RESUMO
Pharmacokinetics and metabolism of mitomycin C (MMC) have been studied in NMRI mice bearing MAC 16 colon adenocarcinoma after direct intratumoural injection of either 500 micrograms free MMC or the same dose incorporated in albumin microspheres. Microspheres produced a tumour pharmacokinetic profile of steady state drug levels, avoiding the much higher early peak (20.5 micrograms/tumour vs 98.9 micrograms/tumour) and lower trough of free MMC, and reducing significantly the levels of drug reaching the systemic circulation (AUC 1.8 micrograms/mL x hr for microspheres vs 6.8 micrograms/mL x hr for free drug). 2,7-Diaminomitosene (2,7-DM), a key intermediate in MMC quinone bioreduction, was used as an indicator of drug metabolic activation in tumour tissue. Peak levels were 10-fold higher (11.2 micrograms/tumour vs 1.1 micrograms/tumour) and area under the curve 5-fold higher after free drug. Even taking into account differences in tumour pharmacokinetic profiles of the parent drug, microspheres actively inhibited 2,7-DM formation 3-fold. However, the microspheres generated a completely different pattern of drug metabolism where four previously uncharacterized mitosane metabolites and elevated levels of cis and trans 1-hydroxy 2,7-diaminomitosene were detected. Despite similar parent drug exposure in tumours, free drug was significantly more active (P < 0.05, Student's t-test) against MAC 16. These results suggest that formation of 2,7-DM correlates more closely with antitumour activity than sustained parent drug levels or appearance of other key metabolites. Potentially, they provide the first direct evidence for an in vivo mechanism of action dependent on bioreductive activation and formation of 2,7-DM.
Assuntos
Antineoplásicos/farmacocinética , Mitomicina/farmacocinética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Albuminas , Animais , Antineoplásicos/administração & dosagem , Biotransformação , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Portadores de Fármacos , Composição de Medicamentos/métodos , Camundongos , Camundongos Endogâmicos , Microesferas , Mitomicina/administração & dosagem , Mitomicina/metabolismo , Mitomicinas/análise , OxirreduçãoRESUMO
In high performance liquid chromatography with electrochemical detection (HPLC/ECD) much attention has been paid to the performance of the applied detection system with respect to reliability and sensitivity. In general, insufficient attention has been paid to relatively easy to implant devices for improved collection and handling of detection signals. Four models of software filtering are studied and compared with hardware filtering. In the investigated chromatographic-electrochemical system, off-line parabolic filtering after on-line averaging of sixteen measurements proved to be the system of first choice, with respect to execution time, noise level, signal to noise ratio, peak height and resolution.
Assuntos
Antineoplásicos/análise , Processamento de Sinais Assistido por Computador , Software , Cromatografia Líquida de Alta Pressão , Eletroquímica , Etoposídeo/análise , Análise de Fourier , Métodos , Mitomicina , Mitomicinas/análise , Porfiromicina/análise , Teniposídeo/análiseRESUMO
The degradation of N6-[(dimethylamino)methylene]mitomycin C, a semisynthetic analogue of mitomycin C, was studied in aqueous solution. The compound degraded rapidly and followed pseudo-first-order kinetics in both acidic (pH less than 5) and basic pH greater than or equal to 9) media. In the near-neutral pH region, however, biphasic kinetics were observed. At the pH of maximum stability (6.5), 10% activity was lost after approximately 6 h at 22 degrees C. Citrate and phosphate species were catalytic at pH 6.5. Spectrophotometric and HPLC methods were used to elucidate the degradation mechanism at pH 7-9. Under these conditions, equilibrium addition of one water molecule into the amidine side chain occurred, followed by parallel formation of mitomycin C and N6-(formyl)mitomycin C. The latter compound subsequently hydrolyzed to mitomycin C.
Assuntos
Mitomicina , Mitomicinas/análise , Soluções Tampão , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Cinética , Soluções , Espectrofotometria UltravioletaRESUMO
Observations were made on living neuroblasts (Nbs) of the grasshopper (Chortophaga viridifasciata) embryo during a 4-h recovery period following 1-h in vitro exposure to 10(-8), 10(-6), and 10(-4) M mitomycin C (MMC). None of these concentrations affected the duration of mid-mitosis (prometaphase, metaphase, anaphase), but one as low as 10(-8) M causes a small reduction in the rate at which Nbs move through the remainder of the cell cycle, primarily by retarding their progress through S. As the concentration is increased there is slower movement through S and also prophase (there are no true G1 and G2 periods in the rapidly dividing Nb: 4-h cell cycle at 38 degrees C). A significant proportion of the cells exposed to 10(-4) M are blocked for 1 or more h at very late prophase, i.e., just before nuclear membrane breakdown. In such retarded prophases the chromosomes resemble c-metaphase chromosomes even though the nuclear membrane remains intact. Mass spectrometry data revealed that one lot of the MMC used contained one or more impurities.
Assuntos
Ciclo Celular/efeitos dos fármacos , Mitomicinas/farmacologia , Neurônios/efeitos dos fármacos , Animais , Gafanhotos , Espectrometria de Massas , Mitomicina , Mitomicinas/análise , Prófase/efeitos dos fármacosRESUMO
Intra-peritoneal chemo-hyperthermia with mitomycin C was used to treat 9 patients with very advanced gastrointestinal cancers with peritoneal seedings. Resection of the primary tumor was possible in 3 cases. After temporary of closure of the abdominal wall, 90 to 120 minutes of intra-peritoneal chemo-hyperthermia was performed under general anaesthesia with 32 degrees C of systemic hypothermia, via 3 intra-peritoneal drains forming a closed circuit, using 10 mg/l of mitomycin C in 61 of peritoneal dialysate warmed at the inflow temperature of 46 to 49 degrees C. We observed no mortality or morbidity. There were only minor and temporary laboratory side effects and for 6 patients, no malignant cells could be found in the ascitic fluid after intra-peritoneal chemo-hyperthermia. In six patients, we conserved an improvement in the Karnofsky index 3 to 7 months after intra-peritoneal chemo-hyperthermia. These results show that intraperitoneal chemo-hyperthermia with mitomycin C is a safe and reliable treatment for peritoneal seedings in severely advanced gastrointestinal cancers and encourage us to proceed with this new therapeutic modality.
Assuntos
Hipertermia Induzida/métodos , Mitomicinas/uso terapêutico , Neoplasias Peritoneais/terapia , Adulto , Idoso , Proteínas Sanguíneas/análise , Feminino , Humanos , Infusões Parenterais , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Mitomicinas/análise , Neoplasias Peritoneais/patologia , Contagem de PlaquetasAssuntos
Antibacterianos/análise , Aminoácidos/análise , Antibacterianos/farmacologia , Bioensaio , Carboidratos/análise , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cefalosporinase/análise , Cromatografia em Papel/métodos , Gentamicinas/análise , Glicosídeos/análise , Concentração de Íons de Hidrogênio , Mitomicinas/análise , Neomicina/análise , Novobiocina/análise , Penicilinas/análise , Peptídeos/análise , Quinonas/análise , Estreptomicina/análise , Estreptotricinas/análise , Relação Estrutura-Atividade , Tetraciclina/análiseRESUMO
To analyze the in vitro release profiles of mitomycin C from albumin microspheres prepared by chemical denaturation in a multiparticulate system, a method to calculate the total cumulative amount of mitomycin C released from a batch of microspheres was developed. Mitomycin C-loaded albumin macrospheres (diameter in mm range) were prepared, and the in vitro release kinetics of mitomycin C from individual macrospheres were determined. Then the relationship between the kinetic parameters and the physical parameters (e.g., diameter, weight) was investigated under the assumption that macrospheres and microspheres behave identically. Further, the size distribution of microspheres was measured, and the total cumulative amount of mitomycin C released from albumin microspheres was calculated. The release profiles of mitomycin C from individual macrospheres fitted first-order release kinetics better than spherical matrix kinetics. The calculated initial mitomycin C contents and first-order release rate constants for individual macrospheres were correlated with the weight and reciprocal of surface area of the macrospheres, respectively. The observed in vitro release profile for the microspheres agreed with the calculated values. These results suggest that this method is valid for calculating drug release from albumin microspheres.
Assuntos
Mitomicinas/análise , Albuminas , Microesferas , Mitomicina , Modelos Teóricos , SolubilidadeRESUMO
Serum albumins and polylactic acid (PLA) have been used as bioerodable polymers in the preparation of drug-containing microspheres for parenteral drug delivery. The albumin microsphere may be prepared via either chemical cross-linking or heat denaturation of the protein. Heat-denatured albumin microspheres containing mitomycin C (MMC) have been used in pre-clinical and clinical investigations. Due to the high reactivity of MMC as a bifunctional alkylating agent, a study on the stability of MMC in the albumin and PLA microspheres has been carried out using a high-performance liquid chromatographic (HPLC) method. Human serum albumin (HSA) microspheres were prepared using an emulsion method via either heat denaturation at 120 or 170 degrees C or the use of 0.5 M biacetyl as a cross-linking agent. The PLA microspheres were prepared by an emulsion method at 55 degrees C. HPLC analysis of the HSA microspheres showed that about 37% of MMC was converted to 2,7-diaminomitosene derivatives in microspheres prepared by heat denaturation at 120 degrees C. The degradation increased to 82% when the microspheres were prepared with a denaturation temperature of 170 degrees C. The use of biacetyl as a cross-linking agent in the preparation of HSA microspheres resulted in a complete degradation of the incorporated MMC. Biacetyl was found to interact with MMC leading to the formation of 7-aminomitosene derivatives. In contrast to the albumin system, MMC may be incorporated into PLA microspheres without degradation.
Assuntos
Albuminas/análise , Ácido Láctico , Mitomicinas/análise , Cromatografia Líquida de Alta Pressão , Isomerismo , Lactatos/análise , Microesferas , Mitomicina , Poliésteres , Polímeros/análise , Espectrofotometria Ultravioleta , TemperaturaRESUMO
Distinguishing between short-lived reactive oxygen species like hydroxyl and superoxide radicals is difficult; the most successful approaches employ electron spin resonance (ESR) spin-trapping techniques. Using the spin trap 5,5-dimethyl-l-pyrroline N-oxide (DMPO) to selectively trap various radicals in the presence and absence of ethanol, an HPLC system which is capable of separating the hydroxyl- and superoxide-generated DMPO adduct species has been developed. The radical-generated DMPO adducts were measured with an electrochemical detector attached to the HPLC system and confirmed by spin-trapping techniques. The HPLC separation was carried out on an ODS reverse-phase column with a pH 5.1 buffered 8.5% acetonitrile mobile phase. The advantage of the HPLC system described is that it permits the separation and detection of hydroxyl and superoxide radicals without requiring ESR instrumentation. The antineoplastic bioreductive alkylating agent mitomycin C, when activated by NADPH-cytochrome c reductase, was shown to generate both hydroxyl and superoxide radicals.
Assuntos
Hidróxidos/análise , Mitomicinas/análise , Superóxidos/análise , Cromatografia Líquida de Alta Pressão , Óxidos N-Cíclicos , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Radical Hidroxila , Mitomicina , Marcadores de SpinRESUMO
The performance of a number of normal phase and reversed-phase systems, with ultraviolet detection at 360 nm, has been investigated with respect to their applicability to pharmacokinetic studies of mitomycin C (MMC). The reversed-phase system developed was also combined with a polarographic detector in order to compare the sensitivity and selectivity of ultraviolet and electrochemical detection. A simple isolation procedure, based on the adsorption of MMC on a non-ionogenic resin, has been developed. The developed assay is applied to a pharmacokinetic study from which some examples are given.
Assuntos
Mitomicinas/análise , Animais , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica , Humanos , Cinética , Mitomicina , Mitomicinas/sangue , Mitomicinas/urina , Polarografia , Ratos , Espectrofotometria UltravioletaRESUMO
A high-performance liquid chromatographic method is described for the determination of mitomycin C (MMC) and its metabolites 2,7-diaminomitosene (2,7-DM), 1,2-cis-1-hydroxy-2,7-diaminomitosene (cis-hydro) and 1,2-trans-1-hydroxy-2,7-diaminomitosene (trans-hydro) in tumour tissue. N-la-Methylmitomycin C (porfiromycin, PM) was used as an internal standard. Two factors were critical in resolving the metabolites: pH and buffer ionic strength, where the retention times of the four components were affected in the order 2,7-DM >> cis-hydro >> trans-hydro >> MMC. The optimal isocratic conditions (flow-rate 1 ml/min) were 18 mM sodium phosphate pH 5.8-methanol (74:26) and a column temperature of 40 degrees C on a Spherisorb ODS-2 column (25 cm x 4.6 mm I.D.). Liquid-liquid extraction [twice with chloroform-propan-2-ol-ethyl acetate (2:2:1)] is described for tumour tissue. Recoveries varied depending on the component: MMC, 71.9 +/- 12.4%; PM, 85.5 +/- 27%; 2,7-DM, 51.7 +/- 5.4%; cis-hydro, 52.0 +/- 16.8%; trans-hydro, 62 +/- 8%. When applied to the analysis of a rat mammary carcinoma treated intra-tumourally with 450 micrograms of MMC five drug-related "metabolite" peaks were detected. Three of these co-chromatographed with standards of 2,7-DM, cis- and trans-hydro, and had identical absorption maxima to their respective standards, with the possible exception of trans-hydro.
Assuntos
Neoplasias Mamárias Experimentais/metabolismo , Mitomicina/análise , Mitomicinas/análise , Animais , Cromatografia Líquida de Alta Pressão , Feminino , Concentração de Íons de Hidrogênio , Ratos , Espectrofotometria UltravioletaRESUMO
A fully automated liquid chromatographic system for the bioanalysis of mitomycin C has been described. The isolation of the analyte from the biological matrix (plasma, ascites and urine) is performed using a continuous-flow system equipped with a dialysis membrane in order to remove proteins. The samples are concentrated on a reversed-phase pre-column and subsequently introduced on to a reversed-phase analytical column by applying column-switching techniques. The drug is detected by absorbance measurements at 360 nm. Using the described system up to 100 samples a day can be analysed with determination limits of the order of 1 ng/ml, with a linear dynamic range of at least three decades for plasma and urine samples. The procedure was applied to pharmacokinetic studies of ovarian cancer patients treated intraperitoneally with mitomycin C.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Mitomicinas/análise , Líquido Ascítico/análise , Diálise , Feminino , Humanos , Microquímica , Mitomicina , Mitomicinas/farmacocinética , Neoplasias Ovarianas/metabolismo , Manejo de EspécimesRESUMO
A procedure has been developed whereby paper chromatograms of agents which induce lambda bacteriophage in Escherichia coli can be developed using bioautographs with a lysogenic test system. Well-defined plaque-forming zones are produced indicating the area on the paper chromatogram where the active inducing material can be located. A mixture of the bacteriophage-inducing antibiotic, mitomycin C, and the noninducing antibiotic, paromomycin, was resolved into its components on paper strips with an ethyl acetate-methanol solvent system. The location of both antibiotics could thus be readily observed. Antibacterial and inducing activities were found to be identical with a crude fermentation solid, NSC-B-158,791. The use of this procedure for resolution of multicomponent inducing activities in antibiotic beers and for characterization of active components which may be potential antitumor antibiotics is indicated.
Assuntos
Cromatografia em Papel , Colífagos , Escherichia coli , Antineoplásicos/análise , Mitomicinas/análise , Paromomicina/análiseRESUMO
A packed-column supercritical-fluid chromatograph was interfaced with a mass spectrometer via a modification of a thermospray probe. This modification allowed a capillary restrictor for the supercritical fluid (CO2) and reagent gas for chemical ionization to be introduced directly into a thermospray source. Chemical ionization conditions were observed when either the filament or discharge electrode was used and the source pressure was above 0.5 torr. The discharge electrode produced more efficient ionization, resulting in approximately a tenfold larger signal than that observed in the filament mode. The usefulness of this instrumentation was demonstrated on several anticancer drugs. Methanol positive ion chemical ionization (PICI) spectra were recorded for cyclophosphamide, diaziquone, mitomycin C and thiotepa. Methane PICI spectra of thiotepa were obtained in the absence of methanol as a mobile-phase modifier. A 50 ng on-column injection of diaziquone produced approximately a 6:1 signal to noise ratio in the scanning mode.
Assuntos
Antineoplásicos/análise , Benzoquinonas , Aziridinas/análise , Cromatografia/instrumentação , Cromatografia/métodos , Ciclofosfamida/análise , Espectrometria de Massas/instrumentação , Espectrometria de Massas/métodos , Mitomicina , Mitomicinas/análise , Tiotepa/análiseRESUMO
High-performance liquid chromatography (HPLC) and thermospray mass spectrometry were combined for the analysis of DNA adducts formed from the interaction of the anticancer drugs mitomycin C, porfiromycin and thiotepa with calf thymus DNA. The adducts formed from reaction of mitomycin C and porfiromycin with DNA were separated from unmodified nucleosides by HPLC on a C18 column and identified by thermospray mass spectrometry. Thiotepa DNA adducts readily depurinated from DNA and were chromatographed and identified by thermospray liquid chromatography-mass spectrometry as the modified bases without the ribose moiety attached. The utility of thermospray mass spectrometry for the identification of microgram quantities of nucleoside adducts and depurinated base adducts of these anticancer drugs was demonstrated.
Assuntos
DNA/análise , Mitomicinas/análise , Porfiromicina/análise , Tiotepa/análise , Animais , Bovinos , Fenômenos Químicos , Química , Cromatografia Líquida de Alta Pressão/métodos , Hidrólise , Espectrometria de Massas/métodos , Mitomicina , Espectrofotometria Ultravioleta , Timo/metabolismoRESUMO
Chemocoagulation therapy was evaluated in an experimental model of metastasis of murine lymph nodes following injection of a suspension of mitomycin C--containing activated carbon particles in 80% ethanol (MMC-CH-ET) into the popliteal lymph node. Lymph node metastasis was induced in the left popliteal and the lumbar lymph nodes 8 days after injection of mouse leukemia P388 cells into the footpad of the left hindleg of BDF1 mice. When MMC-CH-ET was injected into the left popliteal lymph node, it immediately left this site and entered the lumbar lymph node via lymphatic vessels. When compared with tissue concentrations of mitomycin C following injection of an aqueous solution of this drug, the mitomycin C concentration of MMC-CH-ET was maintained at significantly higher levels for 2 hr following injection both at the site of injection and at secondary lymph nodes. Furthermore, coagulative necrosis was identified histologically throughout the injected lymph node and the secondary lymph node, including the metastatic site. The mortality of mice treated with MMC-CH-ET injection was significantly reduced and lymph node metastasis was controlled with MMC-CH-ET when compared with the results for mice treated with an aqueous solution of mitomycin C or treated by surgical lymph node dissection. In this report, we suggest that the use of MMC-CH-ET as a therapeutic agent may be useful in targeting lymph node metastasis.
Assuntos
Leucemia P388/tratamento farmacológico , Linfonodos/efeitos dos fármacos , Metástase Linfática/prevenção & controle , Mitomicinas/administração & dosagem , Animais , Carbono , Cromatografia Líquida de Alta Pressão , Etanol , Injeções Intralinfáticas , Linfonodos/metabolismo , Linfonodos/patologia , Masculino , Camundongos , Camundongos Endogâmicos , Mitomicinas/análise , Mitomicinas/farmacocinética , Mitomicinas/uso terapêuticoRESUMO
Mitomycin C-Dextran conjugates (MMC-D) were intravenously (iv) injected in mice bearing subcutaneous sarcoma 180. The tissue distribution was determined for three 14-C-labeled anionic conjugates (MMC-Dan) with molecular weights of 10, 70, and 500 kd and one cationic 70-kd 14C-conjugate (MMC-Dcat). The anionic conjugates were slowly cleared from the plasma, and their elimination rate decreased with increasing molecular weight. Radioactivity accumulated in liver, spleen, lymph nodes, and tumor but not in heart, lung, intestines, kidney, or muscle after iv injection of all types of 14C-MMC-Dan. In contrast, the cationic conjugate was rapidly cleared from the plasma and accumulated mostly in the liver and spleen, while tumor levels remained low. The antitumor effect of the 70-kd MMC-Dan, which afforded the highest tumor concentration, was superior to that of free MMC. Therefore, anionic mitomycin C-dextran conjugates with a high molecular weight may be useful for tumor targeting in cancer chemotherapy.
Assuntos
Dextranos/farmacocinética , Mitomicina , Mitomicinas/farmacocinética , Pró-Fármacos/farmacocinética , Sarcoma 180/metabolismo , Animais , Dextranos/análise , Dextranos/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos , Mitomicinas/análise , Mitomicinas/uso terapêutico , Peso Molecular , Pró-Fármacos/análise , Pró-Fármacos/uso terapêutico , Sarcoma 180/tratamento farmacológico , Distribuição TecidualRESUMO
Local mitomycin C (MMC) bladder instillation immediately after transurethral resection of superficial transitional cell carcinoma of the bladder caused an MMC serum concentration up to 24.5 ng/ml of an average. Neither bladder perforation by TUR nor vesicorenal reflux are contraindications for local instillations MMC. Systemic side effects are not to be expected. The highest MMC concentrations were found in the cancer tissue. There were measurable concentrations of MMC down to the adventitia. The indication for immediate postoperative local MMC-chemotherapy is discussed.
Assuntos
Antibióticos Antineoplásicos/análise , Carcinoma de Células de Transição/tratamento farmacológico , Mitomicinas/análise , Neoplasias da Bexiga Urinária/tratamento farmacológico , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/sangue , Carcinoma de Células de Transição/análise , Carcinoma de Células de Transição/cirurgia , Humanos , Mitomicina , Mitomicinas/administração & dosagem , Mitomicinas/sangue , Bexiga Urinária/análise , Neoplasias da Bexiga Urinária/análise , Neoplasias da Bexiga Urinária/cirurgiaRESUMO
Mitomycin-C (MMC) is an alkylating agent which has shown significant activity in gynecologic cancers, both in vivo and in vitro. We determined the delivery of MMC to target tissue by comparing plasma and tumor tissue concentrations of MMC as measured by high-performance liquid chromatography (HPLC) in five patients with cervical cancer. In a companion study, we measured MMC concentrations in plasma and selected tumors of female rats given an equivalent dose. In patients, the mean terminal half-life and total body clearance rates of MMC were 40 min and 275 ml/min/m2, respectively. The mean cervical tumor to plasma concentration of MMC was 1.26 +/- 0.34 (mean +/- SE, n = 4). In female rats, the terminal half-life and total body clearance rates of MMC were 28.4 min and 270 ml/min/m2, respectively. Tissue concentrations of MMC in rats were lower than plasma concentrations measured at corresponding times. The highest concentrations were found in lung and uterus (including cervix) with lower concentrations in ovary and liver. The mean half-life for elimination of MMC from tissues of rats was 20.3 +/- 2.8 min (mean +/- SE, n = 6). Based on similar pharmacokinetic parameters in rats and patients, the rat appears to be a suitable model for the disposition of MMC in human patients. The near equivalent drug concentrations found in tumor and plasma of patients suggests that the in vitro tests conducted at concentrations based on plasma level may be relevant to cervical tumor tissue, as well.