Cyclophosphamide levels in sites of preparation and administration of antineoplastic drugs

The extensive use of antineoplastic agents in chemotherapy may be at risk to health care workers involved in the preparation and administration of these drugs. In this study cyclophosphamide, a drug classified as a human carcinogen, was quantified by adapting a previous analytical method using gas chromatography coupled to mass spectrometry (GC-MS) after solid phase extraction with diatomaceous earth. The drug was measured by analysis in surfaces (wipe samples) and gloves, collected from four different hospitals, before and after the practice of cleaning procedures, and the use of a closed-system device for the preparation and administration. Validation results were satisfactory and cyclophosphamide levels ranging from below the quantification limit to 141000 ng. Our findings demonstrated that surfaces and materials contamination was found in all hospitals during the traditional open technique for preparation and administration of cyclophosphamide and a significant reduction in contamination when a closed-system device was used. However, some values were considered unexpected, especially those obtained from samples collected after the cleaning surfaces.

Genetic population data of 12 STR loci of the PowerPlex (R) Y system in the state of Sao Paulo population (Southeast of Brazil)

Allele frequency distributions and population data for 12 Y-chromosomal short tandem repeats (STRs) included in the PowerPlex (R) Y Systems (Promega) were obtained for a sample of 200 healthy unrelated males living in S (a) over tildeo Paulo State (Southeast of Brazil). A total of 192 haplotypes were identified, of which 184 were unique and 8 were found in 2 individuals. The average gene diversity of the 12 Y-STR was 0.6746 and the haplotype diversity was 0.9996. Pairwise analysis confirmed that our population is more similar with the Italy, North Portugal and Spain, being more distant of the Japan. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Violet ZnSe/ZnS as an Alternative to Green CdSe/ZnS in Nanocrystal-Fluorescent Protein FRET Systems

Fluorescent proteins from the green fluorescent protein family strongly interact with CdSe/ZnS and ZnSe/ZnS nanocrystals at neutral pH. Green emitting CdSe/ZnS nanocrystals and red emitting fluorescent protein dTomato constitute a 72% efficiency FRET system with the largest alteration of the overall photoluminescence profile, following complex formation, observed so far. The substitution of ZnSe/ZnS for CdSe/ZnS nanocrystals as energy donors enabled the use of a green fluorescent protein, GFP5, as energy acceptor. Violet emitting ZnSe/ZnS nanocrystals and green GFP5 constitute a system with 43% FRET efficiency and an unusually strong sensitized emission. ZnSe/ZnS-GFP5 provides a cadmium-free, high-contrast FRET system that covers only the high-energy part of the visible spectrum, leaving room for simultaneous use of the yellow and red color channels. Anisotropic fluorescence measurements confirmed the depolarization of GFP5 sensitized emission.

Intrinsic Dissolution as a Tool for Evaluating Drug Solubility in Accordance with the Biopharmaceutics Classification System

The Biopharmaceutics Classification System (BCS) is a tool that was created to categorize drugs into different groups according to their solubility and permeability characteristics. Through a combination of these factors and physiological parameters, it is possible to understand the absorption behavior of a drug in the gastrointestinal tract, thus contributing to cost and time reductions in drug development, as well as reducing exposure of human subjects during in vivo trials. Solubility is attained by determining the equilibrium under conditions of physiological pH, while different methods may be employed for evaluating permeability. On the other hand, the intrinsic dissolution rate (IDR), which is defined as the rate of dissolution of a pure substance under constant temperature, pH, and surface area conditions, among others, may present greater correlation to the in vivo dissolution dynamic than the solubility test. The purpose of this work is to discuss the intrinsic dissolution test as a tool for determining the solubility of drugs within the scope of the Biopharmaceutics Classification System (BCS).

Optimization of preservative system in ophthalmic suspension with dexamethasone and polymyxin B

A simplex-lattice statistical project was employed to study an optimization method for a preservative system in an ophthalmic suspension of dexametasone and polymyxin B. The assay matrix generated 17 formulas which were differentiated by the preservatives and EDTA (disodium ethylene diamine-tetraacetate), being the independent variable: X-1 = chlorhexidine digluconate (0.010 % w/v); X-2 = phenylethanol (0.500 % w/v); X-3 = EDTA (0.100 % w/v). The dependent variable was the Dvalue obtained from the microbial challenge of the formulas and calculated when the microbial killing process was modeled by an exponential function. The analysis of the dependent variable, performed using the software Design Expert/W, originated cubic equations with terms derived from stepwise adjustment method for the challenging microorganisms: Pseudomonas aeruginosa, Burkholderia cepacia, Staphylococcus aureus, Candida albicans and Aspergillus niger. Besides the mathematical expressions, the response surfaces and the contour graphics were obtained for each assay. The contour graphs obtained were overlaid in order to permit the identification of a region containing the most adequate formulas (graphic strategy), having as representatives: X-1 = 0.10 ( 0.001 % w/v); X-2 = 0.80 (0.400 % w/v); X-3 = 0.10 (0.010 % w/v). Additionally, in order to minimize responses (Dvalue), a numerical strategy corresponding to the use of the desirability function was used, which resulted in the following independent variables combinations: X-1 = 0.25 (0.0025 % w/v); X-2 = 0.75 (0.375 % w/v); X-3 = 0. These formulas, derived from the two strategies (graphic and numerical), were submitted to microbial challenge, and the experimental Dvalue obtained was compared to the theoretical Dvalue calculated from the cubic equation. Both Dvalues were similar to all the assays except that related to Staphylococcus aureus. This microorganism, as well as Pseudomonas aeruginosa, presented intense susceptibility to the formulas independently from the preservative and EDTA concentrations. Both formulas derived from graphic and numerical strategies attained the recommended criteria adopted by the official method. It was concluded that the model proposed allowed the optimization of the formulas in their preservation aspect.

Extractive Fermentation of Clavulanic Acid by Streptomyces DAUFPE 3060 Using Aqueous Two-Phase System

The influence of four variables, specifically PEG molar mass (400, 1,000, and 8,000 g/mol), concentrations of PEG and phosphate salts (15, 20, and 25% for both), and agitation intensity (110, 150, and 200 rpm), on clavulanic acid (CA) extraction by extractive fermentation with PEG/phosphate salts aqueous two-phase system was investigated in shaken flasks using a 2(4-1)-fractional factorial design. After selection of the two most significant variables (agitation intensity and PEG molar mass), an optimization study conducted according to a 2(2)-central composite design revealed that 25% PEG 8,000 g/mol and phosphate salts at 240 rpm (run 6) were the best conditions for the extractive fermentation, leading to the best results in terms of partition coefficient (k = 8.2), yield of CA in the PEG-rich phase (eta(T) = 93%) and productivity (P = 5.3 mg/Lh). As a first attempt to make a scale-up of these results, the effectiveness of the extractive fermentation was then checked in a bench-scale bioreactor under conditions as close as possible to the optimum ones determined in flasks. The highest CA concentration obtained in the PEG-rich phase (691 mg/L) was 30% higher than in flasks, thus demonstrating the potential of such a new process, integrating the production and extraction steps, as a promising, low-cost tool to obtain high yields of this and similar products. (C) 2010 American Institute of Chemical Engineers Biotechnol. Prog., 27: 95-103, 2011

LPS Removal from an E. Coli Fermentation Broth Using Aqueous Two-Phase Micellar System

In biotechnology, endotoxin (LPS) removal from recombinant proteins is a critical and challenging step in the preparation of injectable therapeutics, as endotoxin is a natural component of bacterial expression systems widely used to manufacture therapeutic proteins. The viability of large-scale industrial production of recombinant biomolecules of pharmaceutical interest significantly depends on the separation and purification techniques used. The aim of this work was to evaluate the use of aqueous two-phase micellar system (ATPMS) for endotoxin removal from preparations containing recombinant proteins of pharmaceutical interest, such as green fluorescent protein (GFPuv). Partition assays were carried out initially using pure LPS, and afterwards in the presence of E. coli cell lysate. The ATPMS technology proved to be effective in GFPuv recovery, preferentially into the micelle-poor phase (K(GFPuv) < 1.00), and LPS removal into the micelle-rich phase (%REM(LPS) > 98.00%). Therefore, this system can be exploited as the first step for purification in biotechnology processes for removal of higher LPS concentrations. (C) 2010 American Institute of Chemical Engineers Biotechnol. Prog., 26: 1644-1653, 2010

Continuous extraction of alpha-toxin from a fermented broth of Clostridium perfringens Type A in perforated rotating disc contactor using aqueous two-phase PEG-phosphate system

A 2(3-1) factorial experimental design was used to evaluate the performance of a perforated rotating disc contactor to extract alpha-toxin from the fermented broth of Clostridium perfringens Type A by aqueous two-phase system of polyethylene glycol-phosphate salts. The influence of three independent variables, specifically the dispersed phase flowrate, the continuous phase flowrate and the disc rotational speed, was investigated on the hold up, the mass transfer coefficient, the separation efficiency and the purification factor, taken as the response variables. The optimum dispersed phase flowrate was 3.0 mL/min for all these responses. Besides, maximum values of hold up (0.80), separation efficiency (0. 10) and purification factor (2.4) were obtained at this flowrate using the lowest disc rotational speed (35 rpm), while the optimum mass transfer coefficient (0. 165 h(-1)) was achieved at the highest agitation level (140 rpm). The results of this study demonstrated that the dispersed phase flowrate strongly influenced the performance of PRDC, in that both the mass transfer coefficient and hold up increased with this parameter. (c) 2007 Elsevier B. V. All rights reserved.

Liquid-liquid extraction of proteases from fermented broth by PEG/citrate aqueous two-phase system

This work deals with the use of an aqueous two-phase system (ATPS) of PEG/citrate to remove proteases from a Clostridium perfringens fermentation broth. To plan the experimental tests and evaluate the corresponding results, three successive experimental designs were employed, for which the PEG molar mass (M-PEG) and concentration (C-PEG), the citrate concentration (C-C) and the pH were selected as independent variables, while the purification factor (PF), the partition coefficient (K), the activity yield (Y) and the selectivity (S) were selected as responses. PF of proteases in the top phase was shown to increase with increasing MPEG and decreasing Cc, whereas a completely opposite trend was observed for K. On the other hand, Y was favored by simultaneous decreases in both these variables, while S decreased with increasing Cc. Therefore, selecting a simultaneous increase in PF and Y as the most desirable result, the best performance of the system was obtained using M-PEG = 10-000 g/mol C-PEG = 22% (w/w) and C-c = 8.0% (w/w) at pH 8.5. Under these conditions, the activity yield was very high (131 %) but the purification factor (4.2) and the selectivity (4.3) were lower than those ensured by more selective purification methods. According to these results, the ATPS seems to be an interesting alternative primary concentration/decontamination step for vaccine preparation from C. perfringens fermented broth. (C) 2007 Elsevier B.V. All rights reserved.

Phase diagrams of a CTAB/organic solvent/buffer system applied to extraction of enzymes by reverse micelles

A partial pseudo-ternary phase diagram has been studied for the cethyltrimethylammonium bromide/isooctane:hexanol:butanol/potassium phosphate buffer system, where the two-phase diagram consisting of the reverse micelle phase (L-2) in equilibrium with the solvent is indicated. Based on these diagrams two-phase systems of reverse micelles were prepared with different compositions of the compounds and used for extraction and recovery of two enzymes, and the percentage of enzyme recovery yield monitored. The enzymes glucose-6-phosphate dehydrogenase (G6PD) and xylose redutase (XR) obtained from Candida guilliermondii yeast were used in the extraction procedures. The recovery yield data indicate that micelles having different composition give selective extraction of enzymes. The method can thus be used to optimize enzyme extraction processes. (c) 2007 Elsevier B.V. All rights reserved.

Extraction of clavulanic acid using aqueous two-phase micellar system

An investigation of clavulanic acid behavior in an aqueous two-phase micellar system employing the surfactants n-decyltetraethylene oxide (C(10)E(4)) and dodecyldimethylamine oxide (DDAO) was carried out. According to the results, clavulanic acid partitions evenly between the two phases of DDAO micellar system, mixed DDAO C(10)E(4) micellar system, as well as C10E4 micellar system. Therefore, electrostatic interactions between positively charged DDAO-containing micelles and negatively charged drug were not strong enough to influence the partitioning. Nevertheless, clavulanic acid extraction from Streptomyces clavuligerus fermentation broth in C(10)E(4) micellar system employing a previous protein denaturation step provided recovery of 52% clavulanic acid with removal of 70% of the contaminant proteins, which is already promising as a purification strategy. (C) 2011 International Union of Biochemistry and Molecular Biology, Inc. Volume 58, Number 2, March/April 2011, Pages 103-108. E-mail: corangel@usp.br

Bioactivity of nitrolinoleate: effects on adhesion molecules and CD40-CD40L system

The vascular effects of nitrolinoleate (LNO(2)), an endogenous product of linoleic acid (LA) nitration by nitric oxide-derived species and a potential nitrosating agent, were investigated on rat endothelial-leukocyte interactions. Confocal microscopy analysis demonstrated that LNO(2) was capable to deliver free radical nitric oxide ((center dot)NO) into cells, 5 min after its administration to cultured cells, with a peak of liberation at 30 min. THP-1 monocytes incubated with LNO(2) for 5 min presented nitrosation of CD40, leading to its inactivation. Other anti-inflammatory actions of LNO(2) were observed in vivo by intravital microscopy assays. LNO(2) decreased the number of adhered leukocytes in postcapillary venules of the mesentery network. In addition to this, LNO(2) reduced mRNA and protein expression of 2-integrin in circulating leukocytes, as well as VCAM-1 in endothelial cells isolated from postcapillary venules, confirming its antiadhesive effects on both cell types. Moreover, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, a nitric oxide scavenger, partially abolished the inhibitory action of LNO(2) on leukocyte-endothelium interaction, suggesting that the antiadhesion effects of LNO(2) involve a dual role in leukocyte adhesion, acting as a nitric oxide donor as well as through nitric oxide-independent mechanisms. In conclusion, LNO(2) inhibited adhesion molecules expression and promoted (center dot)NO inactivation of the CD40-CD40L system, both important processes of the inflammatory response. (C) 2010 Elsevier Inc. All rights reserved.

Brazilian flavonoid database: Application of quality evaluation system

Much information on flavonoid content of Brazilian foods has already been obtained; however, this information is spread in scientific publications and non-published data. The objectives of this work were to compile and evaluate the quality of national flavonoid data according to the United States Department of Agriculture`s Data Quality Evaluation System (USDA-DQES) with few modifications, for future dissemination in the TBCA-USP (Brazilian Food Composition Database). For the compilation, the most abundant compounds in the flavonoid subclasses were considered (flavonols, flavones, isoflavones, flavanones, flavan-3-ols, and anthocyanidins) and the analysis of the compounds by HPLC was adopted as criteria for data inclusion. The evaluation system considers five categories, and the maximum score assigned to each category is 20. For each data, a confidence code (CC) was attributed (A, B, C and D), indicating the quality and reliability of the information. Flavonoid data (773) present in 197 Brazilian foods were evaluated. The CC ""C"" (as average) was attributed to 99% of the data and ""B"" (above average) to 1%. The main categories assigned low average scores were: number of samples; sampling plan and analytical quality control (average scores 2, 5 and 4, respectively). The analytical method category received an average score of 9. The category assigned the highest score was the sample handling (20 average). These results show that researchers need to be conscious about the importance of the number and plan of evaluated samples and the complete description and documentation of all the processes of methodology execution and analytical quality control. (C) 2010 Elsevier Inc. All rights reserved.

Photocytotoxic activity of a nitrosyl phthalocyanine ruthenium complex - A system capable of producing nitric oxide and singlet oxygen

The synthesis, structural aspects, pharmacological assays, and in vitro photoinduced cytotoxic properties of [Ru(NO)(ONO)(pc)] (pc = phthalocyanine) are described. Its biological effect on the B16F10 cell line was studied in the presence and absence of visible light irradiation. At comparable irradiation levels, [Ru(NO) (ONO)(pc)] was more effective than [Ru(pc)] at inhibiting cell growth, suggesting that occurrence of nitric oxide release following singlet oxygen production upon light irradiation may be an important mechanism by which the nitrosyl ruthenium complex exhibits enhanced biological activity in cells. Following visible light activation, the [Ru(NO)(ONO)(pc)] complex displayed increased potency in B16F10 cells upon modifications to the photoinduced dose; indeed, enhanced potency was detected when the nitrosyl ruthenium complex was encapsulated in a drug delivery system. The liposome containing the [Ru(NO)(ONO)(pc)] complex was over 25% more active than the corresponding ruthenium complex in phosphate buffer solution. The activity of the complex was directly proportional to the ruthenium amount present inside the cell, as determined by inductively coupled plasma mass spectroscopy. Flow cytometry analysis revealed that the photocytotoxic activity was mainly due to apoptosis. Furthermore, the vasorelaxation induced by [Ru(NO)(ONO)(pc)], proposed as NO carrier, was studied in rat isolated aorta. The observed vasodilation was concentration-dependent. Taken together, the present findings demonstrate that the [Ru(NO)(ONO)(pc)] complex induces vascular relaxation and could be a potent anti-tumor agent. Nitric oxide release following singlet oxygen production upon visible light irradiation on a nitrosyl ruthenium complex produces two radicals and may elicit phototoxic responses that may find useful applications in photodynamic therapy. Crown Copyright (C) 2011 Published by Elsevier Inc. All rights reserved.

Precursor system of liquid crystalline phase containing propolis microparticles for the treatment of periodontal disease: Development and characterization

Precursor systems of liquid crystalline phase were prepared using the surfactant PPG-5-Ceteth-20, isopropyl myristate, and water; gelatin microparticles containing propolis were then added into these systems. Homogeneity of dispersion, the in-system microparticle morphology, and sedimentation behavior of each formulation were evaluated. The rheological and mechanical properties (hardness, compressibility, and adhesiveness), the work of syringing, and the propolis release profile were also evaluated. All the formulations exhibited pseudoplastic flow and thixotropy, and they displayed storage modulus, loss modulus, dynamic viscosity, and loss tangent that depended on temperature, frequency, and composition. Mechanical properties varied significantly among the formulations being affected by changes in the composition and temperature. Raising the concentration of surfactant and adding propolis microparticles significantly decreased the work of syringing. The drug release was non-Fickian (anomalous) and there was no significant difference between the tested systems in the times required for 10%, 30%, and 50% release of the initial drug loading.