[Determination of thallium in the urine with colloidal palladium as the matrix modifier by graphite furnace atomic absorption Spectrometry].

Objective: To instruct a method of determining thallium in the urine by graphite furnace atomic absorption spectrometry(GF-AAS) with colloidal palladium as the matrix modifier. Methods: Urine samples were first diluted and then determined by GF-AAS with colloidal palladium while using thermal sample injection. Results: The optimum volume of colloidal palladium was 6 µl and the best ashing temperature was 600-800 ℃ while the atomization temperature was 1700-1900 ℃ . This method showed a good linearity relationship when the concentration between 0.33 and 50.0 µg/L while the correlation coefficient of standard curve line was 0.9992, and the detection limit was 0.33 µg/L and the recovery rate was between 92.7% and 102.3% with the intra-day precision in the range of 2.55% to 3.66% and the inter-day precision in the range of 1.77% to 3.85%. Conclusion: This method has the advantages of low detect limit, high sensitivity and good precision, and it can be used in the biological monitoring and emergency detecting of workers exposed to thallium.

Medication contaminants as a potential cause of anaphylaxis to vincristine.

Vincristine (VCR) is a vinca alkaloid and common chemotherapeutic that is used to treat multiple pediatric and adult malignancies. Despite its common use, cases of anaphylaxis to VCR are rare and typically isolated to a single individual. We report a series of eight patients with adverse reactions to VCR over the course of 11 months at a single institution, four of which progressed to anaphylaxis and one of which resulted in cardiac arrest. Mass spectrometry analysis of medication lots was performed to test for possible contaminant(s). Our findings highlight the risk of anaphylaxis during therapy with VCR.

Multivariate optimization of solvent bar microextraction combined with HPLC-UV for determination of trace amounts of vincristine in biological fluids.

In the current work, an efficient method named solvent bar microextraction-high performance liquid chromatography-UV detection (HPLC-UV) was developed for preconcentration and determining the trace amount of vincristine (VCR) in biological samples such as plasma and urine. Briefly, VCR was extracted from an aqueous sample with pH 10.7 (donor phase) into 1-octanol as the supported liquid membrane (SLM) which is inserted into the pores of the hollow fiber and followed by back extraction into an aqueous receiving phase (pH=3.1). Studying the factors affecting the extraction performance in order to achieve a high extraction efficiency, requires the design of experiments (DOE) approach. In this regards, diverse factors' effects including the pH value of donor and acceptor phases, extraction time, extraction temperature, stirring rate and salt content of the donor phase were considered. The optimum experimental condition was as following: pH of the source phase, 10.7; pH of the receiving phase, 3.1; stirring rate, 1000rpm; extraction temperature, 51°C; extraction time, 60min and 11.3% w/v NaCl in the sample solution. Under the optimal; extraction condition, a favorable preconcentration factor equal to 98.5 was achieved. The linearity range was obtained in the domain of 0.05-5mgL-1. The limits of detection and quantification were 0.015 and 0.05mgL-1. Within-day and between-day RSDs of the proposed SBME method were 4.1% and 12.5%, respectively. Finally, the applicability of the implemented SBME method was evaluated by the extraction and quantification of VCR from biological samples such as urine and plasma and satisfactory results were obtained.

Estudo da variação neutropênica pelo sulfato de vincristina em cães com tvt tratados em um hospital veterinário do noroeste paulista / Neutropenic variation by vincristine sulfate in tvt dogs treated in a veterinary hospital in northwestern são paulo / Estudio de la variación neutropénica por sulfato de vincristina en perros con tvt tratados en el hospital veterinario del noroeste paulista

O presente estudo avaliou dados epidemiológicos de neutropenia induzida por sulfato vincristina em cães com Tumor Venéreo Transmissível (TVT), num Hospital Veterinário do Noroeste paulista. Para tanto, trata-se de um estudo do tipo retrospectivo de protocolos eletrônicos e formulários manuais de dados digitalizados de 51 casos de TVT. O atendimento ambulatorial e de internação desses animais foi realizado no período de setembro de 2006 a dezembro de 2009. Dentre os resultados, destaca-se que 51 animais foram diagnosticados com TVT, sendo 37 fêmeas (73%) e 14 (27%) machos; 46 animais (90,2%) foram tratados exclusivamente com sulfato de vincristina. Os cães Sem Raça Definida-SRD (n=28) foram os maiores acometidos com 54,9%; seguidos pelos Poodles com quatro cães (7,84%). Os animais com idade entre 37 e 84 meses obtiveram a maior porcentagem de acometimento pelo TVT com 20 casos (39,22%). Em doze animais (23,52%) foi observada neutropenia (valores entre 390 a 1927 cél/µL). Conclusão: a possível toxicidade medular induzida pela vincristina foi verificada pela descrição da neutropenia. Dessa forma, a identificação de quadros neutropênicos, por meio da realização de hemogramas semanais, é considerada obrigatória e de extrema relevância devido à prevalência de mielotoxicidade secundária à utilização deste quimioterápico.

The present study aims to assess epidemiological data on neutropenia induced by vincristine sulfate among dogs with Canine Transmissible Venereal Tumor (CTVT) at a veterinary hospital in the Northwestern region in the São Paulo State. Methodology: This is a retrospective study of electronic protocols and digitalized data from manually filled form from 51 CTVT cases. These animals were treated in an outpatient care clinic and hospitalization took place from September 2006 to December 2009. Results: 51 animals were diagnosed with CTVT; among these, 37 were female (73%) and 14 were male (27%). From these, 46 animals (90.2%) were treated exclusively with vincristine sulfate. Among them, mongrels (n=28) were the most common, with 54.9%, followed by Poodles, with 4 dogs (7.84%). Animals aged from 37 and 84 months were the largest age group, with 20 cases (39.22 %). Neutropenia (390 to 1927 cells/µL) was observed in 12 animals. Conclusion: possible vincristine-induced marrow toxicity was verified by the description of neutropenia. Thus, neutropenia identification through weekly blood count cells is considered extremely important and mandatory due to the prevalence of myelotoxicity following treatment with this chemotherapeutic drug.

Este estudio busca evaluar datos epidemiológicos de neutropenia inducida por sulfato vincristina en perros con Tumor Venéreo Transmisible (TVT), en un Hospital Veterinario del Noroeste Paulista. Es un estudio del tipo retrospectivo de protocolos electrónicos y formularios manuales de datos digitalizados de 51 casos de TVT. El atendimiento de ambulatorio y de internación de esos animales se realizó en el período de septiembre de 2006 a diciembre de 2009. Entre los resultados, se destaca que 51 animales fueron diagnosticados con TVT, siendo 37 hembras (73%) y 14 (27%) machos; 46 animales (90,2%) fueron tratados exclusivamente con sulfato de vincristina. Los perros Sin Raza Definida ? SRD (n=28) fueron los más acometidos con 54,9%; seguidos por los Poodles con cuatro perros (7,84%). Los animales con edad entre 37 y 84 meses obtuvieron mayor porcentaje de acometimiento por TVT, con 20 casos (39,22%). En doce animales (23,52%0 se ha observado neutropenia (valores entre 390 a 1927 cél/µL). Conclusión: la posible toxicidad medular inducida por vincristina se ha verificado por la descripción de la neutropenia. Así, la identificación de cuadros neutropénicos por medio de realización de hemogramas semanales, es considerada obligatoria y de extrema relevancia debido a la prevalencia de mielotoxicidad secundaria a la utilización de este quimioterápico.

Estudo da variação neutropênica pelo sulfato de vincristina em cães com tvt tratados em um hospital veterinário do Noroeste Paulista / Neutropenic variation by vincristine sulfate in tvt dogs treated in a veterinary hospital in northwestern São Paulo / Estudio de la variación neutropénica por sulfato de vincristina en perros con tvt tratados en el hospital veterinario del Noroeste Paulista

O presente estudo avaliou dados epidemiológicos de neutropenia induzida por sulfato vincristina em cães com Tumor Venéreo Transmissível (TVT), num Hospital Veterinário do Noroeste paulista. Para tanto, trata-se de um estudo do tipo retrospectivo de protocolos eletrônicos e formulários manuais de dados digitalizados de 51 casos de TVT. O atendimento ambulatorial e de internação desses animais foi realizado no período de setembro de 2006 a dezembro de 2009. Dentre os resultados, destaca-se que 51 animais foram diagnosticados com TVT, sendo 37 fêmeas (73%) e 14 (27%) machos; 46 animais (90,2%) foram tratados exclusivamente com sulfato de vincristina. Os cães Sem Raça Definida-SRD (n=28) foram os maiores acometidos com 54,9%; seguidos pelos Poodles com quatro cães (7,84%). Os animais com idade entre 37 e 84 meses obtiveram a maior porcentagem de acometimento pelo TVT com 20 casos (39,22%). Em doze animais (23,52%) foi observada neutropenia (valores entre 390 a 1927 cél/µL). Conclusão: a possível toxicidade medular induzida pela vincristina foi verificada pela descrição da neutropenia. Dessa forma, a identificação de quadros neutropênicos, por meio da realização de hemogramas semanais, é considerada obrigatória e de extrema relevância devido à prevalência de mielotoxicidade secundária à utilização deste quimioterápico...

The present study aims to assess epidemiological data on neutropenia induced by vincristine sulfate among dogs with Canine Transmissible Venereal Tumor (CTVT) at a veterinary hospital in the Northwestern region in the São Paulo State. Methodology: This is a retrospective study of electronic protocols and digitalized data from manually filled form from 51 CTVT cases. These animals were treated in an outpatient care clinic and hospitalization took place from September 2006 to December 2009. Results: 51 animals were diagnosed with CTVT; among these, 37 were female (73%) and 14 were male (27%). From these, 46 animals (90.2%) were treated exclusively with vincristine sulfate. Among them, mongrels (n=28) were the most common, with 54.9%, followed by Poodles, with 4 dogs (7.84%). Animals aged from 37 and 84 months were the largest age group, with 20 cases (39.22 %). Neutropenia (390 to 1927 cells/µL) was observed in 12 animals. Conclusion: possible vincristine-induced marrow toxicity was verified by the description of neutropenia. Thus, neutropenia identification through weekly blood count cells is considered extremely important and mandatory due to the prevalence of myelotoxicity following treatment with this chemotherapeutic drug...

Este estudio busca evaluar datos epidemiológicos de neutropenia inducida por sulfato vincristina en perros con Tumor Venéreo Transmisible (TVT), en un Hospital Veterinario del Noroeste Paulista. Es un estudio del tipo retrospectivo de protocolos electrónicos y formularios manuales de datos digitalizados de 51 casos de TVT. El atendimiento de ambulatorio y de internación de esos animales se realizó en el período de septiembre de 2006 a diciembre de 2009. Entre los resultados, se destaca que 51 animales fueron diagnosticados con TVT, siendo 37 hembras (73%) y 14 (27%) machos; 46 animales (90,2%) fueron tratados exclusivamente con sulfato de vincristina. Los perros Sin Raza Definida – SRD (n=28) fueron los más acometidos con 54,9%; seguidos por los Poodles con cuatro perros (7,84%). Los animales con edad entre 37 y 84 meses obtuvieron mayor porcentaje de acometimiento por TVT, con 20 casos (39,22%). En doce animales (23,52%0 se ha observado neutropenia (valores entre 390 a 1927 cél/µL). Conclusión: la posible toxicidad medular inducida por vincristina se há verificado por la descripción de la neutropenia. Así, la identificación de cuadros neutropénicos por medio de realización de hemogramas semanales, es considerada obligatoria y de extrema relevancia debido a la prevalencia de mielotoxicidad secundaria a la utilización de este quimioterápico...

Raman micro spectroscopy study of the interaction of vincristine with A549 cells supported by expression analysis of bcl-2 protein.

Understanding the interaction of anticancer drugs with model cell lines is important to elucidate the mode of action of these drugs as well as to develop cost effective and rapid screening methods. Raman spectroscopy has been demonstrated to be a valuable technique for high throughput, noninvasive analysis. The interaction of vincristine with a human lung adenocarcinoma cell line (A549) was investigated using Raman micro spectroscopy. The results were correlated with parallel measurements from the MTT cytotoxicity assay, which yielded an IC50 value of 0.10 ± 0.03 µM. The Raman spectral data acquired from vincristine treated A549 cells was analysed to understand its interaction with the nucleus in the cell and elucidate DNA intercalation. The dose dependent spectral changes in the nucleus are analysed by PLS-Jack knifing for the identification of the more significant changes associated with the mode of action of the drug. Results are correlated with a similar dose dependent expression analysis of the bcl-2 protein, an anti-apoptotic protein associated with DNA damage, in the vincristine treated A549 cells using flow cytometry. The results indicate the co-existence of two modes of action, microtubule binding at low doses and DNA intercalation at high doses.

Structure elucidation of indole-indoline type alkaloids: a retrospective account from the point of view of current NMR and MS technology.

In this review our aim is to look back on how the structure elucidation of bisindoles, especially with focus placed on vinblastine and vincristine analogues, has evolved alongside with the development of MS and NMR over the last 60 years from the perspective of our present-day use of state-of-the-art MS and NMR instrumentation and on the basis of our own accumulated views and experience in the field.

Wipe sampling procedure coupled to LC-MS/MS analysis for the simultaneous determination of 10 cytotoxic drugs on different surfaces.

A simple wipe sampling procedure was developed for the surface contamination determination of ten cytotoxic drugs: cytarabine, gemcitabine, methotrexate, etoposide phosphate, cyclophosphamide, ifosfamide, irinotecan, doxorubicin, epirubicin and vincristine. Wiping was performed using Whatman filter paper on different surfaces such as stainless steel, polypropylene, polystyrol, glass, latex gloves, computer mouse and coated paperboard. Wiping and desorption procedures were investigated: The same solution containing 20% acetonitrile and 0.1% formic acid in water gave the best results. After ultrasonic desorption and then centrifugation, samples were analysed by a validated liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in selected reaction monitoring mode. The whole analytical strategy from wipe sampling to LC-MS/MS analysis was evaluated to determine quantitative performance. The lowest limit of quantification of 10 ng per wiping sample (i.e. 0.1 ng cm(-2)) was determined for the ten investigated cytotoxic drugs. Relative standard deviation for intermediate precision was always inferior to 20%. As recovery was dependent on the tested surface for each drug, a correction factor was determined and applied for real samples. The method was then successfully applied at the cytotoxic production unit of the Geneva University Hospitals pharmacy.

Paraplegia and paraparesis from intrathecal methotrexate and cytarabine contaminated with trace amounts of vincristine in China during 2007.

PURPOSE: The production and administration of drugs used intrathecally requires special care to prevent contamination with neurotoxic agents. In 2007, we investigated a widespread outbreak of paraplegia and paraparesis among Chinese patients who received intrathecal drugs to identify the presumed contaminant and its source to prevent further cases. PATIENTS AND METHODS: We defined a case as onset from January 1 to October 31, 2007, of bilateral flaccid paraparesis or paraplegia or retention and incontinence of stool or urine, in a patient receiving intrathecal drugs. Using a retrospective cohort approach, we selected 12 hospitals from all hospitals that had reported cases. In these hospitals, we identified all 448 patients (including 107 cases) who received intrathecal chemotherapy or chemoprophylaxis in 2007. We calculated attack rates and Mantel-Haenszel adjusted risk ratios for intrathecal drug type and lot. RESULTS: All 12 hospitals used intrathecal methotrexate or cytarabine produced by one pharmaceutical plant. Only two lots of each drug were associated with cases. Lot-specific attack rates ranged from 42% to 100% (risk ratio, ∞; lower confidence bounds, 1.8 to 7.3). Vincristine production had immediately preceded production of the implicated lots on the same equipment. By using ultra performance liquid chromatography, we detected vincristine (0.28 to 18 µg) in unused vials from implicated lots of methotrexate and cytarabine. CONCLUSION: Trace amounts of vincristine that contaminated intrathecal drugs caused a large outbreak of severe neurologic damage. Vincristine and other neurotoxic drugs should not be produced on any equipment that is also used for producing drugs that are to be administered intrathecally.

Intravenous methotrexate as central nervous system (CNS) prophylaxis is associated with a low risk of CNS recurrence in high-risk patients with diffuse large B-cell lymphoma.

BACKGROUND: The outcome of patients with systemic diffuse large B-cell lymphoma (DLBCL) had improved over the past decade with the addition of monoclonal antibody therapy. Unfortunately, approximately 5% of these patients still developed a secondary central nervous system (CNS) recurrence followed invariably by rapid death. This rate is substantially increased in patients with certain high-risk features. Although prophylaxis against CNS recurrence with either intrathecal or intravenous methotrexate is commonly used for such patients, to the authors' knowledge, there is no standard of care. Retrospectively evaluated was the role of high-dose systemic methotrexate combined with standard cyclophosphamide, doxorubicin, vincristine, and prednisone with rituximab (R-CHOP) chemotherapy to decrease CNS recurrence in high-risk patients. METHODS: A total of 65 patients with DLBCL and CNS risk factors were identified at the study institution between 2000 and 2008 who received intravenous methotrexate as CNS prophylaxis concurrent with standard systemic therapy with curative intent. CNS recurrence rate, progression-free survival, and overall survival were calculated. RESULTS: Patients received a median of 3 cycles of methotrexate at a dose of 3.5 gm/m(2) with leucovorin rescue. The complete response rate was 86%, with 6% partial responses. At a median follow-up of 33 months, there were only 2 CNS recurrences (3%) in this high-risk population. The 3-year progression-free and overall survival rates were 76% and 78%, respectively. Complications associated with methotrexate therapy included transient renal dysfunction in 7 patients and a delay in systemic chemotherapy in 8 patients. CONCLUSIONS: Intravenous methotrexate can be safely administered concurrently with R-CHOP and is associated with a low risk of CNS recurrence in high-risk patients.

Influence of blood-brain barrier efflux pumps on the distribution of vincristine in brain and brain tumors.

Vincristine (VCR) is efficacious in some but not all brain cancers and an established substrate of Pgp and Mrp1. However, the extent to which such transporters affect the VCR penetration through the blood-brain barrier (BBB) is poorly understood. To evaluate the role of Pgp and Mrp1 in VCR CNS distribution, VCR concentrations were analyzed under steady-state conditions in normal brain, brain tumor, and bone marrow in wild-type (WT), Mrp1 ko (mrp1-/-), Pgp ko (mdr1a-/-:mdr1b-/-), and TKO (mdr1a-/-:mdr1b-/-:mrp1-/-) mice. VCR normal brain partition coefficients (i.e. tissue/plasma VCR concentrations) in TKO mice were greater than those in WT mice at both targeted 10 and 50 ng/mL plasma VCR concentrations, and ranged from 1.3- to 3.6-fold. VCR brain tumor partition coefficients in Mrp1 mice were greater than WT mice at both doses, being 1.5- and 2.4-fold higher at low and high doses, respectively. TKO mice also showed elevated VCR brain tumor penetration with a brain tumor partition coefficient of 1.9-fold greater than that in WT mice at the high-dose level. The bone marrow partition coefficient in Mrp1 ko mice was 1.65-fold greater than that in WT mice. Within strain comparisons revealed that VCR brain tumor concentrations were significantly greater than normal brain in all strains, ranging from 9- to 40-fold. These findings indicate that disruption of the BBB caused the largest enhancement in VCR tumor concentrations, yet the absence of Mrp1 on the brain tumor vasculature could enhance the penetration compared with that in normal brain.

Development of an analytical methodology for simultaneous determination of vincristine and doxorubicin in pharmaceutical preparations for oncology by HPLC-UV.

A high-performance liquid chromatography-UV methodology (lambda=230 nm) was developed and validated for the simultaneous determination of vincristine and doxorubicin in pharmaceutical preparations used in oncology. The chromatography was carried out on a C18 column using acetonitrile 90% in water-potassium hydrogenphosphate buffer 50 mM, pH 3.2+/-0.1 (32:68, v/v) as mobile phase at a flow rate of 1.5 mL/min. The method proved to be specific, exact, and accurate, in accordance with the ICH standards, presenting linearity in the 1-5 microg/mL and 5-100 microg/mL intervals, and detection (0.19x0.51 microg/mL) and quantification (0.63x1.7 microg/mL) limits for vincristine and doxorubicin, respectively.

[Effects of NaCl on the growth and alkaloid content of Catharanthus roseus seedlings].

Catharanthus roseus seedlings were grown in 1/2 Hoagland solution containing 0-250 mmol x L(-1) of NaCl, and their fresh and dry mass, malondialdehyde (MDA) and chlorophyll contents, tryptophan decarboxylase (TDC) and peroxidase (POD) activities, and vindoline, catharanthine, vincristine and vinblastine contents were measured after 7 days. The results showed that NaCl markedly decreased the fresh and dry mass but increased the MDA content. The chlorophyll content had no difference with the control when the concentration of NaCl was 50 mmol x L(-1), but decreased with increasing NaCl concentration when the NaCl concentration was above 50 mmol x L(-1). There was a significant enhancement of POD activity under NaCl stress. The TDC activity was the highest when the concentration of NaCl was 50 mmol x L(-1), but decreased with increasing NaCl concentration. The vindoline, catharanthine, vincristine, and vinblastine contents were the highest under 50 mmol x L(-1) NaCl stress, with the values being 4.61, 3.56, 1.19, and 2.95 mg x g(-1), respectively, and significant higher than the control and other treatments. Salt stress could restrain the growth of C. roseus seedlings, but promote the metabolism of alkaloid and increase the alkaloid content. 50 mmol x L(-1) of NaCl had the greatest promotion effect on the alkaloid content of C. roseus seedlings.

Effect of a copper gradient on plant community structure.

Vegetation data including plant cover, biomass, species richness, and vegetation height was sampled on a copper-contaminated field with total copper contents varying from 50 to almost 3,000 mg/kg soil. The field was covered by early succession grassland dominated by Agrostis stolonifera. Plant cover, biomass, species richness, and vegetation height generally decreased with increasing copper content, although the highest biomass was reached at intermediate copper concentrations. Multivariate statistical analyses showed that plant community composition was significantly correlated with soil copper concentration and that community composition at soil copper concentrations above 200 mg/kg differed significantly from community composition at lower copper levels. Comparison of single-species (Black Bindweed, Fallopia convolvulus) performance at the field site and in laboratory tests involving field soil and spiked soil indicates that the laboratory tests conventionally applied for risk assessment purposes do not overestimate copper effects. Interaction between copper and other stressors operating only in the field probably balance the higher bioavailability in spiked soil.

Simultaneous determination of vincristine, vinblastine, catharanthine, and vindoline in leaves of catharanthus roseus by high-performance liquid chromatography.

A simple reversed-phase liquid chromatographic method is developed for the simultaneous quantitation of the anticancerous drugs vincristine, vinblastine, and their precursors catharanthine and vindoline using a Merck Chromolith Performance reversed-phase high-performance liquid chromatography column. A better resolution is obtained in comparison with available particulate-type C18 columns. The column provides good reproducibility and peak symmetry. Chromatography is carried isocratically with a mobile phase of acetonitrile-0.1M phosphate buffer containing 0.5% glacial acetic acid (21:79, v/v; pH 3.5) at a flow rate of 1.2 mL/min and UV detection at 254 nm. Parameters such as linearity, limits of quantitation (LOQ) and detection (LOD), precision, accuracy, recovery, and robustness are studied. The method is selective and linear for alkaloid concentration in the range 0.25 microg-25 microg/mL. The LOQ and LOD are 25, 46, 56, and 32 microg/mL and 8, 14, 18, and 10 microg/mL, respectively. The results of accuracy studies are good. Values for coefficient of variation are 2.50, 1.82, 1.33, and 1.13, respectively. The percent recovery of the alkaloids was found to be 96%, 97%, 98%, and 98%, respectively. Peak purity and homogeneity of these compounds in plant extract is studied using a photodiode-array detector. This simple and rapid method of analysis is applied for the determination of these alkaloids in a large number of leaf extracts of Catharanthus roseus..

[A study on the hairy root culture and antitumor alkaloids production of Catharanthus roseus].

OBJECTIVE: To establish transformation system and obtain alkaloids from the hairy root of Catharanthus roseus. METHOD: Hairy roots were obtained by infecting the different explants of C. roseus. Culture conditions of hairy root were optimized. RESULT: The best transformation condition was leaf infected by two-day's pre-culture and two-day's co-culture and additional A(S) (hydroxyacetosyringone) 100 mg x L(-1). The inducing rate of hairy root was up to 86.25%. The best condition of hairy root culture was MS medium with sucrose as carbon material and lactalbumin as nitron material. The analysis result showed that the contents of total alkaloids in hairy roots were higher than explants and calli. CONCLUSION: Hairy root of C. roseus will be useful for the production of active components in C. roseus.

Reliability of preparation procedure for sphingosomal vincristine.

PURPOSE: The reliability of the preparation procedure for sphingosomal vincristine was studied. The effect of minor variations in the constitution conditions on the integrity of the drug product was also examined. METHODS: Two studies were conducted. The laboratory study, which had two parts, was conducted to determine the effects of deliberately varying the constitution conditions, including such key parameters as incubation time and incubation temperature. In the field study, 20 pharmacists unfamiliar with sphingosomal vincristine were asked to constitute the product using the written instructions provided in the package insert as their sole guidance. All samples in both studies were evaluated by measuring key product characteristics, including free (un-encapsulated) vincristine sulfate, total vincristine sulfate, vincristine degradation products, and in vitro release rate. Vincristine loading into sphingosomes was considered acceptable if the percentage of free vincristine sulfate did not exceed 10%. RESULTS: In the laboratory study, samples that were incubated at 60-75 degrees C for 5-60 minutes met all the acceptance criteria. However, acceptable loading was not achieved for samples that were incubated at 55 degrees C for 10 minutes or less. In the field study, all the pharmacist-prepared samples met the acceptance criteria, with the results for free vincristine sulfate demonstrating a high degree of statistical confidence in the reliability of the loading procedure. CONCLUSION: The recommended constitution procedure of sphingosomal vincristine from a three-vial kit can be reliably performed in pharmacies with a high degree of confidence. Small variations in temperature and incubation time had no effects on the quality of the product.

Penetration of intra-arterially administered vincristine in experimental brain tumor.

Vincristine is an integral part of the "PCV" regimen that is commonly administered to treat primary brain tumors. The efficacy of vincristine as a single agent in these tumors has been poorly studied. This study was designed to determine whether vincristine enters normal rat brain or an intracranially or subcutaneously implanted glioma and to assess the presence of the efflux pump P-glycoprotein (P-gp) on tumor and vascular endothelial cells. The 9L rat gliosarcoma was implanted intracranially and subcutaneously in three Fischer 344 rats. On day 7, [3H]vincristine (50 microCi, 4.8 microg) was injected into the carotid artery, and the animals were euthanized 10 or 20 min later. Quantitative autoradiography revealed that vincristine levels in the liver were 6- to 11-fold greater than in the i.c. tumor, and 15- to 37-fold greater than in normal brain, the reverse of the expected pattern with intraarterial delivery. Vincristine levels in the s.c. tumor were 2-fold higher than levels in the i.c. tumor. P-gp was detected with JSB1 antibody in vascular endothelium of both normal brain and the i.c. tumor, but not in the tumor cells in either location, or in endothelial cells in the s.c. tumor. These results demonstrate that vincristine has negligible penetration of normal rat brain or i.c. 9L glioma despite intra-arterial delivery and the presence of blood-brain barrier dysfunction as demonstrated by Evan's blue. Furthermore, this study suggests that P-gp-mediated efflux from endothelium may explain these findings. The lack of penetration of vincristine into brain tumor and the paucity of single-agent activity studies suggest that vincristine should not be used in the treatment of primary brain tumors.

Catharanthus roseus L. plants and explants infected with phytoplasmas: alkaloid production and structural observations.

The results of several experiments concerning the presence and composition of alkaloids in different tissues (stems, leaves, roots) of Catharanthus roseus L. plants and explants, healthy and infected by clover phyllody phytoplasmas, are reported. The alkaloids extracted and determined by the reverse phase high-pressure liquid chromatography were vindoline, ajmalicine, serpentine, vinblastine, and vincristine. The total alkaloid concentration was higher in infected plants than in the controls, in particular the increase of vinblastine in infected roots was very significant. The ultrastructural observations of infected roots showed alterations of the cell walls and of the nuclei. These results demonstrate that phytoplasmas, detected in all infected tissues by light fluorescence and transmission electron microscopy, play an important role on secondary metabolism of the diseased plants, modifying both the total content of alkaloids and their ratio.

Sensitive and rapid spectrophotometric methods for determination of anticancer drugs.

Sensitive, rapid, and simple spectrophotometric methods were developed for determination of the anticancer drugs vinblastine sulfate (VBS) and vincristine sulfate (VCS), which belong to the class of vinca alkaloids. The first method is based on the reaction of VBS and VCS with diazotized dapsone, forming yellow azo products with absorption maxima at 430 nm. The colored species obey Beer's law in the concentration range of 0.5-24 microg/mL for VBS and 0.5-12 microg/mL for VCS. The second method describes the reaction of VBS and VCS with iron(III) and subsequent reaction with ferricyanide in hydrochloric acid medium to yield blue products with absorption maxima at 750 nm. The Beer's law range for this method is 0.1-4 microg/mL for VBS and 0.5-10 microg/mL for VCS. With both methods, colored species were stable for 1 h. The methods are simple and reproducible and are applied for determination of VBS and VCS in pharmaceutical formulations. Commonly encountered pharmaceuticals added as excipients do not interfere in the analysis and the results obtained in the analysis of dosage forms agree well with the labeled contents.