector with a cooling device for sample tubes and a microprocessor. Effluents from the first column, containing a drug of interest, were selectively introduced into the second column for further separation. The columns used were an aqueous gel chromatography column (column 1) and an ODS column (column 2). The solvent for column 1 must be weaker than that for column 2, so that the solutes from the former will be enriched at the top of the latter. The validity and applicability of this procedure for the study of drug metabolism were demonstrated with the antibiotic cefmetazole, the anticoagulant warfarin, the antitumour agent carboquone and the anaesthetic ketamine.

High-performance liquid chromatographic analysis of cefotetan epimers in human plasma and urine.

Cefotetan, a new broad-spectrum 7 alpha-methoxycephalosporin antibiotic, was assayed in plasma and urine by means of reversed-phase high-performance liquid chromatography. Commercially available cefotetan exists in two epimeric forms. The procedure described allows the separation and quantitation of both epimers. For the first time a different pharmacokinetic behaviour (t1/2 = 3 h versus 4 h) for each epimer after intravenous injection to healthy volunteers is demonstrated. It is assumed that one epimer is bound to a greater extent to serum proteins and is therefore responsible for the differences observed. As both epimers exhibit similar antibacterial activity, it seems doubtful whether these differences would have clinical significance. Iothalamic acid was determined simultaneously as a marker of kidney function.

[Fundamental and clinical studies on T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

Fundamental and clinical studies on T-1982 (cefbuperazone), a new cephamycin antibiotic, were carried out, and the following results were obtained. When T-1982 was administered at a dose of 1 g by intravenous drip infusion for 30 minutes or 1 hour, the concentration in serum showed as high as 23.0 micrograms/ml or 25.0 micrograms/ml even 2 hours after administration. The concentrations in the genital tissues about 5 hours after administration ranged 1.2-45.6 micrograms/g for 30 minutes drip infusion and 0.9-26.8 micrograms/g for 1 hour drip infusion. From these results, T-1982 was supposed to maintain the in vivo concentration to inhibit 80-100% the growth of bacteria such as S. aureus, E. coli, Klebsiella, Proteus, S. marcescens and Gram-negative anaerobic bacteria, B. fragilis which were often isolated clinically in the field of obstetrics and gynecology. When T-1982 was administered at a dose of 1-2 g twice a day to 14 patients with female genital infection; 2 intrauterine infection, 2 pyometra, 7 pelveoperitonitis, 1 adnexitis, 1 adnexal abscess and 1 vaginal cuff abscess, the clinical results were excellent in 9, effective in 4 and poor in 1. The efficacy rate was 92.9%. No side effects nor abnormalities in laboratory findings were observed in any of the 14 cases. These results suggest that T-1982 has efficacy for the treatment of obstetrical and gynecological infections.

[Fundamental study on T-1982 (cefbuperazone) in obstetrics and gynecology].

Following results were obtained from intravenous administration of T-1982 (cefbuperazone) 1 g by measuring its concentrations in uterine arterial serum, cubital venous serum, oviduct, ovary and several sites in uterine tissue. Endometrium showed the highest concentration among various uterine tissues by any administration (bolus injection, dripping infusion for 1 or 2 hours). Transfer concentrations about 1 hour after the end of 1 hour drip infusion proved to be almost the same as 2 hours drip infusion. In the field of obstetrics and gynecology, it was considered that T-1982 has good efficacy in infections especially caused by E. coli, Klebsiella and Proteus.

[Fundamental and clinical studies of T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

Fundamental and clinical studies on T-1982 (cefbuperazone), a new cephamycin antibiotic, in the field of obstetrics and gynecology were carried out, and the following results were obtained. The levels of T-1982 transferred to uterine artery, elbow vein and uterus were determined after intravenous drip infusion of 1.0 g for 1 or 2 hours. No difference of concentration between uterine artery and elbow vein was observed from 45 minutes to 5 hours after the end of administration. The concentration of T-1982 in uterine artery ranged from 9.8 to 48 micrograms/ml after drug administration, and decreased slowly, but remained at about 10 micrograms/ml even 5 hours after the end of administration. Endometrium exhibited comparatively higher concentration of T-1982, but the difference of concentration was not observed among the other uterine tissues. T-1982 concentration ratios of various uterine tissues to elbow vein blood ranged from 172 to 10.2%, and mean ratio was 34.7%. Also, T-1982 concentration of more than 3 micrograms/g in each tissue was maintained for 2 hours after the end of administration. Clinical results on abscess of Bartholin's gland (1) and adnexitis (1) were good, although bacteria were not detected. No side effects caused by the drug were observed. These results indicate the usefulness of T-1982 in the treatment of infections in obstetrics and gynecology.

[Fundamental and clinical studies on T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

Fundamental and clinical studies on T-1982 (cefbuperazone) in the field of obstetrics and gynecology were carried out. Transfer of T-1982 to various location in uterus tissue was more than 10 micrograms/g over 2 hours after T-1982 1 g intravenous injection. T-1982 was distributed in cervix uteri at the highest concentration followed by ovarium, oviduct, portio vaginalis, endometrium and myometrium. Mean transfer ratio of cervix uteri to uterus arterial blood was 67.6%. Ten cases of gynecological infections receiving T-1982 demonstrated "good" results in 9 cases, except 1 case excluded from the evaluation of efficacy. Neither side effect nor clinical test abnormality was observed. Based on the results of basic and clinical studies, T-1982 is considered to have efficacy in the treatment of gynecological infections.

[Experimental and clinical evaluation of T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

Experimental and clinical studies of T-1982 (cefbuperazone), a new cephamycin antibiotic, were performed in the field of obstetrics and gynecology, and the following results were observed. T-1982 was determined for its in vitro activity against 180 recent clinical isolates in comparison with cefmetazole (CMZ) and cefazolin (CEZ). The activity of T-1982 was superior to that of CMZ against E. coli (101 strains) and B. fragilis (19 strains), and similar to that of CMZ and CEZ against Peptococcus (34 strains). High concentrations of T-1982 exceeding the MIC values against various bacteria were maintained for a few hours in the female genital organs and postoperative retroperitoneal exudate after intravenous drip infusion of 2 g. T-1982 was administered to a total of 6 patients in daily dose of 2 approximately 3 g for 2 approximately 10 days. The clinical results were excellent or good in 5 cases. Drug eruption was observed in 1 case. These results suggest that T-1982 is highly effective for the treatment of bacterial infections in this field.

[Fundamental and clinical studies on T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

Fundamental and clinical studies were made on T-1982 (cefbuperazone) and the results were obtained as follows. Serum and uterine tissue concentrations of T-1982 were determined at 26 minutes before and at 20 to 80 minutes after the completion of intravenous drip infusion of 1 g. The levels of T-1982 in the fallopian tube, ovarium, endometrium, myometrium and uterine cervix were 23.7, 19.5, 50.5, 10.9 micrograms/g and 17.5 micrograms/g at 20 minutes after the completion of infusion. The levels were sufficiently effective against major pathogens (Gram negative bacteria and anaerobic bacilli) isolated in the field of obstetrics and gynecology. T-1982 was administered to 11 patients, including 7 of acute adnexitis, each one of pelveoperitonitis, pyometra, puerperal fever, and 1 of puerperal fever with sepsis, at a dose of 1-2 g twice a day for a period of 5 to 9 days by intravenous injection or intravenous drip infusion. Clinical responses were excellent in 5, good in 3 and poor in 3. No adverse reactions nor marked changes in laboratory findings were observed in any of the cases treated with T-1982.

Treatment of serious infections with moxalactam.

In 93 hospitalized patients, 111 bacterial infections were treated with moxalactam. Eighty-three infections responded well to therapy, nine infections failed to respond to therapy or relapsed, and nine infections showed superinfection with resistant bacteria. The great majority of bacteria isolated had mean inhibitory concentrations below levels readily achieved in plasma, cerebrospinal fluid, bile, abscess fluid, and peritoneal fluid. Among the commonly identified bacteria, only Pseudomonas aeruginosa, enterococci, and Staphylococcus epidermidis had variable sensitivity to moxalactam.