Determination of unbound cefmetazole in rat blood by on-line microdialysis and microbore liquid chromatography: a pharmacokinetic study

A specific and sensitive microbore liquid chromatographic method for the determination of unbound cefmetazole in rat blood was developed. A microdialysis probe was inserted into the jugular vein/right atrium of a Sprague-Dawley rat. Cefmetazole (10 mg/kg, i.v.) was then administered via the femoral vein. Dialysates were automatically injected into a liquid chromatographic system via an on-line injector. Isocratic elution of cefmetazole was achieved by LC-UV within 10 min. Intra- and inter-assay accuracy and precision of the assay were < or = 10%. The detection limit of cefmetazole was 20 ng/ml. Pharmacokinetic analysis of results indicated that unbound cefmetazole levels in rats best fit a biexponential decay model.

Distribution of free and liposomal cefoxitin in plasma and peritoneal fluid in a porcine intra-abdominal sepsis model

The plasma and peritoneal fluid pharmacokinetic parameters obtained after the intravenous administration of free and liposomal cefoxitin were studied in a porcine model of intraabdominal sepsis. No prior assumptions were made to predict the number of compartments pertaining to drug clearance from the administration of either cefoxitin formulation. The experimental data obtained were applied to fit mathematical models of multiexponential drug clearance and the pharmacokinetic data were found to best fit a two-compartment open model. Liposomal encapsulation significantly altered the plasma drug distribution pattern resulting in changes in the magnitude of a number of pharmacokinetic parameters examined. The mean post-distributive half-life of liposomal cefoxitin was substantially longer than that of free cefoxitin by at least 3 times. The peritoneal cavity appeared to provide a reservoir for the initial distributive phase of rapid drug clearance from the plasma compartment followed by a less-rapid post-distributive phase. The cumulative drug level, as determined by the area under the concentration curve (AUC) as a function of time, in the plasma of animals treated with liposomal cefoxitin was about 3-4 fold as high as that of animals treated with free cefoxitin. The differences in pharmacokinetic parameters appeared to account for the improved therapeutic efficacy of liposomal cefoxitin in this animal model.

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.

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.

[Clinical study on transfer into lung tissue of cefminox]

Nineteen patients who underwent pulmonary resection due to lung diseases were administered with 2 g of cefminox (CMNX) by intravenous drip infusion just before surgery. CMNX levels in the serum and lung tissue were determined and pharmacokinetic parameters were derived. The obtained results are summarized as follows: 1. Pharmacokinetic parameter (K1/K2) derived from serum and lung tissue concentrations using deconvolution method was 0.46. 2. CMNX was useful for prophylaxis of postoperative infections with lung resection.

Cefminox: correlation between in-vitro susceptibility and pharmacokinetics and serum bactericidal activity in healthy volunteers

Plasma concentration of cefminox and serum bactericidal activity against four ATCC strains (Escherichia coli 25992, Klebsiella pneumoniae 13833, Serratia marcescens 8100 and Bacteroides fragilis 25285), were determined over a 24 h period after administration of cefminox 1 and 2 g to six healthy volunteers in a randomized, cross-over, single blind study. The increase observed in the area under the bactericidal curve (AUBC) with the 2 g dose was at least 3.5 times that seen with the 1 g dose for all four test strains and was larger than predicted by the corresponding increase (1.84 times) in the area under the serum concentration versus time curve (AUC); a correlation (r = 0.88, P = 0.0001) between the cefminox concentration and the serum bactericidal titres was, however, observed with all four strains tested. The MBC6h showed a better association with the serum bactericidal titre (P < 0.01) than did the MIC or MBC.

Nanoscale packed capillary liquid chromatography-electrospray ionization mass spectrometry: analysis of penicillins and cephems

A series of seventeen penicillins and cephems (cephalosporins and cephamycins) was examined by electrospray ionization. Separations by nanoscale packed-capillary liquid chromatography, with sub-microliter flow-rates, were performed using methanol-water and acetonitrile-water both containing trifluoroacetic acid gradients. In the on-column analyses, the protonated species usually predominate, and the fragment ions are often present which can be used for confirmation of compound identity. With combined nanoscale packed-capillary liquid chromatography-electrospray ionization mass spectrometry, separations and full-scan mass spectra can be obtained on *q12-15 ng of analyte, allowing the analysis of therapeutic levels of these antibiotics from only a few microliters of serum.

[Study on the concentration of cefminox sodium in serum and prostatic tissue]

The concentration of cefminox sodium (CMNX) in serum and prostatic tissue was determined in 25 patients with benign prostatic hypertrophy. One gram of CMNX was intravenously administered prior to transurethral prostatectomy. Blood and prostatic tissue were obtained 1 hour after the administration of CMNX. The concentration of CMNX was 69.17 +/- 17.47 micrograms/ml (mean +/- SD) in serum and 5.33 +/- 2.33 micrograms/g (mean +/- SD) in the prostatic tissue. The ratio of the prostatic tissue concentration/serum concentration was 8.18 +/- 4.45% (mean +/- SD). There was no correlation between serum and prostatic tissue level of CMNX.

Effects of cefbuperazone on the chemiluminescence of human neutrophils

To investigate the in vivo effect of antimicrobial agent on neutrophil chemiluminescence and serum opsonic activity, cefbuperazone sodium (CBPZ) was administered to healthy male volunteers via an intravenous drip. A peripheral blood sample (10 ml) was collected 7 times: prior to injection, then 1, 3, 6, 9, 12 and 24 h after injection. Neutrophil chemiluminescence and serum opsonic activity was measured by the simultaneous multiple measurement system based on luminol-dependent chemiluminescence and indicated by peak height and peak time. Neutrophils were activated at hour 1 from the point of view of peak height and statistical significance was observed. The fluctuation of serum opsonic activity was small and statistical significance was not observed. CBPZ has an in vivo effect on neutrophils which was not supposed from in vitro study.

[Study of the prostatic tissue cefbuperazone (CBPZ) level]

The concentration of Cefbuperazone (CBPZ) was determined in the prostatic tissue and serum of 23 patients with benign prostatic hypertrophy. One or 2 of CBPZ was injected intravenously prior to transurethral prostatectomy. The mean CBPZ level in prostatic tissue and tissue/serum ratio at 1 hour was 17.4 +/- 7.2 micrograms/g (28.9 +/- 9.1%) in 10 patients administered 1 g of CBPZ, and 34.7 +/- 1C.2 micrograms/g (35.7 +/- 13.2%) in 13 patients administered 2 g of CBPZ. Serum and prostatic tissue CBPZ levels responded satisfactorily to the dose of CBPZ. Weights of resected prostatic tissue were not correlated to the tissue CBPZ level. Judging from the inhibitory concentration of CBPZ (minimum inhibitory concentration 80), the prostatic tissue CBPZ level was sufficient against pathogenic bacteria, particularly E. coli, K. pneumoiae and P. mirabilis for a relatively long time. For this reason CBPZ is a very useful drug for treatment of bacterial prostatitis and postoperative infection of prostate.

[Changes in concentration of cefotetan in blood and lung tissue after intravenous administration]

Cefotetan (CTT), a newly-developed cephamycin antibiotic, has been used widely for the treatment of various infectious diseases because of its excellent antibacterial potency and dynamic transport in vivo. Although the drug transfer to almost every organ, tissue, and body fluid has been studied, only a few reports are available regarding the transfer to lung tissue. In the present study, 1 g of CTT was intravenously injected in a single dose to each of 22 patients subjected to pulmonary resection. Subsequently, its concentrations in blood and lung tissue were measured in sequence. The degree of transfer of the drug to the lung tissue was calculated to evaluate the pharmacodynamics of CTT in vivo. The following results were obtained in this analysis. 1. The T1/2(beta) of the concentration in blood was 4.18 hours, and AUC0-infinity was 478.7 micrograms.hr/ml. 2. Cmax in the lung tissue was 31.5 micrograms/g, and Tmax was 0.83 hour, and tissue concentrations decreased in parallel to blood concentrations. CTT was transferred to the lung tissue to achieve high concentrations following an intravenous administration. Since high concentrations are maintained for a long period of time, this antibiotic is expected to exert an excellent effect in the prevention and the treatment of respiratory infections.

The effects of cefotetan disodium on haemostasis

A 7-day course of intravenous cefotetan disodium was given to nine patients. No significant changes were observed in haematological or biochemical parameters and serum vitamin K1 levels, prothrombin times, factor VII levels, thrombin times and activated partial thromboplastin times remained within the normal ranges throughout the treatment period in all patients. There was no evidence of clinical bleeding in any patient although in two the bleeding time was prolonged up to 13.0 min after 7 days' therapy. Notably, adenosine-5-diphosphate (ADP)-induced platelet aggregation responses were significantly increased (P less than 0.05) at the end of the treatment period. These data indicate that cefotetan disodium at a dose of up to 4 g daily can be used without risk of a bleeding diathesis. In situations associated with vitamin K1 deficiency, potential prolongation of the prothrombin time should be avoided by prophylactic vitamin K1 administration.

[Serum and sputum levels of cefotetan used in respiratory tract infections]

In 5 patients with respiratory tract infections, concentrations of cefotetan (CTT) in serum and sputum after 1 hour intravenous administration of 2 g of CTT to each patient were investigated, and following results were obtained. Serum levels of CTT The mean peak level of CTT was 232.0 +/- 16.2 micrograms/ml immediately after the 1 hour drip infusion, then declined gradually and was 48.0 +/- 8.8 micrograms/ml after 6 hours. Sputum levels of CTT Mean sputum levels of CTT were 2.15 +/- 0.19 micrograms/ml from 2 to 4 hours after the administration and 2.19 +/- 0.18 micrograms/ml from 4 to 6 hours. Clinical evaluation of CTT Clinical effects were excellent in 1 case, good in 3 cases and poor in 1 case. No side effects were observed.

Pharmacokinetics of cefotetan in patients with end-stage renal failure on maintenance dialysis

The pharmacokinetics of a single intravenous dose of cefotetan were studied in 17 volunteer patients with end-stage renal failure, requiring intermittent haemodialysis in 12 cases or undergoing continuous ambulatory peritoneal dialysis in 5 cases. Between haemodialysis the mean plasma elimination half life was 20.4 h (S.E.M. +/- 2.1). This decreased to 7.5 h (S.E.M. +/- 0.6) during haemodialysis. In patients treated by continuous ambulatory peritoneal dialysis the mean plasma elimination half life was 15.5 h (S.E.M. +/- 1.9). Small amounts of cefotetan (5-9% of the administered dose) were recovered in the peritoneal dialysates removed over the 24 h following the dose.

A comparative trial between cefotetan and cephazolin for wound sepsis prophylaxis during elective upper gastrointestinal surgery with an investigation of cefotetan penetration into the obstructed biliary tree

Cefotetan is a cephamycin antibiotic theoretically suited to prophylaxis of wound infection during upper elective gastrointestinal surgery. In a prophylaxis trial 100 patients undergoing this type of surgery were randomly allocated to receive 1g cefotetan or cephazolin iv at induction of anaesthesia. Cefotetan-treated patients had significantly fewer postoperative infections overall (P less than 0.05) and there were no wound infections recorded in this group. In a separate pharmacokinetic study the penetration of cefotetan into common bile duct bile and gallbladder wall was measured in a further six patients, all of whom had been jaundiced preoperatively. At the time of maximum risk concentrations of cefotetan in bile and biliary tissue as well as blood and wound fat were in excess of the minimum inhibitory concentration for the majority of relevant pathogens. Cefotetan appears to be equally or more effective than cephazolin and is a suitable alternative prophylactic agent in elective upper gastrointestinal surgery.

[Cefotetan: clinical trial in elderly persons using a single daily dose of 2 grams as the sole therapy]

Effectiveness of cefotetan, a new generation semisynthetic cephamycin, was studied in a clinical trial in elderly patients. Cefotetan was used as single drug therapy. A single daily injection of 2 g was given to each of 33 elderly subjects (mean age 70.2 years, range 69-92 years). The infections were severe: pneumonia in 13 cases, septicemia in 12, upper urinary tract infections in 3 and miscellaneous infections in the remaining cases. The regimen used proved clinically effective (93% successes) and achieved residual serum levels greater than the MICs of all the Gram negative bacteria and most of the Gram positive cocci isolated. In addition to being efficient, the single daily injection regimen causes minimal damage to peripheral veins, provides optimal comfort to the patient, and saves both material and time.

Effects of phenothiazines and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide on rat colonic absorption of cefmetazole

Rat colonic absorption of cefmetazole was increased significantly by calmodulin inhibitors such as phenothiazines and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) when they were coadministered at a concentration between 1 and 100 microM. The bioavailability of cefmetazole, determined by area under the blood concentration curve method, increased 20 to 30% by the coadministration of calmodulin inhibitors. It is speculated that the enhancing action of agents on rat colonic absorption of cefmetazole takes place by a paracellular route and coadministration of sodium ion increases their actions.

[Transfer of cefotetan into exudates from excoriated skin wounds]

Transfer of cefotetan (CTT) into exudates from excoriated skin wounds was studied in 9 adult patients. Each subject was given an intravenous bolus injection of 50 mg/kg of body weight. Concentrations of CTT in serum and in exudate fluid were determined by bioassay using Escherichia coli NIHJ as the test organism. The mean (+/- S.D.) CTT concentration in serum reached 274.3 +/- 78.3 micrograms/ml at 30 minutes after the injection and decreased to 30.0 +/- 12.0 micrograms/ml at 8 hours after the injection. The peak value of CTT in exudate fluid was 143.1 +/- 22.3 micrograms/ml at 1 hour. Eight hours after the injection, the mean concentration in the exudate was 25.7 +/- 21.1 micrograms/ml. The data obtained were analysed pharmacokinetically: CTT concentrations in serum were analysed by two-compartment model, and those in exudate fluid from excoriated skin wounds were analysed by the model in which skin was considered as a small part of the peripheral compartment. Thus T1/2(beta) of CTT levels in serum was calculated as 2.38 hours, AUC0----infinity was 1,000.2 micrograms X hr/ml and Vd was 164.5 ml/kg. Tmax and Cmax of CTT levels in exudates were calculated as 1.05 hours and 131.2 micrograms/ml, respectively.

Comparison of cefotetan and cefoxitin as prophylaxis in cesarean section

A study comparing the efficacy of cefotetan versus cefoxitin for prophylaxis in patients undergoing cesarean section was carried out at the University of Iowa. After institutional review, 36 subjects who met the study criteria and agreed to participate were entered into the study; of these, 29 were evaluable for efficacy. Twenty subjects received a single 2 gm dose of cefotetan, and nine subjects received three 2 gm doses each of cefoxitin. Both antibiotics were administered intravenously at the time the umbilical cord was clamped. The subsequent doses of cefoxitin were given intravenously at four and eight hours after the initial dose. Clinical and bacteriologic responses were evaluated; there were no statistically significant differences between the two groups, and both antibiotics provided effective prophylaxis against infection. It appears that cefotetan is a satisfactory antibiotic choice for cesarean section prophylaxis. Further, in this small study it appears that a single dose of cefotetan is as effective as three doses of cefoxitin. This implies that cefotetan would not only decrease administration time and supplies but would decrease the cost to the patient while maintaining very acceptable infection rates.

Peri-incisional and preoperative administration of cefmetazole for the prophylaxis of wound infection after appendicectomy

The tissue and blood levels of Cefmetazole are compared after preoperative administration of a single dose of 30 mg/K body weight of the antibiotic administered intravenously (15 patients) and peri-incisionally (30 patients) to patients scheduled for emergency appendicectomy. Local and general tolerance to the antibiotic was good by both routes. No local or general complications arose in any of the patients. As expected, the tissue concentrations achieved with peri-incisional infiltration were significantly higher than those obtained by the intravenous route. With the blood levels, exactly the opposite happens at the start of the operation whereas at the end, there were no significant differences between the two routes employed. The prophylactic administration by peri-incisional infiltration is an easy and safe method which provides high tissue concentrations simultaneously with adequate blood levels and should be considered as useful in the preoperative administration of antibiotics for prophylaxis.

[Cefotetan in the treatment of sinusitis--a kinetic study]

Recent clinical experience shows that in treating sinusitis by tetracyclines more and more cases appear which are resistant to therapy. Cephalosporins are suitable as alternative medical treatment because of their good bactericidal effect. The pharmacokinetic qualities of Cefotetan, a new cephamycin-antibiotic, in plasma and sinus mucosa were examined in treating 13 patients. After an intravenous bolus-injection of 2 g Cefotetan the mean initial plasma concentration was 275 mg/l. After 1, 2 and 6 hours the plasma levels were 160, 96 and 39 mg/l. The average concentration in sinus mucosa reached 42.3 mg/l, 30.9 mg/l, 29.4 mg/l and 33.6 mg/l after 10, 60, 120 and 180 minutes. The pharmacokinetic properties of Cefotetan promise successful clinical application in the treatment of bacterial sinusitis.

[Tissue distribution of cefminox in beagle dogs]

A new cephamycin antibiotic, cefminox (MT-141, CMNX), was intravenously infused into Beagle dogs at a dose of 40 mg/kg in order to study it's distribution to various tissues. The following results were obtained. The maximum serum concentration of CMNX observed at the end of the infusion period was 102.3 micrograms/ml, and then the concentration decreased. The biological half-life of CMNX in serum was 37.0 minutes. This half-life was similar to the results of previous studies with Beagle dogs and rabbits. The maximum concentrations in tissues and body fluids were highest in B-bile followed by kidney, urinary bladder, serum, liver, vagina, uterus, pericardiac fluid, trachea, ovary, lung, gallbladder, parotid gland, heart, tonsil, thymus, spleen, pancreas, aqueous humor and cerebrospinal fluid, in that order and not detected in brain. The maximum concentrations in gallbladder, B-bile, pericardiac fluid and cerebrospinal fluid were found at 1-2 hours after administration. In other tissues and body fluids, they were obtained at the end of the infusion period. The area under the tissue concentration curve (AUC) was highest in the urinary bladder followed by the kidney, vagina, liver, uterus, gallbladder, trachea, ovary and lung, in that order. These results suggest that CMNX is useful for various infectious diseases in these tissues. The pharmacokinetic parameter (K1i/K2i) derived from serum and tissue concentrations using the deconvolution method well correlated to maximum tissue concentrations.

[Fundamental and clinical studies on cefminox in the field of obstetrics and gynecology]

Cefminox (CMNX, MT-141), a new cephamycin antibiotic, was studied both fundamentally and clinically with following results. In 33 cases undergone total hysterectomy and adnexectomy, 1 g of CMNX was administered intravenously by the drip infusion route over 1 hour and changes in drug concentration in the venous blood and uterine arterial blood as well as in various uterine tissues including endometrium, myometrium, cervix uteri, portio vaginalis, oviduct and ovary were studied. In addition, in 3 cases also received 1 g of CMNX over 1 hour by the drip infusion route, changes in the concentration of CMNX in the pelvic dead space exudate were investigated. In each tissue studied, the drug concentration higher than 40 micrograms/g was attained at 20 minutes after completion of drip infusion, showing good transfer of CMNX. In the pelvic dead space exudate, the peak concentration of 24.7 micrograms/ml appeared at 4 hours after completion of drip infusion and at 12 hours still a concentration of 4.5 micrograms/ml was maintained. In the treatment of 15 cases of obstetrical and gynecological infections, CMNX was used. In all of the cases treated, clinical results better than good were obtained, with excellent results in 2 cases and good results in 13 cases. In none of the cases side effects or laboratory abnormalities were observed. From these results CMNX is considered to be a useful drug for the treatment of various infections in the field of obstetrics and gynecology.

[Basic and clinical studies on cefminox in obstetrics and gynecology]

Fundamental and clinical studies on cefminox (CMNX, MT-141), a new cephamycin antibiotic, were carried out and the results were as follows. After the intravenous one shot administration of 1 g CMNX to 17 cases, serum concentrations, tissue concentrations in pelvic organs and protein binding capacities in serum were measured. Blood concentrations ranged between 100-200 micrograms/immediately after the injection and declined gradually. Half-life (T1/2) was 75 minutes. Tissue concentrations were 30-70 micrograms/g (tissue weight) 10 minutes after injection and declined. Half-life was 90 minutes. The average serum protein binding rate was 66.3 +/- 8.4%. Correlation between tissue concentration (Y) and free serum concentration (X) was expressed as Y = 0.42 + 7.14X. Correlation coefficient (r) was 0.80 (r = 0.80). Correlation coefficient in serum concentrations between HPLC and bioassay was 0.83 and that in free concentration was 0.97. In clinical studies, CMNX was administered to 19 cases of obstetric and gynecological infections. The patients were constituted of 3 with puerperal endometritis, 3 with pyometra, 3 with pelvic peritonitis, 3 with parametritis, 3 with adnexitis, 2 with BARTHOLIN's abscess and 1 with retroperitoneal abscess and vulva abscess. Overall clinical efficacy was 89.5% (17/19). Bacteriologically 26 strains were isolated, 6 strains of E. coli, 4 strains of B. fragilis, 2 strains of P. anaerobius and P. asaccharolyticus and each one of E. faecalis, S. epidermidis, N. gonorrhoeae, S. marcescens, P. maltophilia, A. calcoaceticus, K. pneumoniae, P. mirabilis, H. influenzae, S. intermedius, E. lentum and F. varium. Twenty of these 24 strains were eliminated after the administration, K. pneumoniae was decreased, E. faecalis, S. marcescens and P. maltophilia remained unaffected. No side effects were observed but 1 case showed mild elevation of transaminases which normalized 1 week after CMNX was stopped.

[Basic and clinical studies on cefminox in the field of obstetrics and gynecology]

Basic and clinical studies were carried out on cefminox (CMNX, MT-141), a new cephem antibiotic. Results obtained were as follows. Following each 1 g of intravenous drip infusion and intravenous injection, transfer of CMNX to the internal genital organs was good. Transfer of CMNX into exudate of the pelvic dead space was also good and showed high concentration. CMNX was given to 2 cases. Clinical efficacy was good in 1 case, and could not be evaluated in 1 case. No side effects were observed in both cases. The above results show that CMNX is an effective agent.

[Clinical trial and basic study on the tissue transfer of cefminox]

Cefminox (CMNX, MT-141) was studied both fundamentally and clinically with following results: In the treatment of 3 cases of Bartholin's abscess, 2 cases of pyometra, and 1 case each of bartholinitis, inflammation of the pelvic dead space, retroperitoneal abscess and pelvic peritonitis, CMNX was administered at a dosage of 1 g. The global clinical results were rated as good in 9 cases. From these findings it is considered that CMNX is promising as an antibiotic with extremely high efficacy for infections of the field of obstetrics and gynecology. Furthermore, since in none of our cases side effects or laboratory abnormalities were observed, CMNX is considered to be a drug with high efficacy and safety. In 5 cases received 1 g of CMNX intravenously, concentrations of the drug in the serum and tissues of internal genital organs were determined. CMNX was maintained at concentrations higher than 20 micrograms/ml for the serum and 10 micrograms/g for each tissue studied. In the pelvic dead space exudate 10 to 20 micrograms/ml of the drug was still detected even at 8 hours after the administration. These results obtained by our fundamental study support the efficacy of CMNX demonstrated in the clinical part of our study.

[Basic and clinical studies on cefminox in the field of obstetrics and gynecology]

In order to determine transference of cefminox (CMNX, MT-141) into the female genital organ tissues, the drug concentration in the pelvic dead space exudate was measured in cases undergone radical hysterectomy due to uterocervical cancer. For analysis of data the three-compartment model was used. When CMNX was given at a dose of 1 g as an intravenous drip infusion taking 1 hour, the serum concentration of the cubital vein reached its peak of 89.53 microgram/ml at 1 hour after start of administration. In the pelvic dead space exudate the peak concentration of 39.84 microgram/ml was reached at 2.55 hours after administration and a concentration higher than 7 micrograms/ml was still detected even at 12 hours. The area under the curve (AUC) for CMNX concentration in the pelvic dead space exudate was 295.63 microgram X hr/ml. These results suggest that CMNX achieves high concentration in the pelvic dead space exudate and that it is an antibiotic with clinical utility. CMNX was used in the treatment of 6 cases of obstetrical and gynecological infections. The clinical results were excellent in 1 case, good in 2 cases and poor in 2 cases. In the remaining 1 case the results was unknown.

[Basic and clinical studies on cefminox in the field of obstetrics and gynecology]

Fundamental and clinical studies on cefminox (CMNX, MT-141), a new cephamycin antibiotic, were carried out and the following results were obtained. When CMNX was administered at a dose of 1 g by intravenous drip infusion taking 1 hour, the serum concentrations as high as 20 micrograms/ml and 21 micrograms/ml were detected even at 4 hours after administration for the uterine artery and elbow vein, respectively. From these results, CMNX was supposed to maintain in vivo concentrations high enough to inhibit 80 to 100% of the growth of bacteria such as S. aureus, E. coli, Klebsiella, Proteus and anaerobic bacteria, B. fragilis, which are the commonest clinical isolates in the field of obstetrics and gynecology. Clinically, in 7 cases of female genital infections (4 cases of parametritis, 1 case of intrauterine infection, 1 case of pyometra and 1 case of pelveoperitonitis), CMNX was administered at a daily dosage of 2 g in 2 divided doses as intravenous drip infusions taking 90 minutes each. The clinical results were excellent in 1 case, good in 3 cases and poor in 3 cases, with an efficacy rate of 57.1%. In 6 out of these 7 cases progressive carcinoma was present as the underlying disease. No side effects nor abnormalities in laboratory findings were observed in any of the 7 cases. These results suggest that CMNX is effective in the treatment of obstetrical and gynecological infections.

[Study on the transfer of cefminox into female genital organs]

One gram of cefminox (CMNX, MT-141) was injected intravenously to a total of 29 patients prior to abdominal total hysterectomy and drug levels in the uterine and adnexal tissues were bioassayed. Serum samples and uterine tissues were taken at 0.25, 0.5, 1, 2, 4 or 6 hours after the administration, when bilateral uterine arteries were clamped. As to serum levels no difference has seen between cubital venous serum and uterine arterial serum, the half-lives being 2.32 hours and 2.22 hours, respectively. The peak level was 66.7 micrograms/ml for both. The drug level in tissues reached its peak at 15 minutes in the myometrium and cervix uteri, at 30 minutes in the endometrium, portio vaginalis and oviduct and at 1 hour in the ovary. The mean peak level was the highest for the oviduct (55.3 micrograms/g), followed by the portio vaginalis (47.7 micrograms/g), the cervix uteri (46.2 micrograms/g), the myometrium (42.8 micrograms/g), the ovary (37.3 micrograms/g) and the endometrium (34.2 micrograms/g) in this order. After reached the highest levels, the tissue levels decreased gradually in the same manner as the serum levels. From these results it was shown that CMNX is well transferred into various female genital tissues to achieve concentrations higher than MICs for organisms isolated clinically with high incidences in the field of gynecology and obstetrics. It was assumed from these results that CMNX is clinically useful enough in the treatment of genital organ infections.

[A study on transference of cefminox into intrapelvic tissues]

Intravenous administrations of cefminox (CMNX, MT-141) 1 g as both single shot injection and drip infusion were absorbed rapidly. CMNX showed good transference into intrapelvic organs such as uterus, oviduct and ovary, with the tissue/serum ratios of 37.6% for myometrium, 35.1% for endometrium, 41.4% for cervix uteri, 49.5% for portio vaginalis, 54.3% for ovary and 59.7% for oviduct. From these results, usefulness of CMNX in the field of obstetrics and gynecology was confirmed.

[Basic and clinical studies on cefminox in the field of obstetrics and gynecology]

Fundamental and clinical studies on cefminox (CMNX, MT-141), a new cephamycin antibiotic, were performed and the following results were obtained. Concentration of CMNX was examined in serum, internal genital organs and retroperitoneal fluid after a single intravenous administration of 1.0 g dose. The venous serum level of CMNX was 62.8 +/- 7.02 microgram/ml (Mean +/- S.D.) at 30 minutes after the administration. The sufficient transfer of CMNX to internal genital organs and retroperitoneal fluid was demonstrated. In clinical trial, CMNX was given to 10 cases with obstetrical and gynecological infections. The efficacy was evaluated as excellent in 1 case, good in 8 cases and poor in 1 case. No side effects were observed in any of the cases treated with CMNX.

[Basic study on cefminox in the field of obstetrics and gynecology]

In patients with carcinoma of the uterine cervix, cefminox (CMNX, MT-141) was given intravenously after panhysterectomy and the pelvic dead space exudate and serum levels of the drug were determined at various periods. The pelvic dead space exudate level reached its peak of 67.21 +/- 39.81 micrograms/ml at 2 hours, which decreased gradually to 26.04 +/- 6.66 micrograms/ml at 6 hours. In the serum, the drug level attained the peak of 152.98 +/- 85.37 of 7.26 +/- 1.66 micrograms/ml was still detected. The pelvic dead space exudate level was much higher than its MIC or 3h-MBC at all periods studied. From these results it was considered that CMNX achieves levels high enough to be expected of clinical efficacy in the pelvic dead space exudate and serum.

In vivo activity of cefbuperazone (T-1982) against various experimental infections in mice

The protective activity of cefbuperazone (T-1982) was compared with those of latamoxef, cefotaxime, and cefmetazole against intraperitoneal and urinary tract infections in mice. In both tests, cefbuperazone manifested a higher activity than the other cephems against infections with Escherichia coli and Klebsiella pneumoniae. Cefbuperazone also showed a comparatively high degree of prophylactic effect; this activity was observed even when given 4 hours before bacterial challenge. The good in vivo activity of cefbuperazone could not be explained by the differences between the antibiotics on the basis of the serum levels and vitro activity. Mice, treated with cefbuperazone, showed a statistically significant prolongation of survival time against intraperitoneal challenge with Candida albicans, but not when treated with the other cephems. This finding suggests that the host defense mechanisms stimulated by cefbuperazone may contribute to the good in vivo activity of this antibiotic.

[Pharmacokinetic studies of cefbuperazone in the field of gynecology]

Cefbuperazone (CBPZ), a new cephamycin antibiotic, was studied for the distribution in the genital organs and the excretion to the pelvic dead space exudate by bioassay, and the following results were obtained. CBPZ was rapidly distributed into the various tissues by intravenous drip infusion of 0.5 g and 1.0 g for 1 hour. Those levels depended on serum levels and the ratios (tissue level/serum level) were about 15-25%. Obvious dose response between 0.5 g and 1.0 g of CBPZ was recognized for serum levels as well as tissue levels. Serum and tissue levels were respectively analyzed by two- and three-compartment open model. Consequently, the obtained simulation curve approximated to the observed results. The simulation curve and pharmacokinetic parameters by one-compartment open model were appropriate for CBPZ levels in the pelvic dead space exudate.

Concentrations of cefmetazole in plasma and tissue resulting from peri-incisional administration before appendectomy

The levels of cefmetazole in plasma and tissue were determined after injection of a dose of 30 mg/kg into the zone of the wound of each of 15 patients undergoing appendectomy. The mean plasma levels of cefmetazole at the start and end of surgery (8.9 +/- 2.4 and 31.7 +/- 6.4 min after dosage) were 21.1 and 59.0 micrograms/ml, respectively; concentrations of the drug were 14.6 and 4,486.9 micrograms/g in skin, 9,165.0 and 1,756.4 micrograms/g in subcutaneous tissue, and 8,669.6 and 2,022.9 micrograms/g in muscle.

[Concentration of antibiotics in the prostate: cefmetazole]

Sixteen patients who underwent transurethral resection of prostate preoperatively received intravenous injection of cefmetazole in a doses of 2 gram. Pharmacokinetic study revealed that concentration of cefmetazole in prostatic tissue well correlated to serum concentration with nearly the same half-life times.

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.

[Penetration of cefbuperazone, a new cephamycin antibiotic, into human peritoneal exudate]

Pharmacokinetic studies were carried out on cefbuperazone ( CBPZ ) in 9 patients undergoing postoperative drainage. The concentration of CBPZ in serum and peritoneal exudate after one shot intravenous administration of 1 g was measured by bioassay and calculated respectively by two- and one-compartment open model. The results obtained were as follows: The pharmacokinetic parameters calculated from the serum levels were compared to those reported previously; T1/2 = 101 min., Vd = 4.06 L and Cl = 76 ml/min. The simulation curve of the peritoneal exudate level fit fairly with the mean values of 6 patients. It appeared that CBPZ penetrated somewhat slowly into peritoneal exudate with the peak value of 27.05 micrograms/ml at about 1 hour after the administration. The exudate levels thereafter declined more slowly than the serum ones (T1/2 = 134 min.). IT was 6.2 micrograms/ml even at 6 hours after the administration.

Penetration of cefotetan into serum, myometrium, endometrium and salpinges

24 patients received an intravenous 5-min bolus injection of 2 g cefotetan at various times prior to abdominal or vaginal hysterectomy. Cefotetan concentrations in salpinges were significantly higher than in myometrium and endometrium. Tissue concentrations of 16 micrograms/g could be attained for at least 5 h. At this concentration, 90% of most aerobic and anaerobic bacteria causing genital tract infections are inhibited.

[Antibiotic transfer into tissue after total hysterectomy with special reference to the cefmetazole concentration of the retroperitoneal space exudate]

The intent of the study was to investigate the transfer of CMZ to the retroperitoneal space exudate after hysterectomy (11 cases of simple abdominal hysterectomy and 6 cases of radical hysterectomy). Concentration of CMZ in the lymphnode was also measured in 2 cases. The results were as follows. Concentration in the retroperitoneal space exudate of CMZ after administration (intravenous drip infusion 1 or 2 g/hour) reached its peak 2 hours after administration (approximately 1 hour later than its peak in the blood). The peak level in the exudate was 1/3 to 2/3 of the peak level in the blood. After 2 hours, the concentration of CMZ in the exudate decreased gradually. The concentration of CMZ in the retroperitoneal space exudate in cases of simple abdominal hysterectomy was higher than in those of radical hysterectomy. After 1 to 3 days of radical hysterectomy, the transfer of CMZ into the exudate was as good as the transfer of that in the period immediately after operation. CMZ concentration in the lymphnode in the cases of radical hysterectomy reached 9 to 13 micrograms/mg approximately 1 hour after the start of CMZ administration (d.i. 2 g in 1 hour). Research results suggest that lymph circulation, in addition to blood stream, plays an important role in the transfer of antibiotics toward the pelvic dead space.

[Pharmacokinetics of moxalactam in adults]

Specific characteristics of Moxalactam, a new beta-lactam antibiotic, are high serum concentrations, prolonged half-life and good tissular diffusion. After IM injection of a single dose of 0.25, 0.5 and 1 g, the maximum serum concentration, achieved at one hour, averages 13, 16-21 and 30-50 micrograms/ml. After rapid IV injection of 0.5 and 1 g, the average maximum serum concentrations are 90 and 150 micrograms/ml; after an IV infusion of 2 g over 20 minutes, maximum concentrations are 150 to 180 micrograms/ml. Moxalactam elimination kinetics are linear, independent from the dose and route of administration, with a distribution half-life (T 1/2 alpha) between 0.20 and 0.60 hours and an elimination half-life (T 1/2 beta) between 2 and 2.5 hours (range: 1.9 and 3.1 hours). The apparent distribution volume is between 15 and 18 liters, i.e. 20 to 25% of the body weight. Serum or total clearances and renal clearances are respectively 80 to 100 and 50 to 90 ml/mn, with wide variations from one author to another. Approximately 70 to 90% of the administered dose are eliminated in the urine over 24 hours, without any tubular secretion. Renal failure results in a progressive increase of the elimination half-life, which can reach 20 hours in patients with anuria; approximately 50% of the injected dose are recovered by hemodialysis. Many pharmacokinetic studies have demonstrated the excellent diffusion of the agent in the various tissues and body fluids, particularly in the CSF. From the collation of bacteriologic and pharmacokinetic data, dosage regimens adjusted to the renal function can be proposed.

[Comparative pharmacokinetics of moxalactam and other cephalosporins]

A comparative study of the pharmacokinetics of eleven cephalosporins, given in rapid intravenous injections and studied under identical conditions (sampling regimens, assays by high performance liquid chromatography, statistical analyses), is reported. The very low diffusibility of cephalosporins throughout the body typifies this family of antibiotics. Apparent volumes of distribution vary little from the mean volume which is 0.30 liter per kg body weight. Conversely, apparent elimination half-lifes show significant differences, with values ranging from 0.52 h (cephalotin) and 0.75 h (cefotaxim) to 2.74 h (Moxalactam) and 3.07 h (cefazolin). The consequences of the pharmacokinetic differences between cefotaxim and Moxalactam are exemplified by the comparison of dosage regimens capable of generating and maintaining equivalent concentrations in the various body fluids. Table I shows the main parameters which typify the pharmacokinetic patterns of eleven cephalosporins given intravenously (in young, healthy, adults). The relative values of renal clearance and total clearance demonstrate the part played by extrarenal elimination: metabolization for cephalotin, cefapirin and cefotaxim, and biliary excretion which may be inconsiderable, as is usually the case, or predominant for cefoperazone. Compartmental analysis of plasmatic data provides unequivocal confirmation of open pharmacokinetic models with three compartments whose equations, of the type O plasmatic = Ae-gamma t + Be-gamma t + Ce-gamma t, are shown in Table III.

Moxalactam penetration of normal and osteomyelitic bone

The ability of moxalactam, a new cephalosporin, to cross the capillary membrane and enter the interstitial fluid space of normal and osteomyelitic bone in the dog was investigated. Moxalactam was noted to readily traverse the capillary membrane of both normal and osteomyelitic bone. The calculated concentrations of moxalactam in the interstitial fluid space corresponded to the simultaneously obtained serum concentrations determined with a bioassay.

[Transport of cefotetan into the otorhinolaryngeal tissues]

The tissue specimens were taken to evaluate the efficacy of cefotetan (CTT), a new cephamycin antibiotic, for otorhinolaryngological infectious diseases. The concentrations of CTT in palatine tonsils, maxillary sinus mucosa, wall of maxillary sinus cysts, discharge from otitis media and saliva were studied. The serum level determined at 3 hours following intravenous injection of 1 g of the drug was 49.2 micrograms/ml (n = 4). The serum level at 12 hours following intravenous injection of 2 g of the drug was 14.4 micrograms/ml (n = 4). 15-25% of the serum levels of CTT were demonstrated in palatine tonsils, 20.7-35.7% in maxillary sinus mucosa. We detected high levels of CTT in the effusion of acute maxillary sinusitis, 24.0 micrograms/ml (2 g, i.v., 90 min.), 26.3 micrograms/ml (1 g, i.v., 120 min.). On the other hand, we detected only a few per cent of the serum level of CTT in the effusion of chronic maxillary sinusitis.